Category Archives: dinosaurs

Episode 297: Dinosaur Mummies



This week we have a two-ghost rating for our episode about dinosaur mummies! It’s a little spooky because we talk about mummies, but it’s mostly an episode about dinosaurs, which are not spooky.

Further reading:

The lost Tarbosaurus mummy

Dinosaur Mummy Found with Fossilized Skin and Soft Tissues

Dakota the Dinomummy: Millenniums in the Making

Spectacularly Detailed Armored Dinosaur “Mummy” Makes Its Debut

Was a Dinosaur Mummy Dubbed ‘Appalachiosaurus’ Found in Tennessee?

An Edmontosaurus mummy found in 1908:

A 3D model of Dakota’s skin [photo from third link above]:

The Nodosaurid ankylosaur mummy:

Show transcript:

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

It’s monster month and this week we’ve got a monster from ancient times—really ancient times. We’re talking about mummies today, DINOSAUR mummies! On our spooky scale, this one rates two ghosts out of five since we do talk about mummies, but it’s not too spooky because we mostly talk about dinosaurs!

A dinosaur named Tarbosaurus lived around 70 million years ago in what is now Mongolia. It was probably closely related to Tyrannosaurus rex and would have looked very similar, with a big strong body but teeny-tiny front legs. Its front legs were even smaller than T. rex’s in relation to its body. It grew up to about 33 feet long, or 10 meters, and probably stood about 10 feet high at the hip, or 3 meters, and its big head had a big mouth full of really big teeth. It probably killed and ate hadrosaurs, sauropods, and other big dinosaurs. Some scientists think it was so closely related to T. rex that it should be classified as another species in the genus Tyrannosaurus.

We have quite a few Tarbosaurus fossils, including some very well-preserved skulls, so we know quite a bit about it. It had a good sense of smell and good hearing, but its vision wasn’t all that great. Some paleontologists think it might have been nocturnal. We’ve also found lots of bones of big dinosaurs with bite marks from teeth the size and shape of Tarbosaurus’s.

In 1991, though, a team of scientists found something even more incredible. They found a partial skeleton of a Tarbosaurus with lots of skin impressions. In short, they’d sort of found a mummified dinosaur. (It’s not really a mummy.)

The mummy consisted of the back end of the dinosaur, including the pelvis, tail, and hind legs. It had fallen onto sandy sediment that was especially fine-grained, so when the sediment transformed into sandstone over many millennia, it retained an exceptionally clear impression of the skin, including every small pebbly scale.

The expedition members took pictures and measurements, but they didn’t collect the specimen. Another expedition returned to the area to do so in 1993, but by then the specimen was gone. It was probably stolen by fossil poachers, who probably didn’t even realize the skin impressions were far more valuable than the bones and may have destroyed them while removing the skeleton.

The lost Tarbosaurus specimen is called a fossilized mummy since a dead animal’s skeleton with skin is sort of like a mummy. When the soft tissues of a dead animal or person are preserved in some way that causes them to stop decaying, that’s considered a mummy, and there are a lot of causes.

The most famous mummies, of course, are from ancient Egypt. It was important in Egyptian culture at the time to preserve a dead person’s body, and dead animals were also mummified sometimes, especially cats. The body was treated with salt and spices that helped dry the tissues and preserve them from bacteria, and once it was fully dehydrated the body was wrapped in linen bandages, covered with a natural waterproofing material made from plant resins, and placed in a wooden coffin. Sometimes the coffin was then put into a stone sarcophagus to keep it extra safe.

Other cultures across the world have practiced mummification too, and sometimes mummification happens naturally. This mostly happens in deserts and other dry areas, or in places where it’s very cold and the body freezes before it can decay, then dries out slowly. Sometimes a body is preserved after it’s buried, when the soil of the grave or the conditions in an underground crypt are just right, although bodies found in bogs are mummified too since bogs lack oxygen and that stops the decay of soft tissues.

Another dinosaur mummy was found in 1910 in the western United States, in Wyoming. It’s an Edmontosaurus specimen that’s remarkably well preserved and nearly complete, including skin impressions and even the horny beak. Initially the scientists who studied the animal thought the stomach contents had been preserved too, but more modern studies have concluded that the plant material was probably deposited in the body cavity after death. The dinosaur died near water and flooding may have washed plants into the partially decomposed carcass. There was even a little fish among the plant material, which was probably already dead when it was washed into the body cavity.

Edmontosaurus lived in what is now North America around 67 million years ago, surviving right up to the extinction event that killed off the non-avian dinosaurs. It’s one of many species of hadrosaurid, which are often called duck-billed dinosaurs. It could grow up to 39 feet long, or 12 meters, and possibly larger, and it was relatively common throughout its range. It probably walked on all fours most of the time but could stand or walk on its hind legs only, when it wanted to. It ate plants and may have migrated long distances to find food. It probably lived in groups.

The skin impressions of the 1910 specimen were impressive, but it isn’t the only edmontosaurus mummy ever found. We have several, in fact. The earliest was found in 1908, known as specimen AMNH 5060, and it was discovered by a man named Charles Sternberg and his three sons, who all three became paleontologists later in life. They were hoping to find a good triceratops skull to sell to a museum, but they found something even better when one of the sons realized the dinosaur they were uncovering was wrapped in skin impressions.

AMNH 5060 had died in an area that was very dry, so instead of rotting away, all the moisture in the body dried out and the skin remained stretched across the bones. It was essentially a natural mummy at that point. Then, as in the 1910 specimen, flooding probably covered the dead animal with sediment that preserved it in fine detail. Not only is the skeleton mostly intact, it’s also articulated so that the fossilized body parts are in the same places they were when the animal died, instead of having been scattered around after death.

More edmontosaurus mummies were found later, too, but it wasn’t until 2006 when the most important find so far was discovered in North Dakota, part of the United States. It isn’t just skin impressions we have from this specimen, which is nicknamed Dakota. We have actual fossilized skin and muscles and tendons, along with bones.

Dakota was discovered by Tyler Lyson on his uncle’s ranch when he was still in high school. He knew the dinosaur was there but he didn’t realize how important the find was until five years later when he was a paleontology student. The specimen was excavated in 2006 and was identified as an adolescent edmontosaurus that died about 67 million years ago. It was recently given a new 3D scan and results will hopefully be published soon, letting us all know if there are any fossilized organs inside the body.

Because so much of the soft tissues were preserved in place, we know a lot about how edmontosaurus looked when it was alive. For instance, the intervertebral discs that act as little shock absorbers between vertebrae are still in place, which means we know exactly how long Dakota was when it was alive, about 40 feet long, or 12 meters. Because so many of its tendons and muscles are preserved, scientists can calculate how fast it could run. Dakota could probably run 28 mph, or 45 km/hour. We even have a clue about Dakota’s pattern, if not its coloration. Differences in scale size and texture suggest that the dinosaur might have had stripes on at least part of its body.

Edmontosaurus fossils aren’t the only dinosaur mummies, though. In 2011, an amazing ankylosaur fossil was discovered in a Canadian mine. Ankylosaurs had short legs and wide bodies covered in armor, and while some had club-like tails, Nodosaurids had regular tails but spikes on their backs that pointed sideways. The Canadian ankylosaur mummy is a nodosaurid.

Researchers think the dinosaur was probably caught in a flash flood, which swept it out to sea. It probably swam as long as it could, but its armored body made it heavy and it eventually drowned. Its body sank into the bottom sediment, which protected it from decay, scavengers, weathering, and other things that might have destroyed it. 110 million years later, an equipment operator fortunately noticed how weird the rock was that he’d just uncovered, and the world now has an amazing idea of what a living ankylosaur looked like.

The animal’s armored plates from the front of its body, some skin, and even its stomach contents are beautifully preserved, and the body is still articulated. It looks like it lay down to sleep and turned to stone. Some chemical pigments called melanosomes were discovered during study of the skin, which suggests that its skin was probably reddish-brown in color with a lighter-colored belly. It had massive spikes on its shoulders and along the sides of its neck, along with the smaller osteoderms that made up its armor on the rest of its body.

We know it mostly ate ferns because that was mostly what was in its stomach when it died. There was also some charcoal in its stomach, and researchers think it was probably eating ferns that had grown in an area where a wildfire had been recently. The ferns are so well preserved that scientists can determine their stage of growth, which means the dinosaur probably died in early to mid-summer.

Another dinosaur mummy is a Brachylophosaurus nicknamed Leonardo. Leonardo was found in July 2000 and wasn’t full grown when it died, only maybe three or four years old. Its skin and some of its internal organs are fossilized, and 3D scans have allowed scientists to learn a lot about it.

Brachylophosaurus was a hadrosaurid that lived around 80 million years ago in North America, and it could grow up to around 36 feet long, or 11 meters. It may have lived and migrated in groups. It had a flat crest on its head and a frill down the back, although some individuals had big crests and some had small ones. Paleontologists think big crests might have been a trait found only in males or only in females, we’re not sure which.

It ate plants, and we know from studies of Leonardo’s fossilized digestive system that it had eaten a lot of ferns right before it died, as well as leaves and other material from ancient relatives of conifers and magnolias. It also had worms. That’s right, even the parasites in Leonardo’s digestive system were fossilized. They were needle-like bristly worms who left more than 200 tiny burrows in the digestive lining, fossilized for eternity. Leonardo also had an internal pouch in its neck that was similar to a modern bird’s crop, where food was stored immediately after swallowing and where the digestive process may have started.

We’ll finish by talking about a story from April 2022, which discusses a dinosaur mummy found in my own state of Tennessee. The dinosaur was called Appalachiosaurus and was at least 77 million years old, and its skin and even some of its internal organs were reportedly intact—so much so that DNA was able to be extracted from them. The problem is that this particular story was posted to Facebook on April 1, also known as April Fool’s Day, and yes, it was a hoax. But Appalachiosaurus is a real species of dinosaur, a theropod that grew at least 21 feet long, or 6.5 meters, and probably quite a bit longer since the most complete specimen found so far is a juvenile. We don’t know a lot about Appalachiosaurus since only a few partial remains have ever been discovered. It would be fantastic if a fossilized mummy of one really did turn up one day.

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 294: Updates 5 and a New Zealand Parrot!



It’s our fifth updates and corrections episode, with some fun information about a New Zealand parrot, suggested by Pranav! Thanks also to Llewelly, Zachary, Nicholas, and Simon who sent in corrections.

Further reading:

Vitiligo

Tyrannosaurus remains hint at three possible distinct species

Study refutes claim that T. rex was three separate species

The reign of the dinosaurs ended in spring

Impact crater may be dinosaur killer’s baby cousin

California mice eat monarch butterflies

‘Hobbit’ human story gets a twist, thanks to thousands of rat bones

Playground aims to distract mischievous kea

The kea showing off the bright colors under its wings:

A kea jungle gym set up to stop the birds from moving traffic cones around for fun:

Show transcript:

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

This is our fifth annual updates episode, where I catch us up on new studies published about various animals we’ve talked about before. This is mostly just whatever happens to catch my eye and isn’t comprehensive by any means. Also, because things have been so busy for me the last few weeks, I decided to just go with what I’d already finished and not try to add more.

