Episode 129: The blurry line between animals and plants

This week we’re looking at some really strange animals…or are they plants? Or both? We’ll start with the sea anemone, then learn about a sea slug that photosynthesizes like a plant (sort of), then learn a little about whether algae is a plant or an animal…and then we’re off and running through the wild world of carnivorous plants–including some carnivorous plants of mystery!

Thanks to Joshua Hobbs of A Degree in Nonsense for the suggestion, and to Simon for the article link I’ve already managed to lose!

A sea anemone and some actual anemones. Usually pretty easy to tell apart:

The sea onion looks so much like an onion I can’t even stand it. This is an ANIMAL, y’all!

Venus flytrap sea anemone and actual Venus flytrap. It’s usually pretty easy to tell these two apart too.

 

The eastern emerald elysia, a sea slug that looks and acts like a leaf:

Giant kelp. Not a plant. Actually gigantic algae. Algae is neither a plant nor an animal:

The corpse flower (left) and the corpse lily (right). Both smell like UGH and both are extremely BIG:

The pitcher plant can grow very big:

Maybe don’t go near trees with a lot of skulls around them:

Puya chilensis (the clumps in the foreground are its leaves; the spikes in the background are its flower spikes):

Show transcript:

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

This week we’re going to explore the sometimes blurry line between animals and plants. Joshua Hobbs of a great new podcast A Degree in Nonsense suggested a type of carrion flower that smells like rotting flesh to attract insects, and friend of the pod Simon sent me an article about carnivorous plants. Our very first Patreon bonus episode was actually about carnivorous plants, so I’ve expanded on that episode and added lots of interesting new content. Buckle up, folks, because we’re going to cover a whole lot of ground today!

Oh, and Joshua also says, quote, “I never had a pet growing up, but recently gained an interest in animals. Now after getting into your podcast and animal YouTube channels, I’ve got my first pet, a little corn snake named Arnold!” So welcome to podcasting, Joshua and Arnold!

Let’s start by looking at an animal that resembles a plant. The sea anemone looks so much like a plant that it was named after an actual flower, the anemone, but the sea anemone is related to jellyfish. Most sea anemones attach to a rock or other hard surface most of their lives and don’t move much, although they can creep along very slowly—so slowly that snails are racecar drivers in comparison. Many species have a body shaped like a plant stem and colorful tentacles that resemble flower petals. But those tentacles aren’t just to look pretty. The sea anemone uses them to catch prey. The tentacles are lined with stinging cells that contain venom, just like many jellyfish have. The venom contains neurotoxins that paralyzes a fish or other small animal so that the sea anemone can eat it.

So how does something that looks like a plant eat a fish?

The sea anemone has an interesting body plan. What looks like the stem of a plant is called the column, and in some species it’s thin and delicate while in other species it’s thick like a tree trunk. It sticks to its rock or whatever with an adhesive foot called a basal disc, and on the other end of the column is what’s called the oral disc. Oral means mouth. The actual mouth is in the middle of the oral disc, surrounded by tentacles. The mouth is usually shaped like a slit, which if you think about it is sort of how people’s mouths are too. The digestive system is inside the column. But there is no other opening into the body. The mouth is it. So like jellyfish, the mouth takes in food but it also expels waste, so, you know, not precisely a mouth like ours. When the sea anemone wants to eat, it uses its tentacles to push the food into its mouth.

You know the movie Finding Nemo? Nemo and his dad are clownfish, which aren’t affected by sea anemone venom. Clownfish hide among sea anemone tentacles so predators won’t bother them. In return, the sea anemone eats the clownfish’s poops. I wish I were making that up.

If a sea anemone feels threatened, many species can not only suck its tentacles into its mouth, it can retract the whole mouth inside its body. Basically, it can swallow its own mouth. A sea anemone called the sea onion retracts its tentacles and inflates its column so that it looks like an actual onion. The sea onion lives in a burrow it digs very slowly into the sediment at the bottom of the ocean, with just its tentacles sticking out.

Most sea anemones live in relatively shallow water, but there are some deep-sea species. The Venus flytrap sea anemone has been found at 5,000 feet deep, or over 1,500 meters. At first glance looks like a Venus flytrap plant, thus the name. Its body is a long, usually slender column that widens into a big oral disc on top that’s fringed with short tentacles. It mostly eats detritus that drifts down from above, which it filters from the water with its tentacles, although if a living creature strays into its tentacles it’ll eat it too.

That brings us to the actual Venus flytrap. It’s a plant that eats insects and spiders, especially crawling insects like ants and beetles. The ends of its leaves are modified into lobes that look a little like flowers because the insides of the lobes are a cheerful red while the edges and the hair-like cilia are yellow. When a bug touches the receptors inside the lobes it closes tightly. If the insect continues to move around inside, stimulating the receptors even more, the lobes seal and form a sort of stomach. Digestive enzymes are secreted and about ten days later the lobes reopen and there’s nothing left of the insect but its empty exoskeleton.

If bugs made movies, this would be the subject of every single bug horror film.

The Venus flyptrap is only found in one small part of the world, the boggy areas surrounding Wilmington, North Carolina in the United States. They’re so in demand that the plant is almost extinct in the wild due to idiots digging them up to sell. But Venus flytraps really aren’t that difficult to grow, you just have to make sure the soil you use is deficient in nitrogen and phosphorus. So you can buy Venus flytraps that were grown ethically instead of dug up from the wild. As of 2014 digging up a Venus flytrap is a felony in North Carolina.

Before we go on to talk about some other carnivorous plants, let’s discuss an animal that acts like a plant. It’s a sea slug called the eastern emerald elysia and it lives along the east coast of North America in shallow water. Even though it’s a sea slug, it will also live in fresh water. It grows to about an inch long, or 3 cm, and is green. It’s green because it photosynthesizes like a plant…sort of.

The sea slug eats algae, but it doesn’t fully digest the algae it eats. Its digestive system retains the algae’s chloroplasts, which are the parts of a plant cell that convert sunlight into energy, which is what photosynthesis is. The sea slug keeps the chloroplasts in its digestive system and keeps them alive for months, living off the energy the chloroplasts produce. Researchers aren’t sure how the sea slugs keep the chloroplasts alive.

This is pretty amazing, but it’s not the only sea slug that photosynthesizes in this way. The blue dragon sea slug, that lives along coasts around the Indo-Pacific Ocean, doesn’t just keep chloroplasts alive to produce chlorophyll energy. It gets even more complicated about it. The blue dragon eats tiny animals called hydrozoa, which are related to jellyfish and include the freshwater hydra, although since the blue dragon only lives in the ocean it doesn’t actually eat the hydra. The blue dragon eats hydrozoa that themselves contain a type of microscopic algae that live in a lot of animals, like giant clams, some jellyfish, even some sea anemones, and exchange energy from photosynthesis for protection from predators by living in or on its host. So when the blue dragon eats the hydrozoa containing these algae, it retains the algae and keep them alive. So basically it gets to eat its prey and steals its prey’s symbiotic algae.

Speaking of algae, most algae photosynthesize, and in fact many seaweeds, like kelp, aren’t plants but are giant plant-like algae. But algae, technically, aren’t plants. They’re not animals either. Researchers and taxonomists are still working out the ways various algae are related to each other and to other organisms, but most algae are considered more closely related to plants than to animals without actually being plants. They’re usually grouped with plants above the kingdom level of taxonomy, but since at that level animals like humans and fish and worms and mosquitoes are grouped with fungi, this is a really broad category.

And that brings us, in a roundabout way, to the rotten meat smelling plant suggested by Joshua. There are several plants that attract flies and other insects to pollinate their flowers by smelling of rotten meat. Some of these have freakishly large flowers, like the corpse flower. It lives in rainforests in parts of Sumatra and Java and is actually related to the calla lily. It’s a weird-shaped plant and hard to describe. You know how a calla lily has a pretty white petal that wraps around a yellow spike thing? The corpse flower is like that, only it can be ten feet high, or 3 meters. The thing that looks like a petal is actually a specialized leaf and the yellow spike is called the spadix. The yellow part is made up of tiny flowers, so a calla lily isn’t a single flower, it’s lots of flowers that look like one. Well, the corpse flower is like that, although its flowers are actually only at the bottom of the spadix. The petal-like leaf is dark red inside. The top of the spadix is where the rotten smell comes from, and it’s incredibly stinky—something like rotting meat and rotting fish with some extra smell like dung on top of it. It releases this stink mostly in the evenings and the top of the spadix actually grows hot to better disperse the smell.

