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Episode 207: The Dire Wolf!

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This week we’re on the cutting edge of science, learning about the brand new genetic study of dire wolves that rearranges everything we know about the dire wolf and other canids! Also, a bonus turtle update.

Further reading:

Dire Wolves Were Not Really Wolves, Genetic Clues Reveal

An artist’s rendition of dire wolves and grey wolves fighting over a bison carcass (art by Mauricio Anton):

The pig-nosed face of the Hoan Kiem turtle, AKA Yangtze giant softshell turtle, AKA Swinhoe’s softshell turtle:

Show transcript:

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

You may have heard the news this past week about the new study about dire wolves. I thought it would make a great topic for an episode, and we’ll also have a quick update about a rare turtle that’s been in the news lately too.

Dire wolves show up pretty often in movies and TV shows and video games and books, because as far as anyone knew until very recently, the dire wolf was an extra big wolf that lived in North America during the Pleistocene until it went extinct around 13,000 years ago. Researchers assumed it was a close cousin of the modern grey wolf.

Well, in a brand new study published in Nature literally less than a week ago as this episode goes live, we now have results of a genetic study of dire wolf remains. The results give us surprising new information not just about the dire wolf, but about many other canids.

The study started in 2016, when an archaeologist, Angela Perri, who specializes in the history of human and animal interactions, wanted to learn more about the dire wolf. She went around the United States to visit university collections and museums with dire wolf remains, and took the samples she collected to geneticist Kieren Mitchell. Perri, Mitchell, and their team managed to sequence DNA from five dire wolves that lived between 50,000 and 13,000 years ago.

Then the team compared the dire wolf genome to those of other canids, including the grey wolf and coyote, two species of African wolf, two species of jackal, and the dhole, among others. To their surprise, the dire wolf’s closest relation wasn’t the grey wolf. It was the jackals, both from Africa, but even they weren’t very closely related.

It turns out that 5.7 million years ago, the shared ancestor of dire wolves and many other canids lived in Eurasia. At this point sea levels were low enough that the Bering land bridge, also called Beringia, connected the very eastern part of Asia to the very western part of North America. One population of this canid migrated into North America while the rest of the population stayed in Asia. The two populations evolved separately until the North America population developed into what we now call dire wolves. Meanwhile, the Eurasian population developed into many of the modern species we know today, and eventually migrated into North America too.

By the time the gray wolf populated North America, the dire wolf was so distantly related to it that even when their territories overlapped, they avoided each other and didn’t interbreed. We’ve talked about canids in many previous episodes, including how readily they interbreed with each other, so for the dire wolf to remain genetically isolated, it was obviously not closely related at all to other canids at this point.

The dire wolf looked a lot like a grey wolf, but researchers now think that was due more to convergent evolution than to its relationship with wolves. Both lived in the same habitats: plains, grasslands, and forests. The dire wolf was slightly taller on average than the modern grey wolf, which can grow a little over three feet tall at the shoulder, or 97 cm, but it was much heavier and more solidly built. It wouldn’t have been able to run nearly as fast, but it could attack and kill larger animals. Its head was larger in proportion than the grey wolf’s and it had massive teeth that were adapted to crush bigger bones.

The dire wolf lived throughout North America and even migrated into South America and back into east Asia. It preferred open lowlands and its most important prey animal was probably the horse, although it also ate ground sloths, camels, bison, and many others. It probably also scavenged dead animals and probably hunted as a pack.

Researchers think the dire wolf went extinct due to a combination of factors, including increased competition with grey wolves and maybe with humans, climate change, and the extinction of the megaherbivores that made up its diet. It will probably be reclassified into a different genus, Aenocyon, instead of staying in its current genus, Canis.

Before this study, most researchers thought that the ancestor of North American canids evolved in Eurasia, but had already migrated into North America before developing into dire wolves, grey wolves, coyotes, and other canid species. But now the history of canids has changed a lot. From what we now know, pending further study, the dire wolf was the only canid in North America for millions of years. Grey wolves, coyotes, and their relations are relative newcomers. It’s an exciting time for scientists studying ice age megafauna. Hopefully we’ll learn more soon as more studies are conducted into the dire wolf’s history.

Next, let’s look briefly at a type of turtle that’s been in the news lately too. Swinhoe’s softshell turtle is considered the most endangered turtle in the world. In early 2019 there were only two individuals known, a male and a female, but they had never bred despite being kept together in captivity. Then the female died in April of that year. No females meant no eggs, no baby turtles, no more Swinhoe’s softshell turtle. The species would be extinct.

But in October of 2020, researchers found a female Swinhoe’s softshell turtle in the wild! Not only that, they spotted what they think is a male turtle in the same lake, and found evidence of what may possibly be a third turtle nearby.

Swinhoe’s softshell turtle is also known as the Yangtze giant softshell turtle and used to be found in many lakes and rivers in Asia. Unfortunately, people killed it for its meat and dug up its eggs to eat, and pollution and habitat loss also killed off many of the turtles. This is the same turtle we talked about in episode 68, the Hoan Kiem turtle of Vietnam. It’s probably the largest freshwater turtle in the world, and the largest one ever measured weighed 546 lbs, or 247.5 kg. It can grow over three feet long, or 100 cm.

The newly discovered wild turtles are being monitored carefully to make sure they’re healthy, their environment is clean and safe, and to see if the female lays eggs this spring. The female was captured briefly, just long enough to take blood samples and verify that she was healthy. Then they released her back into the lake. Fingers crossed that she hatches some baby turtles soon!

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 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 197: Titanoboa!

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Thanks to Pranav for this week’s suggestion, Titanoboa, the biggest snake that ever lived!

Parts of this episode come from an old Patreon episode about super-gigantic snakes, which is unlocked and you can listen to it here.