We’ll start as usual with corrections, then do some updates, then learn about a parrot from New Zealand, which was a suggestion from Pranav. This part of the episode started as a Patreon episode from 2019, so patrons, I promise your October bonus episode will be brand new and interesting and in-depth!

First, both Llewelly and Zachary pointed out that there are lions living in Asia, not just Africa. It’s called the Asiatic lion and these days, it only lives in a few small areas in India. It’s a protected animal but even though their numbers are increasing, there are probably still no more than 700 Asiatic lions living in the wild.

Next, Nicholas points out that vitiligo isn’t a genetic condition, it’s an autoimmune disorder that can be caused by a number of different diseases and conditions. You still can’t catch it from other people, though. We talked about vitiligo briefly in episode 241, about squirrels. Nicholas included a link, which I’ll put in the show notes for anyone who’s interested in learning more.

For our final correction, Simon questioned whether there really are only six living species of macaw known. This was polite of him, since I was completely wrong about this. In fact, there are six genera of macaws and lots of species, although how many species there are exactly depends on who you ask. Since this mistake made it into the Beyond Bigfoot & Nessie book, I am very irritated at myself, but thank you to Simon for helping me clear this up.

Let’s start our updates with the animal who gets an update every single time, Tyrannosaurus rex. A study published in February 2022 examined the fossilized remains of 37 T. rexes and suggested that there may actually be three distinct species of T. rex instead of just one. The study focused specifically on differences in teeth and leg bones that don’t seem to have anything to do with the individual’s age when it died or whether it was male or female.

However, in July 2022, another study found that all the T. rexes found so far do indeed belong to the same species. This is how science works, because new information is always being discovered and that means we have to reassess the things we thought we knew.

In other dinosaur news, in episode 240 we talked about the last day of the dinosaurs. Results of a study released in February 2022 suggest that the asteroid struck in early spring in the northern hemisphere. The asteroid hit the earth so hard that it rocked the entire continental plate that it struck, which caused massive waves unlike any other waves, since all the water above the continental plate was pushed upwards at once. This pushed all the sediment lying quietly on the bottom of the ocean up into the water, so much of it at once that it actually buried a lot of fish alive. The same thing happened in lakes and every other body of water. The fossil site we talked about in episode 240 is still being studied, the one that appears to date to literally the day of the asteroid impact, and preserved soft tissues in some of the fish have been discovered. Careful analysis of the fish show evidence that they all died in early spring. Researchers suggest that the time of year may have been especially bad for many dinosaurs, who were probably just starting to lay eggs and have babies.

In even more recent last-day-of-the-dinosaurs news, in August 2022 a study was released about a newly discovered crater off the coast of West Africa. Researchers are pretty sure it was from an asteroid impact, although much smaller than the big one that hit what is now Mexico and led to the extinction of all non-avian dinosaurs. They’re also not completely certain when it formed, since it’s deep under the sea floor these days and was only discovered when scientists were examining seismic survey data of the sea floor. But it does seem to have formed about 66 million years ago, and another crater found in Ukraine is also about the same age. In other words, there may have been more than one asteroid that hit earth at the same time, either because a bigger asteroid broke into pieces as it entered earth’s atmosphere, or because smaller asteroids were orbiting the bigger one.

We’ve talked about the monarch butterfly several times, especially in episode 203. The monarch is a beautiful orange and black butterfly that migrates from the United States and Canada into central Mexico for the winter, where it gathers in huge groups. The monarch butterfly caterpillar primarily eats the milkweed plant, which contains toxins that the caterpillar stores in its body. Those toxins remain in the body even after the caterpillar has transformed into a butterfly, meaning the butterflies are toxic too. Birds and other animals learn to recognize the bright orange and black pattern of the butterfly and avoid eating it, because it tastes bad and makes them sick.

But a study from December 2021 determined that one animal does eat monarch butterflies, and a whole lot of them. Many species of mouse that live where monarch butterflies spend the winter, in a few spots in Mexico and California, will eat the butterflies, especially ones that fall to the ground either by accident or because they’re unhealthy and weak. The mice show resistance to the butterfly’s toxins.

Research into the small hominin remains on the island of Flores is ongoing, and the most recent findings shed some light on what might have happened about 60,000 years ago. The so-called Hobbit fossils have all been found at Liang Bua, a giant cave, but lots of other fossils have been found at the same site. A whole lot of those are from various species of rodent, especially rats, ranging in size from mouse-sized to ordinary rat-sized to giant rat sized, over two feet long including the tail, or about 75 cm.

Because we know a lot about the rats that lived on Flores, and in some cases still live there, we can infer a lot about what the area around Liang Bua was like over the centuries. Until about 60,000 years ago, most of the rat remains found were of medium-sized species that like open habitats. That means the area around Liang Bua was probably pretty open. But after about 60,000 years ago, there’s a big shift in what kind of rodents appear in the fossil record. More rats of smaller size moved in, ones that were adapted for life in forests, while the medium-sized rats moved out. That corresponds with other animals disappearing from the fossil record in and around the cave, including a species of Komodo dragon and a subspecies of Stegodon, an elephant relation that exhibited island dwarfism and was about the size of a cow. The Flores little people remains also vanish from the cave during this time, until by 50,000 years ago there are no signs of them.

But that doesn’t mean that H. floresiensis went extinct at that time. Researchers now think that as the land around the cave became more heavily forested, the Flores little people moved to other parts of the island that were more open. We don’t know where yet, and as a result we don’t know when exactly they went extinct. They might even have left the island completely. One neighboring island is Sulawesi, and researchers have found small stone tools on that island that are very similar to those made by H. floresiensis.

Modern humans probably arrived on the island of Flores about 46,000 years ago, and it’s possible that when they did, their small-statured cousins were still around.

We’ll finish with Pranav’s suggestion, a New Zealand parrot called the kea!

The kea is a type of parrot, but it doesn’t look much like a parrot at first glance. Parrots usually have brightly colored feathers but the kea appears more drab initially. It’s olive green with black-laced feathers, but it has bright orange feathers under its wings that show when it flies and the tips of its wings are blue. It’s a big, heavy bird with a wingspan more than three feet across, or one meter, and it has a big hooked beak like other parrots. It lives in the mountains of New Zealand’s South Island, the only parrot that lives in such a cold environment.

The kea is an omnivore but it mostly eats plants and insects. It will eat roadkill, small animals like rabbits, chicks of other species of bird, and trash. For over a century there were rumors that the kea would attack sheep, which led to the New Zealand government paying a bounty for dead keas that wasn’t lifted until 1970. By the time the bounty ended, there were only around 5,000 keas left, and even then the bird wasn’t fully protected until 1986.

So does the kea kill sheep or was that just an excuse to kill birds? Actually, the kea does attack sheep, or at least some keas do. Most of the attacks aren’t fatal, but we definitely know it happens because someone got it on video in 1992.

The keas land on the sheep’s back and pull out hunks of wool, which exposes and injures the skin underneath. Then they use their sharp beaks to dig into the wound and eat the fat from the living sheep. This can result in the sheep dying from infection and shock, naturally, so it’s no wonder sheep farmers disliked the kea. But the sheep is not an animal native to New Zealand while the kea is, plus the kea primarily eats plants—and sheep destroy the plants the kea eats, especially the ones high in vegetable lipids that provide the same high energy food that sheep fat does.

Besides, there’s some tantalizing evidence that the kea used to do the same thing to the moa, a huge flightless bird that lived in New Zealand until it went extinct after humans arrived. Moa bones dating to 4,000 years ago and found in a swamp along with lots of other well-preserved bones show markings on the pelvis that may be from kea beaks.

Like other parrots, the kea is remarkably intelligent and known for its tool use. It’s also infamous for its curiosity and willingness to disassemble things, including cars. I found an article about the kea in New Zealand Geographic that has some awesome stories about the bird, like this one that I’ll quote.

“In September 1983, the Old Pompolona Hut on the Milford Track was destroyed by flood when the pent-up Clinton River broke through its winter avalanche dam. The walking track season was only six weeks away. Planners, builders and helicopter crews worked night and day to complete a new hut complex before the first walkers arrived.

“The local clan of kea took a keen interest in all this frantic activity after a cold and quiet winter. Just what were these people up to? One bird, for whom building materials seemed to hold a particular attraction, began stealing nails. So persistent was the bird’s thievery that an exasperated carpenter chased it (in vain) over the roof of the new main hut. While his back was turned, another kea stole his packet of roll-your-owns, shredding tobacco and papers to the raucous approval of spectator kea perched in nearby trees.

“Weeks later, after the new hut had been completed, the purloined nails were discovered. They had been neatly laid in the gutters of an outbuilding’s iron roof, sorted according to size.”

The kea’s intelligence, tool use, and problem-solving abilities line up with those in corvids like crows and ravens. Studies show that corvids are more successful figuring out tasks that require them to make pecking motions in one way or another while parrots, including the kea, are more successful when the tasks require pulling motions. This makes sense, since parrots have a hooked beak that they use to pull things apart, like rotting logs to get at grubs, while corvids have straight beaks that they use to stab through things to find food.

The kea is also really sociable. Young keas play together, often using items as toys. For instance, from the same article, witnesses at a ski resort watched a kea steal a plastic mug, fly off with it, and start up a game of catch with it with a group of other keas.

The kea even has a particular call it makes to encourage other keas to play. In a recent study, when the call was broadcast to some captive keas over a loudspeaker, the keas immediately started a game of chase. Researchers think the call isn’t so much an invitation to play but is more like laughter which makes other keas want to laugh along, or in this case play.

This is what the play call sounds like:

[kea call]

The kea builds its nests in burrows it digs in the ground, with some burrows 20 feet long, or 6 meters. The nesting chamber is lined with soft plant material. Females lay two to five eggs, which hatch in about three weeks. Despite the parents’ care, more than half of babies don’t survive their first year, mostly due to introduced predators like rats, stoats, and possums. But if a kea survives to grow up, it can live up to 50 years or possibly more.

Young keas, like young adult humans, can cause a lot of mischief that sometimes leads to tragedy. A lot of keas are killed by cars because they find cars and roads interesting. They especially like to move road cones, which of course is also dangerous to humans. One community set up a kea jungle gym well off the road to give keas a safe place to play, and it succeeded so well that other communities have built kea jungle gyms too.

Kea numbers are improving slowly, with an estimated 7,000 individuals alive today. Part of the problem is that keas find humans interesting. They like our things, which they want to steal or destroy, and they like our junk food, which they want to eat. In other words, they’re suspiciously like us. Only they can fly.

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 293: Bat-Winged Dinosaurs and an Actual Bat



We’ll have a real episode next week but for now, here are two Patreon episodes smashed together into one!

Happy birthday to Speed!