The largest single flower in the world is sometimes called the corpse lily and it can grow over three feet across, or about a meter. It’s dark reddish-brown with white speckles and five fleshy petals, which look like meat. It smells like rotting meat too. Flies are attracted to the flower, which pollinate it. The flower can take an entire year to develop but only blooms for a few days. If it’s successfully pollinated, the flower produces a round fruit full of seeds that are eaten by tree shrews, which later poop the seeds out and spread them.

But the corpse lily isn’t any ordinary plant. It doesn’t even have roots or a stem or leaves. All it has is the flower, which grows directly from the roots of the corpse lily’s host plant. That’s right, the corpse lily is a parasitic plant, but it’s no ordinary parasite. It grows not on or around its host plant, but inside it. The host plant is a type of vine called Tetrastigma, related to the grape vine. When a tree shrew poops out a seed, the seed germinates and if it happens to germinate on a Tetrastigma vine, it develops tiny threadlike filaments that penetrate the vine and grow inside it.

The corpse lily lives only in the rainforests of Borneo and Sumatra, and it’s rare and getting rarer since so much of the rainforests in those areas are being destroyed. Fortunately, the corpse lily is actually a tourist attraction since it’s so rare, so spectacular, and so stinky. People who have corpse lilies growing in their yard sometimes protect the flower buds from harm and charge tourists to come look at them, which helps the people of the area and the plants.

There are literally hundreds of carnivorous plant species, with carnivorous habits evolving probably nine different times among plants that aren’t related. Different species use different methods to catch insects. For instance, the pitcher plant has modified leaf that forms a slippery-sided pitcher filled with nectar-like liquid. When an insect crawls down to drink the liquid, it falls in. The insect drowns and is dissolved and digested.

Some carnivorous plants have leaves lined with sticky mucilage, which traps small insects. The sundew has tentacles lined with hair-like structures beaded with mucilage. When an insect becomes trapped in the mucilage, the tentacles bend toward the insect and stick onto it, sometimes quite quickly—in seconds, or in at least one species, a fraction of a second. Generally you don’t think of plants as moving that fast.

Almost all known carnivorous plants are pretty small. The largest are pitcher plants. Two species of big pitcher plants grow in the mountains of the Philippines. Attenborough’s pitcher plant was discovered in 2007 and described in 2009, and is a shrub with pitchers that can hold nearly two liters of fluid. An even bigger pitcher plant was discovered in 2010. But the biggest pitcher plant known is from a couple of mountains in Malaysian Borneo called Nepenthes rajah. It’s been known to science since 1858 and its pitchers can hold over 2 ½ liters of digestive fluid. The biggest pitcher ever measured was over 16 inches tall, or about 41 cm, and the plant itself is a messy sort of vine that can grow nearly 20 feet long, or 6 meters. Mostly pitcher plants just attract insects, but these giant ones also trap frogs, lizards, rats and other small mammals, and even birds.

There’s always the chance that even bigger pitcher plants have yet to be discovered by science, although probably not much bigger than the ones we do know about. The larger an animal, the more likely it is to damage the pitcher while trying to escape. Insects and the occasional small animal are fine, anything bigger than that could just bust through the leaf.

But there have long been rumors about plants that eat much larger animals, even humans. In the 1870s, a German explorer named Karl Liche claimed he’d witnessed a tribe in Madagascar sacrifice a woman to a carnivorous tree. His account is not very believable. He describes the tree as about eight feet high with a thick trunk. A coat of leaves hang down from the top of the tree, leaves about twelve feet long with thorns. At their base is a flower-like receptacle with sweet liquid inside, with six ever-moving tendrils stretching up from it. When the sacrificial woman was made to drink the liquid, the tendrils wrapped around her and the tree’s long leaves folded up and over her. After ten days, the leaves relaxed, leaving nothing but a bleached skull at the base of the tree.

Later expeditions to Madagascar never found any plant that resembled Liche’s. In fact, everyone who’s researched Liche, the tribe he mentioned, and the tree in question haven’t found any evidence that any of them ever existed. It turns out that the account was a hoax from start to finish, written by a reporter named Edmund Spencer for a newspaper called the New York World in 1874.

A 1924 book called Madagascar: Land of the Man-Eating Tree describes a more realistic-sounding carnivorous plant that was supposed to be from India. Its blossoms have a pungent smell that attracts mice and sometimes large insects, which crawl into a hole in the blossom that turns out to be a bristly trap. This sounds a little like the corkscrew plant that lives in wet areas of Africa and Central and South America. It has ordinary leaves aboveground but modified leaves that grow underground. The modified leaves are traps with a stalk lined with hairs pointing in one direction. Tiny water animals, especially single-celled protozoans, stray into the leaves but can’t get out because of the hairs. They’re digested and absorbed by the leaves. But there are no known corkscrew plants or anything like them that trap larger animals or animals that live aboveground.

An 1892 article describes a friend of a friend of a friend’s encounter with a tangle of thin, willow-branch-like vines covered with an incredibly sticky gum. This was supposed to have happened in Nicaragua in Central America. A Mr. Dunstan’s dog was ensnared by the plant but was rescued by Dunstan, who managed to cut the vines with his knife. In the process, both man and dog suffered blistered injuries from the plant, as though it had been trying to suck their blood. The article also says that natives of the area say the plant will reduce a lump of meat to a dried husk in only five minutes.

From these sorts of factual-seeming accounts, it’s a short step to plants of folklore like the Japanese Jubokko tree that grows on battlefields and drinks human blood. It captures people who pass too close to it, sticks its branches into them, and sucks out their blood. If someone cuts into the tree’s bark, blood comes out instead of sap.

Another carnivorous plant was supposedly encountered by a French explorer in 1933 in the jungles of southern Mexico. He doesn’t describe the plant in his 1934 magazine article, just says it’s enormous, but he does say that when a bird alighted on one of its leaves, the leaf closed and pierced the bird with long thorns. The expedition’s guide called it a vampire plant.

A similar story supposedly of a plant found in South America and Central Africa is of a short tree with barbed leaves that grow along the ground, and if an animal or bird steps on the leaves they twine around it and stab it to death, then squeeze the blood out to absorb.

There may actually be a real plant that these stories are based on. It’s called the Puya chilensis and it lives in Chile in South America, on dry hillsides of the Andes Mountains near the ocean. It’s an evergreen plant that only flowers after it’s some 20 years old, with a flower spike that can grow over 6 ½ feet high, or up to 2 meters. The flowers are pollinated by birds. But its leaves are long, edged with hooked spines, and grow in clumps that can be up to six feet wide, or nearly two meters.

Those hooks along the leaves give the plant its other name, the sheep-killer. Sheep and other animals can become entangled in the leaves, which are so tough that locals use the leaf’s fibers to make rope. If the animal can’t escape, it dies and its body decomposes, adding nutrients to the soil around the plant. Yum.

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 127: New World Vultures

This week we’ll learn about some vultures from North and South America–some living, some extinct, and one mystery! Thanks to Maureen and Grady for their suggestions!

Thanks also to Kat White for the Turkey Vulture Song that opens the podcast! If you’d like to buy her album “In the Eye of the Owl,” visit her website at katwhitemusic.com/

Further listening:

CritterCast episode 35 Turkey Vultures

How to tell a turkey vulture apart from a black vulture:

The king vulture has a very bright head:

The Andean condor soaring:

The painted vulture:

Show transcript:

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

Way back in episode 40 we learned about the bearded vulture and some of its close relatives. This was a suggestion from Maureen, and I always meant to revisit vultures so we could learn about more vulture species. Then Grady wanted to know how long buzzards stay in the sky until they come down for food, and why do they soar for so long? That’s a great question that shows some good observation skills, so let’s go back to vultures and learn more about them.

Those of you listening in Europe may be wondering why I’m talking about buzzards in a vulture episode. That’s because we’re going to learn about new world vultures today, and in North America the general term for a vulture is a buzzard. In Europe, a buzzard is actually a type of eagle.