A modern anaconda vertebra next to a Titanoboa vertebra. Guess which one is which:

Carlos Jaramillo, one of the scientists who found Titanoboa and Acherontisuchus (taken from a Smithsonian Channel video):

Show transcript:

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

This has been a really busy week for me and I wasn’t able to finish researching the episode I had planned. Instead, we’ll have a short episode on a topic Pranav suggested ages ago, TITANOBOA! In September 2017 I released a Patreon episode about giant snakes, including Titanoboa, but this episode is all new. Ha ha, I thought it would take me less time to research it than finishing the research for what will be next week’s episode, ha ha I was wrong. Anyway, I’m going to unlock the giant snakes Patreon episode so anyone can listen. There’s a link in the show notes if you want to click through and listen on your browser.

Oh, a big congratulations to the winner of my book giveaway, Arthina! Thanks to everyone who entered.

In 1994, a geologist named Henry Garcia found an unusual-looking fossil in northeastern Colombia in South America. Specifically, it was an area that had been strip-mined for coal. Fifty-eight million years ago the region was a hot, swampy, tropical forest along the edge of a shallow sea. The Andes Mountains hadn’t yet formed. The environment was probably most similar to the Everglades and the Mississippi River delta in North America, but the climate was much warmer than it is now. These days what was once swamp is a field of rock uncovered by coal mining, which is not good for the environment but is unbelievably good for palaeontology.

Garcia thought he’d found a piece of fossilized tree. The coal company in charge of the mine displayed it in their office along with other fossils. And there it sat until 2003, when palaeontologists arranged an expedition to the mine to look for fossil plants. A researcher named Scott Wing was invited to join the team, and while he was there he poked around among the fossils displayed by the mining company. The second he saw the so-called petrified branch he knew it wasn’t a plant. He sent photos to a colleague who said it looked like the jawbone of a land animal, probably something new to science.

In 2007, the fossil was sent for study, labeled as a crocodile bone. But the palaeontologists who examined the fossil in person immediately realized it wasn’t from a crocodile. It was a snake vertebra—but so enormous that they couldn’t believe their eyes. They immediately arranged an expedition to search for more of them, and they found them! Comparisons to living anacondas and boas, the snake’s closest living relatives, helped researchers estimate the snake’s size. They named it Titanoboa cerrejonensis and described it in an article published in 2009 in Nature.

In 2012, a partial Titanoboa skull was found. Snake skulls are fragile and don’t fossilize nearly as often as the more robust vertebrae and ribs. It turned out that Titanoboa had lots and lots of teeth, more teeth than modern boids have.

Palaeontologists have found fossilized remains from around 30 individual snakes, including young ones. The adult size is estimated to be 42 feet, or 13 meters. The largest living snakes are anacondas, which may grow up to 29 feet, or 8.8 meters, but which are usually less than half that length. Reticulated pythons grow up to about 26 feet, or almost 8 meters, and possibly longer, but are also usually less than half that.

Titanoboa might have grown up to 50 feet long, or 15 meters, and could weigh more than 2,500 pounds. That’s one and a quarter tons, or more than 1100 kg. The thickest part of its body would have been waist-high compared to an average human male. Of course, these are all estimations since we don’t have a complete skeleton or a living specimen to examine, and most estimates these days put the maximum length at around 42 feet, or 13 meters. Still humongous. Females were probably larger than males, as is the case with most snakes.

Once the skull was found containing all those little teeth, researchers determined that Titanoboa probably ate a lot of fish. That’s unusual for constrictors, but it makes sense to think that a snake that large, living in a hot, tropical area, would spend most of its time in the water.

Even though snakes are cold-blooded, which means their internal temperature fluctuates with the temperature of their environment, a snake that size would retain a lot of heat and even generate heat from metabolic processes. Metabolic processes are related to digestion, chemical reactions that break down food into nutrients that can be used by the body. This releases heat, and in an animal with a bulky body that heat is retained more than in an animal with a slender body. Titanoboa was so big that some researchers think it would have overheated from its own metabolic processes if it didn’t stay cool somehow. Therefore, it might have lived in deep water where it could stay cool. Modern anacondas spend most of its time in the water, although usually in the shallows where it can hide in wait for prey.

Titanoboa undoubtedly ate a type of lungfish that grew nearly ten feet long, or 3 meters, but it probably also ate anything else it could catch, including crocodilians. A gigantic crocodilian found in the same area as Titanoboa, Acherontisuchus, grew up to 21 feet long, or almost 6.5 meters. It lived in the water too and probably mostly ate fish, but it didn’t so much compete with Titanoboa as avoid it as much as possible. After all, a full-grown Titanoboa was more than twice the size of a full-grown Acherontisuchus and could have swallowed it whole after suffocating it.

Several gigantic freshwater turtles also lived alongside Titanoboa. One had a shell that measured 5 feet 8 inches long, or 1.72 meters. Another grew five feet long, or 1.5 meters, but had a shell that was almost perfectly round. Researchers think its shape kept it safe from Titanoboa, since it would have been too big for Titanoboa to swallow. Snakes have bones and jaws that can dislocate to allow them to swallow large prey whole, and stretchy skin, but they have limits. Another turtle had a shell that was described as being as thick as a dictionary. Since other crocodilians have since been found in the area too, the thick shell was probably a defense against crocodilian jaws and teeth. Basically, this was a dangerous place to live no matter how big you were, unless, of course, you were a gigantic snake.

Titanoboa and the other animals of the swampy rainforest lived only about ten million years after the extinction event that killed off the non-avian dinosaurs. Obviously they’d been evolving to fill ecological niches left empty by the dinosaurs. Little did they know, though, that continental drift would lead to a cooling climate that would drive many reptiles to extinction and give rise to the age of mammals!

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 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 124: Updates 2 and a new human

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It’s our second updates and corrections episode! Thanks to everyone who sent in corrections and suggestions for this one! It’s not as comprehensive as I’d have liked, but there’s lots of interesting stuff in here. Stick around to the end to learn about a new species of human recently discovered on the island of Luzon.

The triple-hybrid warbler:

Further reading:

New species of ancient human discovered in the Philippines: Homo luzonensis

Show transcript:

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

Yes, it’s our second updates episode, but don’t worry, it won’t be boring!

