Category Archives: fossils

Episode 214: Armored Fish and the Late Devonian Mass Extinctions

Posted on by

Podcast: Play in new window | Download (Duration: 21:53 — 22.6MB)

Subscribe: RSS | More

It’s the next in our short series of episodes about mass extinctions! Don’t worry, it won’t be boring, because we’re going to learn about a lot of weird ancient fish too.

Further reading:

Titanichthys: Devonian-Period Armored Fish was Suspension Feeder

Behind the Scenes: How Fungi Make Nutrients Available to the World

Dunkleosteus was a beeg feesh with sharp jaw plates that acted as teeth:

Titanichthys was also a beeg feesh, but it wouldn’t have eaten you (picture from the Sci-News article linked above):

Pteraspis: NOSE HORN FISH:

Cephalaspis had no jaws so it couldn’t chomp you:

Bothriolepis kind of looked like a fish in a mech suit:

Show transcript:

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

Here’s the second in our small series of episodes about extinction events, this one the Late Devonian extinction. We’ll also learn about some weird and amazing fish that lived during this time, and a surprising fact about ancient trees.

The Devonian period is often called the Age of Fish because of the diversity of fish lineages that arose during that time. It lasted from roughly 420 million years ago to 359 million years ago. During the Devonian, much of the earth’s landmasses were smushed together into the supercontinent Gondwana, which was mostly in the southern hemisphere, and the smaller continents of Siberia and Laurussia in the northern hemisphere. The world was tropically warm, ocean levels were high, and almost all animal life lived in the oceans. Some animals had adapted to living on land at least part of the time, though, and plants had spread across the continents. The first insects had just evolved too.

Shallow areas of the ocean were home to animals that had survived the late Ordovician extinctions. There were lots of brachiopods, bivalves, crinoids, trilobites, and corals. Eurypterids were still thriving and ammonites lived in deeper water. But while all these animals are interesting, we’re mainly here for the fish.

The fish of the Devonian were very different from modern fish. Most had armor. Way back in episode 33 we talked about the enormous and terrifying dunkleosteus, which lived in the late Devonian. It might have grown up to 33 feet long, or 10 meters. Since we still don’t have any complete specimens, just head plates and jaws, that’s an estimate of its full size. However long it grew, it was definitely big and could have chomped a human in half without any trouble at all. It’s probably a good thing mammals hadn’t evolved yet. Instead of teeth, dunkleosteus had jaw plates with sharp edges and fanglike projections that acted as teeth.

Another huge fish from the Devonian is called titanichthys, which might have grown as long as dunkleosteus or even bigger, but which was probably not an apex predator. Its jaw plates were small and blunt instead of sharp, which suggests it wasn’t biting big things. It might not have been biting anything. Some researchers think titanichthys might have been the earliest known filter feeder, filtering small animals from the water by some mechanism we don’t know about yet. Filter feeders use all sorts of adaptations to separate tiny food from water, from gill rakers to baleen plates to teeth that fit together closely, and many others. A study published in 2020 compared the jaw mechanisms of modern giant filter feeders (baleen whales, manta rays, whale sharks, and basking sharks) to the jaw plates of titanichthys, as well as the jaw plates of other placoderms that were probably predators. Titanichthys’s jaws are much more similar to those of modern filter feeders, which it isn’t related to at all, than to fish that lived at the same time as it did and which it was related to.

Titanichthys and dunkleosteus were both placoderms, a class of armored fish. That wasn’t unusual, actually. In the Devonian, most fish ended up evolving armored plates or thick scales. What was unusual in placoderms were their jaws. Specifically, the fact that they had jaws at all. Placoderms were probably the first fish to evolve jaws.

Pteraspis, for instance, was an armored fish that wasn’t a placoderm. It had no fins at all but it was a good swimmer, streamlined and possibly a predator, although it might have been a plankton feeder at the surface of the ocean. It grew about 8 inches long, or 20 cm. It used its tail to propel itself through the water, and instead of fins it had spines growing from its armor that helped keep it stable. A spine on its back, near the rear of the body armor, acted as a dorsal fin, while spines on the sides of its armor, just over its gills, acted like pectoral fins. It also had some smaller spines along its back and a big spike on its nose. Probably not a good fish to swallow whole.

Cephalaspis lived in the early Devonian, around 400 million years ago in fresh water. It wasn’t very big, maybe a foot long, or 30 cm. Basically, it would have fit nicely on a dinner plate, but it wouldn’t have looked much like a trout other than its size. It wasn’t a placoderm either although it did have armor. It was probably a bottom feeder and was flattened in shape with a broad, roughly triangular head covered in armor plates. Its eyes were at the top of its head and its mouth was underneath. The rest of its body was thinner and tapered to a thin tail. It probably used its head to dig around in the mud and sand to find small invertebrates, which it slurped up and swallowed whole because it had no jaws to bite with.

In comparison, the placoderm bothriolepis was about the same size as cephalaspis and was also a bottom feeder in fresh water, but that’s where the resemblance ends. It lived later, around 375 million years ago, and probably ate decomposing plant material. Like other placoderms, it had armored plates on its head and the front part of its body. The armor at the front of its head had a little opening for its eyes, which were really close together. Its tail wasn’t armored and was probably only covered in skin without scales. Bothriolepis also had long armored pectoral fins that look sort of like spikes. Its head armor was so heavy that it probably used these spike-like fins to help push itself off the bottom. The pectoral fins of some bothriolepis species had an elbow-like joint as well as a joint at the top of the fin, making them more arm-like than fin-like. Basically, bothriolepis looks like a fish wearing a mech suit that doesn’t cover its tail. It looks like an armored box with a fish tail and spikes for arms. It looks weird.

Bothriolepis was really common throughout the world with lots of species known. The largest was B. rex, which grew up to 5 1/2 feet long, or 1.7 meters, and which had thicker armor than other placoderms. Researchers think its heavy armor would have kept it from being swept to the surface by currents. Most bothriolepis species were much smaller, though.

Because it was so common, we know quite a bit about bothriolepis. In addition to the fossilized armor plates, we have some body impressions and even fossilized internal organs. This is really rare, and the reason it’s happened more than once in bothriolepis is that the internal organs were protected by the armor plates long enough for fine sediment to fill the body before the organs decomposed or were eaten by other animals. We know that the digestive system was simple compared to modern fish but the gut was spiral shaped, which allowed more time for the plant material it ate to stay in the body so more nutrients could be extracted from it. The gills were likewise primitive, and it may have also had a pair of primitive lungs. Yes, lungs! Not all palaeontologists agree that the sacs were actually lungs, but those who do think the fish would have gulped air at the surface like a lungfish. Since most, if not all, bothriolepis species seem to have lived in freshwater, it’s possible it needed lungs to breathe air if the water where it lived was low in oxygen. Some researchers think it might even have been able to use its pectoral fins to move around on land, at least enough to move to a new water source if its home dried up. Because bothriolepis remains are sometimes found in marine environments, some researchers also speculate that it may have migrated from or to the ocean to spawn, and that it used its possible land-walking ability to navigate around obstacles while migrating along rivers.

At least some bothriolepis individuals also had a pair of weird frills at the base of the tail. They might have acted as fins but they might have had something to do with mating, like a male shark’s claspers. It’s not clear if all individuals had them or only some.

Placoderms were the first fish to develop jaws, teeth, and pelvic fins. Pelvic fins were important not just because it made the fish more stable in the water, but because they correspond to hind legs in tetrapods. Here’s something to think about: if pelvic fins hadn’t evolved in fish, would land animals have eventually evolved four legs or would all land animals have just two legs and a tail? Would humans look like mermaids and mermen, or weird seals? Would birds have evolved wings even if it meant they had no feet?

Okay, so, back to the Devonian. There were lots more fish than just the placoderms, of course. Coelacanths, lungfish, and early sharks evolved at this time and are still around, as are ray-finned fish that are the most common fish today.

But maybe with all this talk of weird fish, you’ve forgotten this is an episode about an extinction event. Ocean life in the Devonian was chugging along just fine–but then something happened, something that resulted in the same loss of oxygen in the oceans that caused so many extinctions in the late Ordovician. But no one’s sure what that was.

The extinction event actually took place in several waves millions of years apart. Researchers generally think that the same events that caused the late Ordovician extinction events may have caused the late Devonian extinction events. Toward the end of the Devonian the Earth did appear to go through several rapid temperature changes, and some researchers think the cause of these temperature changes might have been trees.

At the beginning of the Devonian, there were lots of plants on land, but they were all small. You could walk from one side of a continent to another and never encounter a plant taller than knee-high. But plants were evolving rapidly, and before long the first trees appeared. They were related to ferns, club moss, and a type of plant called horsetails, which wouldn’t have looked much like trees to us. The progymnosperms also evolved during this time, and they were ancestors of modern gymnosperms, a group which includes conifers, gingkos, and cycads. Some of these early trees didn’t even have leaves, while some had what looked like fern fronds. Some grew almost 100 feet tall, or 30 meters.

Tall trees need strong roots, and roots loosened the soil and underlying rocks to great depths. This made it more likely that heavy rains would wash soil into the water, potentially causing microbial blooms. All these trees also absorbed enormous quantities of carbon dioxide and released oxygen into the atmosphere. This sounds great, because animals need oxygen to breathe! But as trees spread across the land, growing bigger and taller, they absorbed as much as 90% of the available carbon dioxide, so much that it actually caused the earth to cool enough to cause glaciers to form.

One interesting thing about trees. Trees and other plants contain complex polymers called lignin that harden the cells. Lignin is why trees have bark and wood. Lignin is also really resistant to decay, which is why it takes so long for a fallen tree to rot down into nothing. There are specialized bacteria and fungi that can break down lignin, but most bacteria and fungi can’t affect it at all.

Plants first evolved lignin around 400 million years ago, and early trees contained a lot of it, way more than modern trees have. It took bacteria and fungi a long time to evolve ways to break that lignin down to extract nutrients from it—around 100 million years, in fact. So for 100 million years, whenever a storm knocked over a tree and it died, its trunk just…stayed there forever–or at least for a really long time, becoming more and more buried over the centuries. Lignin isn’t water soluble either, so even trees that fell into a lake didn’t rot, or at least the lignin in the trunks didn’t rot. All those tree trunks were eventually compressed by the weight of the soil above them into coal beds.

Anyway, the peak of this cycle of trees absorbing carbon dioxide and releasing oxygen actually happened in the Carboniferous period, which occurred just after the final wave of the Devonian extinctions. That’s why insects could grow so incredibly large during the Carboniferous, because the atmosphere contained so much oxygen.

But in the build-up to the late Devonian extinction events, there were periods of colder and warmer climate worldwide, possibly caused by trees, possibly by other factors, most likely by a combination of many factors. Glaciers would form and melt rapidly, possibly leading to the same issues that caused the late Ordovician extinction events.

I’ll quote a bit from episode 205 to remind you what scientists think happened in the Ordovician when a whole lot of glaciers suddenly melted:

As the glaciers melted, cold fresh water flowed into the ocean and may have caused deep ocean water to rise to the surface. The deep ocean water brought nutrients with it that then spread across the ocean’s surface, and this would have set off a massive microbial bloom.

Microbial blooms happen when algae or bacteria that feed on certain nutrients suddenly have a whole lot of food, and they reproduce as fast as possible to take advantage of it. The microbes use up oxygen, so much of it that the water can become depleted.