Before we get into the episode, though, I should mention that the intro music we heard is by Kat White, who was kind enough to let me use a snippet. It’s from the album “In the Eye of the Owl,” which is all about animals and so much fun I wanted to let everyone know about it. I’ll put a link in the show notes so you can find out more about the songs.

Kat also let me know about a turkey vulture named Lord Richard who lives in a park called Lindsay Wildlife Experience in California. Lord Richard just turned 45 years old and got a huge birthday party! So as you can see, vultures can live a long time in captivity, although usually not as long in the wild. Then again, the oldest verified vulture is an Andean condor born in captivity in 1930 who died in 2010 at the age of 79. Andean condors in the wild can live more than 50 years. This makes Lord Richard sound like a positive youngster.

New World vultures are native to the Americas and all of them are pretty big. In fact, condors are vultures and they’re extremely large birds. The New World vultures aren’t very closely related to each other but they all share some traits.

Vultures are scavengers that find dead animals to eat. The meat from dead animal carcasses is referred to as carrion. Vultures will also eat rotting fruit and garbage sometimes. Because they eat meat that is often spoiled, vultures have an extremely acidic digestive system that helps the bird digest its food quickly and kills off any bacteria that might make it sick. It also has beneficial bacteria in its digestive system that neutralize toxins.

But that’s not where the adaptations to eating carrion end. The vulture is a highly specialized bird. Most vultures don’t have many feathers on their heads, unlike other birds. If you’re snacking right now, you might want to pause this until you’re done. Quite often a vulture will actually stick its head into a rotting animal carcass to get at the, uh, softer parts. This means its head gets covered in rotting gunk and a lot of bacteria. If it had head feathers, they would be destroyed by bacteria.

One interesting thing about vultures of all kinds is that they actually help stop the spread of diseases like rabies and anthrax. Their digestive tract is so effective that it kills off viruses that caused the animal to die, so it’s actually beneficial to the environment in general and to farmers. Unfortunately, farmers don’t always know this and think vultures spread disease. Many vultures are protected species in most countries to stop farmers and other people from shooting them.

Quite often you’ll see a vulture perched somewhere up high with its wings spread. It does this to dry them when it’s been rainy or foggy, but also so that sunlight will help kill off any bacteria on the feathers. That’s another reason the vulture has no feathers on the head, so that sunlight can kill off any bacteria on its skin.

Vultures do some other gross stuff, like pee on their own legs. They do this to cool down in hot weather, since as the liquid droppings evaporate it cools the legs, and therefore cools the blood flowing through the legs, and therefore cools the vulture’s body temperature overall. But vultures also like to bathe in shallow water, which helps clean the skin and the feathers, and which of course washes any droppings off their legs.

Vultures also puke up what they’ve eaten if they feel threatened. This serves two purposes. The vulture is immediately much lighter and can fly away more easily, and the horrible stench of partially digested rotting meat may drive away a potential predator.

There are seven species of new world vulture alive today. The most common one is the turkey vulture, which lives throughout most of North and South America. The next most common is the American black vulture, which lives in South America up to the southern parts of North America. From a distance it can be hard to tell the two apart, but the black vulture has silvery tips on its wings.

The turkey vulture is the vulture most often referred to as a buzzard. It has a wingspan of about six feet, or over 1.8 meters, although it doesn’t weigh more than about five pounds at most, or 2.4 kg. It’s kind of a picky eater, surprisingly, and doesn’t like really rotten meat. It often hangs out with black vultures, but black vultures are more aggressive even though they’re a little smaller, and the turkey vulture will wait until the black vultures are done eating before it moves in to finish off what’s left.

Black vultures and turkey vultures aren’t very closely related and don’t really look very similar if you see them up close. The turkey vulture has a red head that looks a lot like a male turkey’s, which is where it gets its name. The black vulture has a gray head.

Unlike the turkey vulture, which almost exclusively eats carrion and rotting fruit and sometimes vegetables, the black vulture will also eat eggs and sometimes kills small animals, especially baby animals. It hunts in groups and can even kill newborn calves.

If you want to learn more about the turkey vulture, the Critter Cast Podcast has a really good episode all about it. I’ll put a link in the show notes in case you don’t already listen to Critter Cast.

The other new world vultures are mostly restricted to South America, except for the California condor. We’ll talk about condors in a minute. The king vulture is most common in South America although it also lives in parts of southern Mexico and in Central America. Unlike most vultures, which are mostly black, its feathers are mostly white with some gray and black markings. The skin of its bald head is brightly colored, with different individuals having different coloration—red, orange, yellow, purple, even blue, with an orange crest on its bill in adult birds. It also has a white eye with a red rim, and short bristles on the head. The ancient Maya people considered the king vulture a messenger of the gods, which is pretty neat.

The king vulture is big even for a vulture, with a wingspan of up to about 7 feet, or 2 meters, which makes sense since it’s most closely related to the Andean condor. It has a stronger bill than most vultures, which helps it tear open an animal carcass that other vulture species might not be able to access. Often, other vulture species will wait until a king vulture has opened a carcass and eaten its fill before they move in and eat too. It especially likes the skin and tougher meat of a carcass, and its tongue is raspy to help it pull meat off bones.

The king vulture’s ancestors lived farther north, into parts of North America, but went extinct around 2 ½ million years ago. We don’t really know all that much about the ancestors of the New World vultures, though, because they’re not very common in the fossil record. But the New World vultures are related to the terratorns, huge birds that are extinct now. We’ve discussed terratorns once before way back in episode 17, about the Thunderbird, but let’s discuss them again because they were incredible birds.

We have a decent number of terratorn remains from the La Brea Tar Pits and a few other places. The terratorns were bigger even than condors. A number of species lived throughout the Americas, with even the smaller species having an estimated wingspan of around 12 feet, or 3.8 meters. The largest species known, Argentavis magnificens, lived in South America around six million years ago. It’s estimated to have a wingspan of at least 16 feet, or 6.5 meters, and possibly as much as 26 feet, or 8 meters. That’s the size of a small aircraft.

Researchers think Argentavis was an efficient glider, hardly needing to flap its wings. But it wasn’t very maneuverable, so researchers also think it was probably a scavenger like modern vultures. Smaller terratorns may have been active hunters, more like eagles than vultures. Argentavis had strong legs and probably took off by running into the wind with its massive wings spread, sort of like an airplane taking off, so it didn’t have to flap its wings at all.

That brings us to Grady’s question about why and how buzzards soar for so long. Argentavis would have spent most of its time soaring, hardly ever needing to flap its wings. Its wings weren’t even very strong, and it might not even have been able to flap them when they were extended. The turkey vulture, or buzzard, is especially good at soaring for long periods of time, sometimes for hours, without needing to flap its wings.

If you’ve noticed, soaring birds like vultures, eagles, and hawks tend to fly in circles. There’s a reason for this. When the wind blows over a hill or mountain, it creates an updraft, a breeze that blows directly upward. Similarly, air rises from land that’s been warmed by the sun, causing columns of warm air called thermals. A soaring bird stays in these updrafts and thermals by flying in circles. Vultures also have wingtips where the feathers are spread out, so that each flight feather is separated from the next by a small space. Each of these feathers acts like a tiny wing of its own, which helps keep the vulture gliding forward and not downward. All this wind over the wingtip feathers causes a lot of pressure, though, and vultures have a special bone at the wingtip that helps strengthen and support the flight feathers. Soaring instead of flapping conserves a lot of energy, which is why vultures will soar for as long as they can, looking for food.

Most New World vultures have a good sense of smell, which is unusual for birds. The turkey vulture finds a lot of its food by smell. The black vulture doesn’t have nearly as good a sense of smell, though, and as a result it often follows turkey vultures to find carcasses, then bullies the turkey vultures out of the way to eat first. That’s not very nice, birds. In addition, the turkey vulture has keen eyesight, which helps it find dead animals that might not have started to smell yet.

