Category Archives: extinct

Episode 279: Mean Piggies

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Thanks to Molly for suggesting andrewsarchus and entelodont, our mean “piggies” we learn about this week!

Further reading:

Andrewsarchus, “Superb Skull of a Gigantic Beast”

Dark Folklore by Mark Norman and Tracey Norman

Further listening:

The Folklore Podcast

Andrewsarchus (taken from article linked above):

Andrewsarchus’s skull. I’m not sure who the guy holding it is, but I like to think his name is Andrew:

Entelodont:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

I’m getting really backed up on listener suggestions, so over the next few months I plan to cover as many of them as possible. We’ll start with two suggestions by Molly, who wanted to learn about Andrewsarchus and the related Entelodont. We talked about entelodonts briefly back in episode 116, and if you remember that episode, you may remember that entelodonts are sometimes referred to as the terminator pig or the hell pig. So yes, we are going to learn about some mean piggies this week, with a bonus fun mystery piggy at the end.

Andrewsarchus mongoliensis lived in what is now central Asia about 42 million years ago. It’s only known from a single skull found in 1923 in Inner Mongolia, which is part of China these days. The skull has a long snout and is big and wide, over 2.5 feet long, or 83 cm. It has huge, strong teeth that look ferocious.

When the skull was first found, some paleontologists on the team thought it was from a huge wolf-like carnivore. But others weren’t so sure. They thought it was the skull of a pig relative, and pigs are omnivores. Without more fossil remains, we can’t know for sure what Andrewsarchus’s body looked like, but these days scientists mostly think it was closely related to entelodonts.

Despite being called the terminator pig, entelodonts weren’t very closely related to pigs, although they and Andrewsarchus are in the order Artiodactyla. That’s the order that includes all even-toed hoofed mammals and their close relations, including pigs, but also including hippos and whales. Hippos and whales are actually pretty closely related, and entelodonts and Andrewsarchus were more closely related to hippos than to pigs.

Daeodon [DIE-oh-don] was the biggest entelodont known, and it may have stood up to 7 feet tall at the shoulder, or just over 2 meters. It lived in North America, but there was another species from Eurasia, Paraentelodon intermedium, that was probably close to the same size. Both lived about 22 million years ago.

Entelodonts had big, wide skulls with flared cheekbones and knob-like bony protrusions, so its head may have looked something like a warthog’s head. It also had cloven hooves. We don’t know if Andrewsarchus had hooves since we haven’t found anything but that one huge skull. The larger species of Entelodont had a humped shoulder something like a bison for the attachment of strong neck muscles to support the head’s weight, and Andrewsarchus probably had this too. The rest of the body was much more lightly built, with short, slender legs and a skinny little tail.

Even though Entelodont teeth are fearsome-looking, and at least some species of Entelodont were probably active hunters, they’re considered omnivores and Andrewsarchus probably was too. In fact, because Andrewsarchus was found on what was once a beach along the ocean, some researchers think it might have used its big forward-pointing front teeth to dig shellfish out of the sand. Most likely it ate pretty much anything it could find or catch, including shellfish, turtles, and other small animals, carrion, and plant material like fruit, nuts, and roots.

The teeth of some entelodont species show wear marks that indicate it probably bit through bones pretty frequently, possibly while scavenging already dead animals but possibly also when killing prey. One fossil skull of a herbivorous artiodactyl that lived in North America was found with an entelodont incisor embedded in it.

On the other hand, we have a set of fossil tracks in Nebraska, in the United States, that shows the behavior of what may have been an entelodont called Archaeotherium. Archaeotherium lived around 30 million years ago and grew up to 5 feet tall at the shoulder, or 1.5 meters, although most specimens found were closer to 4 feet tall, or 1.2 meters. The fossil tracks are from three animals: a type of rhinoceros, a predator of some kind, possibly the hyena-like Hyaenodon, and a species of Archaeotherium. The rhinoceros tracks show that it was walking along, then suddenly took off at a run. The Hyaenodon tracks are nearby and possibly indicate pursuit of the rhino, or it might have just happened to be nearby and frightened the rhino. The Archaeotherium tracks, meanwhile, zigzag back and forth. What on earth is going on with that?

Entelodonts had a very good sense of smell, much like pigs do, and walking in a zigzag pattern would allow Archaeotherium to smell things more efficiently. Some researchers suggest it might have been keeping an eye on the rhino hunt, and that if the Hyaenodon managed to bring down its prey, Archaeotherium might have decided to chase Hyaenodon away from its kill. It might also have been waiting for one or both animals to become tired, and then it could attack. Then again, it might just have been looking for some yummy fruit to eat. While some places online will tell you Archaeotherium was hunting the rhino, that’s not what the tracks indicate.

Entelodonts could open their mouths really, really wide. If you’ve ever seen a hippo with its humongous mouth open, that’s what we’re talking about here. Male hippos sometimes fight by jaw-wrestling each other, and researchers think entelodonts might have done something similar. A lot of entelodont skulls show healed puncture wounds in places consistent with jaw-wrestling. The knobby protrusions on its skull might have been an adaptation to this behavior, with thickened skin over them to keep a rival’s teeth from biting too deeply. This is the case with some pigs with similar skull protrusions, which we talked about in episode 128. The head bite wounds are only seen in adult animals, and younger animals didn’t have the massive cheek and jaw muscles seen in adults.

The big question is whether Andrewsarchus was actually an entelodont or just closely related to the entelodonts. That’s the same thing paleontologists have been discussing for the last century. Until we find more Andrewsarchus fossils, though, there’s only so much we can determine about the animal, including how similar it was to the entelodonts. For instance, while entelodonts did have cloven hooves, the two halves of the hoof could spread apart like fingers, which is similar to the way camel feet are structured. This would have helped it walk on soft ground, like sand or mud. If Andrewsarchus turns out to have similar feet, it was probably an entelodont.

Finding more Andrewsarchus remains will allow us to get a good idea of how big it could grow, too. Estimates based on the same proportions seen in entelodonts suggest it might have stood about 6 feet tall at the shoulder, or 1.8 meters.

As we’ve established, entelodonts and Andrewsarchus weren’t actually pigs, although they probably looked a lot like weird oversized warthogs with some features seen in wild boars. There’s no evidence they had a pig-like snout, called a nasal disk, which is flattened at the end. Entelodonts had nostrils on the sides of the snout, something like a horse’s nostrils.

But let’s finish with an actual pig, the mystery of the sewer pig. I got this information from a fantastic book called Dark Folklore by Mark and Tracey Norman, and I read the book because I listen to The Folklore Podcast, which is by folklorist Mark Norman, although I think Tracey Norman helps out with it too. I’ll just quote from the book, and definitely check the show notes for a link if you want to order your own copy.

“Foreshadowing the 1980s panic about baby alligators being taken home as pets and subsequently flushed down the toilet into the sewer system of New York, 1859 London was overtaken by a panic about the Sewer Pigs of Hampstead.

“The sewer pigs were thought to be a monstrous porcine family living entirely below ground in the London sewer system, and even featured in the Daily Telegraph newspaper. A sow had apparently become trapped, it was said, and had given birth to a litter of piglets, the entire family living off the rubbish that accumulated in the sewers and producing litter after litter. The population lived in fear of these terrible creatures escaping from the sewer system and running riot throughout London.

“Obviously, there is nothing within a sewer system that would sustain a pig, let alone a number of them. The fear connected to this particular urban legend is disease and it arose after the hot summer of 1858 caused a devastating outbreak of typhoid and cholera in the city. Unsurprisingly, there has never been any evidence of pigs in London’s sewers, monstrous, lost or otherwise.”

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 277: Rewilding Scotland

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This week is Caitie Sith and Dave’s episode! They want to learn about animals reintroduced to Scotland, especially the Highland wildcat!

The Scottish (or Highland) wildcat:

The Eurasian lynx:

The Eurasian beaver (with babies!):

The white-tailed eagle:

Reindeer in Scotland:

The pine marten:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

This week is Caitie Sith and Dave’s episode, where we’ll learn about the re-wilding of Scotland! Re-wilding is the process of restoring an ecosystem to its natural state, basically reversing habitat loss. Most of the time there’s a lot more to it than just reintroducing native animals, but sometimes that’s all that’s required.

Scotland is a part of the island of Great Britain, north of England. People have lived there since the last glaciers melted at the end of the Pleistocene, around 12,000 years ago. During the Pleistocene and a few thousand years after the glaciers melted, Scotland was connected to Europe by a lot of marshy land where today there’s ocean, and naturally many animals lived in Scotland that were also found in Europe at the time. Some of the ice age megafauna that lived in Scotland included the woolly rhinoceros, woolly mammoth, bison, aurochs, wild boar, saiga antelope, giant deer, red deer, reindeer, moose, wild horse, beaver, walrus, Polar bear, brown bear, lynx, wolf, Arctic fox, and cave lion. Many fossil and subfossil remains of Pleistocene animals were destroyed by the formation and movement of thick glacier ice, which scoured the land down to bedrock in many places, so those are only the animals we know for sure lived in Scotland.

But Scotland wasn’t covered by glaciers all the time. The Pleistocene wasn’t a single ice age but a series of cold events interspersed with warming trends. During these interglacial periods, which lasted some 10- to 15,000 years at a time, animals would move to Scotland from other places or become more numerous than before. Then the climate would start cooling again, glaciers would slowly form over many years, and animals would move to areas where there was more food. This happened repeatedly over a period of more than 2.5 million years.

In other words, while we have some fossils of Pleistocene animals that once lived in Scotland, we don’t have nearly as many as have been found in England, Ireland, and Wales. But what we do know is that Scotland was once teeming with all kinds of animals we’d never associate with the country today, like cave lions and Polar bears!

Much of the ice age megafauna went extinct around 12,000 years ago when the last glaciers melted and the climate started warming. Cold-adapted animals couldn’t always survive in a warmer climate, not to mention that as the climate changed, the types of plants available to eat changed too. Some animals migrated away or went extinct, while some were able to stay in Scotland successfully. This included the red deer, reindeer, wild boar, walrus, brown bear, and lynx.

If you’re wondering why that list is full of animals that don’t actually live in Scotland these days, like the brown bear and lynx, it’s because humans hunted many of the native Scottish animals to extinction. Others went extinct due to habitat loss or competition with introduced animals. Many surviving species are endangered today for the same reasons.

For example, the Scottish wildcat, also called the Highland wildcat. We talked about it briefly in episode 52 way back in early 2018. One of the animals that migrated to Scotland after the Pleistocene, but before sea levels rose and cut the British Isles off from Europe, was the European wildcat. The Scottish population has been separated from the European population for at least 7,000 years, and some researchers think it should be classified as a subspecies of European wildcat.

The Scottish wildcat is a little larger than a domestic cat and is always tabby striped. It has a bushy tail with a black tip, a striped face and legs, never any white markings, and is usually dark in color with black paws. It’s a solitary animal that mostly lives in woodlands, where it eats mice, voles, and other rodents, rabbits, and birds. It used to be common throughout much of the British Isles, but these days it’s only found in parts of Scotland.

You’d think people would be excited to have a genuine wildcat living in their country, since wildcats are pretty awesome and eat animals that can damage crops. But for some reason, until recently people thought these wildcats were pests and would shoot them on sight. Some people thought the wildcats were killing game birds, which is rare, or that they were dangerous, which isn’t true. At the same time, the people shooting wildcats were letting their domestic cats roam freely, which has caused an even bigger problem to wildcats than getting shot at.

Like other wildcat species, the Scottish wildcat can and will cross-breed with domestic cats. The resulting kittens are fertile, meaning they can have babies with either wildcats or domestic cats. Kittens are great, of course, but domestic cats are a different species from wildcats. Hybrid cats are less suited to live in the wild, but too wild to be good pets, and if too many domestic cats breed with wildcats, soon there won’t be any real wildcats left. Not only that, domestic cats carry diseases that wildcats can catch.

The Scottish wildcat is a protected species these days, with conservation efforts in place to keep the wildcats and their habitat as safe as possible. One important step is to encourage people to get their domestic cats neutered. This is healthier for pet cats anyway and will help keep tomcats from spraying and fighting, and of course it stops them from having kittens with wildcats.

Another felid that once lived in Scotland is the Eurasian lynx. It still lives in parts of Asia and Europe, but it went extinct in Scotland several hundred years ago, mainly due to deforestation and hunting for its fur. It’s about 28 inches tall at the shoulder, or 70 cm, and is a heavily built animal with thick spotted fur and a short bobtail. The tip of its tail is black although the rest of the animal is mostly tan or brown with darker brown spots, and it has long black tufts of fur on the tips of its ears. It’s slightly bigger than the related Canadian lynx.

Conservationists have wanted to reintroduce the Eurasian lynx to Scotland for years. Since the lynx is threatened in the rest of its range by habitat loss and hunting, reintroducing it to its former range in Scotland would help it and the ecosystem in general. With no large predators to keep their numbers in check, the population of roe deer in Scotland is too high to be healthy, and the lynx loves to eat roe deer.

