Category Archives: fossils

Episode 032: Some New Zealand birds

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This week’s episode is about several New Zealand birds, from the still-living kiwi to the mmmmmaybe extinct moa! Note: I’m going to start putting a full transcript of each episode in the show notes for those who would like to know what words I’m mispronouncing and for those who may have hearing issues. Transcripts will be below the pictures.

A kiwi:

Superman has fought everything.

The controversial blurry “moa” picture taken by Freaney. Probably not a moa.

Show transcript:

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

Before we get started, apologies for my voice. About the time I finally got over the cough I picked up at WorldCon in Finland, I went to DragonCon in Atlanta and got a big juicy cold. Hopefully I don’t sound too gross. My traveling for the year is over so I’m looking forward to having time to really dig into some fun topics for the podcast. In particular, I’m going to be covering some of the creepier strange animals in October, because Halloween is the best. And yes, Bigfoot is going to make an appearance.

This week’s episode is about some amazing birds from New Zealand. We learned about the takahe way back in episode seven, a big silly-looking flightless bird that was once thought extinct until its rediscovery in the middle of the last century. This week we’ll look at some other birds, some of them happily alive, some that are definitely extinct. At least, we’re pretty sure they are.

New Zealand wasn’t settled by humans until the late 13th century, only about 750 years ago. That’s mind-blowing until you take a look at a globe. New Zealand isn’t just a hop skip and jump away from Australia, it’s 900 miles away over open ocean. It’s 600 miles away from the Pacific Islands. That’s a long, long trip to make in a small boat, especially when you’re not sure if there’s any land out that way. But sometime between the years 1250 to 1300, people from eastern Polynesia discovered this new land. They liked it and stayed, and their descendants are now known as the Maori.

I know we’ve been talking about tectonic plates in a number of episodes recently. I haven’t done it on purpose—it’s just part of learning how and why different animals developed in different places. It’s definitely relevant when it comes to New Zealand.

New Zealand is just a little part of an otherwise submerged continent called Zealandia, or sometimes Tasmantis, which I actually prefer. Tasmantis. If Zealandia weren’t mostly under the ocean, it would be about half the size of Australia. Around 90 million years ago Zealandia, Australia, and Antarctica were all part of the supercontinent Gondwana. As Gondwana broke up, Zealandia separated from Antarctica and Australia around 80 million years ago, then slowly sank into the ocean.

After Zealandia separated from Gondwana, a cataclysmic event, probably a humongous meteor strike, led to the extinction of some 85% of the animals on earth. In most of the world, mammals began to evolve like crazy to fill the vacant ecological niches after the dinosaurs died off. But Zealandia didn’t have very many mammals to start with, and by 25 million years ago it was mostly underwater anyway except for the peaks of New Zealand, which were being pushed up slowly by tectonic forces—a process that’s still ongoing.

When travelers from Polynesia first landed on New Zealand, the only mammals on the islands were three species of bat. But there were birds in abundance, from enormous moas and eagles to tiny kiwi. Almost every ecological niche was filled by a bird.

Europeans first visited New Zealand in 1642. It didn’t go well and no one came back until 1769, and after that things got messy and lots of people died from war and introduced diseases. Around the mid-19th century Europeans started moving to New Zealand. Between them, the Maori, and introduced mammals like rats and dogs, a whole lot of birds went extinct.

I just want you to know that it took me hours and hours and hours to research all that stuff about Zealandia. Hopefully I got it right. I’m ready to talk about birds now.

Let’s start with a bird that is so unique to New Zealand that you’ll sometimes hear people call New Zealanders kiwis. There are five species of kiwi, all of them rare and protected. They’re round brown poofs of birds with long legs and long bills, and they eat worms, insects, seeds, fruit, frogs, and other things like that. They prefer to live in forests and usually mate for life, and can live for 50 years.

The kiwi has a lot of unusual characteristics. It’s flightless but has wings less than an inch long hidden under its feathers. Each wing has a tiny claw at its tip that doesn’t seem to have a use. The kiwi has no tail. Unlike every other bird out there, its nostrils are at the tip of its bill. The kiwi has a good sense of smell and may detect worms and other underground prey by smell, which should make you pause and wonder what earthworms smell like. The kiwi also has sensory pits at the tip of its bill that helps it detect vibrations, though, so it’s possible its good sense of smell is less important than researchers previously thought. When a kiwi detects its prey, it stabs its bill into the ground to catch it, which frequently leads to the kiwi later having to snort dirt out of its nostrils. Evolution does what it can, folks, but it’s not perfect.

Since it can’t fly and doesn’t need flight feathers, the kiwi’s feathers are hair-like and downy. But most curious of all is its egg. The kiwi is about the size of a chicken, but its egg is six times the size of a chicken egg and can weigh an entire pound. It’s so big that the female can’t even eat the last few days before she lays the egg. There’s no room in her body for food.

After the female lays her egg, the male incubates it. That huge egg has a huge yolk to feed the baby inside, so when the baby kiwi hatches, it’s ready to go. After a few days it leaves the nest and starts foraging, usually with its dad alongside for the first few weeks. It takes several years for it to grow to adult size.

The kiwi is territorial and will fight other kiwis that stray into its territory. Only its mate and its own offspring are allowed in its territory. It has powerful legs with claws that can inflict quite a bit of damage, and it can run faster than a human.

Scientists used to think the kiwi was closely related to moas, which we’ll talk about in a minute, but DNA studies have determined that its closest relative is the extinct elephant bird of Madagascar—and the elephant bird is the topic for a future episode.

The Maori describe a huge black swan called a Pouwa that lived in the Chatham Islands, but it had already gone extinct by the time Europeans arrived in the area in the late 1700s. Until recently researchers thought it was just the Australian black swan, either a population that lived in New Zealand or the occasional individual that flies across the Tasman Sea. Australian black swans were introduced to New Zealand in the 1860s.

But a recent study of DNA from fossilized swan remains from New Zealand show that it wasn’t the same bird as the Australian black swan but a related species. Around one or two million years ago Australian black swans lived in New Zealand and evolved into a separate species, heavier than the Australian birds with longer legs and shorter wings. It might have been a poor or reluctant flier and might have been on its way to evolving into flightlessness before it was eaten into extinction by the Maori.

The big name in extinct birds of New Zealand is the moa. Nine species of moa are recognized today, although in the past researchers thought there were a lot more. It turns out that female moas of some species were much larger than the males, so much so that scientists once thought they were looking at two different species. Moas were big flightless birds that in shape resembled big flightless birds from other parts of the world, known as ratites, which includes ostriches. Until DNA testing most researchers thought moas were closely related to the ratites of Australia, emus and cassowaries. But no, they are most closely related to a group of birds from Mexico, Central America, and South America collectively called tinamous. Tinamous are a type of ratite, but they can fly. They’re all fairly small and somewhat resemble quail and other game birds that spend a lot of time foraging on the ground.

Moas, however, are big. They are really big. Originally scientists mounted their skeletons so that the neck stuck more or less straight up, but now we know that they held their necks more like ostriches, with a gentle S-shaped curve. Even so, females of the biggest species, the South Island Giant Moa, stood around six and a half feet high at the back. That doesn’t even count the neck. With the neck outstretched, a big female moa could probably reach leaves twelve feet off the ground.

All moas were plant-eaters. Some ate leaves and fruit, others were adapted to digest tougher plant material like twigs, moss, and bark. Unlike other flightless birds, they didn’t have wings at all, not even for display, not even vestigial wings. They just flat-out didn’t have forelimbs. They did have strong legs although they probably couldn’t run very fast, unlike other flightless birds like ostriches. After all, moas didn’t need to run to escape predators. They only had one predator, and that was one they couldn’t outrun: Haast’s eagle.

Haast’s was the biggest eagle that ever lived, although its wings were comparatively short—only around 10 feet wide for big females, closer to 8 ½ feet wide for big males and more average-sized females. Since much of its hunting range was forested, its shorter wings probably helped it maneuver. It had a long tail too. But it had enormous talons with claws over four inches long, and its bill was similarly big. In fact, its talons were so big that its scientific name, Harpagornis moorei, means Moore’s grappling hook bird.

The Haast’s eagle’s prey was the moa, and when moas went extinct after overhunting, the Haast’s eagle went extinct soon after since it just didn’t have anything to eat. It did apparently try to adapt its hunting habits, though. Maori legends tell of the Pouakai, an enormous bird that would sometimes kill humans.

It’s pretty certain that Haast’s eagle is extinct. If it was still around, ranchers would spot it picking off sheep and calves. But the moa is something else. Moa sightings pop up pretty frequently in remote areas of New Zealand.

One of the smallest species of moa, Megalapteryx, also called the upland moa, may have survived on the south island until the mid-19th century. The upland moa was three or four feet tall including the head and neck, and was completely covered with feathers except for its bill and feet, since it lived in the mountainous areas of New Zealand’s south island where the climate was cool. It laid one or two blue-green eggs a year and the male took care of the babies.

Its accepted date of extinction is around the year 1500, but there have been numerous sightings since then. In 1880, Alice McKenzie, who was then seven years old, saw a three-foot-tall bird with blue feathers, dark green scaled legs, and three claws on each foot. She ran to get her father, but when they returned the bird had gone, although it had left big tracks in the sandy soil. She saw the same bird again in 1889.

The problem with this sighting is that the upland moa had feathered legs, and as far as we know no moas had blue plumage. We have plenty of upland moa feathers, which are grey, black and white. We even have mummified upland moa remains. Not only did Alice describe her bird as blue, she specifically noted it was the blue of a pukeko, which has vibrant plumage that varies from navy blue to violet. This wasn’t a grayish-blue bird. Alice herself thought, later in life, that she might have seen a takahe, which is also blue, but after the takahe was rediscovered she went to view some and was disappointed. They have red legs and she knew her bird’s legs were green.

But that’s not the only sighting. In addition to the sporadic accounts of big birds seen in the distance, in 1993 three men hiking in the Craigieburn Range saw what they described as a red-brown and gray moa some six feet high, including its neck. It ran off when it saw them, but one of the men, Paddy Freaney, ran after it and managed to get a photograph. He also got a few pictures of its footprints where it had stepped in a stream and then on a rock.

The picture is frustrating, to say the least. It’s so out of focus that it could be anything. However, I agree with one of the experts who have examined the photo, palaeoecologist Richard Holdaway, who says the figure’s neck is too thick for a moa. He thinks the picture is probably of a red deer. As far as I can find, Freaney’s photos of the footprints haven’t been released.

In 2007, a pair of cryptozoologists searching for moas in the hill country of the North Island spotted 35 footprints and what appeared to be a nest that they claimed were made by a group of moas, possibly a lesser moa. But considering that the pair of cryptozoologists are Rex and Heather Gilroy, who are notorious for being secretive, vague in their claims of evidence, and somewhat paranoid about their findings, I don’t expect them to show up with a live moa anytime soon. No other moa sightings or even rumors of moas living in the area have ever been uncovered.

It’s easy to dismiss this account, and the others, as wishful thinking, misidentification, and in some cases maybe outright hoaxes. Australian emus are raised in some areas of New Zealand and sometimes escape from captivity, too, which confuses the issue, since emus are big flightless birds that could easily be mistaken for moas at a distance. But there is something that makes me hopeful that the moa might still be around, especially one of the smaller species.