Rivers were also a major source of nutrients flowing into the ocean, as tree roots continued to break up rock and soil, which made its way into the water.

Whatever the cause or causes, the result was that the ocean lost most or all of its oxygen, especially in the deep sea. Oxygen, of course, is what animals breathe. Fish push water over their gills and absorb oxygen from it by a chemical process the same way we absorb oxygen from the air with our lungs. The air contains a lot of other gases in addition to oxygen, but it’s the oxygen we need.

The first wave of extinctions in the Devonian is called the Taghanic Event. A lot of brachiopods and corals went extinct then, among many other animals. About the time life started to rebound from that wave, the Kellwasser Event killed off more brachiopods and corals, a lot of trilobites, and jawless fish. Finally, the biggest and worst wave of all was the Hangenberg Event.

The Hangenberg Event was really bad. Really, really bad. In the late Ordovician extinction event, some researchers think it took three million years for the oceans to recover from their lack of oxygen. In the late Devonian extinction event, it may have taken 15 million years for the oceans to fully recover. Some researchers think that in addition to everything else going on in the world, a nearby star may have gone supernova and damaged the ozone layer that protects the earth, which would have damaged plants and animals that lived on land.

The end result of the late Devonian extinction event was that 97% of all vertebrate species went extinct, especially those that lived in shallow water, and 75% of all animal species. All placoderms went extinct and almost all corals went extinct.

Most people think that oil—you know, the stuff we use to make gasoline and plastic—came from dead dinosaurs, but that’s not the case. A lot of oil actually formed from the animals that died in the Devonian extinction events. Fish and other animals suffocated as the water lost oxygen, and the lack of oxygen at the bottom of the ocean meant that all those bodies that sank into the depths didn’t rot. They were buried by sediment and as the years and then centuries and millennia passed, more and more sediment piled up, causing pressure and heat that transformed the organic remains into a substance called kerogen. Kerogen is still an organic material and if it’s exposed to oxygen it will oxidize and decay, but if it remains deep underground for millions of years the heat and pressure will eventually transform it chemically into hydrocarbons that make up oil. Don’t ask me to explain this in any more detail than that. My mind is still blown about tree trunks not decomposing for 100 million years; there’s really no room left in my brain to wonder about how oil forms.

Anyway, luckily for us, by the time of the late Devonian extinction events, the first land vertebrates had already evolved and they survived. They spread throughout the world and thrived for 110 million years until the next major extinction event, which was so profound it’s called “the great dying” by palaeontologists. We’ll learn about that one in a few months. Next week I promise we’ll have a light, happy episode where nothing goes extinct!

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

Thanks for listening!

Episode 212: The River of Giants

Posted on by

Podcast: Play in new window | Download (Duration: 15:38 — 16.1MB)

Subscribe: RSS | More

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 208: The Happiest Animals in Australia

Posted on by

Podcast: Play in new window | Download (Duration: 16:50 — 17.3MB)

Subscribe: RSS | More

Thanks to Phoebe for suggesting the quokka and the wombat, two of the cutest, happiest-looking animals in Australia!

Further Reading:

Viral stories of wombats sheltering other animals from the bushfires aren’t entirely true

Satellites reveal the underground lifestyle of wombats

Giant Wombat-Like Marsupials Roamed Australia 25 Million Years Ago

Further Listening:

Animals and Ultraviolet Light (unlocked Patreon episode)

The adorable quokka with a nummy leaf and a joey in her pouch:

Quokka (left) and my chonky cat Dracula (right)

Some quokka selfies showing quokka smiles. That second picture really shows how small the quokka actually is:

Wombats!

A wombat and its burrow entrance:

A wombat mom with her joey peeking out of the rear-facing pouch:

Golden wombats. All they need is some Doublemint Gum:

Two (dead, stuffed) wombats glowing under ultraviolet light:

Show Transcript:

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

This week we’re going to look at two super-cute animals from Australia, both of them suggestions by Phoebe. Thank you, Phoebe!

Let’s start with the quokka. It’s a marsupial, which as you may recall means that it’s a mammal that gives birth to babies that aren’t fully formed yet, and the babies then finish developing in the mother’s pouch. It’s related to kangaroos and wallabies but is quite small, around the size of an ordinary domestic cat. It’s kind of a chonk, though, which means it’s probably closer in size to my big chonk cat Dracula. It’s shaped roughly like a little wallaby or kangaroo but with a smaller tail and with rounded ears, and it’s grey-brown in color.

You may have seen pictures of the quokka online, because the reason it’s considered so incredibly cute is because it looks like it’s smiling all the time. If you take a picture of a quokka’s face, it looks like it has a happy smile and that, of course, makes the people who look at it happy too. Those are real pictures, by the way. Because of the way its muzzle and mouth are shaped, the quokka really does look like it’s smiling.

This has caused some problems, unfortunately. People who want to take selfies with a quokka sometimes forget that they’re wild animals. While quokkas aren’t very aggressive and are curious animals who aren’t usually afraid of people, they can and will bite when frightened. The Nature Conservancy of Australia recommends that people who want to take a selfie with a quokka arrive early in the morning or late in the evening, since quokkas are mostly nocturnal, and that they let the quokkas approach them instead of following one around. Touching a quokka or giving it food or drink is strictly prohibited, since it’s a protected animal.

The quokka lives on a few small islands off the coast of western Australia and a few small forested areas on the mainland. The largest population lives on Rottnest Island, and in fact the island was named by a Dutch explorer who thought the quokkas were rats. It means rat’s nest. The island’s actual name was Wadjemup and it was a ceremonial area for the local Whadjuk Noongar people.

Only an estimated 14,000 quokkas live in the wild today, with most of those on Rottnest Island. It used to be much more widespread, but once white settlers arrived and introduced predators like dogs, cats, and foxes, its numbers started to decline. It’s also threatened by habitat loss. It reproduces slowly, since a female only raises one baby a year.

A baby quokka is born after only a month, but like other marsupial babies, called joeys, it’s just a little pink squidge when it’s born. It climbs into its mother’s pouch where it stays for the next six months. Once it’s old enough to leave her pouch, it still depends on her milk for a few more months. While she’s raising one baby, though, the mother has other babies still in her womb ready to be born but held in suspended animation. This means that if something happens to her joey and it dies, the mother can give birth to another baby very quickly.

The quokka is most active at night. It sleeps during most of the day, usually hidden in a type of prickly plant that helps keep predators from bothering it. It gets most of its water needs from the plants it eats, and while it mostly hops around like a teensy kangaroo, it can also climb trees.

The wombat is another adorable Australian marsupial. For some reason, I’ve talked about the wombat several times in Patreon episodes but have barely mentioned it in the main feed–but that’s about to change. Mostly because I am going to recycle a lot of the information from the Patreon episodes, but I’ve also added a lot of interesting new details.

The wombat mainly lives in southern and eastern Australia, including Tasmania. It looks a little like a cartoon bear, a little like a cartoon badger, and a little like a cartoon giant hamster. Perhaps you notice a theme here. It has short legs, no tail to speak of, and is about the size of a medium-sized dog but stockier, with a broad face and rounded ears. The female has a rear-facing pouch to keep dirt and debris from getting on her baby while digging. There are three species alive today.

The wombat is mostly nocturnal and sleeps in a burrow during the day, although it will come out during the day when it’s overcast. It eats grass and other plants. It can dig really well and some people in Australia consider it a pest because it digs under fences.

The wombat has a big round rump with tough skin reinforced with cartilage. If a dingo or other animal chases a wombat, it dives into a hole and blocks the hole with its rump. The predator can’t get a purchase on the tough hide and there’s no tail to grab. The wombat isn’t helpless, though. It can kick hard, bite hard, and if the dingo gets its head over the wombat’s back to grab for its neck, the wombat will push upward and crush the dingo’s head against the roof of the tunnel. The wombat takes no prisoners and presents its butt to danger. Also, its poop is square, as you may remember if you listened to the animal poop episode.

The wombat has a very slow metabolism and takes a week or even two weeks to fully digest a meal. It can run fast when it needs to, although it can’t keep up a fast pace for long. Wombats have even been known to knock people down by charging them, which I personally find hilarious. It can also bite ferociously if it feels threatened, and while it mostly uses its long claws for digging, they also make fearsome weapons. So it’s best to leave the wombat alone.

The wombat’s fur can be gray, tan, brown, black, or any variation on those colors, but there are rare reports of wombats with golden fur. In a 1965 letter to The Times, an anonymous writer reported spotting a golden wombat but couldn’t get anyone to believe him. “Of course you were mistaken, my family said. They said it with an irritating sureness… The golden wombat became the subject of family jokes.” And then two years later, the letter-writer saw the golden wombat again. I thought that would be a fine cryptozoological mystery to share, but when I did a search for golden wombat sightings, actual golden wombats in zoos turned up. Golden wombats are a real thing, just extremely rare. The sunshine golden fur is due to a mutation in coat color.

The Cleland Wildlife Park in Adelaide has a pair of golden hairy-nosed wombats that were discovered in 2011 and sent to the park in 2013. Golden wombats don’t survive long in the wild since their coloring makes them stand out to predators. Wombats in general are having trouble in the wild anyway due to habitat loss, introduced predators like domestic dogs, introduced rabbits and other animals that compete with it for food, the mange mite, also introduced to Australia and spread by domestic dogs, and drought.

Last year, during the awful summer bushfires in Australia, there were reports of wombats saving other animals by herding them into their deep burrows when fires approached. It’s a great story, but like many other stories that seem too good to be true, it’s not completely accurate. The wombats didn’t herd other animals into their burrows like little furry firefighters, but lots of animals did take shelter in wombat burrows to escape the fires. A wombat’s burrow isn’t just a little tunnel with a bedroom at the end. It’s way more elaborate than that, with lots of entrances and adjoining tunnels. One wombat’s burrow complex had 28 entrances and almost 295 feet of tunnels, or 90 meters. A wombat usually only sleeps in one particular burrow for a day or two before moving to a different one, and other animals routinely use the other burrows for themselves. As long as the other animal isn’t a threat, the wombat doesn’t seem to mind. So it’s not surprising that lots of animals hide in wombat burrows to escape fire.

In October of 2020 a team of scientists published a paper about ultraviolet fluorescence in the platypus, which glows greenish in ultraviolet light. The discovery was made by accident but prompted scientists throughout the world, and especially Australia, to borrow black lights from other departments to shine on their mammal collections. It turns out that a lot of nocturnal or crepuscular animals have fur that glows various colors under ultraviolet light. This includes the wombat.

There’s more ultraviolet light at dawn and dusk than during full daylight or at night, so some researchers think the glow may be a way for the animals to blend in with the increased ultraviolet light at those times. If this is the case, it’s a new type of camouflage, or rather a very old type since it’s found in animals like the platypus that have been around for a really, really long time.

Ultraviolet light is the wavelength of light beyond purple, which humans can’t see. Most humans, anyway. In April 2019 I released a Patreon episode about animals and ultraviolet light, and I’ve decided to unlock that episode for anyone to listen to. I’ll put a link in the show notes so you can click through and listen. Be aware that I did make a mistake in that episode, where I mentioned that a black light allows humans to see into the ultraviolet spectrum, but actually what people see when they shine a black light around is fluorescence and ordinary violet light.