So let’s talk about those condors now. There are two species of condor alive today, the California and the Andean. We covered the California condor in episode 44, extinct and back from the brink. The California condor actually went extinct in the wild in 1987, with only 22 birds alive in captivity, but an ongoing captive breeding program saved it from extinction and captive-bred birds started to be released into the wild in 1991. But there are still fewer than 500 individuals alive today, so it’s still in danger of extinction. The California condor only lives in a few small areas of western North America today, but around 40,000 years ago it lived throughout North America. Part of the reason it’s still so rare is that it reproduces very slowly. A pair doesn’t nest every year, and even when they do, the female only lays one egg. A young condor depends on its parents for a full year, both for food and to learn how to fly. It can take a young condor months to learn how to fly properly, and researchers sometimes observe awkward crash landings that are probably pretty funny, although maybe not so funny to the condor.

The California condor’s wingspan can be up to almost ten feet, or 3 meters. This is huge, but the Andean condor is even bigger. Its wingspan is nearly eleven feet, or 3.3 meters. The Andean condor lives in and near the Andes Mountains along the western coast of South America. It’s mostly black with silvery patches on the wings and a white ruff around the neck, and its head is gray in color but can flush reddish to communicate with other condors. The male also has a comb on the top of its head.

The Andean condor’s feet are adapted for walking, not fighting. Its feet aren’t very strong and its talons aren’t very sharp. It does sometimes kill small animals like rabbits, but its feet are so weak that it can’t use them to attack. Instead, it stabs the animal to death with its beak.

Like Argentavis, the Andean condor’s wings are built for soaring, not flapping. It can soar for hours without needing to flap its wings once, sometimes traveling hundreds of miles in a day to find food.

It’s a social bird that mates for life, and one of its courtship rituals is a hopping, flapping dance. Keep in mind that this is a bird with wings over five feet long. That would be a pretty impressive dance. The Andean condor nests high in the Andes Mountains on cliffs that predators can’t reach and lays one or two eggs.

Let’s go back to the king vulture now to finish up, because there’s a mystery associated with the king vulture. In the 1770s, a man named William Bartram traveled through Florida and took notes about the animals and plants he saw. He published a book of his travels in 1791 and in it, he included information about a bird he called a painted vulture. He said it was fairly common in Florida and that he’d even shot one himself. The description he gave sounds like a king vulture except that Bartram described its tail as white with a black tip, not entirely black.

But remember, the king vulture primarily lives in South America. It is known in the very southern parts of North America in Mexico, but not Florida. What’s going on?

Some people think Bartram included the painted vulture as a hoax. Some people think he got it mixed up with a different bird, the Northern caracara, a bird of prey which only looks slightly like a king vulture. Some people think there may have been a small population of king vultures in Florida at the time that later went extinct, possibly a subspecies of king vulture with a mostly white tail instead of all black.

Bartram wasn’t the only person who reported seeing the painted vulture. In 1734 an English naturalist and artist, Eleazar Albin, painted a vulture that looked almost identical to the one Bartram described 30-odd years later, tail and all. It’s not completely clear where Albin saw his bird, but as far as researchers can determine Bartram wasn’t aware of the painting. So it’s possible that a subspecies of king vulture once lived in Florida but went extinct soon after Bartram saw it. If he and Albin hadn’t documented it, no one alive today would have any idea the painted vulture ever existed.

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 126: The Hedgehog and the Moonrat

This week thanks to Romy, who suggested the topic of hedgehogs! And researching hedgehogs led me to their only close relation, the moonrat.

Hedgehogs are adorable:

Pictures of listener QuillviaPlath’s adorable friend Delilah, an African pygmy hedgehog. Delilah has crossed the Rainbow Bridge since these pictures were taken, but QuillviaPlath has a rescue hedgehog named Lily now and will soon be adopting another rescue named Toodles too!

Moonrats are a little less adorable but still cute:

Show transcript:

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

This week we’re going to learn about a humble little animal that’s well-known in much of Europe, Asia, and Africa, but totally unknown in the Americas except as a pet. It’s the hedgehog, a suggestion from Romy. Thank you, Romy! We’ll also learn about the hedgehog’s closest relation, the moonrat.

There did actually used to be a hedgehog native to North America, but it went extinct some 50 million years ago. The hedgehogs alive today pretty much haven’t changed in about 15 million years. The North American hedgehog is called Silvacola and only grew a few inches long, or maybe 7 cm. It lived in what is now British Columbia, Canada. We don’t know if it had quills, but the hedgehogs living in Europe at the same time as Silvacola lived had already evolved quills, so maybe it did.

I have seen exactly one hedgehog in my life, a pet named Button. I got to pet her and everything. She was very sleepy, though, because it was daytime and hedgehogs are nocturnal. But I can verify that hedgehogs do have spines on the back and sides, although if you pet the hedgehog properly you won’t get your fingers poked by the spines. I can also verify that hedgehogs are adorable.

But other than adorable and prickly, what are hedgehogs? Are they related to porcupines? Are they related to hogs? Do they really live in hedges?

The answers are no, no, and yes. Thanks for listening. You can find Strange Animals—ha ha, just kidding!

There are a number of hedgehog species in five separate genera. A few species have been domesticated, although it’s illegal in many places to keep a wild hedgehog as a pet. In some places it’s illegal to keep a hedgehog as a pet at all, since hedgehogs can become invasive pests if released into the wild in areas where they shouldn’t be. This has happened in New Zealand and a few other places, where introduced hedgehogs have no natural predators and have become so numerous they’ve caused damage to the local ecosystems. The hedgehog is an omnivore, and will eat bird eggs, insects, frogs and toads, snails, plants, and pretty much anything else. It’s especially damaging to shore birds that nest on the ground. But in its natural habitat, the hedgehog plays an important role as both a predator of small animals, including garden pests, and as prey to larger animals like foxes, badgers, and owls.

The hedgehog will also eat small snakes, and actually has some natural immunity to certain snake venoms. Of course, if a snake injects enough venom it will overwhelm the hedgehog’s protections and make it sick or kill it anyway. It also has resistance to toxins and will eat toxic toads that would kill other animals. But the hedgehog’s best protection is its spines, more properly called quills. If a hedgehog feels threatened, it will roll itself into a tight ball with its quills sticking out.

The quills are hairs that are hollow and stiffened with keratin. Good old keratin. You know, keratin is the same tough material that fur and fingernails and rhinoceros horns and hooves and baleen are made of. European hedgehogs are famous for the number of fleas they carry, a specific species of flea called the hedgehog flea. Who named that? They were a genius. Hedgehog fleas won’t infest dogs or cats. They only like hedgehogs.

The hedgehog is a good digger and sometimes digs burrows to sleep in during the day. It’s adaptable to many habitats but likes woodlands, meadows, and, yes, hedgerows where it can find lots of food. It has a pig-like snout, short legs, a little stub of a tail, and small ears. Baby hedgehogs are born with a protective membrane over their quills. It grows to around a foot long, or 30 cm, although many of the species are typically smaller than that. Most hedgehogs are brown but some are naturally cream-colored, a rare variety called blonde. This color is bred for in domesticated hedgehogs. Button the hedgehog is blonde with a dark spot on her back, which is why she’s named Button.

The population of West European hedgehogs has decreased substantially in the last few decades, which has conservationists worried. A 2016 study reported that the population has declined over 7% in the UK over the last 50 years, with similar declines in parts of Europe like Sweden and Belgium. Researchers speculate this may be due to habitat loss.

The hedgehog can hibernate although it doesn’t always. It may hibernate in piles of leaves or sticks, or in a burrow it digs underground, or somewhere else that’s protected from predators and cold. If you’ve gathered wood for a bonfire, make sure to check the pile for sleeping hedgehogs before you get the matches out.

One of the most persistent legends about the hedgehog is that it rolls on fruit, especially apples, in order to stick its quills into the fruit. Then it goes home to its burrow, carrying the fruit on its quills to eat later.

So, do hedgehogs actually do this? Probably not. Some observers say hedgehogs will roll in leaves and allow the leaves to stick to its quills, possibly as a form of camouflage. It would be easy for one to accidentally pick up a small rotten apple this way, giving rise to the legend, although the quills aren’t strong enough to hold a large apple without breaking. The sites I read online all say that hedgehogs don’t bring food back to the burrow to eat later, but T.H. White shares an anecdote to the contrary in his Book of Beasts. This is a translation of a 12th century bestiary, and his anecdote appears in a note on page 95. The text repeats the story of hedgehogs carrying apples home, and White adds:

“The Hedgehog constructs a humble nest in ditches, and there it hibernates. In 1939, the present translator dug out such a nest, near an orchard, with an Irish laboring companion who proceeded to tell him that hedgehogs carried apples to their nests on their spines—an anecdote which the translator had just been reading in this manuscript, eight hundred years older than the Irishman. The latter asserted the truth of his statement with passion, pointing to the apples, which were indeed there, and had punctured bruises on them. But the creature had probably trundled them there with its nose, subsequently making the punctures when it curled up to sleep on top of them.”