Further reading:

Yi qi Is Neat But Might Not Have Been the Black Screaming Dino-Dragon of Death

Yi qi could probably glide instead of actually flying:

The Dayak fruit bat [photo by Chien C. Lee]:

Show transcript:

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

I’ve finally finished moving, although I’m still in the process of unpacking and finding places for all my stuff. I haven’t had the chance to do any research this week, so this episode is actually two repurposed Patreon episodes, one from June of 2019 and one from May of 2021. They’re both short episodes so I put them together. I apologize to patrons for not getting something new this week, but I think everyone else will find these animals interesting.

But first, we have a birthday shout-out! A great big happy birthday to Speed! I hope this next year is the very best one yet for you!

Please excuse the varying quality of audio.

Listener Simon sent me an article about a recently discovered dinosaur with batlike wings, only the second batwinged dinosaur ever discovered. I thought that would make a really neat episode, so thank you, Simon!

These are really recent discoveries, both from the same area of northeastern China. In 2007 a small fossil found by a farmer was bought by a museum. A paleontologist named Xing Xu thought it looked interesting. Once the fossil had been cleaned and prepared for study, Xing saw just how interesting it was.

The dinosaur was eventually named Yi qi, which means strange wing. It was found in rocks dated to about 163 million years ago. Yi qi was about the size of a pigeon and was covered with feathers. The feathers were probably fluffy rather than the sleek feathers of modern birds. But most unusual was a long bony rod that grew from each wrist, called a styliform element. Yi qi also had very long third fingers on each hand. The long finger was connected to the wrist rod by a patagium, or skin membrane, and another patagium connected the wrist rod to the body. So even though it had feathers on its body, it probably didn’t have feathered wings. Instead, its forelimbs would have somewhat resembled a bat’s wings.

Paleontologists have studied the fossilized feathers with an electron microscope and discovered the structures of pigments that would have given the feathers color. Yi qi was probably mostly black with yellow or brown feathers on the head and arms. It probably also had long tail feathers to help stabilize it in the air.

Ambopteryx longibrachium was only discovered in 2017, also in northeastern China. It also lived around 163 million years ago and looked a lot like Yi qi. The fossil is so detailed it shows an impression of fuzzy feathers and even the contents of the animal’s digestive tract. Its body contained tiny gizzard stones to help it digest plants but also some bone fragments from its last meal, so paleontologists think it was an omnivore. Its hands have styliform elements, although not a wrist rod like Yi qi, and there’s a brownish film preserved across one of its arms that researchers think are remains of a wing membrane.

Paleontologists think the bat-winged dinosaurs were technically gliders. Careful examination of the wrist rods show no evidence that muscles were attached, so the dinosaurs wouldn’t have been able to adjust the wings well enough to actually fly. Modern bats have lots of tiny muscles in their wing membranes to help them fly.

Yi qi’s wrist rod isn’t unique in the animal world. The flying squirrel has styliform rods made of cartilage that project from the wrists, with the patagia attached to them. When a squirrel wants to glide, it extends its arms and legs and also extends the wrist rods, stretching the patagia taut. It can even control its glide to some extent by adjusting the wrist rods.

These two bat-winged dinosaurs were related, but they aren’t direct ancestors to modern-day birds. They’re scansoriopterygids,[scan-soarie-OPterigid] which are related to the group of dinosaurs that gave rise to birds. We only have five scansoriopterygid fossils, all found in the same area of China, but they’re all exceptionally well preserved fossils. Scansoriopterygids all appear to have been good climbers. They probably mostly lived in trees and mostly ate insects and small animals, gliding from branch to branch like modern flying squirrels do.

Researchers suggest the bat-winged dinosaurs might have gone extinct when bird ancestors evolved true flight with feathered wings, outcompeting the bat-winged dinosaurs’ more limited gliding flight. But with so few fossils, it’s impossible to say how successful the bat-winged dinosaurs were. All we know is they are rare in the fossil record and left no descendants.

So were scansoriopterygids related to pterosaurs? Nope. Pterosaurs weren’t even dinosaurs. They were reptiles and the first vertebrates we’ve found that could actually fly instead of just glide. Pterosaurs first appear in the fossil record around 228 million years ago and they all went extinct about 66 million years ago in the Cretaceous-Paleogene extinction event.

When Yi qi’s description was first published in 2015, the media acted as though it was a radical new find that would change the way we looked at dinosaurs forever. Some people even claimed the fossil was a fake, either a deliberate fraud by Xing and the other paleontologists that worked on the specimen, or that Xing and the others actually had a fossil made up of more than one animal with the bones jumbled together, which they had mistaken for a single animal. But this isn’t the case. Yi qi has been studied extensively with all the technology paleontologists have available these days. It’s the fossil of a single animal and it hadn’t been touched up or altered or messed with in any way before it was prepared by an expert. But while it is a radical new finding, it’s not as radical as some articles made it seem.

In 2008, the description was published of another scansoriopterygid called Epidexipteryx. Epidexipteryx appears to be closely related to Yi qi. It doesn’t have a wrist rod, but its arms were long and its fingers were especially elongated. It had forward-pointing teeth in the front of its jaw and probably had long tail feathers. Paleontologists think it was most likely a strong climber that may have spent most of its time in and around trees. But after that publication, paleontologist Andrea Cau published a paper suggesting that Epidexipteryx’s elongated arms and fingers might have been connected with patagia that allowed it to glide short distances. This was before the first paper about Yi qi was published and before Ambopteryx was even discovered. So the idea of a dinosaur with gliding membranes was already out there.

Hopefully, more scansoriopterygid fossils will be found and studied soon, which will give us more knowledge about what these little animals really looked and acted like. I want one as a pet.

Next, let’s go from bat-winged dinosaurs to some actual bats, specifically an unusual feature found in at least one species of bat, and something of a mystery.

As you probably know, only female mammals lactate. That just means that after a mammal gives birth, the mother produces milk for her baby to drink until it’s old enough to eat the same food that its parents do. All mammals do this, from whales to vampire bats, from humans to kangaroos, from mice to lions. The word mammal actually comes from mammary gland, which is the gland that allows a mother animal to produce milk after she has a baby.

Researchers have examined the genes that allow for milk production and determined that the genes probably developed over 200 million years ago in the common ancestor of all mammals alive today. The genes responsible for making egg yolk proteins started to be lost around 70 million years ago, except in monotremes that still lay eggs. Monotremes are platypuses and echidnas, and while they’re mammals, they retain some features that modern mammals have lost, like egg-laying. But even monotreme mothers produce milk.

Once our far-distant mammal ancestors evolved the ability to feed its babies with milk, the babies didn’t need as much yolk in their eggs. Gradually, over millions of generations, mammals lost the ability to produce egg yolks completely. I mean, except for the monotremes. From now on just assume that any time I talk about modern mammals, in this episode at least, I’m excluding monotremes, because they’re weird.

Ancient mammals laid eggs like reptiles and birds do, with a shell protecting the yolk and other fluids inside, that in turn protected and nourished the growing baby. But eventually a mammal mother retained her eggs in the body, which meant they didn’t need an eggshell since they were safely inside her, and because she was able to feed them nutritious, easy to digest milk as soon as they were born, they didn’t need an egg yolk either. So mammals eventually lost the ability to produce eggs at all.

This gets confusing, of course, because we use the same word, “egg,” to refer to the egg that a chicken or turtle lays, and to refer to the cell that a mother animal produces that can develop into a baby if it’s fertilized by sperm. Obviously I’m just talking about the first kind of egg here.

Anyway, milk production is a complex process that can be hard on the mother’s body, since she has to produce enough nutrients to feed all her babies, whether that’s just one human infant or twin fawns or a whole litter of puppies or kittens. Researchers have compared the genes associated with milk production and discovered that it’s pretty standard across all mammals. While the nutrients available in milk vary from species to species, since not every mammal has the same nutritional needs, how the body produces milk is pretty much identical across the board. All female mammals produce milk after they give birth, but only the females.

If that’s the case, though, why do male mammals have nipples? It turns out that nipples are just part of the basic body plan of a mammal. Some researchers think that originally both males and females lactated, but over the generations males lost the ability.

Except in one case. In that species, the females produce milk…and so do the males.

The Dayak fruit bat lives in parts of southeast Asia and is quite rare. It lives in rainforests and mostly eats fruit, especially figs. It has short, gray-brown fur and only weighs a little more than three ounces, or 95 grams. That’s about the same weight as a deck of cards. Its wingspan is about 18 inches across, or 46 cm. It’s a nocturnal bat but it’s also a megabat, which if you remember episode 88 means that it doesn’t have the advanced echolocation ability that microbats have. It may only navigate through the trees using its vision, since it has large eyes, but it may have some form of echolocation ability we don’t know about yet. There’s a whole lot we don’t know about the Dayak fruit bat.

What we do know is that in summer, female Dayak fruit bats give birth to one or two babies. We also know that in summer, when researchers net bats to examine, both males and females have enlarged breasts that produce milk. The bat, by the way, has breasts toward the sides of its body, basically in the armpits of its wings because that’s most convenient for the baby bats to grab hold of.

That’s all we know so far. We don’t know for sure that the males actually nurse their babies. They don’t produce nearly as much milk as females do, only about 1/10th as much. Some researchers think the father bat may take care of his babies while the mother finds food, but that she takes care of them the rest of the time. That’s just speculation, though, because so little is known about the bat.

Sometimes various diseases, genetic issues, or pollutants in the environment will cause a male animal to produce a little milk, but that’s rare. All the male Dayak fruit bats caught in summer were lactating, as were the females. Males and females caught at other times of the year weren’t lactating. Since mammals stop producing milk after their babies no longer need it, that means both males and females are probably producing milk for babies.

There may be one other bat where males lactate, although I can’t find enough information to verify it. The Bismarck masked flying fox, which sounds like an old-timey superhero, is related to the Dayak fruit bat, since they’re both megabats, but they’re not closely related.

The Bismarck masked flying fox lives in Papua New Guinea and eats fruit and other plant material. Like other flying foxes, it probably finds its food by smell and can’t echolocate. We don’t know much about it either, though, and until 2001 researchers thought it was a subspecies of Temminck’s flying fox. If you do a search for it online, every entry you find will mention that the males lactate, but never with any documentation to back up the claim. So that’s a mystery for now, although I’ll keep trying to find out more.

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 267: The Mystery Sauropod



Show transcript:

Hi. If you’re hearing this, it means I’m sick or something else has happened that has kept me from making a new episode this week. This was a Patreon bonus episode from mid-August 2019. I think it’s a good one. If you’re a Patreon subscriber, I’m sorry you don’t have a new episode to listen to this time. Hopefully I’ll be feeling better soon and we can get back to learning about lots of strange animals.

Welcome to the Patreon bonus episode of Strange Animals Podcast for mid-August, 2019!

While I was doing research for the paleontology mistakes and frauds episodes, I came across the discovery of what might have been the biggest land animal that ever lived. But while I wanted to include it in one episode or the other, it wasn’t clear that it was either a mistake or a fraud. It might in fact have been a real discovery, now lost.