A relative of the wombat, Diprotodon, is the largest marsupial ever known. It went extinct around 45,000 years ago, not long after the first humans populated Australia, and is also an ancestor of the koala. It and some other of the Australian megafauna may have influenced Aboriginal myths of dreamtime monsters. It stood around 6 ½ feet tall at the shoulder, or two meters, and like the wombat it had a rear-facing pouch and ate plants. Recent analysis of the front teeth, which were large and flat and grew continuously throughout the animal’s life, indicated it might have been migratory. Researchers also think it lived in social groups something like elephants do today. Its feet were flat and toed inward like modern wombat feet, and although it had claws it probably only used them to dig plants up.

A partial fossil found in 1973 in South Australia was finally described in mid-2020 as a wombat relation, although it may not be a direct ancestor to modern wombats. It lived about 25 million years ago and was the size of a bear, and had powerful front legs with claws used for digging up roots. It’s named Mukupirna nambensis and is different enough from other wombat relations that it’s been assigned to a new family of its own.

There have been reports for centuries of giant wombats or wombat-like animals in Australia and even from nearby Papua New Guinea. Some cryptozoologists think the sightings are of a smaller relative of the wombat, Hulitherium tomasetti. Hulitherium lived in the rainforests of New Guinea, and probably went extinct about the same time as Diprotodon, possibly due to hunting from newly arrived humans. It was about three feet high, or one meter, and may have eaten bamboo as a primary part of its diet. Like the panda, it seems to have a number of adaptations to feeding on a bamboo diet, including very mobile front legs, more like an ape’s than a wombat’s. It may have been able to stand on its hind legs like a bear too.

An October 26, 1932 story in The Straits Times, a Singapore newspaper, is interesting in light of the hulitherium’s size and possible appearance. I’ll quote the story, which appears in the 2016 Fortean Zoology Yearbook:

“One of our strangest visits was reserved for this morning, when Mr. Paul Pedrini, wild animal hunter and trainer, arrived leading a curious beast, brown, furry, about two feet high and four feet long and looking like no animal one could call to mind. It was very fat and adorning its neck was a large pink bow. This latter fact was the chief cause of the uneasiness shown by the oldest sub-editor. Mr. Pedrini explained that he found his little pet in Australia eighteen months ago.

“He calls it the ‘What Is It?’ because nobody can give it a name. Described as being something like a wombat, it is certainly not a wombat neither does it belong to any other known family. The ‘What Is It?’ is very tame and friendly and has kind eyes. Its chief diet is bananas and toast. We said good bye to Mr. Pedrini, patted the strange animal and returned, slightly shaken, to the normal round.”

The story isn’t sensational enough to feel like a hoax, but it doesn’t really give enough of a description of the animal to be sure it wasn’t just a larger than usual wombat. After all, the wombat does have kind eyes.

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

Thanks for listening!

Episode 205: Sea Scorpions and the Late Ordovician Mass Extinction Event

Posted on by

Podcast: Play in new window | Download (Duration: 16:47 — 17.3MB)

Subscribe: RSS | More

Happy new year! This week we’ll learn about the oldest mass extinction event, some 450 million years ago, and also sea scorpions.

Further reading:

Coming up for air: Extinct sea scorpions could breathe out of water, fossil detective unveils

Sea scorpions could get really, really big:

A fossil Eurypterus:

Show transcript:

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

Hello, 2021, please be better than 2020 was. I’ve got lots of fun, interesting episodes planned for this year, but let’s start the year off right with an episode about, uh, a major extinction event. Specifically it’s the Late Ordovician mass extinction, which occurred around 450 million years ago. This is the first of a series of episodes about extinction events I have planned for this year, which I hope you’ll find interesting. We’ll also learn about an animal called the sea scorpion.

If you’ve listened to episode 69, about the Cambrian explosion, you may remember that the fossil record shows that around 540 million years ago life on earth evolved from simple organisms into much more complicated ones. This happened relatively quickly in geologic terms, about 15 to 25 million years for life to go from microbial mats, simple worms, and single-celled animals to fantastical creatures with shells and spikes and novel ways of feeding as animals adapted to fit new ecological niches.

But what happened after that? A series of extinction events, that’s what.

The first extinction event researchers can identify from the fossil record is called the End-Botomian extinction event, which happened around 510 million years ago in two phases. We’re not sure what caused the extinctions, but the main theory is that a series of massive volcanic eruptions caused climate changes that led to acidification of the oceans and a resulting loss of oxygen from the water. This was followed by another extinction event around 500 million years ago. All told, during these ten million years or so, about 40% of all species of animal went extinct.

But remember, all we have to work with is the fossil record. Researchers know how old particular rock strata are, strata being the term for layers, so when they find a fossil embedded in a rock they know roughly how long ago it lived. Only a small percentage of animals that ever live end up fossilized, and only a small percentage of fossils are ever found by humans, and only a small percentage of fossils found by humans get studied by experts. So while scientists do their best, they’re working with a limited amount of data to determine what happened half a billion years ago. It’s like trying to determine the rise and fall of empires from a series of random photographs.

But when older rocks show a whole lot of fossils of various kinds, and then slightly younger rocks show way fewer or no fossils, researchers can be pretty sure that something catastrophic happened to kill off a lot of animal life in a relatively short amount of time. If they find the same changes in rocks of the same age in different parts of the world, the catastrophe was probably worldwide and serious enough to impact life on Earth for thousands or even millions of years. That’s what happened in the late Ordovician.

Around 460 million years ago, about the time that life was getting back to normal after the last extinction event, glaciers started to form across the land. Most of the continents at this time were smushed together into a supercontinent called Gondwana, which was mostly in the southern hemisphere. Much of the rest of the Earth was one big ocean, and it was hot and tropical just about everywhere. But that changed when temperatures dropped drastically. Glaciers formed, sea levels fell, and some 60% of all life on Earth went extinct, all possibly within about one million years.

We don’t know why, but we do have some clues and some theories. We know there was a major meteor event around 467 million years ago, which can be pinpointed because of the craters and specific minerals and bits of meteorites found that can only come from meteors hitting the earth. The impacts kicked dust into the atmosphere that then reflected sunlight back into space, causing less light to reach the earth.

Another cause might have just been a cyclical movement of the Earth in space. As you hopefully know, Earth rotates on its axis in a 24 hour period, giving us day and night, and at the same time it’s moving in an elliptical orbit around the sun in a 12-month period, which of course is a year. The sun and the other planets and everything else in our solar system are also moving in space in a larger orbit, and there are other even larger orbits that our solar system is part of within our galaxy, which is moving too. With all this movement all the time, it’s not surprising that Earth’s climate is affected in very long cycles, together with the effects of the moon’s gravitational pull making the Earth’s orbit just slightly wobbly. A combination of events, including where the Earth was in its orbit, might have caused the Earth to cool just enough that it set off an ice age. If this happened at about the same time that the meteor event also caused the Earth to cool a little, that would explain why the onset of glaciation happened so quickly in geological terms.

Whatever the cause or causes, it had serious repercussions. The cooling climate and drop in ocean levels as ice formed caused rapid extinctions of animals that lived in shallow water and were adapted to tropical climates.

But the extinction event was a one-two punch. The cold didn’t kill off every animal, of course, and those that remained evolved to take advantage of ecological niches that were suddenly empty. This is always how life manages after an extinction event. But these new species were adapted to the cold. And then, almost as suddenly as they formed, the glaciers melted.

Sea levels rose dramatically. The Earth warmed again, although not to its former levels. As the glaciers melted, cold fresh water flowed into the ocean and may have caused deep ocean water to rise to the surface, a process called upwelling. The deep ocean water brought nutrients with it that then spread across the ocean’s surface, and this would have set off a massive microbial bloom.

Microbial blooms sometimes happen today in small areas of the ocean or in lakes, especially in places where fertilizers make it into the water. Algae or bacteria that feed on certain nutrients suddenly have a whole lot of food, and they reproduce as fast as possible to take advantage of it. But the microbes use up oxygen, so much of it that the water can become depleted. This leads to massive die-offs of fish and other animals. But these modern microbial blooms are relatively small. The ones 450-odd million years ago might have been worldwide. As the glaciers melted they exposed more land, which meant more nutrients flowing into the ocean, feeding the microbial blooms that continued to deplete oxygen from the ocean.

The result was a severe lack of oxygen in the water that would have driven more species to extinction. Some researchers think it took three million years for the oceans to recover.

There are many other possible causes for the Late Ordovician mass extinction, although right now the cooling and then warming of the earth seems to be the most widely accepted among scientists. But whatever the causes, the results were dramatic. Entire families of animal went extinct, probably around 100 of them, and many others were affected. Some 70% of trilobite species went extinct, for instance.

The Late Ordovician mass extinction marks the end of the Ordovician era and the beginning of the Silurian around 443 million years ago. Remember that these names for eras are just the way that geologists and other scientists can indicate the age of an event or rock or fossil. It’s not like trilobites and brachiopods had little calendars and on one particular day that calendar said “Extinction” and everyone died. It was a gradual process, no matter how fast it occurred in geologic terms. If you had a time machine and could travel back to 450 million years ago, whatever day you arrived, the world would just look normal. You’d have to observe for at least hundreds of years to understand that the Earth was in the process of an extinction event.

You’ll be glad to know that the Silurian lasted almost 25 million years and was nice and quiet geologically. Life rebounded after the extinctions, as it always does, and more animals and plants adapted to live on land. Fish evolved rapidly during this time, developing bony skeletons and jaws. The Earth was comfortably warm but stormy, since the warm water and massive oceans would have spawned hurricanes that make the ones today look puny. But for the most part life was good in the Silurian.

The ocean was populated with lots of animals, including early fish, trilobites, crinoids, corals, leeches, and shelled animals called brachiopods as well as the more familiar mollusks. Sea levels were high and the land was mostly flat. There weren’t many mountains. So around Gondwana were lots of islands that were barely higher than the water level.

In the shallow oceans around what is now North America, an arthropod called the eurypterid was incredibly common, with some 250 species known. Many of them persisted until about 250 million years ago and they lived throughout the world. Eurypterids are often called sea scorpions, but they didn’t look much like modern scorpions. The typical Eurypterid looked a lot like the modern horseshoe crab, but with a longer segmented body and tail. But even though it looked sort of like a horseshoe crab, it may have been more closely related to modern scorpions.

The earliest sea scorpion known was Pentecopterus, which has been found in the fossil record in rocks dated to about 467 million years ago. It grew up to five feet 7 inches long, or 1.7 meters. One interesting thing to note is that it lived in a particular round basin some three miles across, or a bit over 5 km, in what is now Iowa in the United States. Researchers think it was actually a crater from a meteor impact near the ocean’s shore, and that the water in it was probably brackish. Remember how there was a major meteor event 467 million years ago? Pentecopterus was probably living in a crater made by one of those pieces of meteorite. It would have been the apex predator in that small environment, eating anything it could catch with its crablike legs. Later sea scorpions developed a pair of crab-like pincers at the front, along with a flattened tail that sometimes had a pointed barb at the end.