Some people worry that if the lynx is reintroduced to Scotland, it will be dangerous to humans and livestock. But the lynx is a shy, solitary animal that avoids humans as much as possible. There are enough roe deer alone to sustain a population of over 400 lynxes in the wilder parts of Scotland, especially in the Highlands. The lynx also spends almost all of its time in forests and doesn’t like open pastures. It’s been successfully reintroduced to its former range in other countries, with a nice side effect being increased tourism to national parks where it’s now found.

Scotland also used to have beavers, which were hunted to extinction in the 16th or 17th century. Then, in 2009, the Eurasian beaver was reintroduced to parts of Scotland and is doing great! There are more than 1,000 beavers living in Scotland now. Beavers are considered a keystone species, a term we haven’t really examined on the podcast before, but it means that an animal is so important to an ecosystem that if it goes extinct in an area, the ecosystem sort of falls apart and many other animals go locally extinct soon after.

Beaver ponds create a winter habitat for many types of fish, and beaver dams don’t stop fish like salmon that migrate upriver to spawn. The dams help reduce flooding, improve water quality, and create cover for lots of fish and other animals.

Naturally, though, some people complain about the beavers, because there will always be someone who complains about anything. Some people think beavers eat fish and will eat up all the fish that humans want to catch. Beavers actually don’t eat fish at all, they only eat plant material. Some people think beavers carry the giardia parasite, which causes a bacterial infection sometimes called beaver fever that’s spread in water, but giardia is actually mostly spread by domestic dogs. Some people complain that beavers fell trees and build ponds, and both these things are true. But the beaver is just doing what it’s supposed to do, and as we just learned, this tree felling and pond-making are good for the environment—unlike humans, who chop down lots of trees and make artificial ponds when landscaping, while simultaneously draining wetlands, which doesn’t help the local environment at all. Besides, the beavers are cute and attract tourists who want to get pictures of them, which is also good for the local economy. Everybody wins when there are beavers around, is what I’m trying to say.

The beavers reintroduced in 2009 aren’t the only beavers in Scotland. In 2001, people started seeing them around the river Tay—but no one knew where they came from. Well, presumably someone knew, because the beavers didn’t get there without help. If this reminds you of episode 48, where we talked about some mystery beavers that appeared in Devon, England, the Devon beavers showed up in 2013, twelve years after the Scottish mystery beavers. At first the Scottish government planned to capture the Tayside beavers and keep them in captivity, but the beavers are still there and doing very well.

It’s great that over a thousand beavers live in Scotland now, but that’s actually not very many. Still, it’s a whole lot better than the number of Eurasian beavers about 150 years ago, when researchers think there may have been as few as 300 individuals alive in the whole world.

Another animal that once lived in Scotland, was hunted to extinction, and then mysteriously reappeared recently is the wild boar. They first appeared in the 1990s and by now there are thousands of them in Scotland. It’s possible they escaped from farms, where they’re sometimes raised for meat like domestic pigs. While they’re a native species, they don’t have any predators in Scotland and are causing a lot of damage as they become more numerous. The wild boar’s natural predator is the wolf, and the last wolf in Scotland was killed in 1743. Lynxes will also kill wild boar piglets.

Some birds have been reintroduced to Scotland too. The white-tailed eagle is a type of sea eagle, closely related to the bald eagle of North America although it’s slightly larger than the bald eagle. The biggest ever reliably measured was a specimen from Greenland with a wingspan of 8 feet 4 inches across, or 2.53 meters, just a smidge larger than the largest bald eagle wingspan known. It’s mostly brown and gray with a yellow bill and feet, and a white tail. It lives around water and eats a lot of fish, but it also eats lots of carrion, gulls and other birds, and occasionally small mammals like rabbits. It always lives near water but it prefers wooded areas, especially lowlands and forested islands.

The white-tailed eagle went extinct throughout Britain in the early 20th century when people decided they wanted all those fish the eagle eats for themselves. Never mind that even a thousand eagles couldn’t eat as many fish that a single commercial fishing boat catches in a day. People also decided that eagles killed lambs, even though this is extremely rare. White-tailed eagles would much rather eat fish and seagulls than lamb. The last white-tailed eagles in Scotland were shot and killed in 1916.

As if that wasn’t bad enough, white-tailed eagles were also killed throughout the rest of their range and were especially vulnerable to the chemical called DDT. DDT was a popular pesticide developed in the 1950s and used to kill insects on crops and gardens. But DDT is dangerous, because like other pesticides it doesn’t just do its job and evaporate. It stays in the environment and ends up in the bodies of animals, including people. It’s especially bad for birds that eat a lot of fish, since a lot of pesticides end up in the water, and it causes their eggshells to become so thin and weak that the eggs break when the mother tries to keep them warm. This is the same thing that almost drove the bald eagle to extinction in North America. By the time DDT use was banned in many countries and the white-tailed eagle was declared a protected species, it was almost too late.

Conservation efforts have helped stop the white-tailed eagle from going extinct and its numbers are slowly growing. Starting in 1975, young eagles were brought from Norway to Scotland, where they were successfully reintroduced in the inner Hebrides islands and have now expanded to other parts of Scotland. Some people still complain about the eagles and sometimes shoot or poison them even though it’s illegal, but most people are happy to have them around, especially birdwatchers.

Scotland even has some reindeer these days. Reindeer probably lived in Scotland until around the 12th century, and in 1952 a Swiss herdsman thought they should still be there. He brought a small herd to the Cairngorm mountains, which is now a national park. The reindeer are semi-domesticated but roam free, and they attract tourists who hope to catch a glimpse of them.

At the same time that many native animals have gone extinct, lots of non-native animals have been introduced to Scotland, including wallabies, American mink, gray squirrels, various species of crayfish, and many more. Conservationists are working to minimize the damage these introduced species cause. Many invasive species were animals kept as pets that either escaped or were released into the wild. We talked about the invasive eastern gray squirrel versus the native red squirrel in episode 241, for instance. People released gray squirrels into parks in England because they were so cute, and a hundred years later, the gray squirrels are taking over in many places. They’re increasingly common in Scotland, although Scotland has a small predator called the pine marten that loves to eat squirrels.

The pine marten is a type of mustelid, or weasel relative, that’s common throughout much of Europe and Asia. It grows about two and a half feet long, or 75 cm, including its bushy tail. It mostly lives in wooded areas and spends a lot of its time in trees, hunting squirrels and other small animals like frogs, insects, and birds. It will also eat carrion, bird eggs, and sometimes fruit. It’s mostly brown with a cream-colored throat. It even has partially retractable claws like a cat to help it climb trees, although it’s not related to the cat.

The pine marten is especially good at catching squirrels, and it tends to target the gray squirrel because it’s easier to catch. The red squirrel is more cautious. Where there are pine martens, there are fewer or no gray squirrels. The problem is, the pine marten is considered a pest that kills game birds, so some people shoot or poison it even though it’s a protected species. Then those same people complain about all the gray squirrels around. The pine marten is doing well in many parts of Scotland, though, and has even expanded its range slightly in the last few years.

Scotland is a beautiful country known for its wild and rugged countryside. It wouldn’t take much to rewild it properly, a process that’s well underway with keystone species like beavers already re-established in many places. The main problem is people who don’t understand that a healthy ecosystem requires predators. Without lynxes, wolves, bears, and other large predators, animals like roe deer and wild boar become so numerous that they can’t find enough to eat and either starve or destroy crops and gardens.

Fortunately, many more people in Scotland do understand the importance of building healthy ecosystems. After all, they’re naturally proud of where they live and want to make it even better.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 276: Hominins and Art

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It’s Nicholas’s episode this week, and Nicholas wants to learn more about hominins, the ancestors and cousins of modern humans!

Happy birthday to Autumn! I hope you have a great birthday!

Further listening:

Humans Part One

Further reading:

Were Neanderthals the Earliest Cave Artists?

Neanderthals Built Mysterious Stone Circles

DNA reveals first look at enigmatic human relative

What does it mean to have Neanderthal or Denisovan DNA?

Hand and footprint art dates to mid-Ice Age

Risky food-finding strategy could be the key to human success

A stone circle in a cave was probably built by Neandertals:

A deer bone with carving on it probably made by Neandertals:

Some cave paintings probably made by Neandertals:

Show transcript:

Welcome to Strange Animals Podcast! I’m your host, Kate Shaw.

This week is Nicholas’s episode! Nicholas wanted an updated episode about hominins, our ancient ancestors or species closely related to modern humans. The last time we talked about hominins was way back in episodes 25 and 26, so it’s definitely time to revisit the topic.

But first, a big birthday shout-out to Autumn! Happy birthday, Autumn, and I hope you have the best birthday so far!

If you haven’t listened to episode 25 in a while, or ever, I recommend you go back and give it a listen if you want background information about how humans evolved and our closest extinct relatives, Neandertals and Denisovans. I’ve transcribed that episode finally, so you can read the episode instead of listen to it if you prefer. There’s a link in the show notes.

Results of a study published in January 2022 in the journal Nature has finally dated the oldest known Homo sapiens remains found so far. The remains were found in Ethiopia in the 1960s but the volcanic ash found over them was too fine-grained to date with any certainty. Finally, though, the eruption has been determined to come from a volcano almost 250 miles, or 400 km, away from the remains. The Shala eruption was enormous and took place 230,000 years ago, so since the remains were found below the ash, the person had to have lived at least 230,000 years ago too.

We’re still learning more about humans and our closest relations because new hominin fossils are being found and studied all the time. But the fossil record doesn’t tell the whole story. Only a small percentage of bones ever fossilize, and of those, only a tiny fraction are ever found by scientists. But technological advances in genetic testing means that scientists can now extract DNA from the soil. All animals shed fragments of DNA all the time, from skin cells and hairs to poop. A study published in 2021 was able to isolate Neandertal DNA from sediments in three different caves. The DNA matched the known fossils found at the sites and gave more information besides. Instead of being restricted to a single individual whose bones were found and tested, genetic testing of sediments gives genetic information about lots of individuals. In the case of a cave in northern Spain, where lots of stone tools have been found but only a single Neandertal toe bone, it turns out that two different populations of Neandertal had lived in the cave over 100,000 years ago.

In episode 25, I mentioned that Neandertals didn’t seem to make things the way humans do, especially art. Some researchers even suggest that they couldn’t think symbolically the way humans do. But in the five years or so since that episode, we’ve learned a lot more about Neandertals–and they seem to have been pretty artistic after all.

The main problem is that historically, whenever scientists found rock art or carvings from prehistoric times, they assumed humans made it. We might be a little biased. Some art originally thought to be made by humans is now thought to have been made by Neandertals. Most of it is found in caves. Remains of animals are often found in caves because the cave protects them from weather and other factors that can destroy them, and the same is true for archaeological remains.

In 1990, a team of cavers dug into a narrow collapsed cave entrance and entered Bruniquel Cave in southwest France that no human—in fact, no animal from the surface world—had entered since the entrance collapsed during the Pleistocene. That was at least 24,000 years ago and probably much, much longer.

The cavers found the bones of long-extinct Pleistocene megafauna near the entrance, including cave bears. But it wasn’t until they reached a chamber deeper inside the cave that they made a stupendous discovery.

The chamber held a big stone circle made of broken-off pieces of stalactite and stalagmite and other rock formations. The pieces are all about the same size and are arranged in a circle almost 22 feet across, or 6.7 meters. There’s a smaller semicircle in the chamber too and heaps of more stone pieces. Some of the stones show signs of fires being lit on top of them, and a piece of burnt bone from a bear or other large animal was found near the semicircle.

The cavers alerted local scientists, who came to investigate. At first they thought the structures had been built by early humans. They took samples for testing, and that’s when they got another shock. The burnt bone, the fire residue, and the minerals growing over both revealed an age long before 40,000 years ago, which is when humans first moved into the area. The stone circle was built 176,000 years ago. And the only hominin known to live in Europe that long ago was the Neandertal.

We don’t know what Neandertals used the stone circles for. It might have been a living space, but it might have been religious in nature instead. Either way, it shows that even that long ago, Neandertals had full control over fire to the point that they could make light sources to find their way deep into a cave, and had the curiosity to want to explore deeper into a cave than they really needed to go for shelter.

There are lots of other examples of Neandertal art and intelligence found in Europe. For instance, paintings in a cave in Spain have been dated to at least 65,000 years ago. Remember, humans didn’t reach Europe until about 40,000 years ago. The paintings are made of red mineral pigment, including elaborate rows of dots, geometric figures, and occasionally animal figures and hand stencils. Other caves in the area also have similar rock art dating to Neandertal times.

In a cave in Germany, researchers found a piece of deer bone dated to 51,000 years ago that has a carved pattern in it. The carving is too elaborate to be simple butcher marks, but again, humans hadn’t yet moved into Europe 51,000 years ago. The bone actually comes from the leg of a giant deer, once called the Irish elk, that we talked about way back in episode 4. In another cave in Gibraltar, cross-hatched patterns carved in the rock have been dated to more than 39,000 years ago and are associated with artifacts made by Neandertals.

Archaeologists have also found a lot of toe bones from eagles that are etched with cut marks, found in various sites throughout southern Europe. They think Neanderthals in this area wore eagle talons as jewelry, and most likely feathers too.