I haven’t found anyone else who reports seeing a hedgehog push an apple home with its nose, or anything else for that matter. But the apples were in the hedgehog’s nest. T.H. White saw them. It could be the apples had fallen from a nearby tree and rolled into the ditch on their own, and the hedgehog just happened to nest on them. Then again, one source I found mentions that hedgehogs may anoint themselves with apple juice to help repel fleas and other parasites. This seems a little on the farfetched side, but the hedgehog does do a weird thing called anointing that might have something to do with controlling parasites. No one’s sure what it’s for.

Anointing seems to be triggered when a hedgehog encounters a new or unusual odor. The hedgehog starts foaming at the mouth, often contorting its body oddly, and then it licks the foam onto its quills. This happens with domesticated hedgehogs as well as wild ones, and one site I read mentions that it may happen if you handle a pet hedgehog after putting hand lotion on.

So what is the hedgehog related to? It’s not a rodent, so it’s not related to porcupines. It’s a placental mammal so it’s not related to echidnas, which are monotremes. Both porcupines and echidnas evolved quills for protection independently. The hedgehog is probably most closely related to the shrew, but the other member of its family is an animal called the moonrat.

The moonrat lives in Southeast Asia, specifically Thailand, Borneo, and Myanmar, and shares a lot of characteristics with the hedgehog, like being omnivorous and digging burrows, but it doesn’t have quills. It looks a lot like the Virginia opossum, or as it’s properly called around where I live, the possum. But the possum is a marsupial, and again, the moonrat, like the hedgehog, is a placental mammal. It also looks a little like a rat, but the rat is a rodent and the moonrat isn’t a rodent.

The moonrat has a relatively long, skinny tail that’s mostly bare of fur and is actually scaly, which makes its tail look kind of like a snake. It also hisses like a snake (it’s not a snake). (Also going to point out that the possum hisses too.) The moonrat also has a long, thin muzzle, small rounded ears, and short legs. It grows to about a foot and a half long, not counting the tail, which can be nearly as long as the body. A foot and a half is about 40 cm. One subspecies of moonrat has light gray or white fur on its head and forequarters except for a black mask, while the rest of its body is black. Another subspecies is mostly white.

The moonrat prefers jungles and forests and is mostly nocturnal. It eats pretty much anything, but it especially likes insects, crabs, worms, and frogs, and will even eat fish when it can catch one.

One interesting thing about the moonrat is its smell. The moonrat marks its territory with a scent that smells like ammonia. You know what else smells like ammonia? Cat pee. That is not a good smell, if you’ve ever had to clean out a cat’s litter box that should have been cleaned out a lot earlier. It also smells kind of like rotten onions. As a result of its scent glands for marking territory, the moonrat smells pretty bad to human noses. But people do occasionally eat it, just as they sometimes eat hedgehogs.

People are omnivores too, after all. But, you know, maybe don’t eat animals that smell like ammonia.

You can find Strange Animals Podcast online at a new URL! I finally had to move to a real podcast hosting platform since I had topped out the memory and usage available without one. Our website is now at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. I will keep the old website up but it won’t be updated. The podcast feed shouldn’t change unless I’ve really messed something up, in which case you probably aren’t hearing this.

If you have questions, comments, or suggestions for future episodes, or just want a sticker, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast where you can get bonus episodes for as little as one dollar a month donation.

Thanks for listening!

Episode 125: Triceratops and other ceratopsids

It’s time to learn about some more dinosaurs, ceratopsids, including the well-known Triceratops!

Triceratops:

An artist’s frankly awesome rendition of Sinoceratops. I love it:

A Kosmoceratops skull:

Pachyrhinosaurus had a massive snoot:

Protoceratops:

Fighting dinos!

Show transcript:

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

Back in episode 107, about ankylosaurus and stegosaurus, I mentioned that one day I’d do an episode all about triceratops and its relations. Well, that day is today. It’s the ceratopsid episode!

Ceratopsids are a family of dinosaurs with elaborate horns on their faces and frills on the back of their heads. They almost all lived in what is now North America and most of them lived in the late Cretaceous. Triceratops is the most well known, so we’ll start with it.

The name triceratops, of course, means three face horns, and it did indeed have three face horns. It had one on its nose and two on its brow, plus a frill that projected from the back of its skull.

Triceratops was a big animal, around 10 feet high at the shoulder, or 3 meters, and about 30 feet long, or 9 meters. Its body was bulky and heavy, sort of like a rhinoceros but, you know, even bigger and more terrifying.

Like the rhinoceros, triceratops was a herbivore. It had a horny beak something like a turtle’s that it probably used to grab plant material, and it had some 40 teeth on each side of the jaw. These teeth were replaced every so often as the old ones wore down, sort of like crocodilians do. Back when triceratops lived, around 68 million years ago, grass hadn’t developed yet. There were prairies in parts of western North America the same way there are today, but instead of grass, the prairies were covered in ferns. Many researchers think triceratops mostly ate ferns, grazing on them the same way bison graze on grass today.

In fact, the first paleontologist to study a triceratops fossil thought it was an extinct type of bison. This was a man called Othniel Charles Marsh. To his credit, Marsh only had a little piece of a triceratops skull to examine, the piece with the brow horns. And since the brow horns of a triceratops do look a little like the horn cores of a bovid, and since this was 1887 before a lot was known about dinosaurs, and since the fossil was found in Colorado where the buffalo roam, it’s understandable that Marsh would have assumed he was looking at a gigantic fossil bison skull. He figured it out the following year after examining another skull with the nose horn intact, since bovids are not known for their nose horns, and he naturally named it Triceratops.

It’s tempting to assume that Triceratops was a herd animal, but we don’t have any evidence that it lived in groups. It was common and we have lots of fossil triceratops, especially the thick-boned skulls, but it seems to have mostly been a solitary animal.

It’s pretty obvious that the triceratops’ horns must have been for defense. It lived at the same time as Tyrannosaurus rex, which preyed on triceratops often enough that we have a lot of Triceratops fossils with T rex tooth marks in the bones. We also have some triceratops fossils with T rex tooth marks in the bones that show signs of healing, indicating that the triceratops successfully fended off the T rex and lived. But what was the frill for?

Researchers have been trying to figure this out for years. There were a lot of different ceratopsid species, many of which may have overlapped in range and lived at the same time, so some researchers suggest the frill’s size and shape may have helped individuals find mates of the same species. Triceratops has a rather plain frill compared to many ceratopsid species, which had frills decorated with points, spikes, scalloped edges, lobes, and other ornaments.

But the ornamental elements of the frills change rapidly through the generations, which suggests that they weren’t for species recognition. If that was the case, the frills would have stayed about the same to minimize confusion. Instead, they get more and more elaborate, which suggests that they were a way to attract mates who liked fancy head frills. You know, like a snazzy hairstyle.

Of course, the frill could have more than one use. It could be attractive to potential mates and also could have protected the back of the skull from T rex bites, just like a snazzy hairstyle still keeps your head warm in cold weather. Then again, in many species of ceratopsid the frill is thin and rather fragile, so it’s more likely to be just for display. It’s very likely that the frills were brightly colored or patterned.

So what were some of these other ceratopsids with strange shaped frills? I’m SO glad you asked! There were so many ceratopsids, and they all had bodies shaped roughly the same but with head frills and horns that looked very different from each other. Some had no horns, just a frill. Some just had a nose horn, some just had brow horns. The horns were shaped differently in different species, too. Researchers group ceratopsids into two major groups: the chasmosaurines, which have longer frills and usually long brow horns and short nose horns; and the centrosaurines, which typically had larger nose horns and small brow horns, and snouts that were thicker top to bottom.