New Zealand’s south island is much less populated than its north island. Alice McKenzie’s sighting in 1880 was on her family’s farm near Milford Sound, which is now part of Fiordland National Park. This is a big nature reserve in the southwest corner of the south island, with rugged terrain and very few tracks passable to even offroad vehicles. The park includes the Murchison Mountains, which is where the takahe was rediscovered in 1948 after being thought extinct. So it’s entirely possible that a small species of moa might be hiding in the area. Maybe one day someone will get a really good picture—or better yet, a hiker or park ranger might come across a newly dead moa carcass and can bring it back for study.

We do have some subfossil moa remains that aren’t just skeletons and feathers. Dessicated body parts turn up occasionally, which has helped with DNA testing and our knowledge of what the living birds looked like. The moa is a good candidate for de-extinction by genetic cloning, and it would be really neat to have moas for sure running around in New Zealand again, so scientists can get right on that as far as I’m concerned.

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 iTunes or whatever platform you listen on. We also have a Pattreon if you’d like to support us that way. Rewards include stickers and twice-monthly bonus episodes.

Thanks for listening!

Episode 026: Humans Part Two

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Part two of our humans episode is about a couple of our more distant cousins, the Flores little people (Homo floresiensis) and Homo naledi, with side trips to think about Rumpelstiltskin, trolls, and the Ebu gogo.

Homo floresiensis skull compared to a human skull. We are bigheaded monsters in comparison. Also, we got chins.

Homo naledi’s skull. I stole that picture from Wits University homepage because I really liked the quote and it turns out it’s too small really to read. Oh well.

Some of our cousins. Homo erectus in the middle is our direct ancestor. So is Lucy, an Australopithecus, although she lived much longer ago.

Show transcript

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

This week is part two of our humans episode. Last week we learned how modern humans evolved and about two of our close cousins, Neandertals and Denisovans. This week, we’re going to walk on the weirder side of the hominin world.

Before we get started, this episode should go live on July 31, 2017, one week before I fly to Helsinki, Finland for WorldCon 75! Don’t worry, I’ve got episodes scheduled to run normally until I get home. If you’re going to be in Finland between August 8 and August 17, let me know so we can meet up. On Thursday, August 10 and 4pm I’ll be on a panel in room 207 about how to start a podcast, so check it out if you’re attending the convention. I’ll also be in Oslo during the day on August 7 and have two birding trips planned with lunch in between, and I’d love you to join me if you’re in Oslo that day too. Then, two weeks after I return from Finland, I’ll be attending DragonCon over Labor Day weekend. blah blah blah this is old news

Now, let’s learn about some of our stranger distant cousins!

In 2003, a team of archaeologists, some from Australia and some from Indonesia, were in Indonesia to look for evidence of prehistoric human settlement. They were hoping to learn more about when humans first migrated from Asia to Australia. One of the places they searched was Liang Bua cave on the island of Flores. They found hominin remains all right, but they were odd.

The first skeleton they discovered was remarkably small, only a bit more than three and a half feet tall [106 cm] although it wasn’t a child’s skeleton. That skeleton was mostly complete, including the skull, and appears to be that of a woman around 30 years old. She’s been nicknamed the Little Lady of Flores, or just Flo to her friends. Officially, she’s LB1, the type specimen for a new species of hominin, Homo floresiensis.

But until very recently, that statement was super controversial. In fact, there’s hardly anything about the Flores remains that aren’t controversial.

At first researchers thought the remains were not very old, maybe only twelve or thirteen thousand years old, or 18,000 at the most. Stone tools were found in the same sediment layer where Flo was discovered, as were animal bones. The tools were small, clearly intended for hands about the size of Flo’s, which argued right off the bat that she was part of a small-statured species and wasn’t an aberrant individual.

The following year, 2004, the team returned to the cave and found more skeletal remains, none very complete, but they were all about Flo’s size. Researchers theorized that the people had evolved from a population of Homo erectus that had arrived on the island more than three quarters of a million years before, and that they had become smaller as a type of island dwarfism. A volcanic eruption 12,000 before had likely killed them all off, along with the pygmy elephants they hunted.

But as more research was conducted, the date of the skeletons kept getting pushed back: from 18,000 years old to 95,000 years old to 150,000 years old to 190,000 years old. Dating remains in the cave is difficult, because it’s been subject to flooding and partial flooding over the centuries. Currently, the skeletal remains are thought to date to 60,000 years ago and the stone tools to around 50,000 years ago.

When news of the finds was released, the press response was enthusiastic, to say the least. The skeletons were dubbed Hobbits for their small size, which made the Tolkien estate’s head explode, and practically every few weeks it seems there was another article about whether there were small people still living quietly on the island of Flores, yet to be discovered.

And, of course, there were lots of indignant scientists who were apparently personally angry that the skeletons were considered a new species of hominin instead of regular old Homo sapiens. Part of the issue was that only one skull has ever been found. It’s definitely small, and the other skeletal remains are all correspondingly small, and the stone tools are all correspondingly small, and the skull shows a number of important differences from that of a normal human. But that doesn’t necessarily mean it’s not a subspecies of Homo sapiens, and of course that needs to be investigated. But some of the arguments got surprisingly ugly. There were even accusations that the entire find was faked. One person even suggested that the skull’s teeth showed evidence of modern dental work.

Amid all this, two unfortunate things happened. First, in December 2004 an Indonesian paleoanthropologist named Teuku Jacob removed almost all the bones from Jakarta’s National Research Centre of Archaeology for his own personal study for three months. When he returned them, two leg bones were missing, two jaw bones were badly damaged, and a pelvis was smashed. Then, not long after, Indonesia closed access to Liang Bua cave without explanation, although the archeological community suspected it was due to Jacob’s influence, and didn’t reopen it until 2007 after Jacob died.

It’s important to note that Jacob was a proponent of the theory that the remains found in Liang Bua cave were microcephalic individuals of the prehistoric local population, not a new hominin species at all. He also had a history of keeping Indonesian fossils from being studied unless he specifically approved of the research.

At any rate, since then, repeated studies of the LB1 skull have suggested that Homo floresiensis is a separate species of hominin and not a Homo sapiens with evidence of pathology, whether microcephaly or another disease, or a population with a genetic abnormality. There’s still plenty of research needed, of course, and hopefully some more skulls will be found. But it seems clear that Homo floresiensis isn’t just a weird subspecies of Homo sapiens.

One of the more common theories in the last few years was that Homo floresiensis was descended from Homo erectus, although Homo erectus was a lot bigger and more human-like than the Flores little people. But results of a study released just a few months ago show that Homo floresiensis shared a common ancestor with Homo habilis around 1.75 million years ago. Homo floresiensis may have evolved before migrating out of Africa, or their ancestor migrated and evolved into Homo floresiensis. Either way, they spread as far as Indonesia before dying out around 50,000 years ago.

Other hominin remains have since been found on the island. Part of a jaw and teeth were found at Mata Menge on the island of Flores, some 50 miles away from the cave. It’s around 700,000 years old and is a bit smaller than the same bones in the later skeletons. Researchers think it’s an older form of Homo floresiensis.

Possibly not coincidentally, modern humans arrived on the island about 50,000 years ago, maybe earlier, bringing with them the arts of fire, painting, making jewelry from animal bones, and killing all of our genetic cousins.

We don’t know if humans deliberately killed the Homo floresiensis people or if they just outcompeted them. It does seem pretty certain that the two hominin species coexisted on the island for at least a while. It’s even possible that knowledge of the strange small people of the island has persisted in folk tales told by the Nage people of Flores. Stories about the ebu gogo have been documented for centuries. They were supposed to be little hairy people around three feet tall [one meter], with broad faces and big mouths. They were fast runners with their own language and would eat anything, frequently swallowing it whole. In some stories they sometimes kidnapped human children to make the children teach them how to cook, although the children always outwitted the ebu gogo.

Supposedly, at some point, tired of their children being kidnapped and their food being stolen, villagers gave the ebu gogo palm fibers so they could make clothes. The ebu gogo took the fibers to their cave, and the villagers threw a torch in after them. The fiber went up in flames and killed all of the ebu gogo.

Until the discovery of Homo floresiensis, anthropologists assumed the stories were about macaque monkeys. But there’s a genuine possibility that the ebu gogo tales are memories of Homo floresiensis. It’s not just cryptozoologists and bigfoot enthusiasts making the connection between the ebu gogo and Homo floresiensis. Articles and editorials have appeared in journals such as Nature, Scientific American, and Anthropology Today. At least, they did back when archeologists thought Flo was only about 12,000 years old.

But we still don’t know for certain when Homo floresiensis went extinct. There may be remains that are much more recent than 50,000 years ago. Locals mostly say there are no ebu gogo left but that they were still around about a century ago. I don’t know how long historical elements can persist in an oral tradition without becoming distorted. As we discussed in episode 17, about Thunderbird, oral history is easily lost if the culture is disrupted by invasion, disease, war, or other major episodes. But some stories are tougher than others, and those that are less history and more entertainment—although they may contain warnings too—can be very, very old.

Researchers have traced some traditional folktales, like Rumpelstiltskin, back some 4,000 or even 6,000 years, although not without controversy. But while Rumpelstiltskin is usually described as a small person, no one’s suggesting that story is about real events. It’s the juxtaposition of the Flores discoveries of small skeletons and the oral tradition or small people living on the island that got researchers excited. And as it happens, there is an oral tradition many miles and many cultures away from Flores that might be something similar.

Old Norse stories about trolls date back thousands of years. The trolls vary in appearance and sometimes have a lot of overlap with other monsters, but generally are described as big and strong, not very smart, often placid unless provoked, and usually evil, or at least godless. Sometimes they capture humans who outwit them to escape. In one story, a man named Esbern Snare wanted to marry a woman, but her father would only agree to the marriage if Esbern would build a church. Esbern struck a deal with a troll, who said he would build the church—on one condition. If Esbern couldn’t guess the troll’s name by the time the church was built, the troll would demand as his payment Esbern’s heart and eyes.

Esbern agreed, but he failed to trick the troll into telling him his name. On the final day, in despair Esbern threw himself down on the bank of a river, where he overheard the troll’s wife singing to her baby:

“Hush, hush, baby mine,

Tomorrow comes Finn, father thine,

To bring you Esbern’s heart and eyes

To play with, so now hush your cries.”

Esbern rushed back to the church and greeted Finn the troll by name. In some version of the story, Finn is so furious that he leaves the church incomplete in some way, usually a missing pillar. For those of you who aren’t familiar with the Rumpelstiltskin story, that’s a variant. Oh, and Esbern Snare was a real person who lived in the twelfth century, although I’m pretty sure he didn’t actually strike any deals with trolls.

But I do wonder if some elements of troll folklore might be derived from memories of Neandertal people. I’m not the first to suggest this, although it is a pretty fringey theory. And in the end, we just don’t have any way to know. But it is interesting to think about.

As you may remember from part one of the humans episode, Homo sapiens evolved roughly 200,000 years ago. But around the same time, or a little earlier, another cousin in our family tree was living in southern Africa. Remains of Homo naledi were only discovered in 2013 by some cavers. Partial skeletons from at least 15 individuals were recovered in one field season, but due to narrow cave passages, the field work had to be done by people of small stature who weren’t claustrophobic, mostly women.

Homo naledi is a mixture of primitive and advanced features. Primitive in this case means more like our ape ancestors, and advanced means more like modern humans. Homo naledi had long legs and feet that looked just like ours, but also had a small brain and fingers that are much more curved than ours—not characteristics that would look out of place a few million years ago, but surprising to discover in our family tree at about the same time that modern humans were evolving.