There’s still controversy when it comes to Neandertals and art. Some researchers think Neandertals only used art after they saw humans making it. Some think the art isn’t art at all but something else, like accidental marks left by other activities. Some think the dating methods used to determine the age of paintings is flawed.

Another criticism is that we don’t actually know that Neandertals made the art; we just know it probably couldn’t have been humans. But there were other human relations living at the same time.

One of those is the Denisovan people, named for Denisova Cave in the mountains of Siberia. Hominins didn’t ordinarily live in caves, but sometimes they did. This seems to be the case in Denisova Cave, where evidence of human habitation, Neandertal habitation, and habitation by another hominin goes back some 180,000 years.

Researchers knew about humans and Neandertals living in the cave, but it wasn’t until 2010 that they realized a third hominin had lived there at various times. The Denisovan people were closely related to both Neandertals and humans and probably looked a lot like Neandertals, with a robust build and big teeth. We still don’t know a whole lot about them, but they lived in parts of what is now Asia and possibly nearby areas, and they might not have gone extinct until about the same time that Neandertals did, around 30,000 years ago.

We talked about the Denisovans in episode 25, but since then new remains have been discovered in other caves. The most exciting is a partial jawbone with two teeth that was found by a Buddhist monk in a cave on the Tibetan plateau in 1980, but not studied until much later. It was identified as a Denisovan mandible in 2019 and dated to 160,000 years ago.

Genetic testing of Denisovan remains indicate that Denisovans and Neandertals were probably more closely related to each other than to humans, although all three species were very closely related. Since there are so few Denisovan remains known, we don’t have a very good idea yet of where they lived and what they were like. We do have genetic markers that indicate the Denisovans had dark skin, brown hair, and brown eyes, while Neandertals, like humans, were more varied in skin, hair, and eye color.

Geneticists have identified traces of Denisovan DNA in some populations of modern humans, including in Asia, New Guinea and surrounding areas, and Australia. This is a reminder that even though some human populations contain DNA traces from our extinct cousins, all humans are thoroughly human. Those bits and bobs of ancient DNA are too small to be significant.

We do have what seems to be art made by Denisovans, although not everyone agrees that it was intended to be art in the way we think of it. It was found in the Tibetan Plateau and we now know that Denisovans lived in the area, although when it was found in 1998 we didn’t even know Denisovans existed. The art was found near hot springs and dated to as much as 226 thousand years ago, although it might have been closer to 169 thousand years ago. Either way, it was well before modern humans are known to have lived in the area. The art consists of footprints and hand prints pressed into the mud, probably by two individuals. The artists pressed their hands, feet, fingers, thumbs, and in one case a forearm into the mud around the hot springs, making patterns. But the thing is, these prints are small even by human standards. Researchers are pretty sure they were made by children, so while it’s certainly possible the children were creating art, they also might just have been messing around having fun in the mud. But the fact that they were making patterns points to an artistic intelligence. Puppies play and may stomp their feet in mud, but they don’t get interested in making patterns of their footprints in the mud. Human children do.

There’s still at least one other hominin that lived at the same time as Neandertals, Denisovans, and humans. We only know about that hominin because researchers have identified their DNA in genetic studies of Denisovans, which means they interbred. It’s a ghost lineage that no one guessed existed until genetic studies of Denisovans and Neandertals were completed in the early 2010s. It might turn out to be a known hominin such as Homo erectus but it might be a completely unknown species.

Of course we have lots of information about art made by ancient humans. It’s been found throughout the world. No one’s in any doubt that our prehistoric ancestors were just as intelligent and artistic as humans who live today, they just didn’t have the technology we have. I can go to an art supply store and buy paints in any color I want, assuming I don’t just want to paint digitally, but in prehistoric times human artists had to make their own paints from the things they found in nature. This included minerals like red ochre and yellow ochre, umber, calcite, hematite, iron oxide, and lots more. They used burnt bones and charcoal for black. These minerals are all still used to make modern oil paints (used in art, not for painting a room or a house), with names like bone black and lime white.

Many minerals have to be processed before they can be used as pigments. Ochre, for instance, has to be heated to 850 degrees Fahrenheit, or 750 Celsius, to change into the rich red-orange that ancient artists especially liked. After processing, the pigments were ground into powder, then mixed with various substances to make a paste. These substances included fat, blood, spit, plant oils, tree sap, water, bone marrow, and even urine.

Ancient artists used their fingers to paint, but they also used twigs, brushes made from animal hair, and mats of lichen. Sometimes they blew pigment onto a surface with their breath, first putting the paint into a hollow tube and then blowing into the tube to spray paint. This is the same way airbrushes work, but no one gets light-headed using an airbrush because a machine is doing the blowing air part. If the artist was working in a cave, they also needed a light source, specifically fire, so they could see what they were doing. It’s all a lot of work.

Aside from all the details involved in getting ready to paint, making art takes one other really important commodity: time. Great apes spend most of their time finding food and eating it. How did ancient humans find time to paint without starving?

A study released in early 2022 points out that hominins developed a much different strategy for getting food than our more distant ape relations. Apes mostly eat plant material, especially fruit, which is nutritious but takes a lot to fulfill the calorie needs of an adult. Early hominins were hunter-gatherers, meaning they both hunted animals and gathered plant material to eat. But because hominins are intensely social and share food, we could take risks that other animals can’t. A group of ancient humans could go out to hunt something big knowing that even if they failed, when they got home they wouldn’t go hungry. Other people would have been gathering food all day and would share. But if the hunters got lucky and brought home a big animal like a deer, everyone had lots and lots of high calorie food to go around. With food available to everyone, people could take time to do things that didn’t directly relate to finding food, like art.

Not only that, another study published in 2019 discovered that some early hominins had already figured out how to preserve food several hundred thousand years ago. The food in question was bone marrow, which is found inside bones and which is extremely nutritious. Researchers have always assumed hominins would crack the bones of animals they killed to get at the marrow as soon as possible. But deer bones found in a cave near Tel Aviv, Israel were stored unbroken, with the skin still on. Researchers determined that the bones were kept in the cave for up to nine weeks before being broken open. By keeping the skin on the bones and storing them in the cave, where the temperature was cool, the marrow stayed fresh. That way there was always something nutritious to eat in the cupboard, so to speak.

Art doesn’t have to be paintings or carvings. Ancient humans were probably using plant fibers to make things more than 34,000 years ago. The fibers are from wild flax plants, and flax is still used today to make linen fabric. Fragments of flax fibers were found in a cave in the Republic of Georgia (which is a country, not the American state of Georgia) where other human artifacts were found. Since flax isn’t edible, at least not by humans, researchers think the fiber might have been used to make thread, rope, baskets, and possibly even cloth. You know, clothing.

One thing to remember is that humans, Neandertals, and Denisovans were so closely related that they could and did interbreed and produce fertile offspring. That means not only were our extinct cousins very similar to us physically, they were probably pretty similar to us mentally too. It would be more surprising if they didn’t produce art that represented symbolic thinking, since it’s such an important part of the human experience.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 265: Penguins!

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Thanks to Page for suggesting we talk about penguins this week!

A big birthday shout-out to EllieHorseLover this week too!

Further reading:

March of the penguins (in Norway)

Rare Yellow Penguin Bewilders Scientists

Giant Waikato penguin: school kids discover new species

An ordinary king penguin with the rare “yellow” king penguin spotted in early 2021 (photo by Yves Adams, taken from article linked above):

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

I was looking over the ideas list recently and noticed that Page had suggested we cover a specific bird way back in 2020! It’s about time we get to it, so thanks to Page we’re going to learn about penguins this week, including a penguin mystery.

But first, we have a birthday shout-out! Happy birthday to EllieHorseLover, whose birthday comes right before next week’s episode comes out. Have a fantastic birthday, Ellie, and I agree with you about horses. They are awesome and so are you.

Also, a quick correction from last week’s episode about Dolly the dinosaur. If you listened to episode 264 the day it came out, you heard the incorrect version, but I was able to correct it and upload the new version late that day. Many thanks to Llewelly, who pointed out that Dolly hasn’t actually been identified as a Diplodocus, just as a sauropod in the family Diplodocidae. Paleontologists are still studying the fossil and probably will be for some time. Also, I said that sauropods aren’t related to birds but that’s not the case. Sauropods share a common ancestor with birds and that’s why they both have the same kind of unusual respiratory system.

So, speaking of birds, it’s time to learn about penguins! We’ve talked about penguins twice before, but not recently at all. It’s about time we really dug into the topic.

Penguins live in the southern hemisphere, including Antarctica. The only exception is the Galapagos penguin, which we talked about in episode 99, which lives just north of the equator. Penguins are considered aquatic birds because they’re so well adapted to swimming and they spend most of their time in the ocean finding food. Instead of wings, their front limbs are flippers that they use to maneuver in the water. They’re incredibly streamlined too, with a smooth, dense coat of feathers to help keep them warm in cold water without slowing them down.

One of the ways a penguin keeps from freezing in the bitterly cold winters of Antarctica and in cold water is by a trick of anatomy that most other animals don’t have. The artery that supplies blood to the flippers crosses over the veins that return blood from the flippers deeper into the body. The arterial blood is warm since it’s been through the body’s core, but the blood that has just traveled through the flippers has lost a lot of heat. Because the veins and the arteries cross several times, the cold venal blood is warmed by the warm arterial blood where the blood vessels touch, which means the blood returning into the body’s core is warm enough that it doesn’t chill the body.

Penguins groom their feathers carefully to keep them clean and spread oil over them. The oil and the feathers’ nanostructures keep them from icing over when a penguin gets out of the water in sub-zero temperatures. The feathers are not only super-hydrophobic, meaning they repel water, their structure acts as an anti-adhesive. That means ice can’t stick to the feathers no matter how cold it is. In 2016 researchers created a nanofiber membrane that repels water and ice with the same nanostructures found in penguin feathers. It could eventually be used to ice-proof electrical wires and airplane wings.

Penguin feathers also trap a thin layer of air, which helps the penguin stay buoyant in the water and helps keep its skin warm and dry.

While a penguin is awkward on land, it’s fast and agile in the water. It mostly eats small fish, squid and other cephalopods, krill and other crustaceans, and other small animals, and it can dive deeply to find food. The emperor penguin is the deepest diver, with the deepest recorded dive being over 1,800 feet, or 565 meters. The gentoo penguin has been recorded swimming 22 mph underwater, or 36 km/hour.

Penguins are famous for being mostly black and white, but in 2010, a study of an extinct early penguin revealed that it looked much different. The fossil was found in Peru and is incredibly detailed. The flipper shape is clear, proving that even 36 million years ago penguins were already fully aquatic. Even some of the feathers are preserved, allowing researchers to reconstruct the bird’s coloration from melanosomes in the fossilized feathers. They show that instead of black and white, the extinct penguin was reddish-brown and gray. The bird was also one of the biggest penguins known, up to five feet long, or 1.5 meters.

Another species of extinct penguin was discovered in 2006 in New Zealand by a group of school children on a field trip. The New Zealand penguin lived between about 28 and 34 million years ago and while it wasn’t as big as the Peru fossil penguin, it had longer legs that made it about 4.5 feet tall, or 1.4 meters. It was described as a new species in September of 2021 and somehow I missed that one when I was researching the 2021 discoveries episode.

The smallest penguin alive today is the fairy penguin, which only grows 16 inches tall at most, or 40 cm. It lives off the southern coasts of Australia and Chile, and all around New Zealand’s coasts. It’s also called the little blue penguin because its head is gray-blue. The largest penguin is the emperor penguin, which lives in Antarctica and can grow over four feet tall, or 130 cm.

The king penguin looks like a slightly smaller version of the emperor penguin, which makes sense because they’re closely related. It can stand over 3 feet tall, or 100 cm. Its numbers are in decline due to climate change that has caused some of the small fish and squid the penguins eat to move away from the penguin’s nesting grounds. Large-scale commercial fishing has also reduced the number of fish available to penguins. As a result, the penguins have a hard time finding enough food for themselves and their babies. King penguins are protected, though, and conservation efforts are in place to stop commercial fishing near their nesting grounds. A ban on commercial fishing around Robben Island in South Africa, where the endangered African penguin nests, increased the survival of chicks by 18%, so hopefully the same will be true for the king penguin.

In early 2021, a Belgian wildlife photographer named Yves Adams was leading a group of photographers on an island where king penguins live. They spotted a group of the penguins swimming nearby when Adams noticed that one of the penguins seemed really pale. It was yellowish-white instead of black and white, although it did have the yellow markings on its head and breast that other king penguins have. It and the other penguins came ashore and Adams got lots of pictures of it. Ornithologists who have studied the pictures aren’t sure what kind of genetic anomaly has caused the penguin’s coloration, but with luck scientists will be able to find it again and take a genetic sample.

The king penguin is also the subject of a small penguin mystery, but the mystery starts with the great auk. As we talked about in episode 78, the name penguin was originally used for a bird also called the great auk or gairfowl, which lived in the northern hemisphere. It was common throughout its range until people decided to start killing them by the thousands for their feathers and meat. By 1844, the last pair of great auks were killed. The great auk was a black and white aquatic bird that looked a lot like a penguin due to convergent evolution.