Eurypterids lived in the water. While some grew less than an inch long, or a few cm, some grew quite large. One species of Jaekelopterus could grow 8 ½ feet long, or 2.6 meters. That doesn’t even include the claws at the front that could extend at least another 18 inches, or 45 cm. It was probably a freshwater animal, and despite its size it was streamlined and lightweight, so it would have been an active predator. We even have fossilized fish bones that show puncture wounds that might have been made by its claws. Some eurypterids weren’t very good swimmers, though, and probably spent more time walking along the bottom of the shallow ocean.

So between Jaekelopterus in fresh water and the earliest known sea scorpion, Pentecopterus, in possibly brackish water, it’s obvious that from the very beginning the sea scorpion could adapt to various environments that other animals couldn’t. This adaptability is probably why the sea scorpion survived the extinction event that killed off so many other animals, and it continued to thrive for hundreds of millions of years afterwards.

Not only that, one fossil takes its adaptability a step farther. A geology professor named James Lamsdell heard about a strange eurypterid found in France that had been in a Scottish museum for 30 years. He arranged to have the fossil imaged with a CT scanner, which revealed its gills. And to Lamsdell’s surprise, the gills contained structures found in modern scorpions and spiders, which keep the gill plates from collapsing when it’s out of water. These structures have been retained in modern arachnids from their marine ancestors, and finding them in a eurypterid was shocking. It means that particular eurypterid could spend time on land. Lamsdell and his team think it came out of the water to lay its eggs, either in sheltered pools or in wet sand.

Eurypterids died out eventually, but their cousins, modern scorpions, are doing just fine after surviving many other extinction events. So try to be more like a scorpion, because obviously they’re doing something right.

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 a rating and review on Apple Podcasts or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us that way.

Thanks for listening!

Episode 202: Terror Birds and Pseudotooth Birds

Posted on by

Podcast: Play in new window | Download (Duration: 17:12 — 17.9MB)

Subscribe: RSS | More

Let’s find out about some gigantic birds this week! Thanks to Pranav and Richard for the suggestions!

Further reading:

Exceptionally preserved fossil gives voice to ancient terror bird

Antarctica yields oldest fossils of giant birds with 21-foot wingspans

Look at that beak! Llallawavis scagliai:

Big birdie!

A red-legged seriema and an unfortunate snake:

Another big birdie!

Toothy birdie!

Show transcript:

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

This week we’re going to learn about some gigantic extinct birds! Pranav wants to hear about Phorusrhacidae, also known as the terror bird. Something called a terror bird is definitely going to be interesting. My brother Richard also tweeted me about some huge extinct birds called pelagornithids, so we’ll talk about them too. Both birds were huge and successful, but extremely different from each other.

Phorusrhacidae is the name for a family of flightless birds that lived from about 62 million years ago to a little under 2 million years ago. Flightless birds may make you think of ostriches and penguins and dodos, but remember that Phorusrhacids were called terror birds. They were carnivores and many of them were enormous.

Most terror birds lived in South America, with one species known from southern North America. A few newly discovered bird fossils from Africa and Europe may have been close relations of terror birds, but palaeontologists are still studying them.

Various species of terror bird ranged in size from about 3 feet tall to 10 feet tall, or 1 to 3 meters, and had long, strong legs that made them fast runners. The terror bird also had a long, strong neck, a sharp hooked beak, and sharp talons on its toes. The beak was strong but the jaw muscles were relatively weak. Researchers think that it ambushed prey and chased it down, then either kicked it to death with its sharp talons or held it down with its feet and stabbed it to death with its beak. Smaller species may have grabbed its prey and thrown it back down with enough force to injure, stun, or outright kill the animal. It may have swallowed small prey whole and regurgitated pellets made up of compressed fur and bones, the way many modern carnivorous birds do today.

Although the beak was strong, it was also hollow. This would have made it weigh less, which meant that the bird could move its head more quickly. Some researchers think that it might also have acted as a resonant chamber, and that the bird could clap its beak closed to make a loud noise to communicate with other terror birds. It had excellent hearing and vision, but a poor sense of smell.

Many details of what we know about terror birds come from a single specimen discovered in 2010 in Argentina. The bird lived around 3 million years ago and stood four feet tall, or 1.2 meters. It was described in 2015 and is named Scaglia’s magnificent bird. I am not going to attempt to pronounce its scientific name [Llallawavis scagliai], but I’ll put it in the show notes along with a picture. Almost the entire skeleton is preserved in stunning detail, including details that hardly ever preserve, like the tiny bones that help the eye focus. Studies of the tiny ear bones and other details of the ear indicate that its hearing was most acute at low frequencies, which meant it would have been good at hearing footsteps. It also probably had a deep voice.

The terror bird had wings, but they were small and probably only used for display. The wings did have claws, though, and may have been used to fight other terror birds over mates or territory. Young terror birds of some species might have been able to fly, although adults certainly couldn’t.

The earliest known terror bird, Paleopsilopterus, lived about 60 million years ago in what is now Brazil. It was relatively small, only about three feet high, or 1 meter. It evolved only a few million years after the non-avian dinosaurs went extinct, and its descendants became larger and more fearsome until they were apex predators throughout South America.

Kelenken, for instance, grew up to ten feet tall, or three meters, and had an enormous beak, 18 inches long or almost 46 cm. It lived in what is now Argentina around 15 mya. It’s the tallest terror bird known but it was more slenderly built than others so was probably a faster runner. It was only discovered in 1999.

Brontornis, however, was the one that puts the terror into terror bird. It grew over 9 feet tall, or 2.8 meters, but it was massively built. It probably wasn’t a very fast runner and would have definitely been an ambush predator. Most likely it hid among trees or other tall vegetation, and when an animal came too close, BOOM! THERE’S A TERROR BIRD! RUN! TOO LATE, ARGH!

Titanis lived in parts of North America, with fossils found in Texas and Florida. It probably stood a little over eight feet tall, or 2.5 meters, although we don’t have any complete skeletons so can only estimate its actual size compared to other species of terror bird. You may find information online that says Titanis lived as recently as 10,000 years ago in Florida, and that it used the claws on its wings like hands to help catch prey. Both these things are wrong, unfortunately. The fossil bones found in the Santa Fe River in Florida had washed out of their original location and were mixed in with much more recent bones, and there’s no evidence that any terror bird used its wings like hands. Terror birds were descended from birds that could fly, not descended directly from dinosaurs, so its wings were still highly modified for flight.

Titanis lived in North America about five million years ago. But how did it get to North America from South America before the Isthmus of Panama formed around three million years ago? Before then, a big stretch of ocean separated the two continents. Researchers think it island-hopped, as the tops of mountains and hills in what is now Central America first emerged from the ocean as sea levels dropped, forming islands. Volcanoes also formed islands in the area. Titanis may have traveled to these islands by swimming or rafting during storms.

Terror birds went extinct after the Isthmus of Panama opened up when sea levels lowered. This connected North and South America, which allowed animals from North America to cross into South America and vice versa. The Andes Mountains also formed about this time and changed the climate of much of South America. Forests became open savanna where terror birds wouldn’t have been able to hide to ambush prey. Climate change combined with increased competition from saber-toothed cats and other North American predators probably led to the terror birds’ extinction.

There are no descendants of terror birds living today, but its closest living relations are probably the seriema birds, the red-legged and the black-legged seriema. Both live in South America and both are carnivorous birds that eat small animals like rodents, lizards, snakes, and even other birds. When it catches an animal, it beats it against the ground until it dies. It will also sometimes eat fruit and eggs.

The red-legged seriema stands a little over three feet tall, or a meter, with long legs, long neck, and long tail. It’s mostly brown and gray and it has a fan-shaped crest low down on its forehead, just above the bill. The gray-legged seriema looks very similar but is mostly gray. The seriema also has a sickle claw on each foot that it uses to cut pieces off its dead prey so it can swallow them more easily.

The seriema can fly, but it prefers to walk or run. It can run up to 15 mph, or 25 km/h. It builds its nest in low bushes so it can just hop up onto the nest instead of having to fly. It’s also aggressive and will attack animals much larger than it is, driving them away from its nest or chicks. Farmers sometimes catch young seriemas and tame them, then allow them to patrol the farmyard to catch rats and snakes and drive away larger predators.

Next, let’s learn about a different giant extinct bird, Richard’s suggestion. Unlike the terror bird, pelagornithids could fly. They’re sometimes called pseudotooth birds because they had teeth, but they weren’t real teeth. They were pointy projections of the jaw bones that grew along the edges of its beak and were covered with keratin. Pelagornithids evolved around the same time as the terror bird, around 62 million years ago, and didn’t die out until about the same time as the terror bird, around 2.5 million years ago.

And like the terror bird, pelagornithids were huge, but in a different way than terror birds. They were sea birds that may have superficially resembled modern albatrosses, but they were much larger. The largest living albatross has a wingspan of about 11 1/2 feet, or 3.5 meters, but the largest known pelagornithid had a wingspan estimated at up to 21 feet, or almost 6.5 meters. Its wings were narrow and pointed like albatross wings are.

Researchers think that the pelagornithid probably mostly ate soft-bodied animals like squid and other cephalopods, because its teeth were not very strong. It probably scooped its prey up from the water while flying, like many modern seabirds do, although it could probably also sit on the water and dip its long, strong beak down to catch anything that swam too close. Its bones were too delicate for diving. It may have had a throat sac like a pelican too. It was probably white or gray in color and its wings and tail were probably black, which is the most common coloration for sea birds of any kind.

It had short legs but enormously long wings, so long that it probably couldn’t flap them. Its strongest muscles were the ones that held the wings out straight. It was definitely a bird, of course, but it was proportioned more like a flying reptile, Pteranodon, even though they weren’t related. You know what that means, of course. Convergent evolution! Researchers think the pelagornithid spent almost all its time soaring on ocean breezes, scooping up cephalopods and fish to swallow whole, and that Pteranodon probably did the same. These days, modern albatrosses fill that particular ecological niche, and the albatross has many similarities to the pelagornithid too.

Pelagornithids of various species were found throughout the world, from the Arctic and Antarctic to the tropics. It was extremely successful and unlike the terror bird, which was restricted to land, it could travel as far as it liked as long as it had a breeze to keep it aloft. It evolved soon after the non-avian dinosaurs went extinct and didn’t die out until the beginning of the Pleistocene. What happened then? Why aren’t these enormous birds still flying around?

The Pleistocene, of course, was the ice age, or more properly the ice ages. Its onset resulted from a lot of factors, including the movement of continents that changed ocean currents radically. Once the changes started, they accelerated quickly. As more water froze and became massive glaciers that weighted down entire continents, sea levels dropped and more land was exposed, including the Isthmus of Panama that connected North and South America. This would have radically changed the air currents that pelagornithids used to travel around the world, from nesting sites to feeding sites and back. It also drove many sea animals to extinction as their environments became too cold or too warm for them to adapt to, or the water where they lived just dried up completely.

The one place where pelagornithids couldn’t go was across continents. They needed constant sea breezes and lots of water where they could catch prey, and steep cliffs near water to nest on. As the ecological changes of the Pleistocene became more pronounced, pelagornithids had more and more trouble surviving, and finally they went extinct. Modern albatrosses, gulls, and cormorants expanded at the same time to fill the ecological niche left open by the pelagornithid.

While there are no living descendants of pelagornithids, researchers tentatively think they’re most closely related to living ducks, geese, and swans. Since most pelagornithid fossils are badly damaged and fragmented, so that we only have one or two bones preserved from any given animal, it’s hard for scientists to make conclusions as to what they were most closely related to. Hopefully more and better fossils will be found soon so we can learn more about these gigantic birds!