First, a few corrections. In episode 45 I talked about monotreme, marsupial, and placental mammals, and Tara points out that the placenta and bag of waters are different things. I got them mixed up in the episode. The bag of waters is also called the amniotic sac, which protects and cushions the growing baby inside with special amniotic fluid. The placenta is an organ attached to the lining of the womb, with the bag of waters inside the placenta. The umbilical cord connects the baby to the placenta, which supplies it with all its needs, including oxygen since obviously it can’t breathe yet.

Next, I covered this correction in in episode 111 too, but Judith points out that the picture I had in episode 93 of the Queen Alexandra’s birdwing butterfly was actually of an atlas moth. I’ve corrected the picture and if you want to learn more about the atlas moth, you can listen to episode 111.

Next, Pranav pointed out that in the last updates episode I said that the only bears from Africa went extinct around 3 million years ago–but the Atlas bear survived in Africa until the late 19th century. The Atlas bear was a subspecies of brown bear that lived in the Atlas Mountains in northern Africa, and I totally can’t believe I missed that when I was researching the nandi bear last year!

Finally, ever since episode 66 people have been emailing me about Tyrannosaurus rex, specifically my claim that it was the biggest land carnivore ever. I don’t remember where I found that information but it may or may not be the case, depending on how you’re defining biggest. Biggest could mean heaviest, tallest, longest, or some combination of features pertaining to size.

Then again, in 1991 a T rex was discovered in Canada, but it was so big and heavy and in such hard stone that it took decades to excavate and prepare so that it can be studied. And it turns out to be the biggest T rex ever found. It’s also a remarkably complete fossil, with over 70% of its skeleton remaining.

The T rex is nicknamed Scotty and was discovered in Saskatchewan. It lived about 68 million years ago, and turns out to not only be the biggest T rex found so far, it was probably the oldest. Paleontologists estimate it was over 30 years old when it died. It was 43 feet long, or 13 meters. This makes it bigger than the previously largest T rex found, Sue, who was 40 feet long, or 12.3 meters. Scotty also appears to be the heaviest of all the T rexes found, although estimates of its weight vary a lot. Of course some researchers debate Scotty’s size, since obviously it’s impossible to really know how big or heavy a living dinosaur was by just looking at its fossils. But Scotty was definitely at least a little bigger than Sue.

Scotty is on display at the Royal Saskatchewan Museum in Canada.

Way back in episode 12, I talked about snakes that were supposed to make noises of one kind or another. Many snakes do make sounds, but overall they’re usually very quiet animals. A snake called the bushmaster viper that lives in parts of Central America has long been rumored to sing like a bird. The bushmaster can grow up to ten feet long, or 3 meters, and its venom can be deadly to humans.

Recently, researchers discovered the source of the bushmaster’s supposed song. It’s not a snake singing. It’s not a bird singing. It’s not even a single animal–it’s two, both of them tree frogs. One of the frogs is new to science, the other is a little-known frog related to the new one.

I tried so hard to find audio of this frog, and I’m very bitter to report that I had no luck. The closest I could find was not great audio of this frog, whose name I forgot to write down, which I think is related to the new frogs.

[frog sound]

Now let’s do some quick, short updates, mostly from recent articles I’ve happened across while researching other things.

A triple-hybrid warbler, its mother a golden-winged/blue-winged hybrid (also called a Brewster’s warbler) and its father a warbler from a different genus, chestnut-sided, was sighted in May of 2018 by a birder in Pennsylvania. Lowell Burket noticed it had characteristics of both a blue-winged and a golden-winged warbler but sang like a chestnut-sided warbler. He contacted the Cornell Evolutionary Biology Lab about the bird with photos and video of it, and they sent a researcher, David Toews, out to look at it. Toews caught the bird, measured it, and took a blood sample for analysis. I think a listener told me about this article but I didn’t write down who, so thank you, mystery person.

Red-fronted lemurs chew on certain types of millipedes and rub the chewed-up millipedes on their tails and their butts. They also eat some of the millipedes. Researchers think the millipedes secrete a substance called benzoquinone, which acts as an insect repellant and may also help the lemurs get rid of intestinal parasites. Other animals rub crushed millipedes on their bodies for the same reasons.

A recent study of saber-toothed cat fossils show that many of the animals with injuries to their jaws and teeth that would have kept them from hunting properly survived on softer foods like meat and fat. Researchers think the injured cats were provided with food by other cats, which suggests they were social animals. The study examined micro-abrasions on the cats’ teeth that give researchers clues about what kinds of food the animals ate.

Simon sent me an article about a 228 million year old fossil turtle, Eorhynchochelys [ay-oh-rink-ah-keel-us]. It was definitely a turtle but it didn’t have a shell. Instead, its ribs were wide, which gave its body a turtle-like shape. Turtle shells actually evolved from widened ribs like these. Researchers are especially interested because Eorhynchochelys had a beak like modern turtles, while the other ancient turtle we know of had a partial shell but no beak. This gives researchers a better idea of how turtles evolved. Oh, and in case you were wondering, Eorhynchochelys grew over six feet long, or over 1.8 meters.

The elephant bird, featured in episode 51, was a giant flightless bird that lived in Madagascar. Recently new research about elephant birds has revealed some interesting information. For one thing, we now know what the biggest bird that ever lived was. It’s called Vorombe titan and grew nearly ten feet tall, or 3 meters, and weighed up to 1,800 lbs, or 800 kg. It was first discovered in 1894 but not recognized as its own species until 2018.

There’s also some evidence that at least some elephant bird species may have been nocturnal with extremely poor vision. This is the case with the kiwi bird, which is related to the elephant bird. Brain reconstruction studies of two species of elephant bird reveal that the part of its brain that processed vision was very small. It resembles the kiwi’s brain, in fact. One of the species studied had a larger area of the brain that processed smell, which researchers hypothesize may mean it lived in forested areas.