The story goes that in the late 1930s people started seeing great auks on the Lofoten Islands off the coast of Norway. Since this was 70 years after the great auk officially went extinct, the reports caused a flurry of excitement.

While a small, scattered population of great auks probably did persist for years or even decades after their official extinction, once an expedition investigated the Lofoten Islands they discovered not auks but penguins. Specifically, a small group of king penguins. How did the penguins get there from their natural range in various sub-Antarctic islands on the other side of the world?

Some reports say whalers captured some penguins as pets and later released them, but it actually appears that the introduction of nine king penguins to two islands off the coast of Norway was done by the Nature Protection Society, backed by the Norwegian government, in 1936. The penguins were still there until at least 1944, with the last sighting coming from 1954.

These weren’t the only penguins released in the islands. In 1938 the Norwegian government released around 60 other penguins from various species onto the islands. The goal was to establish penguin breeding colonies in Norwegian waters in a confused attempt to claim the Antarctic for Norwegian whaling. The real mystery is why they thought that would work.

Very occasionally, a stray penguin is found in the northern hemisphere with no idea how it got there. In the past, people assumed the penguin got lost and swam the wrong way or got pushed away from its homeland by storms, but these days biologists think these lost penguins were transported by fishing boats. Sometimes a penguin will get tangled in a fishing net and hauled aboard by accident, and the fishers will untangle it and keep it as a pet for a while before setting it free. It would be better if the penguin was set free immediately so it could return to its home, but it’s better than being killed. Just ask the penguin.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 256: Mammoths and the End of the Ice Ages

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Further reading:

Million-year-old mammoth genomes shatter record for oldest ancient DNA

Mammoth Genome Project (with pictures of cave art and ancient carvings of mammoths)

The most famous cave painting of a mammoth, from a cave in France:

Sivatherium:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

It’s the last Monday of 2021, which means the very last extinction event episode. There’ve been way more extinction events in earth’s long history than the five we’ve covered this year, and not all of the extinction events I chose to highlight were even necessarily the biggest. This one, for instance.

You may have noticed a pattern when I talk about ice age megafauna. So many animals went extinct about 11,000 years ago. That’s this week’s topic, the end-Pleistocene extinction event.

The Pleistocene is often called the ice age, or ice ages since it consisted of multiple glaciation periods separated by warmer times when the glaciers would retreat for a while. It started roughly 2.6 million years ago and is considered to have ended 11,700 years ago. Keep in mind, as always, that these dates are just a shorthand to help scientists refer to changes in earth’s history. There was no one day where the sun rose and everything had abruptly changed from one era to another. The changes took place over a long time, hundreds of thousands of years, with different parts of the world changing more quickly or slowly than others depending on local conditions.

At the beginning of the Pleistocene, the world’s continents were roughly in their present positions. Two continental plates in what is now Central America collided very slowly over millions of years, which caused the land to buckle up and magma to erupt through the earth’s crust as volcanoes. The volcanoes created islands in the Central American Seaway, a section of ocean between North and South America that connected the Atlantic and Pacific Oceans. By around 5 to 10 million years ago, the volcanoes and land continued to be pushed up, and sediment from rivers filled in between them, until finally instead of islands there was actual land that connected North and South America. That land is called the Isthmus of Panama and it allowed the great American interchange where animals from North America could cross into South America, and vice versa, but that’s a topic for another episode.

Another result of the Isthmus of Panama’s formation is that the Atlantic and Pacific Oceans were more separated. Instead of ocean currents circulating between North and South America, they were cut off and new currents formed. Ocean currents help distribute warm water to colder areas and cold water to warmer areas, which affects air and land temperatures too. Around 2.5 million years ago, the ocean current changes had changed the entire overall temperature of the earth, making it much cooler overall. That wasn’t the only cause of the ice ages, but it was a major factor.

The earth gradually became cooler and dryer, a process that had already started due to other causes and was accelerated by the ocean current changes. As the global temperature dropped, more and more water was locked up in huge glaciers called ice sheets, at first around the poles and then farther south. This meant sea levels dropped a lot. North America was connected to Asia by a stretch of grassland steppe called Beringia that had formerly been submerged.

As the temperatures dropped and the climate changed, animals and plants had to adapt. The ancestors of modern elephants had lived in Africa for millions of years, but they started migrating to other parts of the world around 3 million years ago. Because they were already big, they were good at retaining heat in their bodies and became quite successful as the climate grew cooler and cooler. They evolved long hair to stay even warmer and spread throughout much of the world, including Europe, Asia, and North America. You may know them as mammoths, which were closely related to the modern Asian elephant. The first mammoth known was the South African mammoth that lived around 5 million years ago and stood about 12 feet tall at the shoulder, or 3.7 meters.

We actually know a lot about the various species of mammoth because we have so many remains. Our own distant ancestors left cave paintings and carvings of mammoths and other animals in many parts of the world, we’ve found lots of fossilized remains, and we have lots of subfossil remains too. Because the mammoth lived so recently and sometimes in places where the climate hasn’t changed all that much in the last 10,000 years, namely very cold parts of the world with deep layers of permafrost beneath the surface, sometimes mammoth remains are found that look extremely fresh.

Before people understood extinction and related natural concepts, some people who lived in areas where dead mammoths occasionally weathered out of the permafrost thought they’d only died recently. That’s how fresh the dead animals looked. The people didn’t know what the animals were, though, and assumed that since they were only ever seen partially buried, they must be underground animals. In parts of Siberia, people thought mammoths lived underground and if they accidentally came to the surface, they died.

In February of 2021, a genetic study of mammoth DNA found in teeth was published in Nature. Nature is one of the most important scientific journals in the world and they don’t just publish any old genetic study these days, now that DNA is so much easier to sequence than it used to be. In this case, though, the DNA came from three mammoth teeth that were more than one million years old and possibly around 1.5 million years old. The teeth were found in the 1970s in different places. Before DNA was successfully found in the teeth, the oldest DNA sequenced was from a horse bone that was about 780,000 years old at the most.

Genetic material breaks down relatively quickly once an animal dies, becoming more and more fragmented as the years pass by. That’s why we don’t have any dinosaur DNA—they just lived too long ago for any usable genetic material to remain. The mammoth genetic study is a big deal since it’s pushed back scientists’ ability to sequence ancient DNA, at least of some samples. In the case of both the mammoth teeth and the ancient horse bone, the remains were preserved in permafrost that slowed the fragmentation of the DNA.

The study found that one of the teeth belonged to an early woolly mammoth and the other two were from early steppe mammoths, but it’s not as simple as it sounds. The two steppe mammoth teeth looked alike but their genetic story was very different. One had genetic markers that identified it as an ancestor of woolly mammoths–but the other didn’t. The one that didn’t is called the Krestovka sample and was found in Russia. Researchers aren’t sure yet if it’s actually a new species or subspecies, but it was obviously part of a population isolated from other steppe mammoths.

But it gets even more complicated, because Columbian mammoths from North America do show that some of their ancestors were related to the Krestovka sample–and Columbian mammoths are also related to woolly mammoths. Researchers suspect that the Columbian mammoth was a species that developed from hybrids of the Krestovka steppe mammoths and woolly mammoths. Over half a million years ago, there were enough of these hybrid mammoths that they were actually numerous enough to form their own stable species. Hybrid speciation is still a relatively new concept but as genetic studies get more sophisticated, we’re getting more evidence of it happening.

Researchers are hopeful that even older genetic samples can eventually be sequenced, but there’s a hard limit to DNA found in permafrost. That limit is 2.6 million years, which is when the permafrost began forming. And that brings us back to the ice age.

Mammoths weren’t the only animals adapted to cold conditions, of course. They weren’t even the only elephant lineage that adapted to the cold. Mastodons aren’t actually that closely related to mammoths but they are an elephant relation.

The woolly rhinoceros was about the size of living rhinoceros species but was covered in thick fur. It had a massive hump on its shoulders that was made up of fat reserves and muscle, much like modern bison. It went extinct about 10,000 years ago.

A giraffe relation, Sivatherium, lived in Africa and parts of Asia during the Pleistocene. Its neck wasn’t as long as a modern giraffe’s but it was still tall, over 7 feet tall at the shoulder, or more than 2 meters, and almost 10 feet tall including the head and neck, or 3 meters. The males had two pairs of ossicones that resembled antlers, a large pair on its head and a smaller pair over its eyes. Ossicones are bony projections usually covered with skin and hair, and modern giraffes have ossicones too.

Mammals weren’t the only megafauna, though. Mega just means big, and fauna just means animal. There were megafauna birds and reptiles too, such as the Asian ostrich. It lived throughout much of Asia and the Middle East until around 8,000 years ago and was related to the modern ostrich. The wonambi was an Australian constrictor snake, not related to the snakes living in Australia now, that could grow up to 30 feet long, or 9 meters.

So what happened to cause the extinction of all these amazing animals? Surely we know more about this extinction event than we do about older ones since it happened so recently, right?

Actually, no. Although it feels significant to us now, the end-Pleistocene extinction event actually wasn’t very big compared to the others we’ve discussed this year. A lot of ice age megafauna are still around, including bears, wolves, moose, reindeer, horses, bison, elephants, giraffes, lions, tigers, camels, kangaroos, tapirs, ostriches, condors, and lots more. Even humans are ice age megafauna since we spread throughout the world during the Pleistocene.

We do have hints of what might have caused the end-Pleistocene extinction event, and one big hint comes from what happened in Australia. Like the rest of the world, Australia’s climate was cooler and dryer during the ice ages and animals that had adapted to the cold lived throughout the continent. This included diprotodon that we talked about in episode 224, along with kangaroos, wombats, koalas, and other marsupial mammals that were bigger than the ones living today. But extinctions in Australia started a lot earlier than they did in the rest of the world, around 45,000 years ago. There’s also no corresponding extinction event among marine animals. By about 40,000 years ago almost 90% of all species of Australian megafauna had gone extinct, while smaller animals and marine animals were mostly just fine.

One specific event that happened around 45,000 years ago was the colonization of Australia by humans. Humans had visited and even lived in Australia as far back as 70,000 years ago, but by 45,000 years ago they were really spreading throughout the land. The animals of Australia had never encountered smart, fast tool-users before and didn’t know what to do except try to avoid them. Humans had weapons like spears that could kill at long range, and humans worked together to kill animals that before then had no predators due to their size. Humans also drink a lot of water because we developed in a part of Africa where water is abundant. Fresh water isn’t nearly as abundant in Australia, so humans would stake out water sources and keep other animals away.

The Australian extinctions were probably a combination of climate change, humans hunting large animals that reproduced slowly, and humans outcompeting animals for water sources. The same causes probably led to extinctions in other parts of the world, but because humans took longer to spread to continents like the Americas that are far away from Africa, those extinctions mostly took place later than in Australia. It’s also important to note that Africa showed almost no extinctions at the end of the Pleistocene. Researchers think this is because the animals of Africa evolved alongside humans and knew how to deal with us.

Natural climate change was definitely a contributing cause to the extinctions, though. Ice sheets melted, glaciers retreated, and the world warmed over the course of just a few thousand years. Animals that were well adapted to the cold had to move to places where it was still cold, but those places didn’t always have the right foods or enough food. The sea levels rose too, cutting off access to parts of the world. Beringia became covered with ocean again, for instance, where it remains today, separating Asia from North America.

Humans probably finished off the mammoths by hunting the last ones to extinction, but some populations survived much later than the 10- to 12,000 years ago commonly given as their extinction date. There were still mammoths alive in the world only 4,000 years ago and maybe only 3,700 years ago—but only on an island where humans didn’t live.

Wrangel Island is located in the Arctic Ocean near western Siberia, more than 85 miles from the nearest coast, or 140 km. It has low mountains and sea cliffs and is cold and dry most of the year, which is the kind of climate mammoths preferred.

The woolly mammoths that lived on Wrangel Island were probably cut off from the mainland when sea levels rose and flooded Beringia. They lived on for thousands of years after their mainland relations had gone extinct. Gradually the mammoths became more and more inbred, leading to genetic defects at a much higher rate than in a healthy population. Even so, the mammoths might have managed to survive even longer except for one thing. Around 1700 BCE, humans arrived on the island. Shortly afterwards, the mammoth was extinct.

Wrangel Island is a nature sanctuary these days and home to lots of animals, including polar bears, walruses, Arctic foxes, seals, reindeer, musk ox, and wolves. All of these are considered ice age megafauna, so although the mammoths are gone, other megafauna remain.

While we don’t know for sure that humans played a big part in the end-Pleistocene extinction event, we sure didn’t help. We can’t blame our ancient ancestors for their actions but we can learn from their mistakes. We’re in the middle of another extinction event right now, often called the Holocene extinction or Anthropocene extinction, directly due to our actions. Habitat loss, pollution, overhunting, and human-caused climate change are driving more species of animal and plant to extinction every year.