In late 1877 or early 1878, a man named Oramel Lucas was digging up dinosaur bones for the famous paleontologist Edward Cope. Cope was one of the men we talked about in the paleontological mistakes episode, the bitter enemy of Othniel Marsh. Lucas directed a team of workers digging for fossils in a number of sites near Garden Park in Colorado, and around the summer of 1878 he shipped the fossils he’d found to Marsh. Among them was a partial neural arch of a sauropod.

The neural arch is the top part of a vertebra, in this case probably one near the hip. Sauropods, of course, are the biggest land animals known. Brontosaurus, Apatosaurus, and Diplodocus are all sauropods. Sauropods had long necks that were probably mostly held horizontally as the animal cropped low-growing plants and shrubs, and extremely long tails held off the ground. Their legs were column-like, something like enormous elephant legs, to support the massively heavy body.

We know what Diplodocus looked like because we have lots of Diplodocus fossils and can reconstruct the entire skeleton, but for most other sauropods we still only have partial skeletons. The body size and shape of other sauropods are conjecture based on what we know about Diplodocus. In some cases we only have a few bones, or in the case of Cope’s 1878 sauropod, a single partial bone.

Cope examined the neural arch, sketched it and made notes, and published a formal description of it later in 1878. He named it Amphicoelias [Am-fi-sil-i-as] fragillimus.

The largest species of Diplodocus, D. hallorum, was about 108 feet long, or 33 meters, measuring from its stretched-out head to the tip of its tail. Estimates of fragillimus from Cope’s measurement of the single neural arch suggest that its tail alone might be longer than Diplodocus’s whole body.

Cope measured fragillimus’s partial neural arch as 1.5 meters tall, or almost five feet. That’s only the part that remained. It was broken and weathered, but the entire vertebra may have been as large as 2.7 meters high, or 8.85 feet. From that measurement, and considering that fragillimus was seemingly related to Diplodocus, even the most conservative estimate of fragillimus’s overall size is 40 meters long, or 131 feet, and could be as long as 60 meters, or 197 feet. This is far larger than even Seismosaurus, which is estimated to have grown 33.5 meters long, or 110 feet, and which is considered the largest land animal known.

So why isn’t fragillimus considered the largest land animal known? Mainly because we no longer have the fossil to study. It’s completely gone with no indication of where it might be or what happened to it. And that has led to some people thinking that it either never existed in the first place, or that Cope measured it wrong.

One argument is that Cope wrote down the measurements wrong and that the neural arch wasn’t nearly as large as Cope’s notes indicate. But Lucas, who collected the fossil, always made his own measurements and these match up with what Cope reported. Lucas and Cope both remarked on the size of the fossil, which was far larger than any they had ever found.

Oddly, Cope’s nemesis Marsh inadvertently vouches for him by the things Marsh didn’t do. We know that Marsh kept tabs on Cope, including even paying people to spy on his fossil excavations. Marsh was also always ready to pounce on any of Cope’s mistakes and make them a big deal. But Marsh never said anything about the neural arch not being a real find, and never questioned Cope’s measurements of it.

Cope never mentioned what happened to the fossil. It wasn’t until 1921 that two researchers pointed out that it was missing from the Cope Collection. So what happened to it?

Most researchers suspect it just crumbled away. The fossil formed in a type of rock called mudstone, which fractures easily into little irregular cubes. In fact, Cope gave the sauropod the name fragillimus because the fossil appeared so fragile—not because of the mudstone per se, but because so much of the fossil had already weathered away and as a result it looked too delicate to be part of such a large animal.

These days paleontologists treat fossils with various preservatives to harden them, but that practice didn’t start until 1880, several years after the neural arch was found. Cope only made one drawing of it, which wasn’t his usual practice. It’s possible the fossil was so delicate at that point that just turning it over to draw the other side caused it to fall apart. Many researchers suspect that Cope or one of his assistants eventually discarded it after it crumbled into a pile of mudstone blocks.

Obviously, if we don’t have the fossil Cope examined, maybe we should go looking for more fossils that Cope’s workers might have missed. Cope did mention a femur located near the neural arch that may have been another fragillimus bone, but it’s not clear if the femur was actually collected. We have Cope’s journal entry where he sketched the dig sites Lucas was working, a rough map that shows at least seven sites. But it’s been a century and a half since then and most of the sites have been lost. In 1994 a team tried to relocate the site where Lucas found the neural arch, but without luck. It’s also possible that any remaining fossils have weathered away completely. In the dig sites that have been found, the mudstone has mostly weathered away down to the underlying sandstone.

Researchers have been able to estimate a probable age for fragillimus from Cope’s notes about the stratigraphy where the neural arch was found. Fragillimus probably lived in the late Jurassic, roughly 150 million years ago. This matches up with the age of other enormously large sauropods. But if fragillimus really was so much larger than the others, how did it live? Would an animal that size actually be able to support its weight, feed itself, and function overall? Wouldn’t it overheat in the sun or starve due to not finding enough food to power its colossal body?

Researchers think that sauropods grew to such enormous sizes because their food was nutritionally lacking. That doesn’t make sense until you realize that when a herbivore’s food is poor, the longer it can keep the plant material in its digestive system, the more nutrients it can extract from it. Sauropods were probably hindgut fermenters like all modern herbivorous reptiles and a lot of birds. The best way to keep lots of plant material in the digestive system is to be really big and have a really big digestive tract. This is the case with many herbivores today, like elephants, rhinos, and horses. Other benefits come from being extremely large, too, such as being larger than potential predators.

Sauropods generally lived in semiarid savannas. Grass hadn’t evolved yet, so researchers think the main groundcover plant was ferns, which sauropods probably ate in bulk. There would also have been shrubs, small trees, and some areas with much taller trees. It’s possible that sauropods spent most of the day among the trees, sleeping in the shade, and came out at night to do most of their grazing.

Cope also found fossils from another sauropod that he named Amphicoelias altus. In fact, he described both Amphicoelias species in the same paper. Some researchers have therefore suspected that the two species were actually the same. A. altus is estimated to grow about the same size as Diplodocus, about 82 feet long, or 25 meters.

But in 2018, a paleontologist named Kenneth Carpenter examined Cope’s information on fragillimus and came to some interesting conclusions. He reclassified it from the family Diplodocidae to the family Rebbachisauridae and renamed it Maraapunisaurus fragillimus. As a result, the estimates of its size have changed. Carpenter suggests that it was much smaller, about 99 feet long, or 30 meters, but that Cope’s measurements were correct. Sauropods of this family just have larger vertebrae than Diplodocidae.

The only difficulty with fragillimus being a member of the Rebbachisauridae is that this group of sauropods isn’t known to have lived in North America, just Europe and South America. But the fossil record is incomplete and every find requires researchers to adjust what we know about where dinosaurs lived and how widespread a particular species or family was.

Hopefully, eventually more and better remains of fragillimus will turn up soon. Then we can work out exactly how big it really was.

Thanks for your support, and thanks for listening! The next episode in the main feed will be about an unusual small fish and an extinct pig relative called the unicorn pig. Basically both those animals should have gone in other episodes but I messed up and forgot to add them to strangest small fish and the weird pigs episodes, but they’re both really neat and I wanted to share them.

https://www.patreon.com/rss/strangeanimalspodcast?auth=eb94e995bdf4bc11930eeda8bc5b4a3e


Episode 264: Sick, Sad Dinosaurs



This week we answer a question you probably didn’t ask, did dinosaurs ever get sick? The answer is yes (or else it would be a super short episode). (Thanks to Llewelly for some corrections!)

A big birthday shout-out to Gwendolyn! Have a great birthday!

The unlocked Patreon episode about green puppies

Further reading:

Researchers discover first evidence indicating dinosaur respiratory infection

Sauro-throat, Part 3: what does Dolly’s disease tell us about sauropods?

Dinosaurs got cancer

Giant Dinosaur Had 2 Tumors on Its Tailbone

Dinosaurs got sick, too–but from what?

cough cough:

Show transcript:

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

This week we have a dinosaur episode, but not one you may expect. We’re going to learn about some dinosaur fossils found with evidence of sickness to answer the question, did dinosaurs get sick? Yes, they did. Otherwise this episode would be about two minutes long.

I know some people get squicked when they hear about illness and disease, so I’ve also unlocked a Patreon episode about puppies that are born green. Don’t worry, the puppies are fine! There’s a link in the show notes so you can click through and listen to the episode on your browser, no login needed.

Before we get to the dinosaurs, we have a birthday shout-out! Happy birthday to Gwendolyn, who is turning two years old this week! Oh my gosh, Gwendolyn, you’re going to learn so many new things this year! I hope you have a wonderful birthday.

And now, the dinosaurs.

Just a few days ago as this episode goes live, researchers announced that they’d found the fossilized remains of a young sauropod dinosaur. It lived around 150 million years ago in what is now the United States, specifically in southwestern Montana. The fossil was nicknamed Dolly by the paleontologists who studied it.

Dolly was a sauropod in the family Diplodocidae, and like other sauropods the Diplodocids all had huge neck vertebrae because their necks were so long. The bones weren’t solid, though, but contained air sacs that made the bones lighter and also connected to the respiratory system. This is the case in birds too. Technically the air sacs in the bones are called pneumatic diverticula, but that’s hard to say so I’m just going to call them air sacs.

When a bird breathes, instead of its lungs inflating and deflating, the air sacs throughout its body and bones inflate and deflate. This pumps fresh air through the lungs and allows the bird to absorb a lot more oxygen with every breath than most mammals can.

The bones of Dolly’s neck had unusual bony protrusions around the spaces where the air sacs once were. When the paleontologists made a CT scan of the protrusions they discovered they were abnormal bone growths that probably resulted from an infection. Sauropods share a common ancestor with birds and researchers think they might have sometimes caught a respiratory illness similar to aspergillosis [asper-jill-OH-sus], a disease common in birds and reptiles today.

Dolly would have had a fever, difficulty breathing, coughing, a sore throat, and other symptoms familiar to us as flu-like or pneumonia-like. Aspergillosis can be fatal in birds, so this respiratory infection might have actually been what killed Dolly. I think we can all agree that the worst symptom to have as a sauropod, whose necks were as much as 30 feet long, or 9 meters, is a sore throat.

That’s not the only indication of illness in a dinosaur fossil, of course. A 2003 paper published in Nature detailed the results of a study where paleontologists scanned 10,000 dinosaur vertebrae from over 700 animals to see if any of them showed tumors. They found 97 individuals that did, all of them from around 70 million years ago and all of them hadrosaurs. Those are the duck-billed dinosaurs that were common in the late Cretaceous in many parts of the world, especially in what is now North America and Asia. Hadrosaurs had flattened snouts that made the skull look like it has a duck bill, but it wasn’t a birdlike bill and hadrosaurs had teeth.

The hadrosaur was a plant-eater and it especially liked to eat conifers. Conifers were really common through most of the Cretaceous and are still around today, including pines, cedars, junipers, hemlocks, redwoods, yews, cypresses, larches, spruces, and more. Most are fast-growing evergreens with scaly or needle-like leaves, and many of them produce resins that are high in toxins to help ward off insects and fungus, and help keep many animals from eating the leaves. Amber is fossilized resin from conifer trees.