Another study of the elephant bird bones show evidence that the birds were killed and eaten by humans. But the bones date to more than 10,000 years ago. Humans supposedly didn’t live in Madagascar until 4,000 years ago at the earliest. So not only is there now evidence that people colonized the island 6,000 years earlier than previously thought, researchers now want to find out why elephant birds and humans coexisted on the island for some 9,000 years before the elephant bird went extinct. Hopefully archaeologists can uncover more information about the earliest people to arrive on Madagascar, which may help us learn more about how they interacted with the elephant bird and other extinct animals of the island.

Speaking of humans, humans evolved in Africa and until very recently, evolutionarily speaking, that’s where we all lived. Scientists rely on fossils, archaeological materials, and studies of ancient DNA to determine when and where humans spread beyond Africa. But at the moment, the DNA that researchers have studied doesn’t overlap entirely with what we’ve learned from the other sources. Basically this means that there are big chunks of data we still need to find to get a better picture of where our ancestors traveled. Part of the problem is that DNA preserves best in cold, dry areas, so most of the viable DNA recovered is from middle Eurasia. Fortunately, DNA technology is becoming more and more refined every year.

This brings us to a suggestion by Nicholas, who told me about a newly discovered hominin called Homo luzonensis. Homo luzonensis lived on an island called Luzon in the Philippines at least 50,000 years ago. It wasn’t a direct ancestor to Homo sapiens but was one of our cousins, although we don’t know yet how closely related.

No one thought humans could reach the island of Luzon until relatively recent times, because of how remote it is and because it hadn’t been connected to the mainland for the last 2 ½ million years. But when Homo floresiensis was discovered in 2004 on the island of Flores in Indonesia, which you may remember from episode 26, suddenly scientists got interested in other islands. Researchers knew there had been human settlements on Luzon 25,000 years ago, but no one had bothered to search for older settlements. In 2007 a team of paleoanthropologists returned to the island and found a foot bone that looked human. In 2011 and 2015 the team found some teeth and more bones from at least three different individuals.

We don’t know a whole lot about the Luzon humans yet. The discoveries are still too new. The Luzon hominins have a combination of features that are unique, a mixture of traits that appear more modern and traits that are seen in more ancient hominins. They’re also smaller in stature than modern humans, closer to the size of the Flores people. Homo luzonensis apparently used stone tools since researchers have found animal bones that show cut marks from butchering.

Researchers are starting to put together a picture of South Asia in ancient times, 50,000 years ago and more, and it’s becoming clear that there were a surprising number of hominins in the area. It’s also becoming clear that hominins lived in the area a lot longer ago than we thought. Researchers have found stone tools on the island of Sulawesi that date back at least 118,000 years. Even on Luzon, in 2018 researchers found stone tools and rhinoceros bones with butcher marks that date back over 700,000 years ago. We don’t know who those people were or if they were the ancestors of the Luzon people. We just know that they liked to eat rhino meat, which is one data point.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 097: Unusual Reptiles

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Thanks to listeners Finn and Leo, who suggested this week’s topics of strange lizards, and the thorny devil and mata mata turtle, respectively! Join us this week to learn about those reptiles and a bunch more!

Thorny devil. Definitely do not eat.

The mata mata turtle. Big leafhead boi

A frilled lizard BWAAAAAMP

A Pinocchio lizard. Wonder where that name comes from.

Poke poke poke does this bother you? poke poke

om nom nom

A shingleback, or as I like to call it, an ambulatory poop:

Show transcript:

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

We have more listener suggestions this week! Ages ago, listener Finn suggested strange lizards, and more recently, listener Leo suggested a particular type of strange lizard and a strange turtle.

We’ll start with Leo’s suggestion, the thorny devil. He describes it as “a cool animal with spikes all around it,” which is definitely a good way to put it. The thorny devil is a lizard from Australia, and it does indeed have spikes all over its head, back, and tail, and smaller spikes on its legs. The spikes are modified scales and are sharp.

The thorny devil grows to around 8 inches long, or 20 cm, with females being larger than males on average. In warm weather its blotchy brown and yellow coloring is paler than in colder weather, when it turns darker. It can also turn orangey, reddish, or gray to blend in to the background soil. Its color changes slowly over the course of the day as the temperature changes. It also tends to turn darker if something threatens it.

It has a thick spiny tail that it usually holds curved upward, which makes it look kind of like a stick. It moves slowly and jerkily, rocking back and forth on its legs, then surging forward a couple of steps. Researchers think this may confuse predators. It certainly looks confusing.

As if that wasn’t enough, the thorny devil has a false head on the back of its neck. It’s basically a big bump with two spikes sticking out of the sides. When something threatens the lizard, it ducks its head between its forelegs, which makes the bump on its neck look like a little head. But all its spines make it a painful mouthful for a predator. If something does try to swallow it, the thorny devil can puff itself up to make itself even harder to swallow, like many toads do. It does this by inflating its chest with air.

The thorny devil eats ants and only ants, specifically various species of tiny black ants found only in Australia. It has a sticky tongue to lick them up. Because it has such a specific diet, it’s hard to keep in captivity. Only a few zoos in Australia have thorny devils on display. If you listened to episode 93, where we talked about invasive ant species having an effect on entire ecosystems, the thorny devil is an example of this. Fortunately the ants it eats are doing just fine, but if an invasive ant species were introduced to the areas where it lives, the thorny devil would probably be in trouble. So no moving ants around, everyone, I mean it.

The thorny devil lives in desert and scrubland regions, and in hot weather it digs a burrow to shelter in. Females lay their eggs in burrows. To get enough water in its desert environment, the thorny devil has microscopic grooves between its scales that suck up water by capillary action. At night dew condenses on the lizard’s body, and it also collects dew by brushing against dewy vegetation or just by standing or lying on damp sand. If it does happen across water in a puddle, it will put a leg in the water and the tiny grooves in its skin suck up water and funnel it to the mouth. It’s like a living straw.