It can feel overwhelming, but there are lots of small things you can do to help. Just picking up trash and putting it in the waste bin or remembering to take your reusable bags to the grocery store can make a difference. No one person can fix all the world’s problems, but if everyone does a little bit to help, the big problems get smaller and more manageable. If everyone pitches in, we can make the world a cleaner, better place for animals and for people.

Happy new year! Let’s make it a great one!

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 255: Reptiles with Something Extra

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Thanks to Ethan and Simon this week for their suggestions! This week we’re looking at some extinct reptiles that each have a little something extra (and unexpected).

Further reading:

Two Extinct Flying Reptiles Compared

Cretaceous ‘Four-Limbed Snake’ Turns Out To Be Long-Bodied Lizard

Kuehneosaurids may have resembled big Draco lizards although they weren’t related:

Big turtle:

Purussaurus was big enough to eat even really big turtles (from Prehistoric Wildlife):

Meiolania had a pointy head and a pointy tail:

Not a snake with legs after all:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

This week we’ll learn about an extinct reptile suggested by Ethan, some extinct turtles suggested by Simon, and an extinct snake that might not be a snake at all. All these animals had physical details you wouldn’t expect, as we’ll see.

First, though, a reminder that I have five Kickstarter backers who haven’t sent me their birthday shout-out names and birthdays yet! I sent messages to them last month and haven’t heard back, so if you backed the Kickstarter and added on the birthday shout-out, but never got the opportunity to send me your names and birthdays, please message me as soon as possible! The shout-outs start in January!

So, on to the extinct reptiles that each have something a little extra. Let’s start with Ethan’s suggestion, the kuehneosaurids. Kuehneosaurus, kuehneosuchus, and their relations lived around 225 million years ago in what is now England. The first dinosaurs lived around the same time but kuehneosaurids weren’t dinosaurs. They were lizard-like reptiles that grew about two feet long, or 70 cm, including a long tail, and probably lived in trees and ate insects. Oh, and they had wings.

They weren’t technically wings but extended ribs. Kuehneosaurus’s wings weren’t all that big, although they were big enough that they could act as a parachute if the animal fell or jumped from a branch. Kuehneosuchus’s wings were much longer. In a study published in 2008, a team of scientists built models of kuehneosuchus and tested them in a wind tunnel used for aerospace engineering. It turned out to be quite stable in the air and could probably glide very well.

We don’t know a whole lot about the kuehneosaurids because we haven’t found all that many fossils. We’re not even sure if the two species are closely related or not. We’re not even sure they’re not the same species. Individuals of both were uncovered in caves near Bristol in the 1950s, and some researchers speculate they were males and females of the same species. Despite the difference in wings, otherwise they’re extremely similar in a lot of ways.

Generally, researchers compare the kuehneosaurids to modern Draco lizards, which we talked about in episode 237, even though they’re not related. Draco lizards are much smaller, only about 8 inches long including the tail, or 20 cm, and live throughout much of southeastern Asia. They have elongated ribs that they use to glide efficiently from tree to tree, and they eat insects. Draco lizards can fold their wings down and extend them, which isn’t something the kuehneosaurids appear to have been able to do.

Next, let’s look at Simon’s turtles. Stupendemys geographicus lived a lot more recently than the kuehneosaurids, only about 6 million years ago in northern South America. It was a freshwater turtle the size of a car: 13 feet long, or 4 meters. As if that wasn’t impressive enough, the males also had horns—but not on their heads. The male Stupendemys had projections on its shell, one on either side of its neck, that pointed forward and were probably covered with keratin sheaths to make them sharper and stronger. Males used these horns to fight each other, and we know because some of Stupendemys’s living relations do the same thing, although no living species actually have horns like Stupendemys. They’re called side-necked turtles and most live in South America, although they were once much more widespread.

Stupendemys probably grew to such a huge size because there were so many huge predators in its habitat. It lived in slow-moving rivers and wetlands, where it probably spent a lot of time at the river’s bottom eating plants, worms, crustaceans, and anything else it could find. It was too big and heavy to move very fast, but a full-grown turtle was a really big mouthful even for the biggest predator in the rivers at the time, Purussaurus.

Purussaurus was a genus of caiman, related to crocodiles, that might have grown up to 41 feet long, or 12.5 meters. We don’t know for sure since the only Purussaurus fossils found so far are skulls. It ate anything it could catch, and we even have Stupendemys fossils with tooth marks that show that Purussaurus sometimes ate giant turtles too. One Stupendemys fossil has a 2-inch, or 5 cm, crocodile tooth embedded in it.

Stupendemys is the largest freshwater turtle known and the second-largest turtle that ever lived. Only Archelon was bigger, up to about 15 feet long, or 4.6 meters. Archelon was a marine turtle that lived around 70 million years ago. We talked about it in episode 75.

Simon also told me about another turtle genus, Meiolania, which lived in what is now Australia and parts of Asia around 15 million years ago. It might even have remained in some areas as recently as 11,000 years ago. The shell, or carapace, of the largest species grew over 6.5 feet long, or 2 meters. Even the smallest species had a carapace over 2 feet long, or about 70 cm. Since the fossils of smaller species have only been found on islands, researchers think the small size may have been due to island dwarfism. It probably lived on land and ate plants. It also had horns, but not on its shell. These horns were actually on its head, although they aren’t technically horns.

The horn-like projections pointed sideways and its tail also had spikes at its end. That meant it couldn’t pull its head under its shell to protect it like most other turtles can, but on the other hand, anything that tried to bite its head or tail would get a painful mouthful of spikes.

We don’t know a whole lot about Meiolania, including if it’s related to living species of turtle. When the first fossils were found, early paleontologists thought they were lizards, not turtles. What we do know, though, is that people ate them. Bones of some species appear in the middens, or trash sites, of ancient people in Australia, and there’s evidence that they were hunted to extinction within a few hundred years after humans settled where the turtles lived. That would also explain why the island-dwelling species seemed to have lived longer than the mainland species, since people didn’t live on the islands where they’ve been found.

Finally, we’ll finish with Tetrapodophis amplectus, leading to the philosophical question about whether a snake with legs is really a snake. That’s the same question researchers were asking themselves too until very recently. Tetrapodophis was only described in 2015 and was initially determined to be an early snake that had four legs.

Tetrapodophis lived around 120 million years ago in what is now Brazil in South America. It grew about a foot long, or 30 cm, and had a slender, elongated body with small but well-developed legs. Is it a lizard with snake-like characteristics or an early snake that hadn’t completely lost its legs yet?

It had hooked teeth and we know it ate small animals because one specimen actually has the fossilized remains of its last meal in its fossilized digestive system. Initially researchers thought it might have been a burrowing animal, using its small legs to help it grab onto items and push itself forward.

The type specimen was a complete skeleton, which is really rare. Unfortunately it was illegally exported and the paleontologist who described the species didn’t bother to at least invite a Brazilian paleontologist to study the Brazilian fossil. He was also incredibly rude when asked about it so I’m not going to give you his name, but he seems to be a really sketchy guy, which is too bad.

He also made some mistakes that might not have been mistakes. If a person is dishonest in one area, they’re probably dishonest in other areas too. When he described Tetrapodophis, he mischaracterized some aspects of its anatomy to make it seem more snake-like. A new study published in November 2021 corrects those mistakes and determines that instead of being a flashy exciting snake with legs, Tetrapodophis was most likely just a small member of the lizard family Dolichosauridae. I’m happy to report, by the way, that one of the lead authors of the new study is named Tiago Simões, a paleontologist from Brazil.

Dolichosaurs were marine lizards with small legs and snake-like bodies and were actually pretty closely related to mosasaurs. You know, the marine reptiles that lived at the same time as dinosaurs and could grow more than 50 feet long in some species, or 15 meters.

There’s some controversy in the mosasaur camp too, because some researchers think mosasaurs were most closely related to snakes while others think they were most closely related to monitor lizards. It just goes to show that scientific knowledge is forever growing and adapting to new information as it comes to light, but that answers aren’t always clear.

What is clear is that extinct reptiles are awesome, but you probably already knew that.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 240: The End of the Dinosaurs

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Here we go. It’s the big one, the Cretaceous-Paleogene extinction event!

Further reading:

How Birds Survived the Asteroid Impact That Wiped Out the Dinosaurs

How an asteroid ended the age of dinosaurs

Extinction event that wiped out dinosaurs cleared way for frogs

How life blossomed after the dinosaurs died

66-million-year-old deathbed linked to dinosaur-killing meteor

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

Here it is, the extinction event episode that everyone’s been waiting for, or at least that everyone knows about. It’s the one that killed off the dinosaurs and ushered in the age of mammals. It’s probably the one we know most about and it’s certainly the one we have the most paintings of, usually of a T. rex staring into the sky at an approaching comet.

In episode 227 we talked about the end-Permian extinction event, which took place about 250 million years ago. The Cretaceous-Paleogene extinction event, or end-Cretaceous, took place just over 66 million years ago, which means that for almost 200 million years there was more or less smooth sailing in the world. Dinosaurs evolved during that time, and I think we can all agree that dinosaurs are fascinating animals.

The largest terrestrial animals ever to live were dinosaurs, specifically the sauropods. Sauropods were just unimaginably huge. They were like walking buildings that ate plants, and even that doesn’t give a good idea of their size. Some sauropods had extremely long tails as well as very long necks, which increased their length. Right now the largest sauropod known was probably Argentinosaurus that might have grown as long as 118 feet, or 36 meters, but paleontologists keep finding bigger and bigger sauropods. Some sauropods had extremely long necks that they held up like a giraffe. The tallest was probably Barosaurus, estimated as being 72 feet tall, or 22 meters. And we won’t even get into estimates of how much these massive animals weighed. They make the biggest elephant that ever lived look like a toy elephant.

Sauropods ate plants, with the low-necked species eating low-growing plants and the high-necked species eating tree leaves, although even saying that much is controversial. There’s a lot we don’t know about sauropods in general, since most sauropod fossils are incomplete and many species are only known from one or a few bones. But we do know some surprising things about sauropods. We have a lot of sauropod tracks, which helps us understand how their feet looked and whether they had claws, but it also tells us that some species of sauropod traveled in herds. Paleontologists do generally agree that many sauropods migrated, since animals that big would soon exhaust all the food in one area if they didn’t.

Sauropods were extremely successful and lived all over the world. There were plenty of sauropods alive 66 ½ million years ago, and then…there were no sauropods alive ever again.

These days, there’s so much evidence that a massive asteroid killed off the dinosaurs that pretty much everyone agrees, but when the idea was first proposed in 1980, it was extremely controversial. When I was a kid I remember reading dinosaur books that still said the extinction of the dinosaurs was a mystery but that many scientists thought it was due to disease or volcanoes.

The asteroid strike hypothesis was proposed by the physicist Luis Alvarez and his son, Walter. They worked with a small team of other scientists, including two chemists, Helen Michel and Frank Asaro, to investigate a strange anomaly in rock strata. Rocks dating to the end of the Cretaceous period and the beginning of the Paleogene period are separated by a thin layer of clay that’s visible throughout the world, or at least wherever the rocks remain and can be examined. It’s called the Cretaceous-Paleogene boundary, or K-Pg boundary, although in older books and websites it’s called the K-T boundary. It occurred just over 66 million years ago. The Alvarezes were curious about this layer, and during their investigations they found out that the clay is full of an element called iridium.

Iridium is a silvery-white metal chemically related to platinum, and it’s rare. At least, it’s rare on Earth. It’s a common component of asteroids, which was one of the main reasons why the Alvarezes came to their hypothesis that the K-Pg boundary was the result of a massive asteroid impact. Other scientists had made similar suggestions in the decade or so leading up to the Alvarezes’ theory, but the iridium discovery provided the proof everyone wanted.

Iridium wasn’t the only thing found in the K-Pg boundary layer, either. There were other platinum-group metals present in high concentrations—much higher than found on Earth, and in fact these elements are referred to as rare-earth metals for that reason. In some places, the K-Pg boundary contains grains of shocked quartz and microtektites. We’ll discuss those in a minute.

As we’ve discussed before in various episodes, the earth’s surface is always moving around. It’s slow to us, with continents moving around at the same dizzying speed that our fingernails grow, but over millions of years that adds up. Continents move around and crash into each other, forming new mountain ranges that then wear down to plains, and where continental plates pull apart or push together the crust can weaken and allow magma to erupt through as volcanoes. Ocean levels rise and fall. In other words, a crater made 66 million years ago might have disappeared as all this geologic activity goes on.

But then, we found the crater. The crater.

The Chicxulub crater is in Mexico, specifically the Yucatán Peninsula at the southern portion of the Gulf of Mexico. You can’t see it when you’re walking around because it’s buried under 2,000 feet of soil, or 600 meters, that has built up over the last 66 million years. Two geophysicists found it in the 1970s while surveying for petroleum, but it wasn’t until 1990 that they were able to verify that it was a crater. Asteroid impacts leave clues behind that the geophysicists recognized.

The first clue is shocked quartz. Quartz is a common crystalline mineral throughout the world, and it has a certain structure that’s familiar to geologists. In shocked quartz, that structure has been deformed by intense pressure, but not high temperature. It was first noticed after nuclear bomb tests, and after that scientists recognized it in meteor craters.