On the other hand (with curved fingers), evolution doesn’t have an end goal. Homo sapiens is not the pinnacle of creation to which all other living beings aspire. We’re just another animal, just another great ape. If Homo naledi was successful in their environment with a small brain, that’s all that matters from an evolutionary standpoint.

There are lots of remains left in the cave, so many in fact that some researchers are convinced they didn’t get there by accident. It’s possible that the cave was used as a burial pit, maybe even over the course of centuries. Bodies may have been dropped in a deep shaft and were then moved by periodic flooding to the remote chamber where they were found, or they may have been carried to the cave depths and left there.

Homo naledi wasn’t a direct ancestor of Homo sapiens, but they were definitely a kind of human—no matter how small their brains may have been.

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. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us and get twice-monthly bonus episodes for as little as one dollar a month.

Thanks for listening!

Episode 025: Humans Part I (Neanderthals and Denisovans)

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This week is our first two-parter ever! I don’t intend to do that often but there was just too much to go over for one episode. This week we’ll talk about humans: where we come from, how we evolved, and who our closest cousins are–Neanderthals and Denisovans.

Some young humans. Humans can do many surprising things, including surfing, making stained glass, and repairing helicopters. Most humans like the color blue and enjoy listening to music.

The bracelet found with Denisovan bones in a Siberian cave. Humans didn’t make or wear this lovely thing, Denisovan people did.

Further reading:

How to Think Like a Neandertal by Thomas Wynn and Frederick L. Coolidge

Show transcript:

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

This will be our first two-part episode. There’s so much to cover with this topic that I decided to split it into two. This week we’re going to investigate an unusual family of great apes: both the living representative and their extinct relatives—and I don’t know why I’m saying “their extinct relatives,” because the great apes in question are known as Homo sapiens.

Humans tend to view ourselves as separate from the natural world. Some of us see ourselves as special, above other animals and better than them. Some of us see ourselves as despoilers of nature who can’t be trusted at all. But in reality, we’re neither angels nor devils. We’re animals too, and we fit neatly in the world because we evolved to live here, just like every other animal did too.

Humans have two major things going for us. First of all, we’re really smart. We’re only now learning the ways other animals show high intelligence, but even so, hands down we are the brightest apes in the circus. Our intelligence allows us to invent amazing things to make our lives more comfortable, like beds and shoes and medicine and umbrellas and podcasts. Unfortunately, our intelligence also lets us invent things that aren’t so nice, like bombs, because like our close cousins the chimpanzees, we can be real jerks.

But besides our intelligence, which is an obvious plus, we’ve got something very few other animals have: stamina, and the ability to shed heat efficiently, which makes us tireless hunters. In fact, that combined with our ability to make and use tools made early humans pretty much unstoppable.

Persistence hunting is only practiced by a few species of animal, like grey wolves, spotted hyenas, and humans. Humans aren’t especially fast runners compared to horses and deer and other prey animals, but we can just run on and on, sweating to cool ourselves, while our prey has to rest to cool down. One downside to this is that we can drive ourselves to heat exhaustion without realizing it, when conditions are just too hot to be constantly active.

I just looked this up, because I just realized I didn’t know if other female animals menstruate like human women. It turns out that female chimps do, along with a few other primates—and bats, for some reason. Solidarity with our bat girlfriends.

Actually, all placental mammals prepare a womb lining periodically, but when it turns out they don’t need it because they’re not going to have babies, they just reabsorb the material. Only a few species shed it, and even in humans we reabsorb most of it. Some researchers think we menstruate because it’s actually easier on the body to just dump the last of that unused stuff rather than spend extra energy absorbing it.

Now that we all know a few things about humans that we might not have known before, here’s a somewhat simplified overview of how humans evolved.

Humans and our ancestors are called hominins collectively. There were some apes 6 or 7 million years ago that were probably somewhat bipedal, and which are considered the earliest known hominins. We’re not sure which of the several species is our direct ancestor and which is our last shared ancestor with gorillas and chimpanzees.

Bipedalism is a defining trait of hominins. It took a long time to develop because there are a lot of skeletal and other changes needed to make it work effectively. By about 3 or 4 million years ago, the Australopithecines had evolved, and we know they walked upright at least part of the time because we have a fossilized track.

But why did bipedalism develop in the apes at all? Of all the apes, only humans developed bipedalism, and it actually still gives us a lot of problems: weak backs that are subject to injury, for instance, and even increased difficulty in childbirth, since the human pelvis had to change so much to adapt to walking upright. The cause was probably habitat change.

If you look at a map of Africa, you’ll see what looks like a string of lakes on the eastern side of the continent. Those lakes, and the volcanoes scattered around the area, including Mount Kilimanjaro, are caused by the East African Rift. Researchers are still working out what exactly is causing the rift, but we do know what’s happening in general. The tectonic plate Africa sits on, which is naturally known as the African Plate, is splitting in two.

This sounds alarming, especially if you happen to live there, but it’s a ridiculously slow process from our point of view. The rift widens barely seven millimeters a year. But that adds up when you’re talking millions of years, and the rift started at least ten million years ago and will continue for another ten million years until the plates separate completely and those lakes become part of the ocean.

Around the time the rift started forming, the East African plateau rose up, accompanied by a lot of volcanic activity. This caused a major change in the local habitats. What had once been thick forest and lush jungle became open woodland and savanna. Grasses grew tall, there wasn’t as much cover, and the animals that evolved and moved into the area were fast runners. It wasn’t a great area to be a knuckle-walker like other apes, but it was ideal for apes who could stand and walk upright.

The rift is where we’ve found so many important hominin fossils, including that of Lucy. Lucy was an Australopithecus who lived 3.2 million years ago. In Ethiopia, where the partial skeleton was found, she’s known as Dinknesh, which means “you are marvelous” in the local language.

That kind of makes me want to cry a little. Lucy wasn’t just some ape who could walk upright part of the time while carrying things. She was our great-great-great-a million times-great grandma.

[oops copyright infringement hahahahahahahahahahaha]

By around two and a half million years ago, Homo habilis had evolved. Homo habilis probably still looked a lot like an ape, but was also getting recognizably human. They walked upright all the time and made stone tools. Then, a little less than two million years ago, Homo erectus appears in the fossil record.

Homo erectus was definitely human-looking, with a human-like nose, ordinary human-sized height, and very little hair except on the head. And Homo erectus had dark skin, which is linked to the loss of body hair.

By a little less than one million years ago, Homo erectus was wearing clothes, cooking their food, and were adept in making and using stone tools. If you went back in time and met a Homo erectus, you’d think you were just meeting a really weird-looking person—and you would be right. Also, where did you get the time machine and can I get a ride in it?

By 200,000 years ago, modern humans, Homo sapiens, had fully evolved. If you could go back in time and meet those early humans, they would look, act, and think like the people you see around you today.

Of course, evolution isn’t as cut and dried as it sounds here. When one species evolves over long, slow generations into another, that doesn’t mean the population it evolved from vanishes. You may have heard the so-called argument against evolution: if humans evolved from monkeys, why are there still monkeys?

Well, first of all, apes and monkeys are different animals entirely. Both monkeys and apes, and all the other primates, evolved from a distant ancestor that wasn’t a monkey or an ape, but which had the characteristics that made it distinctly primate instead of feline or canine or hippopotamine…that’s not a word.

Second of all, species evolve because of environmental pressures, and those same pressures may not be present in all parts of the species’s range. Homo erectus survived well into the era of modern humans, and in fact we probably killed them off, either directly (because remember, we can be jerks) or indirectly by outcompeting them in the same habitats.

At some point, humans started moving out of Africa into other parts of the world, maybe about 55,000 years ago although we’re not really sure yet. Researchers are still working it all out, but some research suggests there might be more than one wave of migration, or that the migration started much earlier than 55,000 years ago.

The hominins I’ve mentioned so far weren’t the only ones around. Those were only our direct ancestors. There were others who split off from our ancestors and evolved separately, and if they hadn’t all died out (again, thanks to us, Homo sapiens jerkuses), we’d have populations of living cousins who are much more closely related to us than the other great apes. So let’s learn about some of them!

I’ve actually been putting off doing this episode because right now, we’re in the middle of a golden age of hominin discoveries. I kept thinking that if I just waited a few more weeks or months, new findings might very well be announced. In fact, right after I started research, sure enough, new information was published about a recently discovered Denisovan baby tooth.

There are two known groups of hominins who aren’t direct human ancestors to Homo sapiens, Neanderthals and Denisovans. They were around at the same time as modern humans for at least a while, but not usually in the same places.

Neanderthals spread throughout parts of northern Europe and Asia, and the Denisovans spread into Asia and down through the Malay Archipelago and into Australia. Again, I need to stress that these were not direct human ancestors. While they could and did interbreed with Homo sapiens, and many modern populations carry traces of Neanderthal and Denisovan DNA, there is no practical genetic difference in a human from one continent or background and a human from a different continent or background. We’re all human.

Around 1.8 million years ago, a population of Homo erectus migrated into Eurasia, where they gave rise to Neanderthals and Denisovans. When humans later migrated into the same areas, they encountered their close cousins and lived alongside them for possibly as long as 10,000 years before the human population increased to the point that…those other guys? They had to go.

The first Neanderthal fossils were discovered in 1829 in Belgium, but it’s the 1856 discovery of fossils in a cave in Neader Valley in Germany that gave us their name. “Thal” [pronounced like the word tall] means dale or valley in German, spelled with a TH, which is why so often the name is pronounced Neander-thal. It doesn’t really matter how you pronounce it.

Anyway, there’s still a lot of controversy regarding whether Neanderthals are a subspecies of Homo sapiens or a separate species in their own right. One incredibly “clever” and just precious suggestion in 1866 was that the group be named Homo stupidus. In fact, Neanderthals were probably as smart as humans and were definitely bigger and stronger than us (so don’t make jokes about them). They were well adapted to the cold with a barrel chest, relatively shorter limbs than humans, and an overall more robust build. They probably had better eyesight than we do too. Genetic evidence suggests that some populations may have had light skin and red or blond hair.

But it’s possible they weren’t as socially adept as humans. The average Neanderthal social group consisted of a close family unit—mother, father, and kids, or brothers and their mates, who were not related to one another, plus their kids—rather than extended relatives and related families, as is typical among humans. It’s likely that several family groups sometimes came together to share particular bonanzas in food. Neanderthals frequently killed mammoths, and a full-grown mammoth could feed a whole lot more than one family before the meat spoiled.

Grandparents probably weren’t usually part of most family groups not because no one liked their Grandma back then, but because Neanderthals had short, brutal lives. They speared mammoths at close range to kill them. That is metal as heck, but it’s also really hard on the body. It was rare for a Neanderthal to survive past 30, and by then he or she would look like an old, old person due to all the injuries sustained while hunting.

The authors of the marvelous book How to Think Like a Neandertal, which I’m drawing from quite a lot here, point out that Neanderthals and rodeo cowboys show similar patterns of injury over their lifetimes. And Neanderthals didn’t have hospitals and doctors they could visit.

While Neanderthals did make stone tools and use fire, analysis of their campsites shows sometimes interesting compared to human campsites. There’s no central fire pit. Almost every individual had their own fire where they did their own thing. In prehistoric human campsites, way back 25,000 years ago and even more, there’s generally one central fire that everyone gathers around. We still do this the world over. Can you even imagine going to summer camp and every kid spends the evening alone, tending their own little campfire and not singing camp songs, not spelling spooky stories, not eating s’mores together?