While I was researching this, I found some information on how rattlesnakes drink. When it starts to rain, a rattlesnake will coil up tightly so that rainwater collects in its coils. Then it drinks the water. This sounds like something someone just made up, but it’s real.

Let’s skip right from a snake fact to a weird turtle, because Leo also suggested the mata mata turtle as a topic. This is where I got distracted while researching, and ended up with an entire episode about giant tortoises. If you were wondering, the main difference between a turtle and a tortoise is that turtles spend most or all of their time in water, while tortoises live only on land.

The mata mata turtle lives in shallow, slow-moving water in South America, especially swamps around the Amazon and Orinoco river basins. It isn’t closely related to the snapping turtle of North America, but it does resemble a snapping turtle in some ways. Its shell is brown or black, its skin is grayish, and its plastron, or the belly section of its shell, is yellow or brown. It grows to around two feet long, or 60 cm, with a long, broad neck and wide, triangular head. Its nose comes to a point like the stem of a leaf. In fact, if you look down on a mata mata in the water, the shape of its head looks exactly like a dead leaf. It has notches and ridges on its shell, and its knobbly skin has flaps that helps camouflage the turtle among dead leaves and sticks in the water. It also has claws and webbed toes.

Unlike the snapping turtle, the mata mata is harmless to humans and most animals. It doesn’t have a sharp bill and it won’t bite. It can’t even chew its food, just swallows it whole. It eats fish, water insects, and other small animals that it captures by opening its large mouth suddenly under the water. This creates suction, sucking a lot of water and the prey right into the turtle’s mouth.

The only time the mata mata leaves the water is to lay eggs. Unlike many other turtle eggs, the mata mata eggs have hard shells, more like bird eggs. It takes the eggs about 200 days to hatch.

The mata mata spends almost all of its time motionless in the water, waiting for prey to come near, and occasionally extending its ridiculously long neck so it can take a breath from the surface. Its pointy nose is a proboscis that it breathes through. It can swim, but it usually prefers to walk along the bottom of the pond or marsh. I bet its feet squish in the mud. Squish squish squish.

Speaking of pointy-nosed reptiles, the male Pinocchio lizard has a nose that points forward and slightly upward like a rhinoceros horn. But it’s not a horn, because it’s flexible, made of cartilage. It lives in the Mindo cloud forest in Ecuador, and was only discovered by scientists in 1953, when researchers collected six specimens. And that was the last time anyone saw the Pinocchio lizard—until 2005, when some birdwatchers saw a weird lizard, took pictures and posted them online, and herpetologists started freaking out.

The Pinocchio lizard blends in so well with its environment that it’s hard to spot. It turns white when it’s asleep, which helps it look like part of a tree branch. It always perches on the end of a branch to sleep, too. During the day, it climbs verrry slowly into the treetops. It’s not a big lizard, only about three inches long, or 7.5 cm, not counting its tail, which is as long as its body. We still don’t know much about it because it’s so hard to study.

It’s not the only lizard with a horn on its nose. For instance, the rough-nosed horned lizard lives in Sri Lanka and is an ordinary-looking lizard for the most part, although it’s covered with short bristly scales that make it look like it would work well for scrubbing out dirty pots and pans. But it has a really long nose, also covered in bristly scales. Oh, and yellow or orange markings on its face that make it look like it has a big orange clown mouth. Males have longer horns than females. Male mountain horned agamas, which also live in Sri Lanka, have a single white or cream-colored horn that sticks directly forward from their nose like a tiny unicorn horn, except it’s not spiraled. In fact, it’s not a horn at all, it’s a single big pointy scale. But those lizards aren’t related to the Pinnocchio lizard.

The La Gomera giant lizard doesn’t have any horns and it’s not all that giant, less than two feet long, or around 49 cm long, including the tail. It’s black or brown on its back with a white belly. Males also have a white throat, and during mating season males inflate their throat and bob their head to attract females. It mostly eats plants, although it will eat insects too, and it lives in the Canary Islands. It’s not the most exciting lizard to look at, but it has an interesting history.

The Canary Islands are a group of islands off the coast of Morocco. It was once called the Fortunate Isles, so if you ever see that in an old book you know what islands it’s talking about. Pliny the Elder, a historian from ancient Rome, said the name Canaria came from the number of dogs on the islands. The word for dog in Latin is canis. The people of the islands were supposed to worship dogs, and some modern historians believe the old accounts of dog-headed people may be a garbled account of the Canary Islanders. Oh, and the little yellow songbirds that live on the Canary Islands took their name from the islands, not vice versa.

The islands were probably visited in ancient times by Phoenician and Greek sailors, but reportedly no one lived there when the Romans explored it in the 1st century. But when Europeans returned in the late middle ages, there were inhabitants that may have been settlers from North Africa. The islands were invaded by Europeans, who then spent centuries fighting with each other over who ruled them. It’s Spain, currently. Scientific expeditions started in the late 18th century. One of the animals the expeditions reported seeing was the La Gomera giant lizard, but it disappeared sometime after about 1900. Researchers assumed it had gone extinct.

Then a 1999 expedition from the University of La Laguna on Tenerife, one of the Canary Islands, heard stories from local residents on the island of La Gomera. They said there was a big lizard living in a few places on the island. The biologists in the expedition checked it out…and sure enough, there were giant lizards. Specifically, six of them. Just six lizards. Later they found another small group of the lizards in another area, but the total population was still no more than fifty.

Fortunately, a captive breeding program has been successful and today there are around 250 of the lizards in the wild, living only on two hard to reach cliffs. They’re vulnerable to introduced predators, especially cats, which eat the eggs and young lizards. Another 300 or so live in a recovery center where they’re protected from predators before being released into the wild. So basically, the La Gomera giant lizard isn’t so much strange as just very, very lucky.

Another lizard that is definitely strange is the frilled lizard from northern Australia and southern New Guinea. It’s bigger than the La Gomera giant lizard, almost three feet long, or 85 cm, and eats insects, spiders, and small animals. It lives in trees and is well camouflaged with blotches and spots on a gray or brown background to help camouflage it among branches and against bark.