The second clue is little pieces of glass called tektites. They’re different from obsidian, which is a type of glass formed by volcanic activity. Tektites are usually shaped like droplets or little blobs, but sometimes they’re round. They’re only found around big impact sites and only for relatively recent meteor impacts, because they don’t last forever.

The Chicxulub crater is actually kind of old for its tektites to still be around, except for two things. First, the tiniest tektites, the microtektites, ended up in the K-Pg boundary layer, as I mentioned earlier. Second, we actually have a fossil site in North Dakota, in the middle of North America up near Canada, that seems to date to literally the day of the asteroid impact, and there are tektites all over the site, including clogging the gills of fish. The tektites match the chemical signatures of the Chicxulub crater so we know that’s where they came from.

Before we talk about the North Dakota fossil bed, let’s discuss what exactly happened on the day the asteroid hit the earth. Because we’ve found the asteroid’s crater, we know a lot about the asteroid itself. Most researchers estimate that it was about 6 miles across, or 10 km. It approached the earth at an angle, traveling about 12 km a second. That’s 7.5 miles per second. It hit the earth right on the coast, partly in the ocean, partly on land, forming a crater about 110 miles across, or 180 km, and 12 miles deep, or 19 km.

The asteroid smashed into the Earth so fast that it was completely buried in about the time it takes you to blink. There really wasn’t time for any dinosaurs to look up and wonder what that bright light was, because the time between the asteroid entering earth’s atmosphere and smashing into the earth was maybe five seconds.

The megatsunami resulting from the impact would have been unbelievably huge. Waves may have been a mile high, or over 1.5 km. The initial impact would have thrown water more than 7.5 miles into the air, or 12 km, and when that water fell back down it would have set up another megatsunami. Not only that, the impact actually shook the whole earth like a massive earthquake, which caused landslides all over the place and set up even more tsunamis. It’s like shaking a snowglobe to watch the fake snow swirl around and around, only instead of fake snow it was ocean.

At the same time, everything near the impact site was instantly on fire. It was on fire because the asteroid was traveling so fast that it was glowing white-hot with incandescent heat just from pushing against air molecules, and when it hit the Earth, all that heat had to go somewhere. Also, everything exploded. The water exploded up and outward, the land exploded up and outward. A lot of water turned instantly to steam. The asteroid itself disintegrated and tiny bits of it were carried high into the atmosphere along with ash, dust, molten glass created by the blast, and anything else that was nearby and not instantly incinerated.

The shockwaves from the impact acted as a magnitude 12 earthquake, with follow-up shocks estimated at about magnitude 9 occurring across the entire planet. Volcanoes erupted as a result, pumping even more ash and gases into the atmosphere. All the trees were flattened for about 930 miles around the impact, or 1500 km.

Within a few hours of the impact, fireballs of molten rock and glass were falling across the world, setting fires on land and heating the surface of the ocean to boiling temperature in many areas. And it was already getting really dark as the massive amounts of debris and dust and ash and smoke and everything else spread across the earth.

Okay, deep breath. This happened a long, long time ago and most animals died so quickly they didn’t feel anything. Look out the window if you’re feeling stressed and see how calm it is? Maybe it’s raining where you live or maybe it’s night-time and you can hear frogs or crickets calling, maybe an owl if you’re lucky. It might be daytime and you can hear cars passing by, or a dog barking somewhere, people talking. Whew. Okay, back we go to that awful day 66 million years ago, back to the fossil site found in North Dakota.

Back then, the middle of North America was a shallow sea. The first tsunami wave was probably 30 feet tall, or 9 meters, when it reached the mouth of a river emptying into the sea. It pushed the river backwards and washed hundreds of freshwater fish onto a sand bar. To add insult to injury, or just injury to injury, while the fish were stranded and flopping around trying to get back in the water, globs of molten glass and rocks rained down on them. Then another wave pushed up the river and covered the dead and dying fish with a lot of sand and sediment, which preserved them.

The site was discovered in 2013 and the findings were published in 2019. It’s not just fish at the site, although there are unbelievable numbers of fish. There are also tree trunks and branches that show evidence of burning, ammonites and other marine animals that were washed up the river, even part of a triceratops and a hadrosaur. One charred trunk is covered in amber, which is fossilized tree resin. The amber is full of tektites, which were caught in the resin when it was soft.

Every time I say tektite I think of those spidery things in Zelda, which makes this whole situation seem even worse.

None of the animals at the site show evidence of being eaten by anything. Some researchers estimate that the event took place less than an hour after the asteroid impact. There’s also a layer of clay on top of the sediment that contains high levels of iridium.

In all, roughly 75% of all life on earth went extinct following the asteroid impact. Many animals that survived the immediate aftermath of the impact died out months or years later, and many more scraped along for hundreds or thousands of years before finally going extinct. The massive amounts of dust and ash in the atmosphere blocked sunlight for the next several years or even longer, which means plants died throughout the world. Poisonous gases in the atmosphere led to acid rain that killed more plants and animals. The ocean temperature dropped considerably, as did the overall temperature of the earth, leading to freezing temperatures that would have killed off even more animals. Deep-sea animals fared better than most, but many plankton went extinct very soon after the impact and that meant animals that ate the plankton also went extinct.

But, of course, not everything went extinct. If it had, I wouldn’t be recording this episode and you wouldn’t be listening to it. Awful as it sounds, the Cretaceous-Paleogene extinction event wasn’t nearly as bad as the end-Permian extinction. Full recovery is estimated to have taken as much as 9 million years, when it took 50 million years for the earth to fully recover from the end-Permian extinction.

One thing that isn’t generally known is that things had been getting rough on earth for a couple of million years before the asteroid hit. Some species were already in decline due to climate change. The asteroid just made everything intensely worse.

The first plants to recolonize the blasted wastelands were ferns, lots and lots and lots of ferns. Ferns are tough plants and thrive in areas where nothing else can grow, and ferns grow quickly and provide food for lots of animals. Within a hundred years of the impact the world was carpeted with ferns.

Some dinosaurs did survive, of course, but we call them birds. They would have looked very birdlike even 66 million years ago. Most birds that survived were ones that lived on the ground instead of in trees. Researchers think many birds survived because they were able to eat seeds, which would have remained as a food source even after the plants that dropped the seeds had all died. Insects and other invertebrates that eat rotting leaves would have been just fine, and many birds could find and eat them too.

Mammals also survived the asteroid impact, of course. Look, here we are! We’ve done quite well for ourselves. 66 million years ago most mammals were small and rodent-like, and the ones that survived probably mostly lived in burrows and ate seeds and other plant material or small animals like insects.

Surprisingly, frogs did really well after the asteroid impact. Frogs are small and can survive in small microhabitats. While most of the frogs in North America went extinct, plenty of frogs survived in other parts of the world that weren’t so close to the impact site, and as soon as conditions improved, more species evolved than ever before. That’s why frogs across the world look so similar. They may not all be closely related, but they all faced the same environmental pressures at the same time.

Once plants started to recover, things took a turn for the better as birds, fish, mammals, reptiles, amphibians, insects, and other animal groups suddenly didn’t have to watch out for dinosaurs or the other big predators that had gone extinct. Sauropods and other giant herbivores weren’t eating up all the plants. Life evolved rapidly to fill the available ecological niches, and animals started getting bigger and bigger.

In late 2019, scientists released details of a fossil site found in Colorado, in the western United States. It has an unbroken record of rocks dating from before the asteroid impact to about a million years afterwards. It gives us an excellent record of the changes that took place.

In the years after the impact, there’s not a lot to see, just lots of ferns and some rat-sized mammals. Within 200,000 years palm forests had replaced the ferns and cat-sized mammals were common. By 400,000 years after the impact, plants and trees with nuts evolved and many mammals were the size of dogs. By 700,000 years after, the relatives of modern bean and pea plants appeared, forests were varied and healthy, and the mammals were the size of wolves or bigger. There were animals other than mammals too, including a five-foot-long crocodilian, or 1.5 meters, with teeth adapted to crush turtle shells.

The ancestors of whales evolved about 50 million years ago around what is now India and its neighbors, when a little animal called Indohyus spent a lot of time in the water. It was about the size of a raccoon, which it resembled in some ways, except that its bones were unusually heavy for its size. This helped it stay underwater without effort. The hippopotamus has the same kind of heavy bones for the same reason, and Indohyus was actually related to the hippo’s distant ancestor. Within five million years, descendants of animals like Indohyus were fully aquatic and looked a lot like dolphins with small legs. As whales got bigger and faster, predators evolved too, including the largest shark that ever lived, Megalodon. The first baleen whales evolved around 25 million years ago and ultimately grew to the gigantic sizes of some of the whales alive today.

Every time you feel sad that you’ll never see a real live dinosaur like a sauropod, remember that you live at the same time as the undisputed largest animal that has ever lived, the blue whale. It can grow up to 98 feet long, or 30 meters, and possibly longer. That’s as long as a ten-story building is high. It’s twice the length of Megalodon! If you have the money and time, you can actually charter a boat that will take you out to look at blue whales because they’re still alive!

I guarantee you that millions upon millions of years from now, in some far-distant future that we can’t even imagine, there will be scientists who study whales and write whatever those future people use as books, and there will be young people who read those books and look longingly at drawings of whales. They’ll know about dinosaurs, sure, and those will always be popular, but it’ll be the whales that really catch people’s imagination. There will be the far-future equivalent of movies where people successfully clone whales or bring them back from the past, and the details will be all wrong but no one will know because no one in that far future time will actually know what whales really look like! But you know, and that is the most amazing fact I can ever share with you.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes. There are links in the show notes to join our mailing list and to our merch store.

Thanks for listening!

Episode 236: Updates 4 and a Mystery Snake!

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It’s our fourth annual updates and corrections episode! I’ve already had to make a correction to this episode!

Further reading:

Cassowary, a rare emu-like bird, attacks and kills Florida man, officials say

The dog Bunny’s Facebook page

3D printed replicas reveal swimming capabilities of ancient cephalopods

Enormous ancient fish discovered by accident

A rare observation of a vampire bat adopting an unrelated pup

Pandemic paleo: A wayward skull, at-home fossil analyses, a first for Antarctic amphibians

Neanderthals and Homo sapiens used identical Nubian technology

Entire genome from Pestera Muierii 1 sequenced

Animal Species Named from Photos

Cryptophidion, named from photos:

The sunbeam snake showing off that iridescence:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

 

It’s our fourth annual updates and corrections episode, and to keep it especially interesting we’ll also learn about a mystery snake. Make sure to check the show notes for lots of links if you want to learn more about these updates.

 

First, we have a small correction from episode 222. G emailed with a link about a Florida man who was killed by a cassowary in 2019, so cassowaries continue to be dangerous.

 

We also have a correction from episode 188, about the hyena. I called hyenas canids at one point, and although they resemble canids like dogs and wolves, they’re not canids at all. In fact, they’re more closely related to cats than dogs. Thanks to Bal for the correction!

 

In response to the talking animals episode, Merike told about a dog who uses computer buttons to communicate. The dog is called Bunny and she’s completely adorable. I’ll link to her facebook page. I have my doubts that she’s actually communicating the way it looks like she is. She’s obviously a clever dog but I don’t think she understands the English language so well that she can choose verbs like “is” from her list of words. I think she’s probably mostly taking unconscious cues from her owner. But I would be happy to be proven wrong.

 

Following up from our recent deep-sea squid episode, a team of paleontologists studying ancient cephalopods 3-D printed some replicas of what the animals would have looked like while alive. Then they took the models into a swimming pool and other water sources to study how their shells affected the way they could move through the water. They discovered that a type of cephalopod with a straight shell, called an orthocone, probably mostly moved up and down in the water to find food and could have moved extremely fast in an upward or downward direction. A type of cephalopod with a spiral shaped shell, called a torticone, also spun slightly as it moved around. The same team has previously worked with 3-D models of ammonoids, which we talked about in episode 86. The models don’t just look like the living animals, they have the same center of balance and other details, worked out mathematically.

 

Speaking of ancient animals, a collector in London bought a fossil found in Morocco thinking it was part of a pterodactyl skull. When the collector asked a palaeontologist to identify it, it turned out to be a fossilized coelacanth lung. The collector donated the fossil for further study, and the palaeontologist, David Martill, worked with a Brazilian coelacanth expert, Paulo Brito, to examine the fossil.

 

The fossil dates to the Cretaceous, about 66 million years ago, and is bigger than any coelacanth lung ever found. Modern coelacanths grow a little over six feet long at most, or 2 meters, but the estimated length of this Coelacanth is some 16 ½ feet, or 5 meters. The fossil is being donated to a university in Morocco.

 

We talked about vampire bats way back in episode 11, and I love bats and especially vampire bats so I try to keep an eye on new findings about them. Everyone thinks vampire bats are scary and creepy, but they’re actually social, friendly animals who don’t mean to spread rabies and other diseases to the animals they bite. It just happens.

 

Vampire bats live in colonies and researchers have long known that if a female dies, her close relations will often take care of her surviving baby. Now we have evidence that at least sometimes, the adoptive mother isn’t necessarily related to the birth mother. It’s from a recently published article based on a study done in 2019.