Conifer resins contain carcinogenic chemicals, which means that eating enough conifer leaves can increase the risk of developing tumors. Hadrosaurs ate conifers all the time, so it’s not surprising that the 2003 study found a relatively high percentage of hadrosaur vertebrae with tumors. Most of the tumors were small and benign. Only two dinosaurs showed evidence of cancerous tumors. Most confusing to the researchers is that the tumors are mostly in the hadrosaurs’ tail vertebrae.

A more recent study, from 2016, found two tiny tumors on one vertebra from a titanosaur. It lived 90 million years ago in what is now Brazil in South America. Titanosaurs are some of the largest sauropods known, including one species that was 85 feet long, or 26 meters, but the tumors were only about 8 millimeters across and were benign. This was the first study that found a tumor in a dinosaur that wasn’t a hadrosaur, although they’ve been found in fossils of other animals like mosasaurs and ancient crocodiles.

A study published in 2020 found advanced cancer in the leg bone of a centrosaurus too. Centrosaurus was a ceratopsian dinosaur that lived in the late Cretaceous in what is now Canada. It had a single horn on its nose, two smaller horns over its eyes, and a frill at the back of its head that was decorated with two more small hook-like horns. It lived in herds and ate plants. The individual with the cancerous leg bone would have had trouble running or even walking on its bad leg, but it didn’t die of cancer or predation. Instead, researchers think it drowned in a flood along with the rest of its herd. This means it was protected by its herd and able to live a normal life despite its disease. In fact, when the centrosaurus bone was first discovered, researchers thought it just showed a healed fracture.

That’s the case for a disease seen in some theropod dinosaurs, specifically tyrannosaurids, including Tyrannosaurus rex. Even Sue the T. rex shows evidence of this disease and researchers think it might have been wide-spread among tyrannosaurids. Initially paleontologists thought it was the result of bite wounds from other dinosaurs, but a 2009 study presented evidence that the lesions seen in many tyrannosaurid skulls were due to a parasitic infection similar to that found in some birds today.

The infection is called trichomonosis and is especially common in pigeons, where it’s called canker, and birds of prey, where it’s called frounce. Other birds can catch it too and it can decimate songbird populations. It’s due to a parasite that only affects birds, so you can’t catch it from a sick bird. If you have a birdfeeder or birdbath in your yard, it’s a good idea to give it a good scrub every so often and let it dry out thoroughly before putting it out again in a different area. The parasite is spread from bird to bird and causes lesions in the mouth and throat that can eventually cause the bird to die. 

Researchers think trichomonosis in tyrannosaurids was spread not only between individuals when fighting, but the parasite might have been present in other dinosaurs that tyrannosaurids typically killed and ate. The parasite might not have caused symptoms in other dinosaurs, but when a tyrannosaurid was infected, the parasite completed its life cycle in its host. Other researchers think tyrannosaurids practiced cannibalism, which would also spread the parasite. The parasite actually feeds on the infected animal’s jawbone, causing erosive lesions in the mouth and throat which can stop a bird from being able to swallow, so researchers think many tyrannosaurids died of it the same way birds do.

A 2011 study of a reptile called Labidosaurus, which lived about 275 million years ago in the midwestern United States, showed a bacterial infection in the jaw bone that was the equivalent to an abscessed tooth. Labidosaurus grew about a foot long, or 30 cm, and looked like a lizard with a wide head. It lived long before dinosaurs evolved. This specimen is the first fossil ever found that shows a bacterial infection in a land-dwelling animal. The reptile had bitten something that caused it to lose two teeth, and as the injury healed over, bacteria were trapped inside the jaw. This led to a bad bone infection that was still active when the animal died, although researchers aren’t sure if the infection caused the animal’s death or not.

Most diseases don’t leave any evidence in bones, so we don’t have a fossil record of them. Since all animals get sick sometimes, it’s certain that dinosaurs had various diseases too. Next time you get a sore throat, just be glad that your throat isn’t as long as a sauropod’s.

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 252: Mini Rex



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Thanks to Zachary for suggesting this topic! Let’s learn about some sightings of what look like miniature theropod dinosaurs running around in the American Southwest!

Further reading:

All About Birds: Wild Turkey

A collared lizard running (photo by Joe McDonald from this page):

Basilisks running:

A female wild turkey:

A male wild turkey (note the tuft of hair-like feathers sticking forward, called a beard) (picture from this page):

Show transcript:

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

Thanks to Zachary for his email a while back that helped shape this episode. Zachary has kept a lot of different kinds of pets, which we had a nice conversation about, and one of the reptiles he’s kept as a pet is in this episode. I’ll reveal which one at the end.

But first, a small correction, maybe. Paul from the awesome podcast Varmints! messaged me to point out that the word spelled A-N-O-L-E is pronounced a-NOLL, not a-NO-lee. I’d looked it up before I recorded so that confused me, so I looked it up again and it turns out that both pronunciations are used in different places and both are correct. So if you’ve always heard it a-NOLL, you’re fine, but now I can’t decide which pronunciation I should use.

This week we’re going to learn about an interesting mystery of the American southwest. Even though non-avian dinosaurs went extinct 66 million years ago, occasionally someone spots what they think is a little dinosaur running along on its hind legs. They’re sometimes called mini rexes.

Many reports come from the American southwest, especially Colorado, Arizona, and Texas. For instance, in the late 1960s two teenaged brothers were looking for arrowheads near their home in Dove Creek, Colorado when they were startled by an animal running away from them at high speed. The boys said it looked like a miniature dinosaur, only about 14 inches tall, or 35 centimeters. It was kicking up so much dust as it ran on its hind legs that the boys had trouble making out details. They did note that it seemed to be brown and possibly had a row of spines running down its back, maybe even two rows of spines, similar to an iguana’s. It had long hind legs and shorter front legs that it held out in front of it as it ran.

The animal left behind three-toed footprints that the boys followed until they disappeared into some brush. The boys were familiar with turkey footprints but these were different, with the toes closer together and no rear-pointing toe prints.

In April 1996, in Cortez, Colorado, a woman saw an animal run past her house on its hind legs, seemingly from a nearby pond. It was greenish-gray and stood about 3.5 feet tall, or about a meter. It had a long neck and long, tapering tail. She didn’t notice its front legs but its hind legs had muscular thighs but were thinner below the hock joint.

One night in July 2001, a woman and her grown daughter were driving near Yellow Jacket, Colorado when they noticed an animal at the edge of the road. At first the driver thought it was a small deer and slammed on the brakes so she wouldn’t hit it, but when it darted across the road both women were shocked to see what looked like a small dinosaur pass through the headlight beams of the car. They reported it was about 3 feet tall, or 91 centimeters, and that it had no feathers or fur. Its legs were thin and long, while its arms were tiny and held out in front of its body. It had a slender neck, a small head, and a long tapering tail.

The witnesses in both the 1996 sighting and the 2001 sighting noted that the animal they saw ran gracefully. They also all agreed that the animals’ skin appeared smooth.

Lots of dinosaurs used to walk on their hind legs, but the reptiles living today are all four-footed. There are a few lizards that run on their hind legs occasionally, though, and one of them lives in the American southwest. The collared lizard, also called the mountain boomer, will run on its hind legs to escape predators. Females are usually light brown while males have a blue-green body and light brown head. The name collared lizard comes from the two black stripes both males and females show around their necks, with a white stripe in between. During breeding season, in early summer, females also have orange spots along their sides.

The collared lizard can run up to 16 miles an hour, or 26 kilometers per hour, for short bursts on its hind legs. It uses its long tail for balance as it runs, and its hind legs are three times the length of its front legs. This makes it a good jumper too. It mostly eats insects but will occasionally eat berries, small snakes, and even other lizards. It hibernates in winter in rock crevices.

While the teenaged boys probably saw a collared lizard in the 1960s, the other two sightings we just covered sound much different. The collared lizard typically only grows up to 14 inches long, or 35 centimeters, including its long tail.

A few other lizards are known to run on their hind legs, such as the basilisk that lives in rainforests of Central and South America. It’s famous for its ability to run across water on its hind legs. It’s much larger than the collared lizard, up to 2.5 feet long, or 76 centimeters, including its long tail. It holds its front legs out to its sides when running on its hind legs, and the toes on its hind feet have flaps of skin that help stop it from sinking. It has a crest on its head, and the male also has crests on his back and tail. It can be brown or green in color.

The basilisk is sometimes kept as an exotic pet. In 1981 in New Kensington, Pennsylvania, four boys playing along some railroad tracks saw a green lizard that they thought was a baby dinosaur. It was 2 feet long, or 61 centimeters, and had a crest and an extremely long tail. It ran away on its hind legs but one of the boys, who was 11 years old, managed to catch it. It startled him by squealing and he dropped it again, and this time it got away. It sounds like an escaped pet basilisk.

But let’s go back to our mini rex sightings from 1996 and 2001, the ones of dinosaur-like animals running gracefully on their hind legs with a long neck and long tail. These don’t sound like lizards at all. When lizards run on their hind legs, they don’t look much like how we imagine a tiny raptor dinosaur would look. They appear awkward while running, with their arms sticking out and their heads pointing more or less upward. While all the lizards known that can run on their hind legs have long tails, they all have relatively short necks.

There’s another type of animal that’s closely related to the dinosaurs, though, and every single one walks on its hind legs. That’s right: birds! All the birds alive today are descended from dinosaurs whose front legs evolved for flight. Even flightless birds are well adapted to walk on two legs.

Let’s look at the details of those two sightings again. Both were of animals estimated as about three feet tall or a little taller, or up to about a meter, with long neck, small head, long tapering tail held above the ground, and long, strong legs that were nevertheless thin. Both also appeared smooth. In one of the sightings, the front legs were tiny and held forward; in the other, the witness didn’t notice the front legs.

My suggestion is that in these two sightings, at least, the witnesses saw a particular kind of bird, a wild turkey. That may sound ridiculous if you’re thinking of a male turkey displaying his feathers, but most of the time turkeys don’t look round and poofy. Most of the time, in fact, the wild turkey’s feathers are sleek and its tail is an ordinary-looking long, skinny bird tail instead of a dramatic fan. Its feathers are mostly brown and black, the upper part of its long neck is bare of feathers, as is its small head, and its legs are long and strong but relatively thin. It also typically stands 3 to 3.5 feet tall, or up to about a meter, although some big males can stand over 4 feet tall, or 1.2 meters. As for the front legs seen by witnesses in 2001, a full-grown male turkey has a tuft of long, hair-like feathers growing from the middle of his breast, called a beard. It sticks out from the rest of the feathers and might look like tiny arms if you were already convinced you were looking at a dinosaur instead of a bird.

That’s not to say that all mini-rex sightings are of turkeys, of course, but some of them probably are. The wild turkey lives throughout much of the United States, including most of Colorado. Since birds are the closest animals we have to dinosaurs these days, though, that’s still pretty neat.