The frilled lizard gets its name from the frill on eitherside of its head. Most of the time it keeps the frill folded back against itsneck. When it’s threatened, though, it spreads the frill out and opens itsmouth wide. The inside of its mouth is bright yellow or pink, and the frill hasbright red or yellow scales that don’t show when it’s folded. It’s the lizardequivalent of a jump scare in scary movies. Regular lizard, regular lizard…BWAMP BIG SCARY BRIGHT LIZARD

The frill is made up of spines of cartilage that grow from the lizard’s jaw bones, with skin connecting the spines. It’s not small, either. When expanded, it can be almost a foot across, or 25 cm.

The frilled lizard isn’t dangerous, though, and if its threat display doesn’t scare off a predator, it runs away until it finds a tree to climb. It runs so fast, in fact, that it lifts its body up and just runs on its hind legs, which helps it navigate uneven ground and gives it a better view of what’s around it. It also holds its long tail out as a counterweight to keep its body upright.

That’s supposed to be all the strange details about the frilled lizard…but there are sightings of it doing something unexpected on rare occasions. People occasionally report seeing a frilled lizard fall or jump from a tree, and glide down using its frill as a parachute. There’s no proof that this actually happens, but it sounds plausible.

Another Australian lizard called the shingleback, or bobtail, looks kind of like a pinecone with legs. Or a poop with legs, just going to set that down and walk away. It’s brown with darker and lighter speckles or yellow splotches, large overlapping scales, a stubby thick tail, and a broad head. In fact, its head and tail look a lot alike, which confuses predators. It also stores fat in its tail for winter. It grows about a foot long, or 30 cm, and eats snails, insects, flowers, and other small animals and plants. It lives in arid and desert areas, and their tough skin and overlapping scales help reduce water loss. Its eyes are tiny, like little black beads.

The shingleback looks nothing like the frilled lizard, but it has one thing in common with it. When threatened, the shingleback will open its mouth wide and stick out its large, dark blue tongue. It is an impressively blue, impressively big tongue, and the inside of the shingleback’s mouth is otherwise pale, so it’s startling, to say the least.

The shingleback mates for life. Most of the year the shingleback is solitary, but in spring mated pairs find each other again and go around together while they hunt for food. The female gives birth to two live babies instead of laying eggs.

I could go on and on and on about all the weird reptiles in the world. There are just so many! We’ll definitely come back to this topic in the future, but for now, let’s finish up with a snake called Iwasaki’s snail-eater.

The snail-eater lives on a few small islands southwest of Japan’s main islands. It’s small, only about 7 inches long, or 22 cm, and is orangey in color with darker markings and bright orange eyes. And it only eats one thing: snails.

It’s so perfectly adapted to its diet of snails that its jaw is asymmetrical so it can more easily wedge it into the typical snail’s shell, which coils clockwise. If you remember from the little yard animals episode, some snails very rarely coil the opposite way, and the snail-eater snake is so specialized to eat ordinary snails that it has trouble with counter-clockwise coiled snail shells. It has more teeth on its right mandible. There are other snail-eater snakes closely related to Iwasaki’s snail-eater that have this same adaptation, and in some areas where the snakes are numerous, counter-clockwise snails are much more common than in areas without a lot of snail-eater snakes.

So that’s a reminder that whether you’re a little snail-eating snake or a regular human being, the things you do have an effect on the world around you, even if it’s in ways too small for you to notice without looking very closely.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 075: Archelon and Other Giant Sea Turtles

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This week we’re going to find out about the biggest turtles that ever lived! Spoiler: one of them is alive right now, swimming around eating jellyfish.

A green sea turtle. These guys are adorable:

A hawkbill glowing like a neon sign!

The majestic and enormous leatherback:

Bebe leatherback. LET ME GOW

Seriously, how are baby sea turtles so darn cute?

Archelon was a big tortle:

Further reading:

This is a link to a pdf of that “Historicity of Sea Turtles Misidentified as Sea Monsters” article

Show transcript:

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

This week we’re back in the sea, but not the deep sea this time, because we’re looking at marine turtles!

The oldest known turtle ancestor lived around 220 million years ago, but it wouldn’t have looked a whole lot like a modern turtle. For one thing, it had teeth instead of a bill. It resembled a lizard with wide ribs that protected its belly. It lived in the ocean, probably in shallow inlets and bays, but it may have also spent part of its time on land. Some researchers think it may have had at least a partial shell formed from extensions of its backbone, but that this didn’t fossilize in the three specimens we have.

The oldest sea turtle fossil found so far has been dated to 120 million years old. It was seven feet long, or 2 meters, and already showed a lot of the adaptations that modern sea turtles have. Researchers think it was closely related to the green sea turtle and the hawksbill sea turtle.

Seven species of sea turtle are alive today. They all have streamlined shells and flippers instead of feet. They all breathe air, but they have big lungs and can stay underwater for a long time, up to about an hour while hunting, several hours when asleep or resting. Like whales, they surface and empty their lungs, then take one huge breath. They can see well underwater but can probably only hear low-frequency sounds.

Sea turtles have a special tear gland that produces tears with high salt concentration, to release excess salt from the body that comes from swallowing sea water. They migrate long distances to lay eggs, thousands of miles for some species and populations, and usually return to the same beach where they were hatched. Female sea turtles come ashore to lay their eggs in sand, but the males of most species never come ashore. The exception is the green sea turtle, which sometimes comes ashore just to bask in the sun. Once the babies hatch, they head to the sea and take off, swimming far past the continental shelf where there are fewer predators. They live around rafts of floating seaweed call sargassum, which protects them and attracts the tiny prey they eat.

Six of the extant sea turtles are relatively small. Not small compared to regular turtles, small compared to the seventh living sea turtle, the leatherback. More about that one in a minute. The other six are the green, loggerhead, hawksbill, Kemp’s ridley and Olive ridley, and the flatback.