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

Thanks for listening!

Episode 200: Elephants

Posted on by

Podcast: Play in new window | Download (Duration: 22:56 — 23.7MB)

Subscribe: RSS | More

This week we’re going to learn about elephants! Thanks to Damian, Pranav, and Richard from NC for the suggestions!

Further Reading:

Dwarf Elephant Facts and Figures

An Asian elephant (left) and an African elephant (right). Note the ear size difference, the easiest way to tell which kind of elephant you’re looking at:

Business end of an Asian elephant’s trunk:

An elephant living the good life:

Can’t quite reach:

Elephant teef:

A dwarf elephant skeleton:

An elephant skull does kind of look like a giant one-eyed human skull:

Show transcript:

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

This week we’re going to learn about some elephants! We’ve talked about elephants many times before, but not recently, and we’ve not really gone into detail about living elephants. Thanks to Damian, Pranav, and Richard from NC for the suggestions. Damian in particular sent this suggestion to me so long ago that he’s probably stopped listening, probably because he’s grown up and graduated from college and started a family and probably his kids are now in college too, it’s been so long. Okay, it hasn’t been that long. It just feels like it. Sorry I took so long to get to your suggestion.

Anyway, Damian wanted to hear about African and Asian elephants, so we’ll start there. Those are the elephants still living today, and honestly, we are so lucky to have them in the world! If you’ve ever wished you could see a live mammoth, as I often have, thank your lucky stars that you can still see an elephant.

Elephants are in the family Elephantidae, which includes both living elephants and their extinct close relations. Living elephants include the Asian elephant and the African elephant, with two subspecies, the African savanna elephant and the African forest elephant. The savanna elephant is the largest.

The tallest elephant ever measured was a male African elephant who stood 13 feet high at the shoulder, or just under 4 meters, which is just ridiculously tall. That’s two Michael Jordans standing on top of each other, and I don’t know how you would clone Michael Jordan or get one of them to balance on the other’s head, but if you did, they would be the same size as this one huge elephant. The largest Asian elephant ever measured was a male who stood 11.3 feet tall, or 3.43 meters. Generally, though, it’s hard to measure how tall or heavy a wild elephant is because first of all they don’t usually want anything to do with humans, and second, where are you going to get a scale big and strong enough to weigh an elephant? Most male African elephants are closer to 11 feet tall, or 3.3 meters, while females are smaller, and the average male Asian elephant is around 9 feet tall, or 2.75 meters, and females are also smaller. Even a small elephant is massive, though.

Because of its size, the elephant can’t jump or run, but it can move pretty darn fast even so, up to 16 mph, or 25 km/h. The fastest human ever measured was Usain Bolt, who can run 28 mph, or 45 km/h, but only for very short distances. A more average running speed for a person in good condition is about 6 mph, or 9.6 km/h, and again, that’s just for short sprints. So the elephant can really hustle. Its big feet are cushioned on the bottoms so that it can actually move almost noiselessly. And I know you’re wondering it, so yes, an elephant could probably be a good ninja if it wanted to. It would have to carry its sword in its trunk, though. The elephant is also a really good swimmer, surprisingly, and it can use its trunk as a snorkel when it’s underwater. It likes to spend time in the water, which keeps it cool, and it will wallow in mud when it can. The mud helps protect it from the sun and from insect bites. Its skin is thick but it’s also sensitive, and it doesn’t have a lot of hair to protect it.

The elephant is a herbivore that only eats plants, but it eats a lot of them. An adult elephant eats several hundred pounds of food a day, or more than 100 kg, and will drink enough water every day to fill a bathtub. It eats grass, leaves, twigs, fruit, and bark, and elephants in captivity also eat hay. And since we’re getting close to the winter holidays, some zoos have an agreement with Christmas tree sellers, who donate any unsold Christmas trees to the zoos for the elephants to eat. They can’t feed used trees because there might be leftover ornaments or ornament hangers on them. The elephant just puts one foot on the tree and rips off the branches with its trunk, which it then eats.

The elephant has a pair of big teeth on each side of its mouth that look more like the bottoms of running shoes than ordinary teeth, which it uses to grind up the tough plants it eats. Elephants technically have 26 teeth, two incisors and 24 molars. The incisors are modified into tusks, which we’ll talk about in a minute. The molars aren’t all in the mouth at once, though. Every so many years, the four molars in an elephant’s mouth start to get pushed out by four new molars. It doesn’t happen the same way you lose your baby teeth, though. Instead of a new tooth pushing up through the gum until the baby tooth gets loose and falls out, the new molars grow in at the back of the mouth and start moving forward, pushing the old molars farther forward until they fall out. This happens six times throughout the elephant’s life, with the last set usually growing in around the early 40s. Since elephants can live much longer than that, well into their sixties, that last set may have to last a long time, since there are no elephant dentists that can make gigantic elephant dentures.

The tusks are much different than the molars, naturally. The tusks start to grow from the upper jaw when the elephant is a little over six months old, and continue growing throughout its life. It uses its tusks for all kinds of activities, including moving obstacles from its path, digging for water, and defending itself. But not all elephants have tusks. Many Asian elephants don’t have tusks at all, or only have very small ones. Because poachers who want the tusks to sell as ivory shoot elephants that have the biggest tusks, many populations now have smaller tusks overall or none, since elephants without them are less likely to be killed.

The elephant’s trunk is strong but sensitive, sort of like a human’s arm and hand but with many more uses (and also no bones). The elephant breathes and smells through its trunk, since it’s an extension of the nose and upper lip, but it also makes noise with its trunk to communicate with other elephants, uses it to gather food and move it into the mouth, sucks up water with the trunk and splooshes it into the mouth to drink or onto its body to wash. It can reach plants that are way up high or it can dig into soft ground for roots or to reach water. It can open nuts with its trunk, scratch an itch, play wrestle with a friend, lift incredibly heavy things out of the way, and all sorts of other things. Elephants probably wonder how humans can function without a trunk. I am starting to wonder how I function without a trunk.

The easiest way to tell an Asian elephant apart from an African elephant is by looking at the ears. African elephants have much larger ears, especially savanna elephants. The ears are full of small blood vessels to help release heat from the body into the atmosphere. An elephant will flap its ears to stay cool on a hot day. Asian elephants are also smaller overall and have a different body shape. Asian elephants have somewhat shorter legs, a bulkier forehead, different numbers of toes on the feet, and even different trunks. The African elephant has two little projections at the tip of the trunk that act as fingers, while the Asian elephant only has one.

Elephants evolved in what is now Africa and are the largest land animals alive today. The earliest elephant ancestors lived around 56 million years ago, not long after the extinction of the non-avian dinosaurs. It was still a small animal then, only about a foot tall at the shoulder, or 30 cm. It probably spent a lot of time in the water, eating plants, and it probably had small ears and a large nose, but not an actual trunk. If you could go back in time and look at it, you’d never guess that it was an ancestral elephant.

By 27 million years ago, though, elephant ancestors were starting to look like elephants. Eritreum was a lot bigger, over four feet tall at the shoulder, or 1.3 meters, and it probably had short tusks and a trunk. If you looked at a living Eritreum, you’d definitely know it was a kind of elephant, even though it would have looked weird compared to modern elephants since its head was long and flattened in shape. Eritreum already had the same tooth system that modern elephants have, where new molars continually grow and replace worn-out older ones.

Eritreum’s descendants spread to Eurasia and then to North America. By about 2.5 million years ago, at the beginning of the Pleistocene, elephants were all over the place–not just the ancestors of modern elephants, but relations from other parts of the elephant family tree. This includes Palaeoloxodon, a suggestion by Richard from NC.

Palaeoloxodon namadicus lived throughout much of Asia, with fossils found in India, Japan, and Sri Lanka, and it was enormous. We don’t have a complete skeleton, but estimates of Palaeoloxodon’s size suggest it was the largest elephant that we’ve ever discovered. An estimate of the largest specimen found so far is 17.1 feet tall at the shoulder, or 5.2 meters. This is about the same height at the shoulder as Paraceratherium, which we talked about in episode 50 about tallest animals, but it might have actually been taller than Paraceratherium. The tallest giraffe ever measured was 19.3 feet tall, or 5.88 meters, but that’s at the top of its head, not its shoulder, and giraffes are much less heavy than elephants. Whichever one was actually tallest doesn’t really matter, though, because they all belong to the Ridiculously Tall Animals Club, also known as the Animals That Could Squish You Flat by Accident Club.

We don’t know much about Palaeoloxodon since so few fossils have been found so far. We mostly just know it was a massive animal that probably went extinct 24,000 years ago. That’s really not that long ago in geologic terms. It was probably a member of the straight-tusked elephants, a group of animals that were mostly quite large even for elephants.

Straight-tusked elephants weren’t actually straight-tusked, just straighter than most elephant tusks. They all also had an unusual feature on the head called a parieto-occipital crest, which was a ridge of bone high up on the forehead above the eyes that jutted out. The crest was barely noticeable in young elephants but grew larger as the elephant matured, and researchers think it was the attachment site for massive neck muscles to hold up the animal’s massive head.

One interesting thing about Palaeoloxodon is that some other members of the genus were dwarf species that lived on some Mediterranean islands. Pranav wanted to learn about these and other pygmy elephants of the Mediterranean Islands. Fossil elephants have been found on many islands, including islands in the Mediterranean, in south Asia, and the Channel Islands off the coast of California, although they weren’t all closely related. I think we’ve talked about insular dwarfism before, but let’s go over it again briefly. When a large animal like an elephant becomes restricted to a small environment, like an island, there aren’t enough resources for a full population of full-grown animals. As a result, only smaller individuals get enough food to thrive well enough to reproduce, which means their babies are more likely to be smaller too. Over time this results in a population of animals that are much smaller than their relations who don’t live in a restricted environment.

The opposite of insular dwarfism is island gigantism, by the way. When species that are small ordinarily, like pigeons, colonize an island where there are plenty of resources and very few or no predators, they evolve into much larger animals, like dodos.

Insular dwarfism isn’t just about mammals. Palaeontologists have identified dwarf species of dinosaur too, including a pocket-sized sauropod. Okay, maybe not pocket-sized since they still grew nearly 20 feet long, or 6 meters, but since their mainland relations could grow 100 feet long, or 30 meters, that’s a big difference.

Anyway, back to dwarf elephants. It’s so easy to get distracted by all this neat information. The elephants that lived in the Mediterranean islands were mostly straight-tusked elephants, although at least one was a type of mammoth. During the Pleistocene, when a lot of the world’s water was frozen in enormous glaciers, the sea levels were much lower. This exposed a lot more land, and of course animals lived on that land. Then, during the interglacial periods when much of the ice melted and sea levels rose, animals moved to higher ground and eventually some were cut off from the mainland and lived on islands. All of these species that survived exhibited insular dwarfism. It’s helpful to remember that the islands we’re talking about are mostly pretty big. I mean, they’re not the size of Gilligan’s Island. People live on many of these islands today and there are cities and towns and farms and national parks and so forth. The island of Crete, for instance, which is a part of Greece, is 3,260 square miles in size, or 8,450 square km.