Finally, the reptile Zachary kept as a pet was the collared lizard. I didn’t want to say so at the beginning and potentially spoil part of the mystery for some people!

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

Thanks for listening!


Episode 240: The End of the Dinosaurs



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

Further reading:

How Birds Survived the Asteroid Impact That Wiped Out the Dinosaurs

How an asteroid ended the age of dinosaurs

Extinction event that wiped out dinosaurs cleared way for frogs

How life blossomed after the dinosaurs died

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

Show transcript:

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

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

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

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

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

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

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

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

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

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

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

But then, we found the crater. The crater.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Thanks for listening!


Episode 212: The River of Giants



Thanks to Pranav for his suggestion! Let’s find out what the river of giants was and what lived there!

Further reading:

King of the River of Giants

Spinosaurus was a swimming dinosaur and it swam in the River of Giants:

A modern bichir, distant relation to the extinct giants that lived in the River of Giants:

Not actually a pancake crocodile:

A model of Aegisuchus and some modern humans:

Show transcript:

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

A while back, Pranav suggested we do an episode about the river of giants in the Sahara. I had no idea what that was, but it sounded interesting and I put it on the list. I noticed it recently and looked it up, and oh my gosh. It’s amazing! It’s also from a part of the world where it’s really hot, as a break for those of us in the northern hemisphere who are sick of all this cold weather. I hope everyone affected by the recent winter storms is warm and safe or can get that way soon.

The Sahara is a desert in northern Africa, famous for its harsh climate. Pictures of the Sahara show its huge sand dunes that stretch to the horizon. This wasn’t always the case, though. Only about 5,500 years ago, it was a savanna with at least one lake. Lots of animals lived there and some people too. Before that, around 11,000 years ago, it was full of forests, rivers, lakes, and grasslands. Before that, it was desert again. Before that, it was forests and grasslands again. Before that, desert.

The Sahara goes through periodic changes that last around 20,000 years where it’s sometimes wet, sometimes dry, caused by small differences in the Earth’s tilt which changes the direction of the yearly monsoon rains. When the rains reach the Sahara, it becomes green and welcoming. When it doesn’t, it’s a desert. Don’t worry, we only have 15,000 more years to wait until it’s nice to live in again.

This wet-dry-wet pattern has been repeated for somewhere between 7 and 11 million years, possibly longer. Some 100 million years ago, though, the continents were still in the process of breaking up from the supercontinent Gondwana. Africa and South America were still close together, having only separated around 150 million years ago. The northern part of Africa was only a little north of the equator and still mostly attached to what is now Eurasia.

Near the border of what is now Morocco and Algeria, a huge river flowed through lush countryside. The river was home to giant animals, including some dinosaurs. Their fossilized remains are preserved in a rock formation called the Kem Kem beds, which run for at least 155 miles, or 250 km. A team of paleontologists led by Nizar Ibrahim have been working for years to recover fossils there despite the intense heat. The temperature can reach 125 degrees Fahrenheit there, or 52 Celsius, and it’s remote and difficult to navigate.

For a long time researchers were confused that there were so many fossils of large carnivores associated with the river, more than would be present in an ordinary ecosystem. Now they’ve determined that while it looks like the fossils were deposited at roughly the same time from the same parts of the river, they’re actually from animals that lived sometimes millions of years apart and in much different habitats. Bones or even fossils from one area were sometimes exposed and washed into the river along with newly dead river animals. This gives the impression that the river was swarming with every kind of huge predator, but it was probably not quite so dramatic most of the time.

Then again, there were some really fearsome animals living in and around the river in the late Cretaceous. One of the biggest was spinosaurus, which we talked about in episode 170. Spinosaurus could grow more than 50 feet long, or 15 m, and possibly almost 60 feet long, or 18 m. It’s the only dinosaur known that was aquatic, and we only know it was aquatic because of the fossils found in the Kem Kem beds in the last few years.

Another dinosaur that lived around the river is Deltadromeus, with one incomplete specimen found so far. We don’t have its skull, but we know it had long, slender hind legs that suggests it could run fast. It grew an estimated 26 feet long, or 8 meters, including a really long tail. At the moment, scientists aren’t sure what kind of dinosaur Deltadromeus was and what it was related to. Some paleontologists think it was closely related to a theropod dinosaur called Gualicho, which lived in what is now northern Patagonia in South America. Remember that when these dinosaurs were still alive, the land masses we now call Africa and South America had been right in the middle of a supercontinent for hundreds of millions of years, and only started separating around 150 million years ago. Gualicho looked a lot like a pocket-sized Tyrannosaurus rex. It grew up to 23 feet long, or 7 meters, and had teeny arms. Deltadromeus’s arms are more in proportion to the rest of its body, though.

Some of the biggest dinosaurs found in the Kem Kem beds are the shark-toothed dinosaurs, Carcharodontosaurus, nearly as big as Spinosaurus and probably much heavier. It grew up to 40 or 45 feet long, or 12 to almost 14 meters, and probably stood about 12 feet tall, or 3 ½ meters. It had massive teeth that were flattened with serrations along the edges like steak knives. The teeth were some eight inches long, or 20 cm.

Researchers think that Carcharodontosaurus used it massive teeth to inflict huge wounds on its prey, possibly by ambushing it. The prey would run away but Carcharodontosaurus could take its time catching up, following the blood trail and waiting until its prey was too weak from blood loss to fight back. This is different from other big theropod carnivores like T. rex, which had conical teeth to crush bone.

Dinosaurs weren’t the only big animals that lived in and around the River of Giants, of course. Lots of pterosaur fossils have been found around the river, including one species with an estimated wingspan of as much as 23 feet, or 7 meters. There were turtles large and small, a few lizards, early snakes, frogs and salamanders, and of course fish. Oh my goodness, were there fish.

The river was a large one, possibly similar to the Amazon River. In the rainy season, the Amazon can be 30 miles wide, or 48 km, and even in the dry season it’s still two to six miles wide, or 3 to 9 km. The Amazon is home to enormous fish like the arapaima, which can grow up to 10 feet long, or 3 m. Spinosaurus lived in the River of Giants, and that 50-foot swimming dinosaur was eating something. You better bet there were big fish.

The problem is that most of the fish fossils are incomplete, so paleontologists have to estimate how big the fish was. There were lungfish that might have been six and a half feet long, or 2 meters, a type of freshwater coelacanth that could grow 13 feet long, or 4 meters, and a type of primitive polypterid fish that might have been as big as the modern arapaima. Polypterids are still around today, although they only grow a little over three feet long these days, or 100 cm. It’s a long, thin fish with a pair of lungs as well as gills, and like the lungfish it uses its lungs to breathe air when the water where it lives is low in oxygen. It also has a row of small dorsal fins that make its back look like it has little spikes all the way down. It’s a pretty neat-looking fish, in fact. They’re called bichirs and reedfish and still live in parts of Africa, including the Nile River.

There were even sharks in the river of giants, including a type of mackerel shark although we don’t know how big it grew since all we have of it are some teeth. Another was a type of hybodont shark with no modern descendants, although again, we don’t know how big it was.

The biggest fish that lived in the River of Giants, at least that we know of so far, is a type of ray that looked like a sawfish. It’s called Onchopristis numidus and it could probably grow over 26 feet long, or 8 meters. Its snout, or rostrum, was elongated and spiked on both sides with sharp denticles. It was probably also packed with electroreceptors that allowed it to detect prey even in murky water. When it sensed prey, it would whip its head back and forth, hacking the animal to death with the sharp denticles and possibly even cutting it into pieces. Modern sawfish hunt this way, and although Onchopristis isn’t very closely related to sawfish, it looked so similar due to convergent evolution that it probably had very similar habits.

The modern sawfish mostly swallows its prey whole after injuring or killing it with its rostrum, although it will sometimes eat surprisingly large fish for its size, up to a quarter of its own length. A 26-foot long Onchopristis could probably eat fish over five feet long, or 1.5 meters. It wouldn’t have attacked animals much larger than that, though. It wasn’t eating fully grown Spinosauruses, let’s put it that way, although it might have eaten a baby spinosaurus from time to time. Spinosaurus might have eaten Onchopristis, though, although it would have to be pretty fast to avoid getting injured.

But there was one other type of animal in the River of Giants that could have tangled with a fully grown spinosaurus and come out on top. The river was full of various types of crocodylomorphs, some small, some large, some lightly built, some robust. Kemkemia, for instance, might have grown up to 16 feet long, or 5 meters, but it was lightly built. Laganosuchus might have grown 20 feet long, or 6 meters, but while it was robust, it wasn’t very strong or fast. It’s sometimes called the pancake crocodile because its jaws were long, wide, and flattened like long pancakes. Unlike most pancakes, though, its jaws were lined with lots and lots of small teeth that fit together so closely that when it closed its mouth, the teeth formed a cage that not even the tiniest fish could escape. Researchers think it lay on the bottom of the river with its jaws open, and when a fish swam too close, it snapped it jaws closed and gulped down the fish. But obviously, the pancake crocodile did not worry spinosaurus in the least.

Aegisuchus, on the other hand, was simply enormous. We don’t know exactly how big it is and estimates vary widely, but it probably grew nearly 50 feet long, or 15 meters. It might have been much longer, possibly up to 72 feet long, or 22 meters. It’s sometimes called the shield crocodile because of the shape of its skull.

We don’t have a complete specimen of the shield crocodile, just part of one skull, but that skull is weird. It has a circular raised portion called a boss made of rough bone, and the bone around it shows channels for a number of blood vessels. This is unique among all the crocodilians known, living and extinct, and researchers aren’t sure what it means. One suggestion is that the boss was covered with a sheath that was brightly colored during the mating season, or maybe its shape alone attracted a mate. Modern crocodilians raise their heads up out of the water during mating displays.

The shield crocodile had a flattened head other than this boss, and its eyes may have pointed upward instead of forward. If so, it might have rested on the bottom of the river, looking upward to spot anything that passed overhead. Then again, it might have floated just under the surface of the water near shore, looking up to spot any dinosaurs or other land animals that came down to drink. Watch out, dinosaur! There’s a crocodilian!

Could the shield crocodile really have taken down a fully grown spinosaurus, though? If it was built like modern crocodiles, yes. Spinosaurus was a dinosaur, and dinosaurs had to breathe air. If the shield crocodile hunted like modern crocs, it was some form of ambush predator that could kill large animals by drowning them. You’ve probably seen nature shows where a croc bursts up out of the water, grabs a zebra or something by the nose, and drags it into the water, quick as a blink. The croc can hold its breath for up to an hour, while most land animals have to breathe within a few minutes or die. The shield crocodile and spinosaurus also lived at the same time so undoubtedly would have encountered each other.

Then again, there’s a possibility that the shield crocodile wasn’t actually very fearsome, no matter how big it was. It might have been more lightly built with lots of short teeth like the pancake crocodile’s to trap fish in its broad, flattened snout. Until we have more fossils of Aegisuchus, we can only guess.