In addition, while there have been some controversial theories over some findings, as far as we can determine, Neanderthals didn’t make art. Some perforated seashells have been found at two Neanderthal sites in Spain that researchers think may have been worn as pendants, and we have evidence that Neanderthals, like other hominins for at least 300,000 years, used mineral pigments as body decoration. But they didn’t appear to use ceremonial items, didn’t create clothing beyond rough hide blankets or wraps, and they only had the barest minimum of funerary rites. Neanderthals may have been strong and smart, but they don’t appear to have been especially creative by our standards.

One old man Neanderthal, who was probably not more than 35 when he died, was so injured that he could probably not walk or do much of anything else by the final years of his life. He had lost most of his teeth and wouldn’t have been able to eat. But he lived for years, because someone helped him. Someone brought him food. Someone probably chewed it for him. And when he died, someone tucked him in a shallow hole and scattered dirt over his body. So however different Neanderthals were from us, they were also people.

By about 40,000 years ago, Neanderthals were extinct. That was probably too long ago to have left any traces in human collective memory, but that’s something I’ll bring up in part two of this episode next week.

We still don’t know much about the Denisovans because we only discovered the first specimen, a fragment of a finger bone, about ten years ago. The bone is from a young woman who lived about 41,000 years ago and was found in the Denisova Cave in Siberia, in the mountains not far from China and Mongolia. Since then, scientists have also found some teeth from two different adult males, and a baby tooth from a little girl who lived much earlier than the others.

According to DNA testing done on the finger bone, Woman X, as the finger’s owner is called, was neither a modern human nor a Neanderthal, although she was related to both and could interbreed with both. Denisovan DNA has been found in some populations of humans. Not only that, Woman X contained some Neanderthal DNA and DNA from an ancient human lineage that we don’t yet recognize. So there’s at least one other hominin we haven’t yet discovered. A toe bone has also been found that may be from a hybrid Denisovan-Neanderthal, but we don’t know for sure yet, since studies are still ongoing.

We don’t know what the Denisovans looked like, but just going from Woman X’s finger bone, which is much thicker than even a big human’s finger bones, we can guess they were pretty robust people. They may have looked a lot like Neanderthals. Some fossils thought to belong to Neanderthals may actually be Denisovan, so I bet a lot of museum and university collections are being examined closely right about now.

The Denisova Cave was used as a home by humans, Neanderthals, and Denisovans at different times going back some 125,000 years, and as recently as the 18th century, when a Russian hermit named Denis lived there. A bracelet discovered in the same layer of soil where Woman X’s finger bone was found has been dated to about the same time as the bone and is not a human artifact as far as archaeologists can tell.

It’s a green chlorite bracelet, carefully carved and beautifully polished. It was probably worn on the right wrist. It’s delicate, fragile, and probably belonged to someone important who wore it on important occasions. In other words, Denisovans wore and probably made jewelry. Unlike Neanderthals, they probably had important occasions.

A marble ring was found at the same time as the bracelet, but no information on it has been released yet. Hopefully, it won’t be long before we learn more about these new cousins of ours. They seem like interesting people.

That’s it for part one of our episode on humans. Next week we’ll take a look at some less closely related and more mysterious human relations, especially ones known as Hobbits for their small stature. Maybe by then you’ll have gotten that Toto song out of your head.

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 019: The Dodo and the Clam

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Thanks to Varmints! podcast for suggesting the dodo for this week’s topic.

And thanks to Two Clams Gaming podcast for suggesting clams as this week’s topic.

It’s two suggestions in one fun episode! Learn all about that most famous of extinct birds and all about a thing that tastes great deep-fried. (Well, okay, everything tastes great deep-fried. But you know what I mean.)

The dodo:

A giant clam and its algae pals:

Stop, thief! Put that clam down!

The disco clam looks as awesome as its name implies. It looks like a Muppet clam:

Calyptogena magnifica hanging out around a hydrothermal vent:

Show transcript:

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

We’re getting backed up on suggestions, so I’m going to combine two in one episode today even though they don’t really have anything to do with each other. The first suggestion is from the podcast Varmints, a super fun podcast about animals. They want to know about the dodo. After that, we’ll go on to learn about clams. Yes, clams! Totally not anything to do with dodos, but the hosts at Two Clams Gaming suggested it. That’s another fun podcast, this one about video games—which you may have guessed. I’ll have links to both podcasts in the show notes for you to check out.

The dodo isn’t just extinct, it’s famously extinct. Dead as a dodo. That makes it difficult to research the dodo, too—type “dodo” into the search bar at Science Daily, for instance, and you get a ton of hits that have nothing to do with the actual dodo bird, like the article that says “Researchers believe they now know why the supersonic trans-Atlantic Concorde aircraft went the way of the dodo.” I don’t care. I’m here for the birds. Lots of animals and birds have gone extinct over the years, unfortunately. Why is the dodo special?

The first known sighting of a dodo was in 1598 by Dutch sailors who stopped by the island of Mauritius in the Indian Ocean. The last known sighting of a dodo was in 1662, just 64 years after those Dutch sailors noticed a weird-looking bird walking around. The dodo went extinct so quickly, and was so little known, that for a couple of centuries afterwards many people assumed it was just a sailor’s story. A big stupid bird that couldn’t fly that would walk right up to a sailor and let itself be killed? No way was that real.

But there were remains of dodos, and in the 19th century scientists gathered up what they could find and studied them. More remains were found on Mauritius. Pretty soon researchers had a pretty good idea of what had happened. The dodo had no predators on Mauritius so was able to live in a birdie garden of Eden, eating fruit and nuts, wandering around admiring the scenery, making new dodos. It grew big and happy, lost the ability to fly, and nested on the ground since almost nothing was around that might eat its eggs. Then humans showed up, happy to eat not just the eggs but the meat of any dodos they could find, although reports were that while the meat tasted pretty good, it was really tough. What the sailors didn’t eat, the animals they brought with them did, like pigs and dogs. It was a stark and clear picture of human-caused extinction, shocking to the Victorian naturalists who studied it. The dodo became a cautionary tale and early rallying cry for conservation.

We all have a mental image of what the dodo looks like just because it’s appeared in so many cartoons and children’s stories, from Alice in Wonderland to that Madagascar movie. But what did the dodo actually look like?

Well, it looked just like the cartoon versions of itself. This really was a silly-looking bird. It was big, over three feet tall, with brown or gray feathers, a floofy tuft of gray feathers as a tail, big yellow feet like a chicken’s, and a weird head. The feathers stopped around the forehead if birds had actual foreheads, making it look sort of like it was wearing a hood. Its face was bare and the bill was large, bulbous at the end with a hook, and was black, yellow, and green. The dodo looks, in fact, a lot like what you might expect pigeons to evolve into if pigeons lived on an island with no predators, and that’s exactly what happened. The dodo is closely related to pigeons and doves. Its closest living relative is the Nicobar pigeon, a large, gorgeous bird with iridescent feathers. Like other pigeons, the dodo’s feathers probably had at least some iridescence too.

The dodo wasn’t clumsy and it wasn’t necessarily fat. A lot of the drawings and paintings we have of dodos were made from badly taxidermied birds or from overfed captive birds. At least eleven live dodos were brought to Europe and Asia, some bound for menageries, some intended as pets. The last known captive dodo was sent to Japan in 1647. In the wild, the dodo was a sleek bird that could run quite fast. It may have eaten crabs and other small animals as well as roots, nuts, seeds, and fruit. The dodo was also probably pretty smart. People only thought it was dumb because it didn’t run away from sailors—but it had never had to worry about anything more dangerous than an occasional egg-stealing crab before.

The dodo wasn’t the only creature on Mauritius to die out after ships started visiting the island, either. Other birds went extinct too, like the red rail, the broad-billed parrot, the Mauritius owl, and many others. So did animals like the Mauritian giant skink, two species of giant tortoise, and the small Mauritian flying fox. Even some plants, like the palm orchid, are long gone. Worse, there were undoubtedly dozens of species that went extinct without any human ever seeing them. We’ll never know the extent of the loss.

The stuffed dodos some museums display aren’t real. All we have of real dodos are bones and one dried head. Back in the 17th century, taxidermy was pretty primitive. Skins often weren’t treated with preservatives at all, and the preservatives that were in use didn’t last very long. There aren’t any taxidermied animals from before around 1750. Bugs ate them up.

The dodo is frequently mentioned when people bring up de-extinction. That’s the term used for cloning an extinct animal or genetically modifying a living animal to closely resemble an extinct ancestor. The dodo would be a good candidate for de-extinction since its habitat still exists. The problem is that we don’t have much genetic material to draw from. But DNA sequencing gets more sophisticated every year, so fingers crossed that a hundred years from now, there might be dodos on Mauritius again.

We know a decent amount about the dodo, but one of its close relatives, the spotted green pigeon, is an utter mystery. It’s extinct too, but we only have one specimen—there used to be two, but no one knows where the second one went. For a long time researchers weren’t even sure the spotted green pigeon was a distinct species or just a Nicobar pigeon with weird-colored feathers, but in 2014, DNA testing on two of the remaining specimen’s feathers showed it was indeed a separate species. Researchers think the spotted green pigeon, the dodo, and another extinct bird, the Rodrigues solitaire, all descended from an unknown pigeon ancestor that liked to island hop. Sometimes some of those pigeons would decide they liked a particular island and would stay, ultimately evolving into birds more suited to the habitat.

Because there were no scientific studies of Mauritius and its two closest islands until the 19th century, there’s been a lot of confusion about what birds lived where before they went extinct. For a long time researchers thought there was a variety of dodo on the island of Reunion with light-colored or white plumage. The white dodo was sometimes called the solitary dodo, causing confusion with the related flightless bird, Rodriguez solitaire. The island of Rodriguez is about 300 miles east of Mauritius. In 1987 fossils of a type of ibis were found on Reunion, and in 1995 they were connected with accounts of the Reunion solitaire, a flightless white bird with black markings that went extinct around the same time as the dodo. Researchers now believe reports of the white dodo from Reunion were actually describing the Reunion solitaire, now called the Reunion ibis. No dodo remains have ever been found anywhere except on Mauritius.

If all that sounds confusing, consider that when dodos were still alive, people referred to them as everything from ostriches to penguins. And no one has any idea where the name dodo actually came from.

As far as we know, the dodo only laid one egg at a time. It probably fed its baby with crop-milk like other pigeons and doves. That’s a substance that’s formed from the protein-rich lining of both parent bird’s crops, which detaches from the crop, is regurgitated by the parent and fed to the babies. It’s not anything like mammal milk but it’s pretty neat. The only other birds known to produce something similar are flamingos and some species of penguin, although in those birds the secretion comes from the lining of the esophagus. In pigeons and doves, the parents feed the babies exclusively on crop milk for the first week of life, then start mixing in regular food that’s been softened in the parent’s crop. I suppose I should explain that the crop is a sort of extra stomach where food is stored before being digested. It allows a bird to gorge itself if it comes across a lot of food. Not all birds have a crop.

One last interesting thing about the dodo. In 1973, botanists studying Mauritius couldn’t figure out why the tambalacoque, also called the dodo tree, was dying out. Supposedly only 13 trees remained, all around 300 years old, although that number seems to be mistakenly low. While the dodo trees produced seeds, very few of them germinated. Biologist Stanley Temple suggested that the tough-shelled seeds needed to pass through the digestive tract of the dodo to germinate properly. The dodo had a powerful gizzard that it filled with small stones it swallowed, which helped grind up tough plant materials. Temple hypothesized that by passing through the gizzard, the dodo tree seeds were abraded enough to germinate. He fed some of the seeds to turkeys, which have similar gizzards, and the recovered seeds promptly germinated. Botanists now use gem polishers—and sometimes turkeys—to abrade the seeds.