Almost all the ceratopsids have been found in North America, where they were super common in the Cretaceous. But Sinoceratops was discovered in 2008 in China. It wasn’t as big as Triceratops, topping out at about 6 ½ feet tall, or 2 meters, but what it lacked in bulk it made up in head frill ornamentation. Its frill was relatively short and was edged with small horns that curve forward. Its frill also had knobs along its edge and down the middle, which is unique among all ceratopsids and may have been the base for small keratin horns. Since keratin doesn’t fossilize, we have no way of knowing. It also had two holes in the frill that made it lighter, but they would have been covered with skin (no matter what a certain movie may have led you to believe). Its single nose horn pointed almost straight up, and in front of the nose horn it had a bony knob. It basically had no brow horns, just what may have been bony knobs above its eyes.

Kosmoceratops had probably the most ornamented skull of any known ceratopsid, and maybe any known dinosaur, with 15 horns growing from it. The rear of its frill curled forward like a collar, edged with flat, pointed projections. The frill was scalloped along its sides. Its brow horns were long, pointy, and arched sideways and slightly downward. Kosmoceratops also had a cheek horn under each eye and a flattened nose horn just in front of the brow horns. It lived in what is now Utah, in the United States, some 76 million years ago, and was only described in 2010.

Pachyrhinosaurus had flattened bony nose and brow horns more properly called bosses, since they aren’t actually horns. But Pachyrhinosaurus did have horns on its frill, although the size, shape, and number of the frill horns vary from individual to individual.

These bosses resemble the base of rhinoceros horns, which as you may recall are made of keratin. Some researchers think the bosses found in Pachyrhinosaurus and other ceratopsids may have also had keratin horns growing from them.

Remember how I said Triceratops didn’t appear to be a herd animal? Triceratops is considered a chasmosaurine, and chasmosaurines all seemed to be fairly solitary animals. But the other big group of ceratopsids, centrosaurines, may have been herd animals. Pachyrhinosaurus was a centrosaurine, for instance, and several bonebeds containing dense collections of fossil pachyrhinosaurus have been found where the individuals appear to have died at the same time. The biggest found so far is in Alberta, Canada, where paleontologists have excavated thousands of bones, from full grown adults to babies. Researchers suggest a herd of the animals may have died trying to cross a flooded river. The species of Pachyrhinosaurus found in the Alberta bonebed had both bosses and short brow horns.

Even though only one species of ceratopsid has been discovered in Asia so far, earlier basal forms were common in Asia. Protoceratops, which only stood about two feet tall, or 60 cm, lived in what is now the Gobi Desert in Mongolia around 80 million years ago. Researchers think some of these early species in the genus Protoceratops migrated into North America on the Bering land bridge, where they evolved into ceratopsids.

Protoceratops looked like a mini ceratopsid with a simple neck frill and no horns. We have a lot of Protoceratops fossils and some of them are frankly amazing.

For instance, a Protoceratops fossil found in 1965 was preserved with its own footprint in the ground near it. The fossils of baby protoceratopses have been found together in one nest, which suggests the parents cared for their young. We even have a fossil of a protoceratops and a Velociraptor that both died together while fighting. The velociraptor’s hind leg is extended where it kicked protoceratops with its vicious claws, but the velociraptor’s arm is in protoceratops’s jaws, broken.

Fighting dinosaurs. It’s one of those things that makes life worth living, you know?

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

Thanks for listening!

Episode 124: Updates 2 and a new human

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

The triple-hybrid warbler:

Further reading:

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

Show transcript:

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

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

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

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

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

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

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

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

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

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

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

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

[frog sound]

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Thanks for listening!

Episode 123: Linnaeus’s mystery animals

Carolus Linnaeus was a botanist who worked out modern taxonomy and binomial nomenclature, but there are two mystery animals associated with his work. Let’s find out about them!

Rembrandt sketched this elephant whose skeleton is now the type specimen of the Asian elephant:

Linnaeus’s original entry about Furia infernalis:

Further reading:

Ewen Callaway, “Linnaeus’s Asian elephant was wrong species

Karl Shuker, “Linnaeus’s Hellish Fury Worm – The History (and Mystery) of a Non-Existent Micro-Assassin

Show transcript:

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

This week let’s learn a little something about binomial nomenclature, which is the system for giving organisms scientific names. Then we’ll learn about a couple of mystery animals associated with the guy who invented binomial nomenclature.

That guy was Carlolus Linnaeus, a Swedish botanist who lived in the 18th century. Botany is the study of plants. If you’ve ever tried to figure out what a particular plant is called, you can understand how frustrating it must have been for botanists back then. The same plant can have dozens of common names depending on who you ask.

When I was a kid, the local name for a common plant with edible leaves that tasted deliciously tart was rabbit grass. I’ve never heard anyone anywhere else call it rabbit grass. Maybe you know it as sourgrass or false shamrock or wood sorrel.

There are over a hundred species of that plant throughout the world in the genus Oxalis, so it’s also sometimes just called oxalis. The species that’s most common in East Tennessee where I grew up is Oxalis dellenii, but all species look pretty much the same unless you get down on your stomach and really study the leaves and the flower petals and the stems. So if you were a botanist wanting to talk to another botanist about Oxalis dellenii back in the early 18th century, you couldn’t call it Oxalis dellennii. Not yet. You’d have to say, hey, do you know what rabbit grass is? And the other botanist would say, why no, I have never heard of this no doubt rare and astounding plant; and you’d produce a pot full of this pretty little weed that will grow just about anywhere, and the other botanist would look at it and say, “Oh. You mean sourgrass.” But imagine if you weren’t right by the other botanist and didn’t have the plant to show them. You’d have to draw it and label the drawing and write a paragraph describing it, just so the other botanist would have a clue about which plant you were discussing. Nowadays, all you have to do is say, “Hey, are you familiar with Oxalis dellenii?” and the other botanist will say, “Ah yes, although I myself believe it is the same as Oxalis stricta and that the differences some botanists insist on are not significant.” And then you’d fight. But at least you’d know what plant you were both fighting about.

Before Linnaeus worked out his system, botanists and other scientists tried various different ways of describing plants and animals so that other scientists knew what was being discussed. They gave each plant or animal a name, usually in Latin, that described it as closely as possible. But because the descriptions sometimes had to be really elaborate to indicate differences between closely related species, the names got unwieldy—sometimes nine or ten words long.

Carl Linnaeus sorted this out first by sorting out taxonomy, or how living creatures are related to each other. It seems pretty obvious to us now that a cat and a lion are related in some way, but back in the olden days no one was certain if that was the case and if so, how closely related they were. It’s taken hundreds of years of intensive study by thousands upon thousands of scientists and dedicated amateurs to get where we are today, not to mention lots of technological advances. But Linnaeus was the first to really attempt to codify different types of animals and other organisms depending on how closely they appeared to be related, a practice called taxonomy.

Linnaeus’s system is beautifully simple. Each organism receives a generic name, which indicates what genus it’s in, and a specific name, which indicates the species. This conveys a whole lot of information in just two words. A zoologist who hears the name Stenella longirostris will know that it belongs to the genus Stenella, which means it’s a type of dolphin, which means it’s in the family delphinidae. If they’re familiar with dolphins they’ll also know they’re talking about the spinner dolphin, and in this case they can even get an idea of what it looks like, since the specific name longirostris means ‘long beak.’ To make things even clearer, a subspecies name can be tagged on the end, so Stenella longirostris centroamericana is a subspecies of spinner dolphin that—you guessed it—lives in the ocean around Central America.

Carl Linnaeus was a young man when he started working out his classification system. He was only 25 when he traveled to Lapland on a scientific expedition to find new plants and describe them for science. This was in 1732 so travel was quite difficult. Linnaeus traveled on horseback and on foot, which as you can imagine took a long time and gave him lots of time to think. Within three years he had worked out the system we still use today.

You know what else Linnaeus invented? The index card. He needed index cards to keep track of all the animals and plants he and other scientists named using his binomial nomenclature system.

Linnaeus named a whole lot of plants and animals himself—something like ten thousand of them during his lifetime. And naturally enough, some mistakes crept in that have since been corrected. But a couple of his mistakes have led to mysteries, and those are the ones we’re going to look at today.

In 1753 Linnaeus got to examine a fetal elephant preserved in a jar of alcohol. Back then hardly anyone outside of Asia and Africa had seen an elephant, so Linnaeus was enormously excited about it and wrote to a friend that the specimen was as rare as a diamond.