Fortunately, palaeontologists are still exploring the Kem Kem beds for more fossils from the river of giants. Hopefully one day soon they’ll find more shield crocodile bones and can answer that all-important question of who would win in a fight, a giant crocodile or a giant swimming dinosaur?

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

Thanks for listening!


Episode 181: Updates 3 and a lake monster!



It’s our annual updates and corrections episode, with a fun mystery animal at the end!

Thanks to everyone who contributed, including Bob, Richard J. who is my brother, Richard J. who isn’t my brother, Connor, Simon, Sam, Llewelly, Andrew Gable of the excellent Forgotten Darkness Podcast, and probably many others whose names I didn’t write down!

Further reading:

Northern bald ibis (Akh-bird)

Researchers learn more about teen-age T. rex

A squid fossil offers a rare record of pterosaur feeding behavior

The mysterious, legendary giant squid’s genome is revealed

Why giant squid are still mystifying scientists 150 years after they were discovered (excellent photos but you have to turn off your ad-blocker)

We now know the real range of the extinct Carolina parakeet

Platypus on brink of extinction

Discovery at ‘flower burial’ site could unravel mystery of Neanderthal death rites

A Neanderthal woman from Chagyrskyra Cave

The Iraqi Afa – a Middle Eastern mystery lizard

Further watching/listening:

Richard J. sent me a link to the Axolotl song and it’s EPIC

Bob sent me some more rat songs after I mentioned the song “Ben” in the rats episode, including The Naked Mole Rap and Rats in My Room (from 1957!)

The 2012 video purportedly of the Lagarfljótsormurinn monster

A squid fossil with a pterosaur tooth embedded:

A giant squid (not fossilized):

White-throated magpie-jay:

An updated map of the Carolina parakeet’s range:

A still from the video taken of a supposed Lagarfljót worm in 2012:

An even clearer photo of the Lagarfljót worm:

Show transcript:

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

This is our third annual updates and corrections episode, where I bring us up to date about some topics we’ve covered in the past. We’ll also talk about an interesting mystery animal at the end. There are lots of links in the show notes to articles I used in the episode’s research and to some videos you might find interesting.

While I was putting this episode together, I went through all the emails I received in the last year and discovered a few suggestions that never made it onto the list. I’m getting really backed up on suggestions again, with a bunch that are a year old or more, so the next few months will be all suggestion episodes! If you’re waiting to hear an episode about your suggestion, hopefully I’ll get to it soon.

Anyway, let’s start the updates episode with some corrections. In episode 173 about the forest raven, I mentioned that the northern bald ibis was considered sacred by ancient Egyptians. Simon asked me if that was actually the case or if only the sacred ibis was considered sacred. I mean, it’s right there in the name, sacred ibis.

I did a little digging and it turns out that while the sacred ibis was associated with the god Thoth, along with the baboon, the northern bald ibis was often depicted on temple walls. It was associated with the ankh, which ancient Egyptians considered part of the soul. That’s a really simplistic way to put it, but you’ll have to find an ancient history podcast to really do the subject justice. So the northern bald ibis was important to the ancient Egyptians and sort of considered sacred, but in a different way from the actual sacred ibis.

In episode 146 while I was talking about the archerfish, I said something about how I didn’t fully understand how the archerfish actually spits water so that it forms a bullet-like blob. Bob wrote and kindly explained in a very clear way what goes on: “Basically, the fish spits a stream of water, but squeezes it so that the back end of the stream is moving faster than the front. So it bunches up as it flies and hits the target with one big smack. Beyond that, the water bullet would fall apart as the back part moves through the front part of the stream, but the fish can apparently judge the distance just right.” That is really awesome.

In another correction, Sam told me ages ago that the official pronouns for Sue the T rex are they/them, because that’s what Sue has requested on their Twitter profile. I forgot to mention this last time, sorry.

While we’re talking about Tyrannosaurus rex, researchers have IDed two teenaged T rex specimens found in Montana. Originally paleontologists thought the specimens might be a related species that grew to a much smaller size, Nanotyrannus, but the team studying them have determined that they were juvenile T rexes. To learn how old the specimens were and how fast they grew, they cut extremely thin slices from the leg bones and examined them under high magnification.

The study of fossil bone microstructure is called paleohistology and it’s a new field that’s helped us learn a lot about long-extinct animals like dinosaurs. We know from this study that T rex grew as fast as modern warm-blooded animals like birds and mammals, and we know that the specimens were 13 and 15 years old when they died. T rex didn’t reach its adult size until it was about twenty, and there are definite differences in the morphology of the juvenile specimens compared to an adult. The young T rexes were built for speed and had sharper teeth to cut meat instead of crush through heavy bones the way adults could. This suggests that juvenile T rexes needed to outrun both predators and smaller prey.

In other fossil news, Llewelly sent me a link about a pterosaur tooth caught in a squid fossil. We know pterosaurs ate fish because paleontologists have found fossilized fish bones and scales in the stomach area of pterosaur remains, but now we know they also ate squid. The fossil was discovered in Bavaria in 2012 and is remarkably well preserved, especially considering how few squid fossils we have. One of the things preserved in the fossil is a sharp, slender tooth that matches that of a pterosaur. Researchers think the pterosaur misjudged the squid’s size and swooped down to grab it from the water, but the squid was about a foot long, or 30 cm, and would have been too heavy for the pterosaur to pick up. One of its teeth broke off and remained embedded in the squid’s mantle, where it remains to this day 150 million years later.

And speaking of squid, the giant squid’s genome has been sequenced. Researchers want to see if they can pinpoint how the giant squid became so large compared to most other cephalopods, but so far they haven’t figured this out. They’re also looking at ways that the giant squid differs from other cephalopods and from vertebrates, including humans, to better understand how vertebrates evolved. They have discovered a gene that seems to be unique to cephalopods that helps it produce iridescence.

The Richard J. who is my brother sent me an article about giant squid a while back. There’s a link in the show notes. It has some up-to-date photos from the last few years as well as some of the oldest ones known, and lots of interesting information about the discovery of giant squid.

The Richard J. who is not my brother also followed up after the magpies episode and asked about the magpie jay. He said that the white-throated magpie jay is his favorite bird, and now that I’ve looked at pictures of it, I see why.

There are two species of magpie jay, the black-throated and the white-throated, which are so closely related that they sometimes interbreed where their ranges overlap. They live in parts of Mexico and nearby countries. They look a little like blue jays, with blue feathers on the back and tail, white face and belly, and black markings. Both species also have a floofy crest of curved feathers that looks like something a parrot would wear. A stylish parrot. Like other corvids, it’s omnivorous. It’s also a big bird, almost two feet long including the long tail, or 56 cm.

In other bird news, Connor sent me an article about the range of the Carolina parakeet before it was driven to extinction. Researchers have narrowed down and refined the bird’s range by researching diaries, newspaper reports, and other sightings of the bird well back into the 16th century. It turns out that the two subspecies didn’t overlap much at all, and the ranges of both were much smaller than have been assumed. I put a copy of the map in the show notes, along with a link to the article.

One update about an insect comes from Lynnea, who wrote in after episode 160, about a couple of unusual bee species. Lynnea said that some bees do indeed spin cocoons. I’d go into more detail, but I have an entire episode planned about strange and interesting bees. My goal is to release it in August, so it won’t be long!

In mammal news, the platypus is on the brink of extinction now more than ever. Australia’s drought, which caused the horrible wildfires we talked about in January, is also causing problems for the platypus. The platypus is adapted to hunt underwater, and the drought has reduced the amount of water available in streams and rivers. Not only that, damming of waterways, introduced predators like foxes, fish traps that drown platypuses, and farming practices that destroy platypus burrows are making things even worse. If serious conservation efforts aren’t put into place quickly, it could go extinct sooner than estimated. Conservationists are working to get the platypus put on the endangered species list throughout Australia so it can be saved.

A Neandertal skeleton found in a cave in the foothills of Iraqi Kurdistan appears to be a deliberate burial in an area where many other burials were found in the 1950s. The new skeleton is probably more than 70,000 years old and is an older adult. It was overlooked during the 1950s excavation due to its location deep inside a fissure in the cave. The research team is studying the remains and the area where they were found to learn more about how Neandertals buried their dead. They also hope to recover DNA from the specimen.

Another Neandertal skeleton, this one from a woman who died between 60,000 and 80,000 years ago in what is now Siberia, has had her DNA sequenced and compared to other Neandertal DNA. From the genetic differences found, researchers think the Neandertals of the area lived in small groups of less than 60 individuals each. She was also more closely related to Neandertal remains found in Croatia than other remains found in Siberia, which suggests that the local population was replaced by populations that migrated into the area at some point.

Also, I have discovered that I’ve been pronouncing Denisovan wrong all this time. I know, shocker that I’d ever mispronounce a word.

Now for a lizard and a couple of corrections and additions to the recent Sirrush episode. Last year, Richard J. and I wrote back and forth about a few things regarding one of my older episodes. Specifically he asked for details about two lizards that I mentioned in episode 21. I promised to get back to him about them and then TOTALLY FORGOT. I found the email exchange while researching this episode and feel really bad now. But then I updated the episode 21 show notes with links to information about both of those lizards so now I feel slightly less guilty.

Richard specifically mentioned that the word sirrush, or rather mush-khush-shu, may mean something like “the splendor serpent.” I totally forgot to mention this in the episode even though it’s awesome and I love it.

One of the lizards Richard asked about was the afa lizard, which I talked about briefly in episode 21. Reportedly the lizard once lived in the marshes near the Tigris and Euphrates rivers in what is now Iraq. Richard wanted to know more about that lizard because he wondered if it might be related to the sirrush legend, which is how we got to talking about the sirrush in the first place and which led to the sirrush episode. Well, Richard followed up with some information he had learned from a coworker who speaks Arabic. Afa apparently just means snake in Arabic, although of course there are different words for snake, and the word has different pronunciations in different dialects. He also mentioned that it’s not just the water monitor lizard that’s known to swim; other monitors do too, including the Nile monitor. I chased down the original article I used to research the afa and found it on Karl Shuker’s blog, and Shuker suggests also that the mysterious afa might be a species of monitor lizard, possibly one unknown to science. We can’t know for certain if the afa influenced the sirrush legend, but it’s neat to think about.

Next up, in cryptid news, Andrew Gable of the excellent Forgotten Darkness podcast suggested that some sightings of the White River Monster, which we talked about in episode 153, might have been an alligator—especially the discovery of tracks and crushed plants on the bank of a small island. This isn’t something I’d thought about or seen suggested anywhere, but it definitely makes sense. I highly recommend the Forgotten Darkness podcast and put a link in the show notes if you want to check it out.

And that leads us to a lake monster to finish up the episode. The Lagarfljót [LAH-gar-flote] worm is a monster from Iceland, which is said to live in the lake that gives it its name. The lake is a pretty big one, 16 miles long, or 25 km, and about a mile and a half wide at its widest, or 2.5 km. It’s 367 feet deep at its deepest spot, or 112 m. It’s fed by a river with the same name and by other rivers filled with runoff from glaciers, and the water is murky because it’s full of silt.