[bird sound]

Until I started my research for this episode, the only thing I knew about clams was that they’re really good fried. Oh, and that they have two shells that are super common and boring when you’re beachcombing. Specifically, they’re bivalve mollusks, but they’re not the only bivalve mollusks. Scallops, oysters, and mussels are too, and some close relations include slugs, snails, and squids.

Clams live in oceans and fresh water throughout the world. They start life as microscopic larvae that drift through the ocean eating plankton for a few weeks before attaching themselves to a piece of sand, gravel, shell, or whatever. At that point they burrow into the mud or sand until they develop their own shells. The adults live most of their lives partially buried in the sand in shallow water. Clams are filter feeders, sucking in water through a tube called a siphon and straining it with tiny hair-like structures called cilia.

The smallest clams are just .1 millimeter long. The biggest clam is the giant clam that lives in the Pacific and Indian oceans. These are the ones that used to be featured in short stories about divers in peril, their arm trapped by a giant clam and their air supply running out. What to do?? Or maybe I just read some weird stuff as a kid.

The giant clam can grow over four feet across and can live for more than a hundred years. It’s the only clam that can’t close its shell completely, especially as it gets bigger. Its mantle, the inside fleshy part of its body, protrudes past the edges of the shell like big stripey clam lips. But the giant clam spends most of the day with its shell open so that sunlight reaches the algae that live inside its mantle. The algae help feed the clam.

Giant clams are edible and have the reputation as being an aphrodisiac. As a result, they’re becoming more and more endangered, especially since the biggest shells are also worth money on the black market. Who knew there was a black market for clam shells? Seriously, people will spend money on anything. The next person contemplating dropping cash for an illegally harvested giant clam, do me and the clams a favor and buy me a nice set of cymbals for my drum kit instead, okay? Fortunately, giant clams can be raised in captivity and released into the wild.

And no, divers don’t get caught and drowned by giant clams. That’s a myth.

While most pearls are made by oysters, lots of mollusks can make them, including clams. The giant clam naturally produced the largest pearl ever found. It weighs 75 pounds. The Filipino fisherman who found it kept it under his bed for ten years as a good luck charm. It’s a foot in width and over two feet in length. It’s supposed to be worth over a million dollars, but don’t think about turning to a life of crime. A few months ago, in March of 2017, ten men were arrested for illegal possession of giant clam pearls and the giant clams themselves. Book em, Danno.

Different species of mollusk produce pearls of different color. The Ko-hog clam, which is frequently made into chowders, occasionally produces a purple or lavender pearl. They’re not always very pretty—they may not have much of a lustre compared to oyster pearls, or are lumpy in shape. But when a pretty one does turn up, they can be worth a lot. In 2009, a man eating seafood stew at his birthday meal discovered a pearl in his bowl the size of a big pea, which he later sold for $16,500. I could buy, like, so many cymbals for that kind of money.

There are some weird species of clams out there. The disco clam lives in underwater caves in the Indo-Pacific Ocean. They flash brightly to scare off predators. Until a few years ago researchers assumed the lights were a type of bioluminescence, but it turns out that the flashes are caused by double-layered tissues. One of the layers is light absorbent and the other is highly reflective. The clam rolls and unrolls the tissues to flash the reflected light. The disco clam also appears to secrete noxious mucus to repel predators.

While most clams live in the shallows, there are some species that are found much deeper. In parts of the deep sea with a lot of volcanic activity, hydrothermal vents attract all kinds of marine life, including specialized clams. Calyptogena magnifica and its close relatives, which are big white clams that live around thermal vents, has no digestive organs. Instead, hydrogen-oxidizing bacteria live in its gills. The clam absorbs nutrients produced by the bacteria. Hydrothermal vents don’t last forever—they go cold as magma under the sea floor moves, and new vents will open up elsewhere. Researchers have recently discovered that some animals that live near hydrothermal vents, including clams, can also survive on sunken whale carcasses by chemically leaching energy from the oily whale bones with the help of bacteria.

One of the most popular edible types of clam is the Pacific gooeyduck. It has a relatively small shell, generally no bigger than about 8 inches long, but its siphon can be more than three feet long, with occasional record-setting individuals caught with siphons over six feet long. It’s another long-lived clam—it can live for hundreds of years. The siphon is considered a delicacy the world over, but frankly, if it’s not cut into strips and deep-fried, I don’t want to bother with eating clams. Not even if I might find a pearl.

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, give us a rating and review on iTunes or whatever platform you listen on. We also have a Patreon if you’d like to support us that way. Rewards include exclusive twice-monthly episodes and stickers.

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Episode 015: Hammerhead shark and Megalodon!

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This week’s episode is all about some awesome sharks: the hammerhead shark, which used to scare the poop out of me when I was a kid, and the unbelievably huge but fortunately for all the whales extinct megalodon! Thanks to Zenger from Zeng This! for recommending such a great topic!

The great hammerhead, a huge and freaky-looking shark.

A ray leaping out of the water to escape a hammerhead. The article I pulled this from is here.

A guy with a teeny adorable bonnethead, a newly discovered species of hammerhead.

Hello there. I am a great white shark.

Show transcript:

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

This week’s episode was suggested by Zenger from the fun pop culture podcast Zeng This!, which I recommend if you don’t already subscribe. He suggested megalodon as a topic, so since I was already researching hammerhead sharks, I decided to put together a shark episode.

We’ll start with the hammerhead shark, because hammerheads scared the crap out of me as a kid. They just look so weird! You know what else scared me as a kid? Skeletons. It’s a good thing no one ever showed me the skeleton of a hammerhead shark.

There are a lot of species of hammerhead shark, some of them small like the new species of bonnethead discovered earlier this year that’s only about as long as your forearm, and some of them huge, like the great hammerhead, which can grow up to 20 feet long [6 meters]. One of the biggest sharks ever caught was a great hammerhead. At fourteen feet long [4.2 meters], it wasn’t the longest shark ever, but it weighed 1,280 pounds [580 kg]. It was caught in 2006 off the coast of Florida.

If it weren’t for its weird head shape, the hammerhead wouldn’t seem all that interesting. It’s mostly plain gray in color, hardly ever attack humans, and is common all over the world. But they’ve got that head! The shape is called cephalofoil, and not only are the shark’s eyes on the end of the stalks, the head is flattened.

Researchers think the shape serves two purposes. A hammerhead shark can see really well since its eyes are so far apart, and the shape actually provides a certain amount of lift when water flows over it, like an airplane’s wing, which helps the shark maneuver. Plus, of course, a wide head allows for even more electroreceptor cells so the shark can sense prey better.

Hammerheads have relatively small mouths compared to many other sharks. They do a lot of feeding on the ocean floor, snapping up rays, fish, crustaceans, octopus, even other sharks. Oh yeah, and a hammerhead will actually use its head as a weapon. Hammerheads like eating stingrays and will pin one to the ocean floor with its head to keep it from escaping until the shark can bite it. In February of 2017, tourists surfing near Panama saw a spotted eagle ray escape a hammerhead shark by leaping out of the water like a bird. The stingray actually beached itself on an island, too far up the beach for the shark to reach. After it gave up, the ray managed to catch a wave that carried it back out to sea. That’s pretty epic.

Hammerhead sharks are considered a delicacy in many countries, but since their fins are the most valuable part of the fish, fishermen sometimes catch a shark, cut its fins off, and toss the still-living shark back in the ocean. It always dies, because it can’t swim without fins. The practice is horrific and banned in many countries. Overfishing has also threatened many hammerhead species. Researchers estimate that the great hammerhead in particular has decreased in numbers some 80% in the last 25 years.

Ironically, recent studies have found repeatedly that shark fins and meat contain high levels of mercury and a neurotoxin called BMAA, which is linked to neurodegenerative diseases in humans. The frequent eating of shark fin soup and other dishes made of shark meat, and cartilage pills which some people take as a diet supplement, may increase the risk of developing diseases like Alzheimer’s and Lou Gehrig’s disease. (I ate shark once, a shark steak. It was terrible.)

You may think a 20-foot hammerhead is a really big shark, and it is. Great white sharks aren’t much bigger. But before the great white and the hammerhead, a 60 foot [18 meter] shark ruled the oceans. Megalodon is first found in the fossil record around 23 million years ago, and died out about 2 ½ million years ago. Because shark skeletons are made of cartilage instead of bone, they don’t fossilize well. We have a whole lot of megalodon teeth, but except for some vertebrae we don’t know much about the rest of the shark.

Researchers generally compare megalodon with the great white, since while they’re not necessarily closely related, they occupy the same ecological niche. We do know how the teeth were arranged, since associated teeth in formation as they had been in the jaw, although the jaw itself wasn’t preserved, have been discovered in North Carolina and Japan.

At a rough estimate, megalodon probably grew 60 or even 70 feet long [18 to 21 m]. Its jaws were over six feet across [1.8 meters] with some 276 teeth in five rows. Due to the size of its teeth and jaws, it probably mostly preyed on large whales, and was probably a lot blockier looking than the great white. If the great white is a racecar, megalodon was that bus from Speed.

Some researchers want to classify megalodon as a close relative of the great white shark, which has serrated teeth like megalodon’s. But others argue the great white is more closely related to the mako shark, which does not have serrated teeth. For a long time the megalodon hypothesis was more accepted, but a study published in the March 12, 2009 issue of Journal of Vertebrate Paleontology concluded that mako sharks and great whites probably share a recently discovered fossilized ancestor some 4 to 5 million years old. Its teeth have coarse serrations, which researchers think are a transitional point between no serrations and the serrations in modern great white shark teeth. The similarities between the great white and megalodon are due to convergent evolution.

This points to something many people don’t understand about science. It’s messy. It’s incomplete. Our collective body of knowledge is being added to, adjusted, reinterpreted, and hopefully corrected all the time. From the outside it can look like people arguing over ridiculous minutiae, or a bunch of eggheads who can’t make up their minds. In reality, as new information is added to what we know, what we used to think was true has to be changed to fit new facts. It’s exciting!

For a long time researchers though megalodon died out around the beginning of the Pleistocene because the world grew colder as the world entered into the ice ages. New findings suggest that climate change didn’t push the megalodon into extinction, other sharks did. Newcomers like the great white and the orca, which of course isn’t a shark but a whale, starting expanding into new territory, out-competing megalodon around the same time that a lot of marine mammals were also going extinct. Megalodon needed a lot of food to survive—more than the much smaller upstarts.

Back when megalodon was king, though, there was plenty of food to go around. It wasn’t even the only mega-predator hunting the oceans. In 2008, fossils of an ancestor of today’s sperm whale were discovered in Miocene beds dated to around 12 or 13 million years ago. The whale has been dubbed Livyatan melvillei and estimates of its length, from the partial skull, lower jaw, and teeth that were found is around 57 feet [17 meters]. Since modern sperm whales are frequently some 60 feet long [18 m] and 80-foot [24 m] monster males were reported in the past, it’s possible the newly discovered Leviathan could attain similar lengths. Its biggest teeth were two feet long [61 cm] compared to modern sperm whales’ 8-inch teeth [20.5 cm]. It also apparently had teeth in its upper jaw as well as its lower. The sperm whale only has teeth in its lower jaw, and since it mostly eats squid, it doesn’t really need teeth at all. Individuals who have lost their teeth survive just fine.