One dwarf elephant that once lived on Crete may have only grown 3.7 feet tall at the shoulder, or 1.13 meters. That was the mammoth relation, but a species of Palaeoloxodon also lived on Crete, although not necessarily at the same time as the dwarf mammoth. As the sea levels rose and fell over the centuries, different species of elephant and other animals ended up living on the islands at different times.

We don’t know a whole lot about these dwarf elephants, unfortunately, since we don’t have a lot of remains. Mostly we have teeth, which do tell a lot about the elephant but not everything. But we do know roughly when the various species finally went extinct, and you will not be surprised to learn that these dates often coincide with human arrival on the islands. The Tilos Island elephant probably didn’t go extinct until 6,000 years ago. That’s well into the modern era, and humans lived or at least hunted on the island starting around 10,000 years ago. If you are Greek, your ancestors may have hunted Tilos Island dwarf elephants. It grew up to around 5 feet 3 inches tall, or 1.6 meters, which coincidentally is my height.

Many historians think that the bones and fossils of dwarf elephants may have led to the legend of the cyclops in ancient Greece. The skull of an elephant has a big opening in the front for the nasal passages, with relatively small eye sockets on the sides of the skull. If you’re not familiar with living elephants and you see an elephant skull, it really does look like an enormous human skull with one eye socket in the middle of the forehead.

All elephants live in small family groups that consist of a leader, called the matriarch, who is usually the oldest female in the group, and her close relations and their babies, usually her daughters and grandchildren. When a young male elephant grows up, he leaves his family group, but daughters usually stay.

Although elephants live in these small groups, they’re social animals. The family groups interact with each other when they meet, and they may meet up purposefully just to say hi. A family with a lot of babies may meet up with another family for help taking care of the young ones. When a member of the group is in estrus, meaning she can get pregnant, local males will join the group and try to get her attention. But although the males don’t spend all their time with family groups, they make friends with other males and sometimes form small bachelor groups of their own led by an older male. The older male not only teaches the younger ones how to find food and react to danger, he keeps them from running wild and acting up. During the 1990s, a nature reserve in South Africa introduced a lot of young males that were orphaned and had no family–but without an older male to keep them in line, they went on a rampage and killed 36 rhinoceroses. Finally the park introduced an older male and he put a stop to all that. The young elephants straightened up and left the rhinos alone.

Females usually come into estrus during the rainy season, which is in the second half of the year in Asia and parts of Africa. During this time, mature males may enter a condition called musth for at least some of the time. During musth a male is more aggressive and struts around showing off. It’s easy to tell when a bull elephant is in musth because a gland on each side of his face releases fluid that makes his cheeks wet. Females prefer to mate with males in musth, and usually in a group of males only the most dominant male will be in musth.

Elephants these days are all threatened by poaching, especially for their tusks. Elephant tusks are known as ivory, and ivory sales are banned throughout most of the world. Unfortunately, people still kill elephants to sell the ivory on the black market. Elephants are also threatened by habitat loss, since they need a whole lot of land to find enough to eat and people want that land for their domestic animals or crops.

I could go on and on about elephants for hours. There’s so much to learn about them that it’s just not possible to fit into one podcast episode. I haven’t even touched on their intelligence, their use as working animals in Asia and other parts of the world, and many other interesting things. But we’ll finish with this interesting fact: elephants are afraid of bees, so farmers can keep elephants from eating their crops by making a fence out of bee hives.

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

Thanks for listening!

Episode 198: Pop Goes the Mustelid

Posted on by

Podcast: Play in new window | Download (Duration: 22:30 — 23.2MB)

Subscribe: RSS | More

Let’s learn about a whole lot of mustelids, including some otters, weasels, and their relations and ancestors! Thanks to Jacob for the suggestion!

Further reading:

Weasels in Stone: Mustelid Evolution

With voices joined in chorus, giant otter families create a distinct sound signature

Further watching/listening:

Video of giant river otters making noise

Giant river otters:

The least weasel is possibly the most cute:

This mink would like to keep its fur for itself please and thank you:

The Patagonian weasel:

The greater grison looks like a badger and a honey badger:

The fisher:

The Chinese ferret badger has a long nose compared to most mustelids:

Show transcript:

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

This week we’ll learn about some mustelids, better known as weasels and their close relations! Thanks to Jacob for this week’s suggestion.

The weasel is a member of the family Mustelidae. Members of the family are called mustelids, which includes wolverines and badgers, which we talked about in episode 62, otters, which we talked about in episode 37, and ferrets, which we talked about in episode 150. Most mustelids have short legs and long, slender, flexible bodies, although badgers are an exception since they’re broad-bodied. This body shape allows a mustelid to enter the burrows of other animals and kill them, because mustelids are carnivores.

But not all animals that look like weasels and ferrets are actually mustelids. The mongoose, for instance, is not a mustelid.

The study of how mustelids evolved and spread throughout much of the world is a pretty hot topic these days, which makes it confusing to summarize since so much new knowledge keeps shaking up what we know. But I’ll do my best.

The first mustelids evolved around 30 million years ago in what is now Eurasia, and spread to North America much later and eventually into South America. The oldest mustelid fossils found in North America are a group of animals called oligobunines. I read that word as oligobunnies every single time, but they didn’t look like bunnies. They probably looked like wolverines, which are related to badgers but look more like miniature bears with longer tails, but they probably spent more time underground than wolverines do.

At least one oligobunid might have grown as big as a black bear, at least a small bear. Megalictis was probably an ambush predator and lived around 21 million years ago in what is now the upper Midwest of North America. It had teeth meant for crushing bones. Another oligobunid, Zodiolestes, is one we talked about briefly in episode 103, about trace fossils. The first fossil Zodiolestes was found in a corkscrew-shaped Palaeocastor burrow, presumably because it got stuck in the burrow while it was hunting, but Zodiolestes was also adapted to dig. The oligobunids went extinct around 10 million years ago, possibly outcompeted by a new wave of modern mustelids that evolved in Asia and spread into North America.

One mustelid, Ekorus ekakeran, lived about six million years ago in what is now Africa, with fossils found in Kenya. But it didn’t look like any other mustelid. It had long legs, for one thing. It stood almost two feet tall at the shoulder, or 60 cm, and was built more like a leopard than a mustelid. It would have been a much faster runner than other mustelids as a result, although it was probably an ambush predator. Researchers think it was eventually outcompeted by big cats when they evolved as the forests changed into grasslands.

The biggest mustelid that ever lived, as far as we know, is Enhydriodon, a type of gigantic otter. It lived in Africa around 4 million years ago and may have been the size of a small bear, even bigger and heavier than Megalictis. We only have a single fossil of Enhydriodon, though, a skull, so scientists can only estimate the animal’s size compared to what we know about extinct and living otters. It probably lived on land, although that’s about as far as our knowledge of it goes.

Another giant mustelid was Plesiogulo, which evolved in Asia and crossed into North America 6 1/2 or 7 million years ago when the continents were connected by the Bering land bridge. Researchers weren’t sure for a long time if Plesiogulo was directly ancestral to living wolverines, but recent studies indicate that it probably was. It was larger than modern wolverines.

But what about living mustelids? The biggest known mustelid that’s still alive is the giant otter, which lives in much of northern and central South America, especially around the Amazon River, although it’s increasingly rare due to habitat loss, hunting for its fur, and pollution. It can grow up to 5 1/2 feet long, or 1.7 meters. It mostly eats fish but will eat other animals too, including crabs, snakes, turtles, and even small caimans. It’s a social animal that lives in family groups of up to twenty members that hunt and play together. It has short dense fur that’s usually brown or sometimes reddish, but it has white markings on its throat and upper chest. When it pops its head and neck out of the water, called periscoping, other otters can see its unique white markings and recognize who they’re looking at. It’s also really noisy as it communicates with other otters with barks, whines, growls, and softer sounds like humming. Each family group has a unique vocalization that identifies the group to other otters, and if a strange otter approaches the territory the whole family will scream at it to get out or else.

The sea otter is a little shorter than the giant otter, just under 5 feet long, or 1.5 meters, but it’s heavier than the giant otter. A big male can weight up to 119 pounds, or 54 kg. It lives along the coast of the North Pacific and while it can walk, it spends almost all its time in the water. Instead of blubber to keep it warm, the sea otter has incredibly dense fur, the densest coat ever measured. For almost two centuries people hunted it so aggressively for its fur that by 1911, there were fewer than 2,000 of them left. Fortunately, conservationists worked to get an international ban on sea otter hunting, and its numbers have rebounded although it’s still endangered.

The sea otter eats fish and anything else it can catch, especially shellfish, and it uses its front paws while hunting. It catches fish with its paws instead of with its mouth, it turns over rocks to look underneath them, and it pulls mollusks off of rocks and twists them open with its paws. This is all really unusual. No other otter uses its paws in this way. Not only that, the sea otter is a tool-user. It uses rocks to break open shellfish that it can’t twist open or bite through, and will in fact use two rocks at once for this purpose. One of the rocks it holds, but the other it keeps in a little pouch of skin under its arms to act as a hard surface to set the mollusk on. The sea otter also uses this built-in pocket to hold food. It has two pockets, one under each front leg, and it usually keeps its rock in the right pocket while it keeps its food in the left pocket. It floats on its back to eat, then rolls over and over in the water to clean its fur of any bits of food. It has to keep its fur incredibly clean for it to insulate the otter properly, so it grooms itself throughout the day. Pascal in Animal Crossing is a sea otter, by the way, and adorable.

The smallest living mustelid is the least weasel, which is native to northern North America and much of Eurasia but has been introduced in New Zealand and several islands throughout the world, where it’s an invasive species. The smallest subspecies of least weasel grow less than 10 inches long, or 26 cm, with a short tail. It’s brown with a white belly during the summer but its winter coat is completely white. It eats mice, voles, and other small rodents and will even kill rabbits although rabbits are much bigger than it is. Generally it only attacks young rabbits, though.

So that gives us some background about mustelids. Let’s talk about some interesting kinds of mustelid next, starting with the mink. You may have heard something about the mink in the news lately, because mink are kept in large numbers in fur farms and they’ve started to contract a mutated version of the Covid-19 virus. The virus is so widespread among mink in the country of Denmark that as of last week as this episode goes live, Denmark has decided to kill every single mink in captivity. That’s as many as 19 million animals. Keep in mind that these animals were eventually going to be killed anyway for their fur. That doesn’t make it any less sad, though. The same mutated virus has spread through fur farms in other countries, including Spain and the United States, leading to thousands of animals being killed to stop the spread. So far studies do not indicate that the minks are spreading the mutated version of the virus to humans. The Netherlands had already been planning to ban mink farming in a few years, but after an outbreak of the coronavirus earlier in 2020 the country decided to ban it by the end of this year. Good for them.

In the wild, where it belongs, the mink lives near rivers, lakes, or other sources of fresh water, and sometimes even along the coast. It eats fish, rabbits and other small mammals, eggs, small crustaceans like crayfish, and anything else it can catch. A big male can grow up to two feet long, or 62 cm, and it’s brown in color with a dense undercoat that helps keep it warm in cold weather. There’s a species that lives in North America and a species that lives in Europe, but while they look almost identical, they’re actually not very closely related.