 

A team researching how unrelated vampire bats form social bonds captured 23 common vampire bats from three different colonies and put them together in a new roost where their interactions could be recorded by surveillance cameras. One particular pair of females, nicknamed Lilith and BD, became good friends. They groomed each other frequently and shared food. If you remember from episode 11, vampire bats share food by regurgitating some of the blood they drank earlier so the other bat can lap it up. Since vampire bats can starve to death in only a few nights if they can’t find blood, having friends who will share food is important.

 

During the study, Lilith gave birth to a baby, but shortly afterwards she started getting sick. She had trouble getting enough food and couldn’t groom or take care of her baby as well as a mother bat should. Her friend BD helped out, grooming the baby, sharing food with Lilith, and eventually even nursing the baby when Lilith got too sick to produce milk. After Lilith died, BD adopted the baby as though it was her own. By the time the study ended, BD was still caring for the baby bat.

 

We talked about spiders in the Antarctic in episode 221, and mentioned that Antarctica hasn’t always been a frozen wasteland of ice and snow. In a new study of fossils found in Antarctica, published in May of 2021, the first Antarctic amphibian skull has been identified. It lived in the early Triassic, not long after the end-Permian mass extinction 252 million years ago. It’s been named Micropholis stowi and is a new species of temnospondyl that was previously only known from South Africa. The skull, along with other fossils from four individuals, was discovered in the Transantarctic Mountains in 2017 and 2018, and the research team studied them from home during the 2020 pandemic lockdowns.

 

In news about humans and our extinct close relations, a new finding shows that Neanderthals and humans used the same type of tools. Researchers studied a child’s tooth and some stone tools, all found in a cave in the mountains of Palestine, and determined that the tooth was from a Neanderthal child, not a human. The tooth was discovered in 1928 but was in a private collection until recently, so no one had been able to study it before now. The tools are a specific type developed in Africa that have only been found associated with humans before. Not only that, but until this finding, there was no evidence that Neandertals ever lived so far south.

 

The child is estimated to have been about nine or ten years old, which is the age when you’re likely to lose a baby tooth as your adult teeth start growing in. I like to think about the child sitting next to their Mom or Dad, who were either creating new tools or using ones they’d already made to do something like cut up food for that evening’s dinner. Maybe the child was supposed to be helping, and they were, but they had a loose tooth and kept giving it a twist now and then, trying to get it to come out. Then, finally, out it popped and bounced onto the cave floor, where it was lost for the next 60,000 years.

 

Researchers have just announced that they’ve sequenced the genetic profile of a woman who lived in what is now Romania about 35,000 years ago. Judging from her skull shape and what is known about ancient humans in Europe, the team had assumed she would be rather restricted in her genetic diversity but that she would show more Neanderthal ancestry than modern humans have. Instead, they were surprised to find that the woman had much more genetic diversity than modern humans but no more Neanderthal genes than most human populations have these days.

 

This was a surprise because modern humans whose prehistoric ancestors migrated out of Africa show much less genetic diversity than modern humans whose ancestors stayed in Africa until modern times. Researchers have always thought there was a genetic bottleneck at some point during or not long after groups of humans migrated out of Africa around 80,000 years ago. Lots of suggestions have been made about what might have caused the bottleneck, including disease, natural disaster, or just the general hardship of living somewhere where humans had never lived before. A genetic bottleneck happens when a limited number of individuals survive long enough to reproduce—in other words, in this case, if so many people die before they have children that there are hardly any children left to grow up and have children of their own. To show in the general population as it does, the bottleneck has to be widespread.

 

Now researchers think the genetic bottleneck happened much later than 80,000 years ago, probably during the last ice age. Humans living in Europe and Asia, where the ice age was severe, would have had trouble finding food and staying warm.

 

I’m getting close to finishing the Strange Animals Podcast book, which I’ll talk about a little more in our Q&A episode later this week. It’s a collection of the best mystery animals we’ve covered on the podcast, along with some new mystery animals, and I’m working hard to update my research. If you remember back in episode 83, about mystery big cats, we discussed the Barbary lion, which was thought to be an extinct subspecies of lion that might not actually be extinct. Well, when I looked into it to see if any new information had turned up, I found more than I expected. I rewrote those paragraphs from episode 83 and I’ll read them here as an update:

 

Lions live mostly in Africa these days, but were once common throughout southern Asia and even parts of southern Europe. There even used to be a species called the American lion, which once lived throughout North and South America. It only went extinct around 11,000 years ago. The American lion is the largest species of lion ever known, about a quarter larger than modern African lions. It probably stood almost 4 feet tall at the shoulder, or 1.2 meters. Rock art and pieces of skin preserved in South American caves indicate that its coat was reddish instead of golden. It lived in open grasslands like modern lions and even in cold areas.

 

Much more recently, the Barbary lion lived in northern Africa until it was hunted to extinction in the area. The Barbary lion was the one that battled gladiators in ancient Rome and was hunted by pharaohs in ancient Egypt. It was a big lion with a dark mane, and was thought to be a separate subspecies of lion until genetic analysis revealed in 2006 that it wasn’t actually different from Panthera leo leo.

 

The last wild Barbary lion was sighted in 1956, but the forest where it was seen was destroyed two years later. The lions in a few zoos, especially in Ethiopia and Morocco, are descended from Barbary lions kept in royal menageries for centuries.

 

Lions are well known to live on the savanna despite the term king of the jungle, but they do occasionally live in open forests and sometimes in actual jungles. In 2012 a lioness was spotted in a protected rainforest in Ethiopia, and locals say the lions pass through the reserve every year during the dry season. That rainforest is also one of the few places left in the world where wild coffee plants grow. So, you know, extra reason to keep it as safe as possible.

 

Finally, we’ll finish with a mystery snake. In 1968, during the Vietnam War, the United States Naval Medical Research Unit discovered a small snake in central Vietnam. It was unusual enough that they decided to save it for snake experts to look at later, but things don’t always go to plan during wartime. The specimen disappeared somewhere along the line. Fortunately, there were photographs.

 

The photos eventually made their way to some biologists, and in 1994 a paper describing the snake as a new species was published by Wallach and Jones. They based their description on the photos, which were good enough that they could determine details like the number of scales on the head and jaw. They named it Cryptophidion annamense and suggested it was a burrowing snake based on its characteristics.

 

Other biologists thought Cryptophidion wasn’t a new species of snake at all. In 1996 a pair of scientists published a paper arguing that it was just a sunbeam snake. The sunbeam snake is native to Southeast Asia, including Vietnam, and can grow over 4 feet long, or 1.3 meters. It’s chocolate-brown or purplish-brown but has iridescent scales that give it a rainbow sheen in sunshine. It’s a constricting snake, meaning it squeezes the breath out of its prey to kill it, but it only eats small animals like frogs, mice, and other snakes. It’s nocturnal and spends a lot of its time burrowing in mud to find food.

 

Wallach and Jones, along with other scientists, argued that there were too many differences between the sunbeam snake and Cryptophidion for them to be the same species. But without a physical specimen to examine, no one can say for sure if the snake is new to science or not. If you live in or near Vietnam and find snakes interesting, you might be the one to solve this mystery.

 

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us that way.

 

Thanks for listening!

Episode 228: Monkey Lizards and Weird Turtle…Things

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Thanks to Ethan for this week’s topic, two weird animals that developed after the Great Dying we talked about last week!

Further reading:

Monkey Lizards of the Triassic

Placodonts: The Bizarre ‘Walrus-Turtles’ of the Triassic

Drepanosaurus (without a head since we haven’t found a skull yet, but with that massive front claw):

Drepanosaurus’s tail claw:

Hypuronector had a leaf-like tail:

Placodus was a big round-bodied swimmer:

Some placodonts [art by Darren Naish, found at the second article linked above]:

Henodus was the oddball placodont that probably ate plant material:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

 

Last week we talked about the end-Permian mass extinction, also called the Great Dying. This week let’s follow up with a couple of weird and interesting animals that evolved once things got back to normal on Earth. Thanks to Ethan who suggested both animals.

 

The great dying marks the end of the Permian and the beginning of the Triassic period, which lasted from about 251 million years ago to 201 million years ago. In those 50 million years, life rebounded rapidly and many animals evolved that we’re familiar with today. But some animals from the Triassic are ones you’ve probably never heard of.

 

We’ll start with a reptile called the drepanosaur. Drepranosaurs are also sometimes called monkey lizards for reasons that will soon become clear. Paleontologists only discovered the first drepanosaur in 1980, Drepanosaurus, and within a few years they recognized a whole new family, Drepanosauridae, to fit that first discovery and subsequent closely related specimens. Drepanosaurs were weird little reptiles that probably looked like lizards in many ways, although they weren’t lizards.

 

How weird was Drepanosaurus? Very weird. Very, very weird.

 

It was obviously a climbing animal that probably spent all of its life in the treetops. It had lots of adaptations to life in trees, such as hind feet where all the toes pointed in the same direction and were somewhat curved, sort of like a spider monkey’s hand. That would help it get a good grip on branches. But those hind feet aren’t why it’s called the monkey lizard.

 

Drepanosaurus and its relatives are called monkey lizards because of their tails. Many monkeys have prehensile tails, which act as a fifth limb and help keep the monkey stable in a tree by curling around branches and hanging on. Drepanosaurus had something similar. Instead of being mobile from side to side like most reptile tails, Drepanosaurus’s tail could mostly only curve downward. Modern chameleons have an even more pronounced downward-curving tail that helps them climb. But the chameleon’s tail is still just a tail. The end of Drepanosaurus’s tail had several modified caudal bones that were probably exposed through the skin. Those modified bones acted as a claw to help the animal grab onto tree trunks and branches. So Drepanosaurus had claws on its front feet, claws on its hind feet, and a claw on its tail. It’s sort of like having five feet.

 

As if that wasn’t weird enough, let’s talk about those claws on the front feet. It had five toes on each foot, and four of them had ordinary claws. They were sharp but fairly small, about what you’d expect from an animal that grew about 19 inches long at most, or 50 cm. But the second toe on each foot, which corresponds to the pointer finger on a human hand, had a much bigger claw. MUCH BIGGER CLAW. It was as big as its whole hand! Most researchers think it used the claw to dig into rotting wood, insect nests, and bark to find insects and other small animals to eat.

 

But that’s not all. Drepanosaurus also had a structure called a supraneural bone at the base of its neck, made up of fused vertebrae, that would have made it look like it had a little hunch on its shoulders. While we don’t have a skull of Drepanosaurus, since we only have three specimens so far, this structure is also present in other drepanosaur species where we do have the neck and head, and they all have fairly long, slender necks and birdlike skulls with large eyes. It’s possible that the supraneural bone was the attachment site for special muscles that helped Drepanosaurus extend its neck very quickly to grab insects and other small animals.

 

Drepanosaurs in general shared many of the traits seen in Drepanosaurus, although with some differences. Many drepanosaurs had opposing toes on the feet that would help them grasp branches and twigs more securely. Most don’t have the giant claw on the front feet although most do have the tail claw. But one monkey lizard doesn’t live up to its name at all.

 

A little drepanosaur called Hypuronector limnaios, which only grew about five inches long, or 12 cm, had a much different tail from its relations. Its tail didn’t curve downward at all—in fact, it stuck up behind it and was probably not very flexible. Not only was the tail longer than the body and head together, it had long points growing down from the vertebrae, called haemal arches, which made the tail extremely large top to bottom but flattened from side to side.

 

In other words, its tail looked like a leaf. The drepanosaur could cling to a branch with its tail sticking up, and any nearby predators would probably think it was just another leaf growing from the branch, especially if the tail was covered in green skin. Some researchers speculate that it could have used its tail as a sail to glide from branch to branch too, or it might have acted as a parachute if it had to jump from a branch to escape a predator. Hypuronector’s front legs were longer than its hind legs, unlike other drepanosaurs, which suggests it might have had a flap of skin that helped it glide.

 

Drepanosaur fossils have been found in parts of the United States and western Europe, but were probably more widespread than that. We still don’t know a whole lot about them, so every new specimen that’s found can give paleontologists lots of new information. Most drepanosaurs resembled weird chameleons with birdlike heads, but they weren’t related to birds or chameleons. We don’t actually know what they were closely related to.

 

Ethan also suggested placodonts, another reptile that evolved in the Triassic. Don’t confuse them with placoderms, the armored fish that went extinct in the great dying. The “placo” part of both words means tablet or plate. Therefore, placoderms have skin—that’s the “derm” part—covered in plates, while placodonts have flattened teeth, because the “dont” part refers to teeth. That’s why you get braces on your teeth at the orthodontist but you go to the dermatologist for skin problems.

 

What did placodonts do with their flattened teeth? They used them to crush the shells of shellfish and crustaceans. From that you can infer that they were marine reptiles, and you would be right. The earlier species had big round bodies with heavy bones, which helped them dive to the ocean floor to find food. They lived in shallow coastal waters and had large flattened ribs that helped protect them from injury if currents pushed them into rocks. While the teeth in the back of the mouth were flattened to crush shells, the teeth in the very front of the mouth were sharp and pointed forward to grab prey.