Sightings of the monster go back centuries, with the first sighting generally thought to be from 1345. Iceland kept a sort of yearbook of important events for centuries, which is pretty neat, so we have a lot of information about events from the 14th century on. An entry in the year 1345 talks about the sighting of a strange thing in the water. The thing looked like small islands or humps, but each hump was separated by hundreds of feet, or uh let’s say at least 60 meters. The same event was recorded in later years too.

There’s an old folktale about how the monster came to be, and I’m going to quote directly from an English translation of the story that was collected in 1862 and published in 1866. “A woman living on the banks of the Lagarfljót [River] once gave her daughter a gold ring; the girl would fain see herself in possession of more gold than this one ring, and asked her mother how she could turn the ornament to the best account. The other answered, ‘Put it under a heath-worm.’ This the damsel forthwith did, placing both worm and ring in her linen-basket, and keeping them there some days. But when she looked at the worm next, she found him so wonderfully grown and swollen out, that her basket was beginning to split to pieces. This frightened her so much that, catching up the basket, worm and ring, she flung them all into the river. After a long time this worm waxed wondrous large, and began to kill men and beasts that forded the river. Sometimes he stretched his head up on to the bank, and spouted forth a filthy and deadly poison from his mouth. No one knew how to put a stop to this calamity, until at last two Finns were induced to try to slay the snake. They flung themselves into the water, but soon came forth again, declaring that they had here a mighty fiend to deal with, and that neither could they kill the snake nor get the gold, for under the latter was a second monster twice as hard to vanquish as the first. But they contrived, however, to bind the snake with two fetters, one behind his breast-fin, the other at his tail; therefore the monster has no further power to do harm to man or beast; but it sometimes happens that he stretches his curved body above the water, which is always a sign of some coming distress, hunger, or hard times.”

The heath worm is a type of black slug, not a worm or snake at all, and it certainly won’t grow into a dragon no matter how much gold you give it. But obviously there’s something going on in the lake because there have been strange sightings right up to the present day. There’s even a video taken of what surely does look like a slow-moving serpentine creature just under the water’s surface. There’s a link in the show notes if you want to watch the video.

So let’s talk about the video. It was taken in February of 2012 by a farmer who lives in the area. Unlike a lot of monster videos it really does look like there’s something swimming under the water. It looks like a slow-moving snake with a bulbous head, but it’s not clear how big it is. A researcher in Finland analyzed the video frame by frame and determined that although the serpentine figure under the water looks like it’s moving forward, it’s actually not. The appearance of forward movement is an optical illusion, and the researcher suggested there was a fish net or rope caught under the water and coated with ice, which was being moved by the current.

So in a way I guess a Finn finally slayed the monster after all.

But, of course, the video isn’t the only evidence of something in the lake. If those widely spaced humps in the water aren’t a monstrous lake serpent of some kind, what could they be?

One suggestion is that huge bubbles of methane occasionally rise from the lake’s bottom and get trapped under the surface ice in winter. The methane pushes against the ice until it breaks through, and since methane refracts light differently from ordinary air, it’s possible that it could cause an optical illusion from shore that makes it appear as though humps were rising out of the water. This actually fits with stories about the monster, which is supposed to spew poison and make the ground shake. Iceland is volcanically and geologically highly active, so earthquakes that cause poisonous methane to bubble up from below the lake are not uncommon.

Unfortunately, if something huge did once live in the lake, it would have died by now. In the early 2000s, several rivers in the area were dammed to produce hydroelectricity, and two glacial rivers were diverted to run into the lake. This initially made the lake deeper than it used to be, but has also increased how silty the water is. As a result, not as much light can penetrate deep into the water, which means not as many plants can live in the water, which means not as many small animals can survive by eating the plants, which means larger animals like fish don’t have enough small animals to eat. Therefore the ecosystem in the lake is starting to collapse. Some conservationists warn that the lake will silt up entirely within a century at the rate sand and dirt is being carried into it by the diverted rivers. I think the takeaway from this and episode 179 is that diverting rivers to flow into established lakes is probably not a good idea.

At the moment, though, the lake does look beautiful on the surface, so if you get a chance to visit, definitely go and take lots of pictures. You probably won’t see the Lagarfljót worm, but you never know.

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 if you’d like to support us that way.

Thanks for listening!


Episode 170: Spinosaurus



This week let’s find out what has paleontologists so excited about this dinosaur!

Further reading:

The Nature article that kicked this all off (you can only read the abstract for free but it’s full of good information)

Paleontologist Who Uncovered Prehistoric River Monster’s Tail Explains Why It’s Such a Game Changer (Newsweek)

Further watching:

A good video about the new findings

Spinosaurus’s updated look:

This trackway from a swimming animal may have been made by a Spinosaurus (photo by Loic Costeur):

A male Danube crested newt, with a tail that somewhat resembles that of Spinosaurus:

Show transcript:

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

If you follow any paleontologists on social media, you’ve probably heard them talking about the new spinosaurus article just published in Nature. It sounds like the sort of discovery that makes other paleontologists take a closer look at fossils of dinosaurs related to spinosaurus, so this week let’s find out what the discovery is and what it means!

I could swear we’ve talked about Spinosaurus before, but a quick search revealed that we actually learned about its relative, Baryonyx, in episode 151. Baryonyx grew at least 33 feet long, or 10 meters, and lived around 125 million years ago. It had a skull similar to Spinosaurus’s but otherwise didn’t resemble it that much, and as far as we know it waded in shallow water to catch fish and other aquatic animals.

Spinosaurus was a therapod dinosaur that lived in the Cretaceous, roughly 112 to 93 million years ago. It lived in what is now North Africa and the species we’re talking about today is Spinosaurus aegyptiacus, which as you can probably guess was first discovered in Egypt.

Spinosaurus was as big as Tyrannosaurus rex, possibly larger depending on what measurements you’re looking at. It could probably grow some 52 feet long, or 16 meters, possibly as much as 59 feet long, or 18 meters. But it didn’t look very much like a T. rex. For one thing, its front legs were large and strong. Instead of T. rex’s massive skull and jaws, Spinosaurus had a more slender, narrow skull that was shaped something like a crocodile’s. It also had long neural spines on its back that may have formed a type of sail similar to Dimetrodon’s, although of course Spinosaurus and Dimetrodon weren’t related at all. Dimetrodon wasn’t a dinosaur or even technically a reptile, as we learned in episode 119.

Spinosaurus’s neural spines could grow almost five and a half feet long, or 1.65 meters, and if they did form a sail, it was roughly squared off instead of shaped like a half-circle. Some researchers think it wasn’t a sail at all but a fatty hump on its back something like a buffalo’s shoulder hump or a camel’s humps. The neural spines would help give the hump structure. Other researchers think it was a sail used for display, while one team of paleontologists suggested as early as 2014 that it was a sail that acted as a dorsal fin in the water, since it’s shaped like a sailfish’s dorsal fin.

Spinosaurus probably ate both meat and fish, so it makes sense that it lived in swampy areas like mangrove forests and tidal flats where it could hunt both terrestrial and water animals. Its hind legs were short, its feet were flat with long toes, and its toes may have been webbed. Its hind feet actually share features found in modern shorebirds, which suggests it spent a lot of time walking on soft ground like sand, marsh, and shallow water.

Despite its body length and short legs, Spinosaurus walked on its hind legs. Its tail was very long to balance the front of its body. And it’s the tail that is the focus of the Nature article everyone’s talking about right now.

See, despite Spinosaurus’s fish-eating, almost no one thought it was an aquatic dinosaur. No one thought any dinosaur swam around routinely to catch fish. The big predators that lived in oceans and fresh water at the same time as the dinosaurs were not dinosaurs, but were reptiles like the crocodile and Mosasaurus.

A few paleontologists, like the team that suggested Spinosaurus’s neural spines formed a sort of dorsal fin, had started suggesting Spinosaurus and its close relations were semi-aquatic. But almost no one agreed. Most scientists pointed out that Spinosaurus looked like an ordinary wading animal, not a swimming animal.

Then, in an article published in Nature on April 29, 2020, a new study revealed that Spinosaurus’s tail isn’t the ordinary long, skinny dinosaur tail. Instead, new physical models of its tail show “unambiguous evidence of [the tail acting as] an aquatic propulsive structure”. In other words, Spinosaurus could not only swim, it could probably swim quite well.

Its tail had tall neural spines like the ones on its back, some of them two feet long, or 61 cm, which gave it more surface area to push against the water. It was flexible and strong too.

So how come no one had noticed this before? Well, no one had the right fossils. Most of the tail bones studied were only found in 2018 and 2019 in Morocco by a team of Italian paleontologists. And guess what! The team of paleontologists were the same ones who suggested a few years ago that the neural spines on Spinosaurus’s back acted as a dorsal fin, led by a man named Nizar Ibrahim. While we still don’t know for sure, it’s looking more and more like they were correct. A dorsal fin provides stability in the water, and of course it could also act as a display feature to attract mates.

We don’t have very many Spinosaurus fossils. The only good specimen ever found was destroyed by a bomb in World War II, and it didn’t have a tail anyway. Until the 2018 expedition started turning up Spinosaurus vertebrae, no one knew what the tail looked like at all. The expedition found most of its tail and a lot of the rest of its bones, including part of the skull. While the fossils were found in the Sahara, back when Spinosaurus was alive the area was swampy and full of rivers, home to lots of large animals, including coelacanths and crocodiles. But Spinosaurus was probably the largest.

There is an animal that has a similar body plan to Spinosaurus’s, an amphibian called the Danube crested newt. It lives in parts of central Europe. It grows to about 7 inches long, or 18 cm, although males are smaller. It’s dark brown with black and white spots and an orange belly with larger black spots. During breeding season, the male develops a crest on its back and tail that does look a little bit like Spinosaurus’s sails. During the fall and winter it lives in the forest, but the rest of the year it lives in water. It eats small animals like insects and tadpoles.

The paleontologists studying Spinosaurus’s tail made a model of the Danube crested newt’s tail and some other animal tails and tested them to see which tail worked best to provide thrust underwater. The newt’s tail won.

That doesn’t mean Spinosaurus was necessarily a fast swimmer. The tail alone would allow it to move forward at around five miles an hour, or 1.6 km per hour. You can walk faster than that with a little effort. But if Spinosaurus also had webbed feet, it could have used them for extra propulsion in the water. It may have cruised through the water at a leisurely pace and ambushed unwary fish and other animals. In shallow water it could have used its hind feet to push off the bottom while it remained buoyant, and in fact we even have fossilized underwater tracks that may be made by Spinosaurus.

Other Spinosaurids were probably at least semi-aquatic too, although they don’t seem to be as well adapted to the water as Spinosaurus was. But now that they know what to look for, it could be that paleontologists will discover more evidence of aquatic dinosaurs soon.

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

Thanks for listening!