If you think of weasels, you probably think of an animal that looks a lot like the mink or the ferret, with sleek fur. But the Patagonian weasel is quite different in many ways. It lives in Patagonia, which is the southern part of South America, and is the only member of its own genus. Its coat is shaggy with a bushy tail. It’s mostly white or off-white with brown patches and grows up to 14 inches long not counting its short tail, or 35 cm. We know almost nothing about the Patagonian weasel. We’re not even sure what it eats, except that it does probably eat small burrowing rodents, and it’s sometimes been kept by ranchers to kill rats the way ferrets were once used in England.

The greater grison is another unusual-looking mustelid native to Central America and northern South America. It’s shaped sort of like an otter but instead of brown fur it’s gray on top and black underneath. A white stripe separates the gray and black fur on its head and the sides of its neck. Most of its face is black, then the white stripe usually just above the eyes, then gray on top of its head. It can grow up to two feet long, or 60 cm, not counting its bushy tail, which can grow up to 14 inches long, or 20 cm. Like all mustelids, its ears are small and round and its body is long with short legs. Although it looks like an otter, including having webbed toes, it’s probably more closely related to the Patagonian weasel, and like the Patagonian weasel, we don’t know a whole lot about it.

The fisher is a mustelid that lives in North America, mostly in parts of Canada and in mountainous areas of northern and western United States. It used to be more widespread, but, you guessed it, it was trapped and killed for its fur until the 1930s and even as late as the 1980s in some areas.

Despite its name, the fisher doesn’t actually eat fish very often. The name fisher comes from a Dutch word, visse, which refers to a different mustelid, the European polecat. The fisher is also sometimes called the fisher cat even though it and the polecat are not cats. It’s a big animal, too. A big male fisher can grow nearly four feet long, or 1.22 m, although females are much smaller, and part of that length is the tail that can be as much as 16 inches long, or 41 cm.

The fisher has big feet that helps it walk on snow, retractable claws, and it can even rotate its hind feet nearly completely backwards, which means it can climb down trees headfirst. It lives in forests and spends a lot of time in trees, hunting birds and other small animals, but it mostly eats showshoe hares and porcupines. Yes, porcupines! Almost nothing will bother a porcupine, but the fisher will attack it from the front, biting its less protected face repeatedly until it dies. In areas where fishers were hunted to extinction, porcupines became so numerous that they started killing trees, since in winter porcupines eat tree bark and will also eat sapling trees. Fortunately, the population of fishers has grown and conservationists have reintroduced it into parts of its former range. It’s no longer considered endangered, hurrah! This is good because they’re hard to keep in captivity and they’re also susceptible to accidental poisoning when they eat rodents that have died from eating poison.

The fisher is supposed to be a loud animal with a terrifying scream at night, but people who study fishers don’t report hearing them scream or make loud sounds at all. The calls are all probably made by the red fox, which sounds like this:

[fox sound]

There are so many mustelids that I don’t even know what other ones to feature. It’s surprising how little we know about so many of them. The Vietnam ferret-badger was only described in 2011, for instance, and only known from two specimens. It’s related to other ferret-badgers found in Asia, including the Chinese ferret-badger. As you might guess from the name, it looks sort of like a badger but also like a ferret, which is a neat trick because those two animals do not actually look very much alike. It grows around 17 inches long, or 43 cm, plus another 9 inches, or 23 cm, for its tail. It’s dark brown above and lighter brown underneath, with a white stripe on its head and neck and a black mask on its face. Its muzzle is longer than most mustelids’, who usually have quite short noses. It’s an omnivore that eats fruit as well as insects, worms, frogs, and other small animals.

In general, as I’ve mentioned over and over, mustelids have historically been killed for their fur. Sable and ermine are both names of furs that come from mustelids. At least one species was driven to extinction by fur hunters, the sea mink. It lived along the northeastern coast of North America and was related to the American mink. We don’t even know exactly how big it was, because it was driven to extinction before it could be examined by scientists, except that it was probably bigger than the American mink. We don’t even have a complete specimen, just some skull fragments and teeth. It wasn’t as aquatic as otters are, but it occupied a similar ecological niche and spent much more time in the water than its close relations. It probably went extinct in the late 19th century. Other species of mustelid may have been driven to extinction without ever being known to science too. Certainly many species came close to extinction and are still threatened by habitat loss and other factors.

That’s depressing to think about, so let’s finish with a mystery that’s a little different from our usual mystery animals. This one’s a mystery song called “Pop Goes the Weasel.” You’re probably familiar with the tune even if you’re not sure about the words. There are lots of different lyrics to the song with various versions in different places. I learned it this way:

Round and round the mulberry bush / The monkey chased the weasel / The monkey stopped to pull up his socks / Pop! Goes the weasel.

A penny for a spool of thread / A penny for a needle / That’s the way the money goes / Pop! Goes the weasel.

What on earth do those lyrics mean? Do they mean anything? Why is there a weasel in the song?

The earliest lyrics known date back to at least the early 19th century in England, because the oldest versions of the song reference a famous pub in London from the time. The melody was probably much older and the words were fitted to the song at some point. By 1850 it was a popular dance, but even then no one knew what the lyrics meant.

There are lots of suggestions, some of which make more sense than others. The oldest lyrics seem to be these:

Half a pound of tuppenny rice / Half a pound of treacle / That’s the way the money goes / Pop! Goes the weasel.

Up and down the City road / In and out the Eagle / That’s the way the money goes / Pop! Goes the weasel.

The line “that’s the way the money goes” basically tells the story. It’s a song about how everything is a penny here, a penny there, and suddenly you’re broke. And if you’re going in the Eagle Tavern on London’s City Road too often, you’re drinking up whatever money you have left. But that still doesn’t explain the weasel.

One explanation is that to pop something was slang for pawning it, and that the term weasel is Cockney rhyming slang for a coat. You know, “weasel and stoat” rhyme with coat, therefore you can just say weasel and everyone who knows the rhyme knows that you’re talking about a coat. So if you pop a weasel, you’re pawning your coat to get a little extra money.

This sounds plausible, and there’s some evidence that the line “pop goes the weasel” was the only line of the song originally, with the other lyrics added later, which would explain why that one line is slang while the other lines aren’t. Anyway, it’s a fun song that you will not be able to get out of your head now.

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

Thanks for listening!

Episode 197: Titanoboa!

Posted on by

Podcast: Play in new window | Download (Duration: 9:39 — 10.0MB)

Subscribe: RSS | More

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

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

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

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

Show transcript:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Thanks for listening!

Episode 190: The Northern Gannet and Plotopterids

Posted on by

Podcast: Play in new window | Download (Duration: 12:33 — 12.8MB)

Subscribe: RSS | More

Thanks to Lorenzo for suggesting the northern gannet this week! We’ll also learn about an extinct ancestor of the gannet, called plotopterids!

Don’t forget to enter our book giveaway! Details here.

The northern gannet is the assassin of the bird world, probably:

DIVING! It’s what they do:

Northern gannets hanging out on their nesting grounds:

An artist’s rendition of a plotopterid, with the silhouette of a modern emperor penguin for comparison. Picture from March of the Fossil Penguins.

Show transcript:

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

This week let’s learn about two interesting birds! Thanks to Lorenzo for the suggestion!

But first, an announcement! I’m doing a giveaway of my books Skytown and Skyway! The giveaway runs through October 31, 2020 and is open to anyone in the world. To enter, just let me know you’d like to enter. You can email me at strangeanimalspodcast@gmail.com, leave me a message on Twitter or Facebook, or anything else. All I ask is that you make it clear that you want to enter and let me know how to contact you if you win. On Halloween night at midnight I’ll choose one name at random from everyone who enters and that person will win one paperback copy of each book, and I’ll also throw in some stickers, bookmarks, a pencil that says “I bite mean people,” and probably some other stuff. I’ll also sign the books if you like. If you want to take a look at the books to see if they sound interesting, I made a new page on the strangenanimalspodcast.blubrry.net website with links. Please enter. It will be embarrassing if no one does.

Anyway, Lorenzo wants to hear about the northern gannet, a sea bird that sort of looks like a gull who mastered the blade and is probably an assassin. Its bill is large, silvery-blue, and dagger-like, outlined with black at the base that makes a dramatic mask. This mask is actually bare of feathers, showing the bird’s black skin. Otherwise it’s mostly white, with a wash of pale golden on the head and neck, black-tipped wings, and gray legs with webbed toes. But it’s also really big, almost the size of a pelican. Its wingspan can be over six feet, or 184 cm. It can weigh almost 8 lbs, or 3.6 kg, too.

Like many sea birds, the northern gannet breeds in colonies that can number in the thousands, and it only breeds on oceanside cliffs, mostly on islands off the coast of eastern Canada, Iceland, and western Europe. It’s especially common around the British Isles. So many birds may be nesting at once that the cliffs appear white from a distance, like snow fell on the clifftops, but instead of snowflakes, it’s gannets!

While the northern gannet will sit on the water after diving, the only time it actually sets foot on land is when it breeds. It doesn’t walk very well, which is why it nests on cliffs. It’s easier for it to get airborne from a cliff. It can only take off from the water by facing into the wind and flapping hard, but if it’s not windy enough it can’t get airborne and it just has to float there until the wind picks up, probably feeling pretty foolish. But it swims well so if it is stuck on the water, it can swim along with its head under water, looking for fish it can grab.

But most of the time the northern gannet is in the air, and it is built for speed and efficiency. Its long, narrow wings allow it to reach high speeds, up to 40 mph, or 65 km/h. It’s not very maneuverable, though, except for one specific move. The northern gannet is a diver. It’s a diver extraordinaire! It can reach incredible speeds while diving, up to 62 mph, or 100 km/h. When it dives, it holds its body rigid and angles its wings back, then folds the wings tight against its body just before it hits the water. It can dive up to 36 feet deep, or 11 m, and then it will swim farther down, sometimes over 80 feet deep, or 25 m. Its eyes are sharp and adapted to seeing both underwater and above water, so that as soon as it plunges into the water it can look around for fish. It uses both its feet and its wings to maneuver underwater.

The northern gannet mostly eats fish, but it will also eat squid if it happens to come across one. It prefers small fish like sardines and anchovies, but any fish that swims in a shoal is its favorite. Groups of northern gannets will dive together into a shoal of fish, and swallow the fish underwater. The northern gannet especially likes to follow whales and fishing boats to grab fish trying to escape, injured fish, or fish that are discarded as too small or the wrong kind.

Northern gannets live a long time, with the oldest known bird living past 34 years old. It’s not considered an adult until it’s about five years old. Breeding season starts in spring. The male finds a nesting site, or reclaims the nesting site he used the previous year, and defends it from other males, while females fly over the island and look for a male with a nesting site they like. Pairs generally mate for life, so many females are looking for their mates from the previous year. When a female has found a mate, she lands and displays her wings, while the male displays his neck and shakes it in a little courtship dance.

The male collects seaweed, grass and other plants, feathers, even dirt to build the nest. He’ll basically bring back anything he can find to add to the nest, and researchers have found some weird stuff in gannet nest walls. This includes golf balls, a set of false teeth, a gold watch, and a plastic frog. Not all in the same nest, though. Nests are always just a few feet apart, or maybe 60 cm, even though gannets are fiercely territorial and will fight any other gannet that comes into its little territory.

The female lays one egg. Both the male and female take turns keeping the egg warm, which they do by wrapping their big webbed feet around it. Usually their feet are cool, but during nesting season their feet stay much warmer. The parents will keep the baby warm the same way, wrapping their feet around it. One parent will stay with the chick while the other flies out to fish.