Linnaeus described the species and named it Elephas maximus, also known as the Asian elephant today. But from records that still survive, the specimen was marked as having come from Africa. A Dutch pharmacist and collector had acquired the specimen around 1736, and after he died it was sold to King Adolf Frederick of Sweden, who let Linnaeus examine it. The auction catalog where it was listed for sale indicates that it was from Africa, but in his official description of the elephant Linnaeus wrote that it was from Ceylon, which is now called Sri Lanka, which is in Asia.

So ever since there’s been a mystery as to whether the elephant specimen was actually an Asian elephant or an African elephant, and if Linnaeus even knew that there were elephants in Africa. Because the specimen is of a fetal elephant—that is, a baby that died before it was fully developed, probably when its mother was killed while she was pregnant—it’s hard to tell just by looking if the specimen is an African or Asian elephant. We do still have the specimen, fortunately, which is held in the Swedish Natural History Museum’s collection.

A mammal expert at the London Natural History Museum, named Anthea Gentry, got curious about the specimen in 1999, when she saw it on a trip to Sweden. Gentry’s husband was a paleontologist who specialized in mammals, and later she showed him a photograph of the specimen and asked what he thought. He said he was pretty sure it was an African elephant, not an Asian elephant. Gentry got permission to do DNA testing on the specimen, but since it had been in alcohol for so long, not even the most advanced technology and the world’s most experienced expert in ancient DNA could get a usable genetic sequence from the tissue.

The world’s most experienced expert in ancient DNA was Tom Gilbert of the University of Copenhagen in Denmark. He did his best and failed, but he couldn’t forget about the little mystery elephant. In 2009 he got an idea for extracting genetic material from the specimen in a new way that might yield results. It took years, but he and his team got it to work. In 2012 the mystery was finally solved. Linnaeus’s little elephant was actually an African elephant.

But that’s not the end of the story. When a scientist describes a new species and gives it its scientific name, the first specimen described is known as the type specimen. Linnaeus’s elephant was the type specimen of the Asian elephant—but since it was proven to be an African elephant, it couldn’t continue to be the type specimen of the Asian elephant. But that meant that there was no official type specimen of the Asian elephant. They needed a specimen that was still available and that had been described by someone who had examined it scientifically.

When an animal is described officially, it’s a formal process. The International Commission on Zoological Nomenclature decides whether a suggested name is acceptable and makes decisions on type specimens and taxonomy. So researchers connected with the Commission started digging around for a new type specimen, preferably one from Linnaeus’s time or earlier.

A type specimen isn’t always a whole animal. A lot of times it’s just a little piece of a skeleton or a partial fossil, although the more complete a specimen is, the better. Linnaeus had described a partial elephant tooth at some point which was still available in a Swedish museum, and taxonomists were considering using that as a type specimen when they got an email from a paleontologist who specialized in elephants. He sent a copy of a travel journal from an amateur naturalist named John Ray, who had visited Florence in 1664 and wrote his observations of an elephant skeleton and skin on display in the duke’s palace.

And, it turned out, the elephant skeleton John Ray had described was in the collection of a museum in Florence. And it was definitely the skeleton of an Asian elephant—in fact, we even have what amounts to a photograph of the elephant when it was alive, because none other than the artist Rembrandt sketched it. So that skeleton was designated as the type specimen of the Asian elephant and all is well.

That brings us to the other mystery associated with Linnaeus, and this one is a lot less cute than a misidentified baby elephant. But before I tell you what the mystery animal is, let me tell you something that happened to Linnaeus before he’d even come up with his system of nomenclature. This happened in 1728, when Linnaeus was a broke college student staying with a professor and spending all his free time collecting botanical specimens in the marshes.

One day Linnaeus was searching for plants he didn’t already have specimens of when something stung him on the neck. Since he was wading around in a marsh, this was not really that unusual. But this wasn’t the usual insect sting or midge bite. Before long Linnaeus’s neck was painfully swollen, and soon one of his arms had swollen up too.

These days we’d recognize this as an allergic reaction, but back in 1728 they didn’t know what allergies were. By the time Linnaeus got home, he was in such bad shape that the doctor they called worried he wouldn’t survive.

Fortunately for Linnaeus and for science and humanity in general, he survived and went on to invent his naming system only eight years later. Some thirty years after he almost died, he published the tenth edition of his book, Systema Naturae, and included a formal description of the animal that had almost killed him. He named it the fury worm, Furia infernalis.

But there was no type specimen of a fury worm. Linnaeus hadn’t seen the one he believed had bitten him, and the only one anyone had shown him was a tiny worm so dried up and old that he couldn’t see any details. But he knew the fury worm existed because it had bitten him, and anyway everyone knew it was a real animal.

The fury worm was supposed to be tiny and slender, so small that it could be picked up by the wind and blown to other places. If it landed on a person or an animal it would immediately bite them with its sharp mouthparts, breaking the skin, then burrow into the flesh through the wound. It would dig in so quickly and so deeply that it was impossible to find, and even if you did find it, it was impossible to get out because of the backward-pointing bristles on its tail that kept it anchored in place. A person or animal bitten by the worm was likely to die within a day, sometimes within half an hour, unless a poultice of cheese or curds was applied to the bite.

Fortunately for most of the world, this horrible worm only lived in swampy areas in northern Sweden and Finland, Russia, and a few other nearby areas. In one year, 1823, some 5,000 reindeer died from fury worm attacks, and the export of reindeer furs was banned so the worm wouldn’t spread.

But. Where. Are. The. Worms??? And why would a parasitic worm kill its host so quickly? A parasite depends on its host staying alive for enough time that the parasite can benefit from whatever it’s getting from the host, whether that’s nutrients or a protected place to develop into its next life stage. This isn’t going to happen in half an hour.

So we have all this anecdotal evidence of the fury worm’s existence, even from such noted a scientist as Linnaeus himself, but no worms. And the symptoms reported from fury worm attacks varied quite a lot from patient to patient.

Doubts about the fury worm’s existence were already common in the 19th century, and even back in the late 18th century Linnaeus started to have doubts. And as technology and scientific knowledge improved, the fury worm started to look less and less like a real animal and more and more like an explanation for things people had once not understood—like allergies, infection, and bacteria. The death of 5,000 reindeer in 1823 was finally traced to a disease called neurocysticercosis [neuro-cyst-iser-kosis], which is actually caused by a parasite, but not a fury worm. It’s caused by tapeworm larvae that only kill its host after the larvae have matured and are ready to infect a new animal, which happens when something eats the meat of the animal that has died.

So was the fury worm ever a real animal? Almost certainly not. I tried to find out if people are still reporting fury worm bites in northern Sweden and Finland, but I didn’t come up with anything. On the other hand, I did check and it doesn’t look like there’s a band named Furia infernalis, so if you were trying to think of a really cool name for your band, I got you.

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

Thanks for listening!

 

Episode 122: Strange Shark Ancestors

This week let’s learn about some ancestors of sharks and shark relatives that looked very strange compared to most sharks today!

Stethacanthus fossil and what the living fish might have looked like:

Two Falcatus fossils, female above, male below with his dorsal spine visible:

Xenacanthus looked more like an eel than a shark:

Ptychodus was really big, but not as big as the things that ate it:

A Helicoprion tooth whorl and what a living Helicoprion might have looked like:

Show transcript:

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

This week we’re going back in time again to learn about some animals that are long-extinct…but they’re not land animals. Yes, it’s a weird fish episode, but this one is about shark relatives!

The first shark ancestor is found in the fossil record around 420 million years ago, although since all we have are scales, we don’t know exactly what those fish looked like. The first true shark was called Cladoselache [clay-dough-sell-a-kee] and lived around 370 million years ago, at the same time as dunkleosteus and other massive armored fish. We covered dunkleosteus and other placoderms back in episode 33. Cladoselache grew up to four feet long, or 1.2 meters, and was a fast swimmer. We know Cladoselache ate fish because we have some fossils of Cladoselache with fish fossils in the digestive system—whole fish fossils, which suggests that cladoselache swallowed its prey whole. Cladoselache also had fin spines in front of its dorsal fins that made the fins stronger, but unlike its descendants, it didn’t have denticles in its skin. It didn’t have scales at all.