The Leviathan, though, used its teeth. Like megalodon, it may have preyed on baleen whales. Megalodon teeth were found in the same fossil deposits where the Leviathan was discovered. I bet they battled sometimes.

So how do we know Megalodon isn’t still around, cruising the oceans in search of whales? After all the megamouth shark was only discovered in 1976 and it’s almost 20 feet long [6 m]. Well, we have two big clues that there isn’t a population of Megalodon sharks still living. Both involve its teeth.

Sharks have a lot of teeth, and they lose them all the time as new teeth grow in. Shark teeth are among the most common fossils around, and any dedicated beachcomber can find shark teeth washed up on shore. If megalodon still lived, we’d be finding its teeth. We’d also probably be finding whales and other large marine animals with scars from shark attacks, the way we find scars on sperm whales from giant squid suckers.

Wait, you may be saying, no one was talking about megamouth shark teeth found on beaches before it was discovered. Well, megamouth sharks have tiny, tiny teeth that they don’t even use. They gather food with gill rakes that filter krill from the water. Megalodon teeth can be seven inches long [18 cm]. Great white teeth are only two inches long [5 cm]. Occasionally a fossilized megalodon tooth washes up on shore, and when it does, it makes the news.

So okay, you might be saying, you fractious person you, what if megalodon survived into modern times but has died out now. Well, we’d probably still know. Not only would the non-fossilized teeth still be found, since nothing is going to eat them and they don’t decay readily, but a lot of cultures have incorporated shark teeth into weapons over the centuries. A seven-inch serrated tooth is a weapon worth having.

Consider the Gilbert Islands in the Pacific. Sharks were important in the Kiribati culture there, and the people crafted amazing weapons with shark teeth. Anthropologists studying the weapons discovered that some of the teeth used in older weapons come from sharks that are now extinct in the area.

So no, I’m going to insist that whatever you saw on Shark Week, megalodon is not out there and hasn’t been for a couple of million years. But what about other mystery sharks?

There aren’t very many reports, surprisingly. Even Karl Shuker comes up empty, with just one mention of a reportedly hundred-foot [30 m] shark called the Lord of the Deep by Polynesian fishermen, but I can’t find any additional information about it.

That doesn’t mean there aren’t mystery sharks out there, of course, just that they’re probably not gigantic or radically different from known shark species. In fact, new sharks are discovered all the time. In just the last few months, a three-foot [1 m] ghost shark with rabbit-like teeth, and a tiny hammerhead called a bonnethead have been described. And yeah, I’d love to be wrong about the megalodon’s existence.

Researchers are studying the genetics of sharks’ rapid healing, which could have important medical applications for humans. A recent study published in the January 2017 BMC Genomics Journal provides evidence that the genes linked to the immune system in sharks and rays have evolved in ways that their counterparts in humans have not. One gene is involved in killing cells after a certain amount of time, which is something cancer cells manage to avoid. It’s possible that as researchers learn more, new therapies for treating cancer in humans could be developed.

So maybe we should stop eating so many sharks. Shark meat isn’t good for you anyway.

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. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us and get twice-monthly bonus episodes for as little as one dollar a month.

Thanks for listening!

Episode 005: The Unicorn

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Everyone knows the legend of the unicorn and most of us know unicorns don’t really exist. But how did the legend get started? And more importantly, can we talk about narwhals a whole lot? Narwhals are rad.

Narwhal. So rad.

I haven’t seen this show but apparently it’s pretty good. I love that elasmotherium.

Unicorns are (sort of) real. Unicorning certainly is.

Thanks to Jen and Dave for suggesting this week’s topic!

Show transcript:

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

This week’s episode is about the unicorn, or at least about almost-unicorns. This is a re-record of the original episode to improve sound quality and update some information.

When I was a kid, I was convinced unicorns were real. I’m not alone in this, apparently. A lot of people assume the unicorn is a real animal. Take away the magical trappings and it’s just a horse-like animal with one spiral horn. It seems a lot more plausible than squids, for instance.

I’m sorry to tell you that that kind of unicorn doesn’t exist, and never has, or at least we have no fossil or subfossil evidence that an animal resembling the classical unicorn actually existed. But the animals that probably inspired the unicorn legend are fascinating.

Everyone knows that the unicorn has one spiral horn growing from its forehead. The horn was supposed to have curative properties. If you ground up a little bit of the horn, known as alicorn, it acted as a medicine to cure you of poisoning or other ailments. If you actually made a little cup out of alicorn, you could drink from it safely knowing any poison was already neutralized. People in the olden days were really worried about being poisoned, probably because they didn’t understand how food safety and bacteria worked and they didn’t have refrigerators or meat thermometers and so forth. I suspect a lot of so-called poisoning cases were actually food poisoning. But this re-record is already off the rails, so back we get to the main topic.

All this about alicorn wasn’t legend, either. You could buy alicorn from apothecaries up until the late 18th century. Doctors prescribed it. It was expensive, though—literally worth its weight in gold. Pharmacies kept their alicorns on display but chained down so no one could steal them.

The alicorn, of course, was actually the tusk of the narwhal, and the narwhal is as mysterious as the unicorn in its own way. In fact, the narwhal seems a lot less plausibly real than a unicorn and a lot of people actually don’t realize it’s a real animal. I had that discussion with a coworker last year and had a lot of fun astonishing her with science facts, or maybe boring her. It’s a fairly small whale, some 13 to 18 feet in length not counting the tusk. That’s about four to five and a half meters long. It’s pale gray in color with darker gray or brown dapples, but like gray horses, many narwhals get paler as they age. Old individuals can appear pure white.

The narwhal and the beluga whale are similar in size and physical characteristics, such as their lack of a dorsal fin. They live in the same areas and are the only two living members of the family Monodontidae. They even interbreed very rarely.

But the narwhal is the one with the horn, or more accurately a tusk. It’s not a horn at all but a tooth. Most males and about 15% of females grow a tusk. Occasionally an individual grows two tusks, but almost always it’s the left canine tooth that pierces through the lip and continues to grow, sometimes up to ten feet long, or 3 meters.

It’s a weird, weird tooth too. It can bend as much as a foot without breaking, or 30 cm, not something teeth are generally known for. It also grows in a spiral. And we still don’t know what the narwhal uses its tusk for.

For a long time, researchers assumed that male narwhals used their tusks the same way male deer use their antlers, to show off for females and to battle other males. Males do exhibit behavior called tusking, where two individuals will rub their tusks together in what researchers once assumed was a ritual fight display. But that seems not to be the case.

A 2005 study discovered that the tusk is filled with nerves and is extremely sensitive. Through its tusk, the whale can identify changes in water temperature and pressure, water salinity, and the presence of fish and other whales. It even acts as an antenna, amplifying sound. The study was led by Martin Nweeia of the Harvard School of Dental Medicine. Nweeia is a dentist, basically, which delights me. Okay, he’s a clinical instructor in restorative dentistry and biomaterials scientist, but dentist is funnier.

I liked Nweeia even more when I found this quote: “Why would a tusk break the rules of normal development by expressing millions of sensory pathways that connect its nervous system to the frigid arctic environment?” As someone who has trouble biting ice cream without wincing, I agree.

In other words, the narwhal’s tusk has scientists baffled. You hear that a lot in a certain type of article, but in this case it’s true. Especially baffling in this case is why the tusk is found mostly in males. If having a tusk confers some advantage in the narwhal’s environment, why don’t all or most females grow one too? If having a tusk does not confer an advantage beyond display for females, why does the tusk act as a sensory organ?

The narwhal lives in the Arctic, especially the Canadian Arctic and around Greenland, and it’s increasingly endangered due to habitat loss, pollution, and noise pollution. Overall increased temperature of the earth due to climate change has caused a lot of the sea ice to melt in their traditional breeding grounds, and then humans decided those areas would make great oil drilling sites. The noise and pollution of oil drilling and exploration threatens the narwhal in particular, since when a company searches for new oil deposits it sets off undersea detonations that can deafen or even outright kill whales. But it’s hard to count how many narwhals are actually alive, and some recent studies have suggested that there may be more around than we thought. That’s a good thing. Now we just have to make sure to keep them safe, because narwhals are awesome.

The narwhal eats fish and squid and shrimp and sometimes accidentally rocks, because instead of biting its prey the narwhal just hoovers it up, frequently from the sea floor, and swallows it whole. It does that because it doesn’t actually have any teeth. Besides the one.

As a final narwhal mystery, on December 17, 1892, sailors aboard a ship in the Dundee Antarctic Expedition spotted a single-horned narwhal-like whale in the Bransfield Strait. But narwhals don’t live in the Antarctic…as far as we know.

One of the reasons why so many people believe the unicorn is a real animal is because it’s mentioned in some English-language versions of the Bible. When the Old Testament was first translated from Hebrew into Greek in the third century BCE, the translators weren’t sure what animal the re’em was. It appeared in the texts a number of times but wasn’t described. The translators settled on monokeros for their translation, which in English is unicorn. The King James Version of the Bible mentions the unicorn seven times, giving it a respectability that other animals (like squids) can’t claim.

These days, Biblical scholars translate re’em as a wild ox, or aurochs. You can learn more about the aurochs in episode 58, Weird Cattle. The aurochs was the ancestor to domestic cattle and was already extinct in most parts of the world by the third century BCE, but lived on in the remote forests north of the Alps until its final extinction in 1627.

So while the Greek translators didn’t know what the re’em was, why did they decide it was a unicorn? It’s possible they were drawing on the writings of Greek physician Ctesias, from the fourth century BCE. Ctesias described an animal from India he called a type of wild ass, which had “a horn on the forehead which is about a foot and a half in length.” But it seems clear from his writing that he was describing a rhinoceros.

In fact, any description of a rhino given by someone who hasn’t actually seen one, just heard about it, comes across as a unicorn-like animal. So it’s quite likely that the translators made a wild guess that the fierce re’em was a rhinoceros, which they would have known as a horse-like animal with one horn.

But while the unicorn is mentioned in the Bible, it isn’t a specifically Christian legend. The karkadann is a huge monster in Muslim folk tradition, with a horn so big it could spear two or three elephants on it at the same time. In Siberia, some tribes told stories of a huge black ox with one horn, so big that when the animal was killed, the horn alone required its own sledge for transport. In some Chinese tales, the kilin was supposed to be a huge animal with one horn. For more information about the kilin, or kirin, you can listen to episode 61.

It’s probable that all these stories stem from the rhinoceros, which is a distinctive and unusual animal that we only take for granted today because we can go visit it in zoos. But some researchers have suggested a more exotic animal.

Elasmotherium was an ice age animal sometimes called the steppe rhino, giant rhino, or Siberian unicorn. The largest of the three species of elasmotherium was the size of a mammoth, some seven feet tall at the shoulder, or 2.1 meters. It was a grazer like horses and cattle today, and like them it had long legs, much longer than living rhinos. It could probably gallop at a pretty good clip. It lived at the same time as the smaller woolly rhino, but while the woolly rhino resembled modern rhinos in a lot of respects, notably its large horn on the nose with a smaller horn farther up, elasmotherium only had one horn…one enormous horn. On its forehead.