 

One of the most common early placodonts was Placodus [PLAK-oh-dus], which grew nearly six and a half feet long, or 2 meters. Its long tail was flattened laterally to help it swim and it probably had webbed toes. Since its legs were small and relatively weak considering how heavy its body was, it probably couldn’t get around very well on land, so it would have stayed close to the water. It probably looked kind of like the modern marine iguana, which we talked about in episode 92, but with longer jaws. On the other hand, unlike the marine iguana, placodus had a third eye.

 

THIRD EYE ALERT! If you remember way back in episode 3, where we talked about the tuatara, we learned a little bit about the parietal eye, or third eye. Parietal eyes are found on the top of a few animals’ heads, including the tuatara, but they aren’t the same as ordinary eyes. They’re very small photoreceptive eyes that can only sense light and dark. In Placodus’s case, researchers think that ability helped it figure out which way was up more easily when it was underwater. If you’ve ever been knocked down by a wave you’ll understand how easy it is to get disoriented underwater.

 

Placodus and other early placodonts had a ridge of bony scutes on the back to help protect it from predators. In later placodonts those scutes were bigger and bigger until they were more like armor, which added weight to the body and meant that the bones didn’t have to be so dense. This meant that instead of having barrel-like bodies, later placodonts were a little more streamlined. Their bodies were more flattened than round, but still broad across with big plates protecting the back. Their legs were more like flippers.

 

Does this make you think of something? Something like a sea turtle?

 

Later placodonts looked a lot like turtles, a classic case of convergent evolution because they weren’t related to turtles at all. If you saw Placochelys, for instance, you’d probably just think it was a weird sea turtle, unless you got a really close look at it. It grew about three feet long, or 90 cm, with a triangular head, a knobby shell, and flippers with clawed toes at the ends. It had a beak like a turtle’s instead of Placodus’s forward-pointing teeth, but unlike a turtle it also had teeth in the back of the mouth. These were still big flat teeth used for crushing shellfish, but like other placodonts the upper teeth grew from the palate, or the roof of the mouth.

 

Other placodonts would have looked strange to us, like Psephoderma. It grew up to six feet long, or 180 cm, and instead of a single turtle shell, it had two shells. One covered its body from the back of the head down to the pelvis. The other covered its pelvis and was smaller. It had a long tail and a pointy nose.

 

At least one placodont didn’t live in the ocean and didn’t eat shellfish and crustaceans. Henodus grew about three feet long, or one meter, and lived in brackish water or possibly freshwater. Its shell was twice as broad as it was long. It also had a lower shell, or plastron, on its belly. Its nose was short and squared-off and it had a turtle-like beak, and instead of teeth it had denticles on the sides of its jaws. Some researchers think it was a filter feeder, filtering tiny animals from the water through the denticles, while other researchers think it may have eaten water plants. It might have done both.

 

There’s a lot we don’t know about placodonts. We don’t know if they laid eggs or gave birth to live young, and we don’t know what exactly they ate. Obviously their teeth were best suited to crushing shells, but we don’t actually know what kind of shellfish they preferred or if they only ate crustaceans or something else. Placodont remains have been found in Europe, the Middle East, and China, but they were probably more widespread than that. During the Triassic, as the supercontinent Pangaea broke up, it created lots of shallow oceans and island chains that would have been ideal for placodonts.

 

Unfortunately for the placodonts, as the landmasses moved farther apart over millions of years, the shallow seas became deeper. Populations would have become isolated from each other. Eventually placodonts went extinct, probably by a combination of habitat loss and competition from other animals as dinosaurs and their relatives spread throughout the world.

 

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us that way, and don’t forget to join our mailing list. There’s a link in the show notes.

 

Thanks for listening!

Episode 227: The Great Dying

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It’s another extinction event episode! This one’s about the end-Permian AKA the Permian-Triassic AKA the GREAT DYING.

Further Reading:

Ancient mini-sharks lived longer than thought

Lystrosaurus’s fossilized skeleton:

Lystrosaurus may have looked something like this but I hope not:

This artist’s rendition of lystrosaurus looks a little less horrific but it might not be any more accurate:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

It’s time for our next extinction event episode, and this week it’s the big one. Not the extinction event that killed the dinosaurs, but one you may not have heard of, one that almost destroyed all life on earth. I mean, obviously it didn’t and things are fine now, but it was touch and go there for a while. It’s the Permian-Triassic extinction event, or end-Permian, which took place just over 250 million years ago. It was so bad that scientists who aren’t given to hyperbole refer to it as the Great Dying.

Don’t worry, we won’t talk about extinction the whole time. We’ll also learn about some interesting animals that survived the extinction event and did just fine afterwards.

We have a better idea of what happened at the end of the Permian than we have about the earlier extinction events we talked about in episodes 205 and 214. Right about 252 million years ago, something caused a massive volcanic eruptive event in what is now Siberia. Some researchers speculate that the cause of the volcanic eruptions may have been a huge asteroid impact on the other side of the Earth, which was so powerful that it caused magma to move away from the impact like water sloshing in a jostled glass. The magma rose up toward the earth’s crust and eventually through it onto the surface.

The result was probably the largest volcanic event in the last half-billion years and it continued for an estimated two million years. Most of the eruptions were probably pretty low-key, just runny lava pouring out of vents in the ground, but there was just so much of it. Lava covered almost a million square miles of land, or 2.6 million square km. Ash and toxic gases from some eruptions also ended up high in the atmosphere, but one big problem was that the lava poured through sediments full of organic material in the process of turning into coal. Lava, of course, is molten rock and it’s incredibly hot. It’s certainly hot enough to burn a bunch of young coal beds, which added more ash and toxic gases to the air—so much ash that shallow water throughout the entire world became choked with ash.

The carbon dioxide released by all that burning coal caused severe ocean acidification and ocean anoxia—a lack of oxygen in the water. But it gets worse! A lot of lava erupted into the ocean right at the continental shelf, where the shallow coastal water becomes much deeper. This is exactly the place where you find methane deposits in the sediments on the ocean floor. When those deposits were suddenly disturbed by lava flowing into them, all the methane in the formerly tranquil depths was released and bubbled to the surface. Methane is a powerful greenhouse gas, meaning that if a whole lot of it ends up in the atmosphere in a short amount of time, it can cause rapid global warming—much faster than that caused by carbon dioxide. This global warming would have happened after a period of global cooling due to reduced sunlight reaching the earth through ash clouds, which lasted long enough and was severe enough that sea levels dropped as glaciers formed. Then everything heated way, way up. The ice caps melted, which may have led to a stagnation of ocean currents. This in turn would have contributed to the water’s anoxicity and toxicity. The average temperature of the ocean would have increased by almost 15 degrees Fahrenheit, or 8 degrees Celsius. Atmospheric warming may have been as much as 68 degrees Fahrenheit in places, or 20 degrees Celsius. That’s not the average temperature of the world, that’s the temperature increase.

So, basically, everything was terrible and it happened very quickly in geologic terms. A 2018 study found that everything looked pretty much fine for the 30,000 years leading up to the great dying. Some researchers even think the initial extinction event might have taken place over just a few centuries.

Marine animals were affected the most, especially marine invertebrates. Trilobites and placoderms went extinct, eurypterids went extinct, and corals went extinct until about 14 million years later when modern corals developed. Some researchers estimate that 95% of all marine species went extinct.

Things were better on land, but not that much better. At the end of the Permian, life was good on land and it was especially good for insects because of the high percentage of oxygen in the air and the variety of plant life in huge swamps around the supercontinent Pangaea. The largest insects that ever lived were buzzing around in the Permian. This included an order of insects called Meganisoptera, or griffinflies. Griffinflies looked like dragonflies and may be related to them. Some species had a wingspan 28 inches across, or 71 cm. The arthropod Anthopleura, sometimes called the giant millipede, lived in the Permian too. Some species grew six feet long, or 2.5 meters, and were about 18 inches wide, or 45 cm. It looked like a millipede but had even more legs. It probably looked scary, but it only ate plants as far as we know.

Instead of actively breathing the way most vertebrates do, most invertebrates use a passive system to absorb oxygen from the air. This is great when there’s a lot of oxygen. When the level of oxygen drops, though, the largest species can’t absorb enough oxygen to function and die out rapidly. That’s one reason why you don’t have to worry about spiders the size of bears. So all the large invertebrates and a lot of the smaller ones went extinct as oxygen was replaced with carbon dioxide, methane, and other toxic gases in the atmosphere.

The acid rain caused by toxic gases and the reduced sunlight caused by ash in the atmosphere also killed off plants. Forests died, so that the fossil record during and after the extinction event contains massive amounts of fungal spores from fungi that decompose trees. Some researchers think all of the world’s trees died. Forests disappeared for some four million years. Since trees absorb carbon dioxide from the atmosphere and release oxygen, the lack of trees made oxygen levels drop even more.

Animals that depended on forests to survive also went extinct, including about two-thirds of all amphibians, reptiles, and therapsids. Therapsids were proto-mammals and it’s a good thing they didn’t all die out because they eventually gave rise to mammals.

Everything I’ve described sounds so incredibly bad, you may be wondering how anything survived. One stroke of luck was probably the size of Pangaea. That was the supercontinent made up of most of the world’s landmasses all smushed together. Before the extinction event, the middle of Pangaea was probably pretty dry with swampier climates around the edges. After the extinction event, the interior of the supercontinent was the safest place to be.

One of the most common land animals after the extinction event was a herbivore called Lystrosaurus. Lystrosaurus was a therapsid, and it was nothing exciting to look at unless you were also a lystrosaurus. Some species were the size of a cat while some were much larger, up to 8 feet long, or 2.5 m. It had a short snout, a short tail, and a semi-sprawling gait. A lizard walks with its legs stuck out to the sides, while a dog or cat or pig walks with its legs underneath its body. Lystrosaurus was somewhere between the two.

It probably lived in burrows that it dug with its strong front legs. While it had a pair of tusks that grew down from the upper jaw, those were its only teeth. Instead it probably had a turtle-like beak that helped it bite off pieces of vegetation.

Lystrosaurus lived in the central part of Pangaea, in what is now Asia, Antarctica, South Africa, and eastern Europe back when all those areas were all scrunched up close together. It survived the extinction event and expanded its range, and for millions of years it was almost the only big land animal in the world. It had almost no predators because they’d all gone extinct, and it had very few competitors for food because they’d all gone extinct. Lystrosaurus made up 90% of all land vertebrates for millions of years.

How did it survive when so many other animals died out? There are several theories, but the most important factor was probably its lack of specialization. It could survive on any kind of plant instead of needing to feed on specific species of plant. There’s also evidence that it could enter a torpor similar to hibernation where its metabolism slowed way down. This would have been a literal lifesaver during the time when the air and water were toxic and very little plant life survived. Lystrosaurus could hunker down in its burrow for long stretches of time, then come out and find enough food and water to keep it going for another stretch of torpor.

Just imagine the world back then, after the initial extinction event but before the world had recovered—say, a million years after the volcanic activity stopped. Picture a series of gentle rolling hills dotted with grazing animals. It’s peaceful and very open because there are no trees. Grass hasn’t evolved yet so the ground is covered in fern-like plants from the genus Dicroidium, which lives in dry conditions. As you look closer with your mind’s eye, you realize that every single one of those grazing animals—thousands of them visible in every direction—are the same kind of animal that looks sort of like a fuzzy pig with a stumpy lizard tail, clawed feet, and a turtle’s beak. Lystrosaurus, living the good life.

In the ocean, the situation was similar. The shallows were toxic waste dumps of ash where the water had so little oxygen that nothing could survive. But the deeper ocean was still livable for some animals.

For a long time, scientists thought a group of early sharks called cladodontomorphs had gone extinct during the great dying. Their distinctive teeth had been common in the fossil record, but after the extinction event they disappeared. Cladodontomorphs only grew about a foot long at most, or 30 cm, and may have had a weird-shaped dorsal fin that pointed forward. They lived in shallow coastal waters. You know, the worst possible place to be 252 million years ago.

Then palaeontologists found some of those teeth in rocks that were in much deeper water 135 million years ago. It turns out the little sharks had survived the extinction event by moving into the open ocean where conditions were better. And they didn’t just survive, they lasted for another 120 million years.

So let’s break it down. It was probably four million years before trees developed again from different plants. It was some 14 million years before coral reefs could rebuild as modern corals developed after their cousins went extinct. It took 30 million years for terrestrial vertebrates to recover from the great dying and 50 million years for all the ocean’s ecosystems to fully recover. That’s a colossally long time. But it did recover.

So what animals arose once the recovery was well underway? Icthyosaurs. Archosaurs, which eventually evolved into pterosaurs, crocodilians, dinosaurs, and birds. And therapsids that eventually gave rise to modern mammals.

I don’t usually tease the following week’s show, but next week we’re going to learn about some weird and interesting animals that developed in the early to mid Triassic, after the extinction event was over and life started evolving in new directions. As I’ve said in the previous extinction event episodes: no matter how bad things get, there’s always going to be some little animal stumping along out of the carnage to get on with the business of surviving and thriving.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us that way.

Thanks for listening!