When northern gannet chicks are ready to learn how to fly, they don’t get a chance to practice. I mean, they nest on cliffs. You get one try and you better be lucky or splat. And once they’re flying, they’re on their own and don’t return to the nest. They stay at sea for the next few years, then return to the nesting ground where they hang out in groups near the edges. Even though they don’t breed for a few more years after that, hanging out in the colony helps them learn where the best fishing spots are in the area.

I can’t count how many times I’ve had to say that an animal is threatened by habitat loss, hunting, and so on, but I’m happy to report that the northern gannet is not threatened by anything. It’s doing just fine, and in fact its numbers are increasing after it stopped being hunted extensively in the early 20th century. Its main problem in life is probably a bird called the skua, another sea bird that’s mostly black, brown, and gray. The skua is much smaller than the northern gannet but it’s aggressive, and will kill and eat smaller birds. The northern gannet is much too big to kill, so instead the skua will fly up to a gannet and grab its wing. The gannet falls to the water, where the skua will either keep hold of its wing so it can’t take off again, or will just peck it. Either way, it won’t leave the gannet alone until it regurgitates whatever fish it’s eaten recently but hasn’t digested, which the skua eats.

This is what the northern gannet sounds like:

[northern gannet sounds]

While I was researching the northern gannet, I ran across an article about extinct relations called plotopterids. Plotopterids probably looked a lot like penguins. They also probably acted like penguins, using their short wings as flippers while swimming to catch fish. But they weren’t penguins. They weren’t even related to penguins, or even to the similar-looking great auk, which we talked about in episode 78. They were related to gannets, cormorants, and boobies, which are all sea birds that can fly.

Plotopterids lived in the northern hemisphere between around 35 and 25 million years ago, with fossils of the birds discovered in various places around northwestern North America and Japan. But they were huge! They were even bigger than the extinct giant penguins of the southern hemisphere that could grow almost five and a half feet long, or 1.6 meters. The biggest species of plotopterid known could grow six and a half feet long, or 2 meters.

The similarities between penguins and plotopterids are due to convergent evolution, where animals that share similar environmental conditions develop similar traits. We don’t know whether plotopterids had the same black and white coloring that penguins have, but it’s a good bet that they did. Most sea birds are black and white. Even most diving ducks that live in fresh water are black and white, whereas dabbling ducks have more varied colors. The most obvious difference between penguins and plotopterids, though, is the neck. Penguins have relatively short necks. Plotopterid necks were longer.

Researchers are studying plotopterids to learn why these birds and penguins evolved to swim using their wings. Most birds that can swim use their feet to propel them along in the water. One scientist in the study I read about, Dr. Gerald Mayr, says, “We think both penguins and plotopterids had flying ancestors that would plunge from the air into the water in search of food. Over time these ancestor species got better at swimming and worse at flying.”

I bet the young northern gannets who are about to try flying for the first time wish they were a little more like plotopterids and could just swim away from the nest.

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

Thanks for listening!

Episode 188: The Hyena and Hyaenodon

Posted on by

Podcast: Play in new window | Download (Duration: 13:24 — 13.3MB)

Subscribe: RSS | More

This week we’re going to learn about hyenas and the not-related-but-similarly-named hyaenodon! BUT we’ve got a PARENT WARNING WHOOP WHOOP WHOOP *klaxon sounds, red lights flash*

Parents and others who listen with small kiddos, you may want to pre-screen this episode since we go into some details of hyena anatomy that may not be appropriate for younger listeners.

CORRECTION! Thanks to Bal who pointed out that despite what I say on the episode, the hyena is not a canid! Oops, that was a really basic mistake.

Further watching:

Two hyena cubs pester their napping mom until she wakes up and lets them nurse.

A spotted hyena:

TEETH:

An aardwolf. My friend, your ears are very pink:

Show transcript:

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

This week we’ve actually got a PARENT WARNING. Parents, grandparents, and other adults who listen with younger children may want to pre-screen this episode. I go into detail about some aspects of hyena anatomy and reproduction that may not be appropriate for your kiddo to listen to. This is only a small part near the end of the episode, though, and I’ll give you a heads-up when we reach it in case you want to skip forward or stop listening at that point. To make up for all this, I’ve also released a Patreon episode about animal poop that will go live at the same time as this episode so you can download it just like any other episode.

So, this episode is about hyenas. Thanks to Pranav for suggesting both hyenas and hyaenadon!

The hyena is [NOT] a canid that lives in Africa. There are only four species in its family, with three genera. Although it’s a canid, the hyena has a lot of traits associated with felids, and some traits associated with viverrids [vy-VERrids]. Viverrids are interesting animals that look sort of like cats and sort of like weasels, and one day I need to do a whole episode about them. Hyenas belong to the suborder Feliformia along with cats, viverrids, mongooses, and some other animals, so even though hyenas are canids, they’re very different from wolves and dogs and foxes.

The hyena has a distinctive body shape, with a back that slopes downward to a rounded rump with shorter hind legs. It also has a relatively short tail. Its forequarters are strong while the hindquarters are less powerful. Its neck is short and thick and its face has a short muzzle. The sloping back and rounded rump actually serve an important purpose. If a predator tries to grab a hyena from behind, not only will it find it hard to get a purchase on the rump, the hyena can use its strong front legs to scramble out of a predator’s grip and run away.

But let’s talk about the hyena’s ancestors before we talk about modern hyena. The first hyena ancestor, called Protictitherium, was a tree-dwelling animal with short legs and long body. Protictitherium had retractable claws like a cat and probably mostly ate small animals and birds. It first appears in the fossil record around 18 million years ago, but although its descendants evolved into much larger ground-dwelling animals starting around 17 million years ago, it actually didn’t go extinct until around 4.5 million years ago.

Around 10 million years ago, some hyaenids started to look more doglike than their ancestors, developing into a jackal-like animal that chased its prey through open forests in Europe. And around 6 or 7 million years ago, the first bone-crushing hyaenids developed, which would probably have looked a lot like modern hyenas, but bigger, with a few species as big as a lion.

Hynaeids were doing great throughout Europe and Asia…until other canids made their way to Eurasia from North America. Around 3 or 4 million years ago the first wolf-like canids moved into Europe and almost immediately hyaenids started becoming rarer and rarer in the fossil record as their distant relatives outcompeted them. Almost the only exception was the cave hyena, which lived throughout much of Europe up into Siberia and which primarily killed horses, bison, and woolly rhinoceroses. They also killed wolves, which is probably why the cave hyena didn’t go extinct until around 11,000 years ago when most of its megaherbivore prey also went extinct. We have rock art of cave hyenas made by ancient humans, which means we know it looked a lot like a modern spotted hyena.

Modern hyenas all live in Africa. They have a reputation as a cowardly scavenger, but this isn’t actually the case. While the hyena will scavenge food occasionally, it’s a fierce hunter, especially the spotted hyena. Not only that, it can and will eat every part of the animal, including skin, bones, and hooves.

The only species of hyena that doesn’t have stripes is the spotted hyena, but that’s not the only difference. Let’s look into what makes the spotted hyena so different from its hyena cousins.

The spotted hyena is indeed spotted, although the color and pattern of its coat is variable. Generally, though, it’s yellowish or pale brown with darker spots in an irregular pattern. It’s also the only hyena species that doesn’t have a mane on its neck. It’s a large animal too, up to three feet tall at the shoulder, or 91 cm. Females are generally larger than males.

The spotted hyena has a complicated social life. It lives in sometimes large groups, called clans, with up to 80 hyenas. This isn’t the same as a wolf pack. The spotted hyena’s clan structure is actually very similar to that of some monkeys like baboons and macaques, with an individual’s status in the group coming from who its friends and immediate family members are, not how big or strong it is. Clans are also matriarchal, meaning that females are leaders of the group and are considered more socially important than males. In fact, even the lowest ranking spotted hyena female is more important to the clan than the highest-ranking spotted hyena male.

That brings us to the spotted hyena female’s extraordinary differences from other hyenas, and to our content warning. Bing bing bing, content warning for small ears time! We’re going to go into some details of mating and anatomy that may not be appropriate for everyone. If you want to skip forward about two minutes, you can learn about a living hyena relation and an extinct hyena-like animal at the very end of the episode.

The female spotted hyena has what’s called a pseudo-penis. We’ve mentioned this before in one or two other species, but we need to go into detail about this one because it’s so unusual. The pseudo-penis is formed from the female’s clitoris and doesn’t just look like a penis, it acts like one. The female can actually get an erection. She also urinates through the pseudo-penis. The labia are also fused to form a pseudo-scrotum, which means the entrance to the female’s vagina is blocked. This means that it’s actually difficult for the male to mate with the female, because her pseudo-penis is in the same place that a male’s penis is and he has to mate with her through it.

But things get even more complicated when it’s time for the female to give birth. She has no vaginal opening, remember, just a pseudo-penis. Well, she actually has to give birth through the pseudo-penis, and as she does, the clitoris ruptures because—and this is the worst thing of all—spotted hyena cubs are actually quite large. Females usually give birth to one or two cubs in a litter, but about a quarter of the time, one of the cubs will kill the other within a few weeks.

Whew. I think that covers it. If you didn’t wince and cross your legs protectively during that fun little segment, you are made of sterner stuff than me.

All clear, bing bong. It’s safe for little ears to come back and learn about the aardwolf, an animal that lives in eastern and southern Africa. It’s nocturnal and spends its days in a burrow, sometimes digging a burrow itself but most often just moving into burrows abandoned by other animals. It has black stripes on a yellowish coat, a mane down its neck and back, large ears, and a bushy tail. It’s about the size of a big dog, about 20 inches tall at the shoulders, or 50 cm, but it looks like a small, slender hyena. That’s because it is actually considered a hyena, although it’s not very closely related to other hyenas, and it has evolved to eat mostly insects. It especially likes termites and can eat up to a quarter million termites a night. Its teeth are weak and its tongue is long and sticky.

Let’s finish up with a family of animals called Hyaenodontidae, which means “hyena tooth.” Despite the name, Hyaenodonts weren’t related to hyenas or canids at all. They evolved much earlier and died out about the time that little Protictitherium was climbing around in trees eating birds.

The first hyaenodonts evolved in Africa around 60 million years ago and soon spread into Europe and Asia, and eventually into North America. It was a big carnivore with long, slender jaws, a long tail, and big flat feet sort of like a bear’s paws. There were lots of species, including one that lived along the coast and specialized in eating shellfish, and which was adapted to swim sort of like an otter. But the largest Hyaenodont was Hyaenodon gigas, and it was huge even by modern standards. It stood 4.5 feet tall at the shoulder, or 1.4 meters.

Hyaenodon had massive jaw muscles that allowed it to bite right through an animal’s skull to kill it. We know because we have a fossil skull of a small cat-like mammal that has puncture wounds that exactly match up to Hyaenodon’s tooth pattern. Hyaenodon’s rear teeth were sharper than its front teeth, though, and it used them to slice its meat into smaller pieces before swallowing it. But it also crushed and ate a lot of bones, just like modern hyenas do. It was probably an ambush predator, and we have a lot of Hyaenodon fossils found in areas that were once watering holes. So even though Hyaenodon had a small brain compared to modern hyenas and other mammals, it was pretty smart about where to find food.

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 and get twice-monthly bonus episodes.

Thanks for listening!