We don’t actually have any elasmotherium horns to look at. Rhino horns aren’t true horns at all but a keratin structure. Keratin is an interesting fiber. It can be immensely tough, as it is when it forms rhinoceros horns, but it’s also what our nails and hair are made of. It doesn’t fossilize any more than hair fossilizes. The main reason we know elasmotherium had a horn is because of its skull. While rhino horns are made of keratin fibers instead of bone, the skull shows a protuberance with furrows where blood vessels were that fed the tissues that generated the horn. In elasmotherium, the protuberance is five inches deep, or 13 cm, and three feet in circumference, or just over a meter. Researchers think the horn may have been five or six feet long, or 1.5 to 1.8 meters.

Researchers have also found an elasmotherium fossil with a partially healed puncture wound. It’s possible the males sparred with their enormous horns and sometimes inflicted injuries. At least it happened once.

For a long time researchers thought elasmotherium died out 350,000 years ago, much too long ago for humans to have encountered it. But a skull found a few years ago in Kazakhstan was radiocarbon dated to about 29,000 years old. If elasmotherium and humans did cross paths, it wouldn’t be at all surprising that the animal figured in stories that have persisted for millennia. More likely, though, our early ancestors found carcasses partially thawed from the permafrost the way mammoth carcasses are sometimes found today. This might easily have happened at the end of the Pleistocene, a relatively recent 11,000 years ago or thereabouts. A frozen carcass would still have a horn, and while the carcasses are long gone now, it’s not unthinkable that stories of a massive animal with a monstrous single horn were passed down to the present.

Of course, this is all conjecture. It’s much more likely that the stories are not that old and are about the modern rhinoceros. But it’s definitely fun to think about our ancestors crossing a vast hilly grassland for the first time in search of new hunting grounds, and coming across a herd of towering monsters with five-foot horns on their foreheads. That would definitely make an impression on anyone.

One final note about the unicorn. When I was a kid, I read a book called A Grass Rope by William Maine, published in 1957 so already an oldie when I found it in my local library. It concerns a group of Yorkshire kids who hunt for a treasure of local legend, which involves a unicorn. I was an American kid from a generation after the book was written, so although it’s set in the real world it felt like a fantasy novel that I could barely understand. When one of the characters discovers a unicorn skull, it didn’t seem any more extraordinary to me than anything else. But on rereading the book in my late teens, I was struck by a character at the end who tells the children “it’s not very hard to grow unicorns.”

By that time, I pretty much had Willy Ley’s animal books memorized, including the chapter about unicorns. In it, he talks about unicorning animals that have two horns.

The practice of unicorning has been known for centuries in many cultures, but the first modern experiment was conducted in 1933 by Dr. Franklin Dove in Maine. He removed the horn buds from a day-old bull calf and transplanted them to the middle of the calf’s forehead. The calf grew up, the horn buds took root and grew into a single horn that was almost completely straight and which sprouted from the bull’s forehead.

Dr. Dove reported that the bull was unusually docile, although I suspect his docility may have come from being handled more than the usual bull calf, so he became tamer than most bulls. Either way, the experiment proved that unicorning wasn’t difficult. Any animal that grows true horns, such as sheep, goats, and cattle, can be unicorned.

More recently, in the 1980s, neopagan writer Oberon Zell Ravenheart and his wife Morning Glory unicorned mohair goats that looked astonishingly like the unicorns of legend. So technically, kid me was right. Unicorns are sort of real.

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. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us and get twice-monthly bonus episodes for as little as one dollar a month.

Thanks for listening!

Episode 004: The Irish Elk

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(re-recorded audio)

In which your host calls her own podcast by the wrong name! And doesn’t catch it until it’s too late to change (i.e. five minutes ago). This week’s episode of Strange Animals Podcast is about the Irish Elk specifically and the Pleistocene era in general, especially as regards to humans spreading out across the world from Africa. Did the Irish elk’s enormous antlers really have anything to do with its extinction? And is it really for-sure extinct? (Spoiler alerts: no and yes.)

The Irish elk (more accurately called the giant deer) could stand as tall as seven feet high at the shoulder.

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. This is a re-record of the original episode to improve audio quality and bring some of the information up to date.

This week’s episode is about the Irish elk, the first of many episodes about Ice Age megafauna. But before we learn about the Irish elk, let’s start with the span of time popularly known as the ice age, along with information about how humans spread across the world.

The last two million years or so of history is known as the Pleistocene, which ended about 12,000 years ago. The end of the Pleistocene coincides roughly with the extinction of a lot of the Pleistocene megafauna and the beginning of modern historical times.

During the Pleistocene, the earth’s axis tilt and plane of orbit resulted in reduced solar radiation reaching the earth. The process is due to what is called Milankovitch cycles, which I won’t go into since I don’t actually understand it. To grossly oversimplify, the earth got colder for a while because there wasn’t as much sunshine as usual, and all of these glaciers formed, and then it would warm up again and the glaciers would melt. This happened repeatedly throughout the Pleistocene, which was actually a series of ice ages with interglacial times in between.

Our current era is called the Holocene, and it’s considered an interglacial period. But if you’re hoping that the next ice age is a neat solution to global warming associated with climate change, the next glacial period isn’t expected for another 3,000 years.

The word megafauna means “giant animals.” You might hear dinosaurs referred to as megafauna, and that’s accurate. It’s a general term applied to populations of animals that grow larger than a human. Humans are also considered a type of Ice Age megafauna. high five, all my ice age peeps yes I kept that dumb line in this re-record

During the Pleistocene, humans migrated from Africa and spread across the world, rubbing shoulders with Neandertals, making awesome stone tools, and killing megafauna whenever they could. Humans are good at killing animals. In elementary school, I remember reading about ancient tribes of people stampeding mastodons over cliffs, eventually killing them all off. I didn’t believe it, but that’s actually true. We have lots of evidence that many types of animals were killed in this way, and it may have led to the extinction of some of the megafauna. It certainly didn’t help them. Wherever humans showed up, extinctions followed. The only exception is Africa, probably because the animals in Africa evolved alongside humans and knew how to deal with us. But when the first bands of humans showed up in Eurasia and the Americas, the native animals didn’t even know we were predators. They certainly didn’t know how to avoid being stampeded over cliffs. That’s a skill you don’t get many chances to practice.

Many people, especially Europeans, think that native peoples of whatever part of the world are natural conservationists. They live in harmony with nature, taking only what they need and using, for instance, every part of the buffalo. But human nature is human nature. Sure, when you live in a comfortably established village with a set territory, and your hunters and fishers start noticing that there’s not much game left, you learn conservation or you starve. But when you’ve got an entire world ahead of you—vast continents that have never seen a tool-using great ape with wicked intelligence and an insatiable appetite, you don’t need to live in harmony with nature. Our ancestors would find a nice area, settle there for a while, and when all the easily obtainable food was gone, they’d move on.

Humans still act this way. That’s why we leave trash all over the place. But the good news is that we are also good at recognizing when we’re causing a problem and deciding to fix it. So even though our first impulse might be to throw trash everywhere, we can also stop doing that and clean up trash already on the ground.

By the beginning of the Pleistocene, the continents were in their current spots. The world looked about the way it did now. But during the glacial periods, so much water froze that sea levels dropped around 300 feet. This exposed huge areas of continental shelf, making the continents bigger and joining some of them together. For instance, during glaciation, Alaska was connected to Asia. In some books you’ll see this talked about as a land bridge, which I always imagined as narrow and muddy. But it wasn’t just a bridge, it was a huge chunk of continent, and it stayed that way for thousands of years.

Then the temperature would warm up, sometimes dramatically. Within a few decades, the glaciers had mostly melted, the sea levels rose and flooded the low-lying land, and animals scrambled to find a comfortable habitat. It’s easier for an animal to move than to adapt to a changing habitat.

Even though a lot of land was flooded, other land opened up as glacial barriers disappeared. Animals that had traveled to Alaska on a land bridge from Asia could now move deeper into North America. Animals from deeper in North America could enter Alaska.

This colder-warmer-colder pattern happened a few dozen times during the Pleistocene, shaking the climate up repeatedly and leading to extinctions, with or without human help, and animals that look strange to us now because we don’t fully understand the environments they adapted to. But one thing is for sure. The megafauna were all awesome.

Fast forward to a few hundred years ago. European humans are in the middle of a territorial war with North American humans, and as they pushed their way farther into North America, they started to find interesting things: giant bones in the southerly areas, actual frozen carcasses in the permafrost of the northerly areas. Some of those carcasses looked so fresh, and the interior of North America was so little explored by Europeans that a lot of people assumed they’d find living mammoths if they looked in the right spot. When Thomas Jefferson sent Lewis and Clark on their turn of the 19th century expedition, one of their goals was to find mastodons and other megafauna.

They didn’t, of course. Instead they almost died repeatedly and had to be rescued by Sacajawea, who I like to imagine kept sighing with exasperation but who at least got to hang out with the expedition’s Newfoundland dog. Newfies are the best. (I miss you, Jasper.)

So, now we have a little bit of background about Ice Age megafauna. If you’re interested in learning more about how humans evolved and spread across the world, and our extinct close cousins, you can listen to episodes 25 and 26.

The Irish elk was the reason I started this podcast. I happened across the so-called fact I learned in elementary school, that the Irish elk died out because its antlers became so big that it couldn’t escape from predators.

I hadn’t thought of the Irish elk in literally decades. But that antler thing didn’t sound right. I caught myself thinking about it on and off, even getting angry. It didn’t make sense. It’s not like evolution is a power-up in a video game, and as soon as one elk got extra super gigantic antlers, suddenly all elk had them. If overlarge antlers were an issue, only stags with the biggest antlers would die. Does would mate with the remaining stags with smaller antlers and their offspring would be more likely to have small antlers. Besides, deer of all kinds shed their antlers every year and regrow them, which means the stags with biggest antlers wouldn’t have to deal with them for more than a few months of the year.

I did some research, which I found so much fun I decided to turn it into a podcast. Then I realized I couldn’t really make an ongoing podcast exclusively about Irish elk, which is pretty obvious now that I think about it.

So, it turns out that the Irish elk is neither exclusively Irish nor an elk. It did live in the area now called Ireland, but it also lived all across Eurasia and even in northern Africa. Like many deer it liked open woodland and was a browsing animal, meaning it didn’t eat grass but did eat lots of other plants, including green twigs and bark, and if it lived nowadays it would undoubtedly come to my yard and eat my garden.

Recent genetic analysis suggests it’s more closely related to the fallow deer than to elk. For these reasons, many publications these days refer to it as the Giant Deer. Officially it’s Megaloceros giganteus.

Megaloceros did have huge antlers, that’s for sure, sometimes as much as a twelve-foot span, or 3.7 meters. If you’re sitting in an ordinary house, the ceiling is probably eight feet high, maybe nine, or 2.4 to 2.7 meters. The biggest male giant deer could stand about seven feet at the shoulder, or 2.1 meters, and weigh as much as 1500 pounds, or 680 kg. That’s the size of a bull Alaskan moose, although moose antlers are maybe six feet across, or 1.8 m.

So, giant deer had giant antlers, the biggest of any known deer species. But were they really that big relative to the animal’s size? Stephen Jay Gould published a study in 1974 that concluded that compared to the deer’s body size, Megaloceros’s antlers weren’t actually out of proportion at all. They’re just big animals. Sexual selection did encourage antler size—the ladies liked stags with big racks, and stags with bigger antlers could intimidate rival males more easily. But since Megaloceros shed and regrew their antlers every year, in years where the foraging wasn’t as good, everybody’s antlers tended to be smaller.

So why did Megaloceros die out? When did it happen? And are there pockets of giant deer still living in Siberia?