Let’s start with the green sea turtle, since I just mentioned it. Its shell is not always green. It can be brown or even black depending on where it spends most of its life. Green turtles that live in colder areas of the Pacific have darker shells, which probably helps them stay warm by absorbing more heat from sunlight. Young turtles have darker shells than old turtles for the same reason.

The green sea turtle can grow up to five feet long, or 1.5 meters, can live some 80 years, and mostly eats plants, especially seagrass, although babies eat small animals like worms, jellyfish, and fish eggs. A recent satellite tracking study of green sea turtles in the Indian Ocean tracked the turtles to a huge underwater seagrass meadow that no human realized existed until then. The meadows were farther underwater than the ones researchers knew about, up to 95 feet deep, or 29 meters. Researchers think the seagrass can grow at these depths because the water is so clear in the area, which means more light for the plants.

Unlike the green sea turtle, which lives throughout much of the world’s oceans, the flatback sea turtle is only found around Australia. It’s greenish or grayish and only grows around 3 feet long, or 95 cm, and eats invertebrates of various kinds, including jellyfish, shrimp, and sea cucumbers. It stays near shore in shallow water and doesn’t migrate, so it’s mostly safe from getting tangled in commercial fishing nets that kill a lot of other sea turtle species.

The smallest sea turtle is the olive ridley, which only grows around two feet long, or 60 cm. Its shell is roughly heart-shaped and is usually olive green. It mostly lives in tropical waters and is the most common sea turtle of all the living species, but getting rarer. It likes warm, shallow water and eats small animals like snails, jellyfish, and sea urchins.

Kemp’s ridley sea turtle is closely related to the olive ridley, and is not much larger. It grows to around 28 inches long, or 70 cm, and eats the same things as the olive ridley. It also likes the same warm, shallow waters, but it nests exclusively along the Gulf Coast of North America. Oil spills in the Gulf have killed so many turtles that the species is now listed as critically endangered. Conservationists sometimes remove eggs to safer, cleaner beaches where babies are more likely to hatch and survive. Besides oil spills and other types of pollution, Kemp’s ridley sea turtles are often killed when they get tangled in shrimp nets and drown. Fortunately, shrimp trawlers in the Gulf now use turtle excluders, which help keep turtles from getting tangled.

The hawksbill sea turtle grows to around three feet long, or 1 meter, and lives around tropical reefs. It has a more pointed, hooked beak than other sea turtles, which gives it its name. You might think it eats fish or something with a beak like that, but mostly it eats jellyfish and sea sponges. It especially likes the sea sponges, some of which are lethally toxic to most other animals. It also doesn’t have a problem eating even extremely stingy jellies and jelly-like animals like the Portuguese man-o-war. The hawkbill’s head is armored so the stings don’t bother it, although it does close its eyes while it chomps down on jellies. People used to kill hawksbill sea turtles for their multicolored shells, but don’t eat them. Its meat can be toxic due to the toxins it ingests.

The hawksbill is also biofluorescent! Researchers only found this out by accident in 2015, when a team studying biofluorescent animals in the Solomon Islands saw and filmed a hawksbill glowing like a UFO with neon green and red light. Researchers still don’t know why and how the hawksbill glows. They think the red color may be emitted by certain algae that grow on hawksbill shells, but the green appears to be emitted by the turtle itself. Since the hawksbill lives mostly around coral reefs, where many animals biofluoresce, researchers hypothesize it might be a way for the turtle to blend in. If everyone’s glowing, the big turtle-shaped spot that isn’t glowing would give it away. Then again, since male turtles glow more brightly than females, researchers also think it may be a way to attract mates.

Finally, the loggerhead sea turtle grows to a little longer than three feet, or 95 cm, and its shell is usually reddish-brown. It lives throughout the world’s oceans and while it nests in a lot of places, many loggerheads lay their eggs on Florida beaches. It eats invertebrates like bivalves and sponges, barnacles and jellyfish, starfish, plants, and lots of other things, including baby turtles. Its jaws are powerful and it has scales on its front flippers that stick out a little, called pseudoclaws, which allow it to manipulate its food or tear it into smaller pieces.

All sea turtles are endangered and are protected worldwide, although some countries enforce the protection more than others. Some people still eat sea turtles and their eggs, even though both can contain bacteria and toxic metals that make people sick. But mostly it’s habitat loss, pollution, and fishing nets and longlines that kill turtles.

People want to build houses on the beach, or drive their cars on the beach, and that destroys the habitat female turtles need to lay their eggs. Turtles also get stuck in fishing equipment and drown. And there’s so much plastic floating around in the sea that all sorts of animals are affected, not just turtles. A floating plastic bag or popped balloon looks like a jellyfish to a sea turtle that doesn’t know what plastic is. A turtle can eat so much plastic that its digestive system becomes clogged and it dies. One easy way you can help is to remember your reusable bag when you go shopping. The fewer plastic bags that are made and used, the fewer will find their way into the ocean. Some countries have banned plastic shopping bags completely.

Now let’s talk about the leatherback turtle. It’s much bigger than the others and not very closely related to them. It can grow some nine feet long, or 3 meters, and instead of having a hard shell like other sea turtles, its carapace is covered with tough, leathery skin studded with tiny osteoderms. Seven raised ridges on the carapace run from head to tail and make the turtle more stable in the water, a good thing because leatherbacks migrate thousands of miles every year. Not only is the leatherback the biggest and heaviest turtle alive today by far, it’s the heaviest living reptile that isn’t a crocodile. It has huge front flippers, is much more streamlined even than other sea turtles, and has a number of interesting adaptations to life in the open ocean.

The leatherback lives throughout the world, from warm tropical oceans up into the Arctic Circle. It mostly eats jellyfish, so it goes where the jellyfish go, which is everywhere. It also eats other soft-bodied animals like squid. To help it swallow slippery, soft food when it doesn’t have the crushing plates that other sea turtles have, the leatherback’s throat is full of backwards-pointing spines. What goes down, will not come back up, which is great when the turtle swallows a jellyfish, not so great when it swallows a plastic bag.