Those questions are all interrelated and surprisingly hard to answer—although I’m not going to lie, if you’re packing your bags for Siberia to look for giant deer, you’re probably going to be disappointed. But there is evidence that Megaloceros survived much later than formerly thought.

Until recently, the last known remains of Megaloceros were dated to the end of the Pleistocene, about 11,000 years ago. Then a partial giant deer skeleton was found on the Isle of Man, and an antler was found in southwest Scotland. Both were dated to about 9,000 years ago, as published in a year 2000 paper in Nature. In 2004, another paper in Nature revealed that giant deer remains found in western Siberia had been dated to about 7,700 years ago.

So, giant deer were around several thousand years later than previously thought, at least in Siberia. Back in the mid-19th century, some naturalists thought Megaloceros might even have survived well into modern days and been hunted to extinction by modern humans. Well preserved skulls were sometimes found in Irish peat bogs, and it wasn’t uncommon for the antlers to be mounted and displayed. I would.

In 1846, a huge cache of bones was found on a small island in a lake near Limerick in Ireland. Among the bones were Megaloceros skeletons. What interested researchers at the time were the Megaloceros skulls. The stags’ skulls were normal. The smaller skulls, thought to be from females, had holes in the front. They looked for all the world like the skulls of cows that had been slaughtered by being poleaxed in the head—a common butchering practice in the area up until recent times. Researchers thought they might have found evidence of limited domestication of giant deer, where the less dangerous females were raised in captivity while stags were hunted in the wild.

Unfortunately, excavation methods in those days left a lot to be desired. There’s no way now to determine whether the Megaloceros bones were actually mixed in with more recent domestic animal bones or whether they were in older deposits. There’s also doubt that the doe skulls were actually Megaloceros. It’s more likely they were elk or moose skulls. Both animals lived in the area well into the Holocene before going extinct, and the skulls are very similar to those of Megaloceros. As far as I can find out, the bones are gone so they can’t even be DNA tested or radiocarbon dated to see how old they are.

As to why the giant deer went extinct, I’m not saying it was humans…but it was humans. Actually we don’t really know. In some places extinction may have been caused by environmental pressures, including a shortened growing season that would have made food scarce. In other places humans may have been at least a partial cause. But isolated pockets of Megaloceros remained for thousands of years afterwards. Why aren’t they still around?

Hopefully, as more remains are found we’ll learn more. It’s likely that the Siberian deer, which survived longest, migrated onto the plains as the foothills of the Urals became more heavily forested about 8,000 years ago. But that coincided with a dry period and with settlers moving into the area. A combination of reduced fodder, loss of habitat, and hunting may have finally driven the giant deer to extinction.

But don’t be sad! Even if we don’t have Megaloceros in zoos these days, we do have a lot of fascinating deer and relatives of deer—moose, reindeer, elk, and so forth. You can still appreciate them.

I do sometimes think that being extinct makes an animal seem more interesting, just because we know we can never see a living specimen. If moose were extinct, this episode would probably be about the moose, and how awesome it was, and how little we know about it, and how it’s a shame they’re all dead. But hey, moose are still around. Take a little time out of your day today to appreciate the moose. (Also, you can check out episode 30 for lots more information about moose and reindeer.)

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 003: The Tuatara and the Sea Lamprey

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In this week’s episode, we look at a couple of so-called living fossils: the tuatara and the lamprey. One of them hasn’t changed appreciably in almost 400 million years. Tune in to find out which one and learn about how gross it is and how cute the other one is! (I may be biased.) (re-recorded audio)

The adorable tuatara! It eats anything, including baby tuataras. Not cool, lizardy guy:

A face not even a mother could love. The sea lamprey:

A recently discovered fossil lamprey, complete with impression of its body:

Show transcript:

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

This week’s episode is about my favorite reptile and a revolting sea creature, and just to be clear, those are two different animals.

If you look at a tuatara, it appears pretty ordinary. It’s a brownish-grayish-green lizard with lighter-colored spines along its back, and it can grow to about two feet long, or 61 cm. It’s a hefty lizard, sure, but you’d probably think it was nothing special. But dang, is it special.

First of all, it’s not strictly a lizard. It’s the only surviving member of its own order, Rhynchocephalia. It also has many physical traits not shared by lizards—or any other living reptile. Or mammal. Or bird. Or anything else.

Its teeth, for instance. The tuatara has two rows of teeth in the upper jaw, one in the lower, with the lower jaw’s teeth fitting neatly between the two upper rows. Some snakes have two upper rows of teeth and one lower row, but not arranged like the tuatara’s. Not to mention that the tuatara’s teeth aren’t even teeth at all. They’re just pointy projections of the jaw bone.

The tuatara also chews in a literally unique way. When the lower teeth mesh between the upper rows of teeth, the animal moves its jaw forward and back. This slices its food against the sharp tooth edges.

The tuatara also has a third eye. I’m not making this up. It legit has a photoreceptor on top of its head called the parietal (pahRAYetal) eye with a lens, cornea, retina, and so forth. Hatchling tuataras have a translucent patch of skin above the eye, but as the hatchling grows and molts its skin, the patch darkens until the third eye is no longer visible. Researchers think it may help with thermoregulation and hormone production. The tuatara isn’t the only creature with a third eye, but it has the most well developed one.

Like the turtle, the tuatara has a primitive auditory system. It has no external ears and no eardrum, although it can hear. Its skeleton has some features apparently retained from its fish ancestry, such as its spine and some aspects of its ribs. Males don’t have a penis—but a lot of birds don’t either and we still have lots of birds, so obviously they make it work.

Because it has such a slow metabolism—the lowest body temperature of any other reptile—the tuatara grows slowly. It won’t reach breeding age until it’s ten to twenty years old, and females only lay eggs about once every four years. The average lifespan of a tuatara is 60 years. Researchers believe it could live to 200 years in captivity.

Baby tuataras are active in the daytime, probably so their parents won’t eat them. Tuataras eat pretty much anything they can catch. Adult tuataras are active at night, and sleep during the day in dens. Sometimes a tuatara digs its own den, sometimes it shares a den with burrowing seabirds. The birds leave in the morning and the tuatara comes home to sleep until night, when the birds return.

The Tuatara is native to New Zealand, and in an all-too-common situation, when people showed up, the tuatara promptly went extinct on the mainland. It was restricted to 35 islands where it was mostly safe from introduced rats, until its reintroduction in the fenced Karori Sanctuary in 2005. Tuataras have begun to breed in the sanctuary.

One thing I didn’t know about New Zealand—one of many many things, since pretty much all of my New Zealand knowledge comes from watching the Lord of the Rings movies, is that it was underwater for millions of years. Some 82 million years ago, New Zealand separated from Gondwana, the chunk of land that eventually separated into the southern continents we know today. The entire continent containing New Zealand was partially drowned some 25 million years ago, and for a long time scientists thought New Zealand was completely underwater. In the late 2000s, though, a fossil tuatara was found in New Zealand that was dated to about 18 million years ago. If New Zealand was underwater for a few million years, how did the tuatara recolonize it after the sea receded? Tuataras are not good swimmers, and it’s a long distance to float on driftwood without water.

Researchers now think that the highest elevations of New Zealand remained above sea level, allowing tuataras and some other species of plants and animals to survive the inundation.

You’ll see the tuatara referred to as a living fossil in a lot of articles. The media loves to call things living fossils. The tuatara has been around for 225 million years, but so have crocodiles and alligators. In fact, crocs and gators are found in the fossil record even earlier, 250 million years ago. The tuatara in particular has a lot of modern adaptations, including a number of cold-weather adaptations. A 2008 study discovered that the tuatara has the highest molecular evolution rate of any animal ever measured.

Basically, you can’t keep the tuatara down. Drown its entire continent? No problem. Run a couple of ice ages through there? It’ll adapt. And now we realize that this isn’t even its final form.

I take you now from a chunky little lizardy thing eating crickets in New Zealand to a two-foot-long monstrosity that drills into living creatures to drink the blood and bodily fluids it rasps from their tissues, the sea lamprey.

What does the tuatara have to do with the sea lamprey? I mean beyond the fact that the tuatara would happily slurp up any lampreys it could get into its mouth? Well, if the tuatara is the most rapidly evolving creature ever studied, the lamprey has remained basically unchanged for at least 360 million years.

Lampreys are eel-like parasites that lack jaws. Instead, they have a circular mouth rimmed with rows and rows of rasping teeth, for lack of a better word. I saw this described in one paper as a feeding apparatus, and it’s as good a description as any although it doesn’t convey the utter, utter horror that is the lamprey’s mouth. I may be showing my prejudices here.

Those aren’t teeth, by the way, they’re made of cartilage. The lamprey doesn’t have any bones at all, but it does have a cartilage tooth-studded tongue used to drill into its prey once it’s clamped on with its sucker-like mouth. Dear God.

Not all lampreys are parasitic. Some are filter feeders as larva and don’t eat at all once they grow up, just live on their bodily reserves until they breed and die, but I’m just talking about parasitic lampreys today because they’re gross. The most common parasitic lamprey is the sea lamprey, which lives in the Atlantic Ocean, parts of the Mediterranean and Black Seas, and in the Great Lakes as an introduced pest. The sea lamprey can grow up to four feet long, or 120 cm.

Because of their lack of bone, lampreys don’t fossilize well, but one fossil found in South Africa has revealed a lot about the lamprey. In a 2006 paper in Nature, researchers describe a beautifully preserved lamprey dated to 360 million years ago. Not only are the gills and mouth perfectly visible, so is an impression of its body. It was the oldest lamprey fossil found at the time, and it shows that the lamprey basically hasn’t changed ever since. If anything deserves to be called a living fossil, it’s the lamprey.

Back when the lamprey first evolved, it wasn’t preying on true fish. There weren’t any yet. The lamprey has held fast through at least four major extinction events. It’s a vertebrate, but has never evolved those things other vertebrates—except the hagfish, which is just weird—have developed: jaws, scales, paired fins. On the other hand, some lampreys do have a third eye.

Because lampreys are so primitive from an evolutionary standpoint, scientists can study them to learn how other vertebrates evolved. For instance, the lamprey has seven pairs of gill arches. In other vertebrates, the interior pair of gill arches evolved into upper and lower jaws and middle ear bones. That includes us.

Lampreys today prefer fresh water that’s not too warm, although the sea lamprey spends most of its adult life in the ocean, although it will also be fine in fresh water. The sea lamprey migrates upriver to spawn. After the female lays her eggs, she and the male both die. When the eggs hatch, the larvae migrate downstream to quiet water where they feed on plankton until they metamorphose into adult lampreys. Then they continue their migration downstream to the ocean or lake. They live about a year before returning upstream to spawn and die.

Lamprey larvae live as filter feeders, and until about 2014 scientists didn’t know if this was a recent development or not. Then some fossilized lamprey larvae were discovered in inner Mongolia rocks dating back 125 million years, and they look identical to modern larvae.

Old and “primitive” as it is, the lamprey is able to tolerate all sorts of environments. Most water animals can either live in saltwater or freshwater, not both, but the sea lamprey does just fine in either. In the Great Lakes, sea lampreys are so damaging to the native fish that researchers have been trying for decades to get rid of them. The sea lamprey can also feed on fish that are toxic to pretty much any other predator.

In many cultures, lamprey is considered a delicacy, and it’s supposed to taste quite good, but make sure you clean those things well. Their mucus is a toxin. You will not catch me eating lamprey if I can possibly avoid it.

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!