The leatherback can dive as deep as 4,200 feet, or almost 1,300 meters. Even most whales don’t dive that deep. But it’s a reptile, so how does it manage to survive in such cold water, whether in the Arctic Ocean or nearly a mile below the water’s surface?

The leatherback’s metabolic rate is high to start with, and it swims almost constantly. Its muscles generate heat as they work, which keeps the turtle’s body warmer than the surrounding water, as much as 30 degrees Fahrenheit warmer, or 18 degrees Celsius. Its flippers and throat also use a system called countercurrent heat exchange, where blood that has been chilled by outside temperatures returns to the heart in veins that surround arteries containing warm blood flowing from the heart. By the time the cool blood reaches the heart, it’s been warmed by the arterial blood. This keeps heat inside the body’s core.

Unlike other sea turtle species, leatherbacks don’t necessarily return to the same beach where they were hatched to lay their eggs. Females usually nest every two or three years and lay about 100 eggs per nest. No one is sure how long leatherbacks live, but it may be a very long time. Most turtles have long lifespans, and many sea turtle species don’t even reach maturity until they’re a couple of decades old.

One interesting thing about sea turtles, which is also true of many other reptiles, is that the temperature of the egg determines whether the baby turtle will develop into a male or female. Cooler temperatures produce mostly male babies, warmer temperatures produce mostly female babies. This is pretty neat, until you remember that the global temperature is creeping up. A new study of sea turtles around Australia’s northern Great Barrier Reef found that almost all baby turtles hatching there are now female—up to 99.1% of all babies hatched. Another study found the same results in sea turtle nests in Florida, where 97 to 100% of all babies are female. The studies also found that the amount of water in the nest’s sand also contributes to whether babies are male or female, with drier nests producing more females. Researchers are considering incubating some nests in climate-controlled rookeries to ensure that enough males hatch and survive to produce the next generation.

So those are the seven types of sea turtle alive today. Now let’s talk about an extinct sea turtle, a relative of the leatherback. This is archelon, and it was huge.

Archelon was the biggest turtle that has ever lived, as far as we know. The first fossil archelon was discovered in 1895 in South Dakota, in rocks that were around 75 million years old. The biggest archelon fossil ever found came from the same area, and measures 13 feet long, or 4 meters. It’s even broader from flipper to flipper, some 16 feet wide, or 5 meters. It lived in the shallow sea that covered central North America during the Cretaceous, called the Western Interior Seaway. I like that name. Its shell was leathery and probably flexible like the leatherback’s, but unlike the leatherback, it wasn’t teardrop shaped. In fact, it was very round. Since it lived at the same time as mosasaurs, its wide shell may have kept it from being swallowed by predators. It probably ate squid and jellyfish like the leatherback, and researchers think it was probably a slow swimmer. It went extinct at the same time as the dinosaurs, but fortunately its smaller relations survived.

We don’t know if that 13-foot-long archelon was an unusually large specimen, an average specimen, or a small specimen. It was probably on the large size, but it’s a good bet that there were larger individuals swimming around 75 million years ago. We don’t know if leatherbacks occasionally get bigger than nine feet long, for that matter. But we do have reports of sea turtles that are much, much bigger than any sea turtles known.

In August of 2008, a 14-year-old boy snorkeling in Hawaii reported swimming above a sea turtle that was resting on the bottom of a lagoon. He estimated the turtle was eight to ten feet across with a round shell. At the time he didn’t realize that was unusual. He also reported seeing a geometric pattern on the shell, which is not a feature of the leatherback or archelon but is present in other sea turtles. So if his estimation of size is correct, he saw a sea turtle far bigger than any living today.

In 1833, a schooner off the coast of Newfoundland came across what they thought was an overturned boat. When the crew investigated, they discovered it wasn’t a boat at all but an enormous leatherback turtle, which they reported was 40 feet long, or 12 meters.

Many sea serpent sightings may actually be misidentifications of sea turtles. Sea turtles do have relatively long necks which they can and do raise out of the water. A long neck with a small head sticking out of the water, with a hump behind it, describes a lot of sea serpent reports. It’s also possible that some sea serpent reports are actually sightings of sea turtles entangled with fishing nets and other debris that the turtle drags with it as it swims, which may look like a long snake-like tail behind a humped body.

For instance, in 1934 some fishermen off the coast of Queensland, Australia spotted what they thought was a sea serpent. I’ll quote the description, which is from an article with the lengthy title of “Historicity of Sea Turtles Misidentified as Sea Monsters: A Case for the Early Entanglement of Marine Chelonians in Pre-plastic Fishing Nets and Maritime Debris” by Robert France. I’ll put a link in the show notes in case you want to read the article, if I can find it again. I printed it out so I could keep it.

Anyway, the fishermen reported that the sea serpent looked like this:

“The head rose about eight feet out of the water, and resembled a huge turtle’s head…the colour was greyish-green. The eye…was small in comparison to the rest of the monster. The other part in view was three curved humps about 20 feet apart, and each one rose from six feet in the front to a little less in the rear. They were covered with huge scales about the size of saucers, and also covered in barnacles. We could not get a glimpse of the tail, as it was under the water.”

Robert France suggests that this was a sea turtle entangled with a string of fishing gear, specifically fishing floats. He also gives a number of other examples dating back hundreds of years. Fortunately for sea turtles and other animals in the olden days, most fishing nets were made from rope, usually hemp and sometimes cotton, which eventually rotted and freed the animal, if it survived being entangled for months on end.

So if you live around the ocean, or any kind of water for that matter, make sure to pick up any litter you find, especially plastic bags. You could save a lot of lives. Who knows, maybe the sea turtle you save from eating that one fatal plastic bag will grow up to become the biggest sea turtle alive.

As a companion piece to this episode, Patreon subscribers got an episode about the Soay Island Sea Monster sighted in 1959, which was probably a sea turtle of some kind. Just saying.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. 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 whatever platform you listen on. We also have a Patreon if you’d like to support us that way.

Thanks for listening!