The denticles in shark skin aren’t just protection for the shark, they also strengthen the skin to allow for the attachment of stronger muscles. That’s why sharks are such fast swimmers.

[Jaws theme]

Stethacanthidae was a family of fish that went extinct around 300 million years ago. It was related to ratfish and their relatives, including sharks. Stethacanthus is the most well-known of the stethacanthidae. It grew a little over 2 feet long, or 70 cm, and was probably a bottom-dwelling fish that lived in shallow waters. It ate crustaceans, small fish, cephalopods, and other small animals.

We have some good fossils of various species of Stethacanthidae and they show one feature that didn’t get passed down to modern ratfish or sharks. That’s the shape of its first dorsal fin, the one that in shark movies cuts through the water just before something awful happens.

[Jaws theme again]

Stethacanthidae’s dorsal fin was really weird. It was shaped sort of like a scrub brush on a pedestal, with the bristles sticking upwards, which is sometimes referred to as a spine-brush complex. Researchers aren’t sure why its fin was shaped in such a way, but since it appears that only males had the oddly shaped fin, it was probably for display. It also had a patch of the same kind of short bristly denticles on its head. Males also had a long spine that grew from each pectoral fin that was probably also for display. Some researchers think the males fought each other by pushing head to head, possibly helped by the odd-shaped dorsal fin.

In the past, before researchers figured out that only the males had the strange dorsal fin, some people suggested that the fish may have used the fin as a sucker pad to attach to other, larger fish and hitch a ride. This is what remoras do. Remoras have a modified dorsal fin that is oval-shaped and acts like a sucker. The oval contains flexible membranes that the remora can raise or lower to create suction. The remora attaches to a larger animal like a shark, a whale, or a turtle and lets the animal carry it around. In return, the remora eats parasites from the host animal’s skin. But remoras aren’t related to sharks.

Other shark relatives had dorsal spines. Falcatus falcatus lived about the same time as Stethacanthus, around 325 million years ago. It grew up to a foot long, or 30 cm, and ate shrimp, fish, and other small animals. We have so many fossils of falcatus from the Bear Gulch Limestone deposits in Montana that we know quite a bit about it. It probably detected prey with electroreceptors on its snout like many modern sharks do, and it was probably a fast swimmer that could dive deeply. Its eyes are unusually large for a shark too. Females would have looked like a small, slender sharklike fish, but males had a spine that grew forward from just behind its head, sort of like a single bull’s horn. It’s called a dorsal spine and is actually a modified dorsal fin. It was probably for display, although males may have also used it to fight each other. We have a well preserved fossil of a pair of falcatus together, a male and female, where it looks like the female may be biting the male’s dorsal spine. Some researchers suggest the spine was used in a pre-mating ritual, but it’s probable that the fish just happened to die next to each other and no one was actually biting anyone.

Another shark relative with a dorsal spine is Hybodus, which grew up to 6 ½ feet long, or 2 meters. Hybodus was a successful genus of cartilaginous fish that lived from around 260 million years ago up to 66 million years ago. Researchers think its dorsal spine was used for defense since both males and females had the spine. Hybodus would have looked like a shark but its mouth was relatively small. It probably ate small fish and squid, catching them with the sharp teeth in the front of its mouth, but it also probably ate a lot of crustaceans and shellfish, which it crushed with the flatter teeth in the rear of its mouth.

Xenacanthus had a dorsal spine too, but it was a much different shark ancestor from the ones we’ve talked about so far. It lived until about 208 million years ago in fresh water. It grew to about three feet long, or one meter, and would have looked more like an eel than a shark. It was slender with an elongated body, and its dorsal fin was short but extended along the back down to the pointed tail. This suggests it probably swam like an eel, since eels have a similar fin structure. It probably ate crustaceans and other small animals.

Xenacanthus’s spine grew from the back of the skull and, unusually for a shark relation, it was made of bone instead of cartilage. Both males and females had the spine and some researchers suggest that it may have been venomous like a sting ray’s tail spine.

Rays are closely related to sharks, and if you want to see a fish that makes every single weird extinct shark look normal, just look at a sawfish. The sawfish is a type of ray and it’s alive today, although it’s endangered. I’m going to do a whole episode on rays pretty soon so I won’t go into detail, but the sawfish isn’t the only fish alive today with a long snout with teeth that stick out on either side. The sawshark is related to the sawfish but is actually a shark, not a ray. And there’s a third type of fish with a saw, related to both sawfish and sawsharks, called the Sclerorhynchidae. Sclerorhynchids went extinct around 55 million years ago and are considered part of the ray family, although they’re not ancestors of living rays. Sclerorhynchids grew around three feet long, or about a meter, and probably looked a lot like modern sawfish although with a rostrum, or snout, that was more pointed and less broad than most sawfish rostrums. The teeth that stuck out to either side were also relatively small. Researchers think Sclerorhynchids used their saws the same way modern sawfish and sawsharks do, to find small animals living on or near the bottom in shallow water and slash them to death before eating the pieces.

[Jaws theme again]

Most of the shark relatives we’ve talked about so far were pretty small, certainly compared to sharks like the great white or megalodon, which by the way we covered in episode 15 along with the hammerhead shark. But a shark called Ptychodus grew up to 33 feet long, or ten meters. It went extinct about 85 million years ago. Its dorsal fin had serrated spines and its mouth had lots and lots of really big teeth–up to 550 teeth, but they weren’t sharp. Instead, they were flattened with riblike folds that helped Ptychodus crush the mollusks it ate. It probably also ate squid and crustaceans, along with any carrion it might come across. It lived at the bottom of the ocean, but in relatively shallow areas where there were plenty of mollusks but not too many mosasaurs or other sharks that might treat Ptychodus as a nice big meal.

In episode 33, the one about dunkleosteus, we also talked about helicoprion and some of its relations. Helicoprion looked like a shark but was actually less closely related to true sharks than to ratfish. Helicoprion lived until about 250 million years ago and some researchers estimate it could grow up to 24 feet long, or 7.5 meters.

Instead of a weird dorsal fin, helicoprion had weird teeth. Weird, weird teeth. It had a tooth whorl instead of the regular arrangement of teeth, where its teeth grew in a spiral that seems to have been situated in the lower jaw. It looked like the blade of a circular saw. Now, this is bizarre but it’s not really all that much more bizarre than sawfish teeth, which aren’t even inside the mouth and stick out sideways. But the frustrating thing for researchers is that we still don’t have any helicoprion fossils except for the teeth whorls and part of one skull. Like most sharks and shark relatives, almost all of helicoprion’s skeleton was made of cartilage, not bone, and cartilage doesn’t fossilize very well. So even though helicoprion was widespread and even survived the Permian-Triassic extinction event, we don’t know what it looked like or what it ate or how exactly its tooth whorl worked. But I think it’s safe to say that it would not be good to be bitten by helicoprion.

[stop playing the Jaws theme omg]

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

Thanks for listening!

[Jaws theme again]

Episode 121: Cave Dwelling Animals

This week let’s learn about some animals that live in caves!

The dipluran Haplocampa:

Oilbirds and their big black eyes:

A swiftlet:

The angel cave fish that can walk on its fins like a salamander walks on its feet:

Leptodirus, carrying around some air in its abdomen in case it needs some air:

The cave robber spider and its teeny hooked feet:

The devils hole pupfish:

Show transcript:

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

Way back in episode 27 we learned about some animals that live deep in caves. Cave dwelling animals are always interesting because of the way they’ve adapted to an unusual environment, so let’s learn about some of them!

We’ll start with an invertebrate. Diplurans are common animals that are related to insects but aren’t insects. They live all over the world, with hundreds of species known to science, but most people have never seen one because of where they live. They like moist, dark areas like soil, dead leaves, and caves. They’re also small, usually only a few millimeters long, although a few species grow larger, up to two inches long, or five cm.

Diplurans have long bodies with a number of segments, six legs, long antennae, and a pair of tail appendages called cerci. Depending on the species, the cerci may just be a pair of straight filaments like an extra pair of antennae, or they may look like pincers. Diplurans with pincer-like cerci use them to help capture prey, while ones with antennae-like cerci eat fungi and plant material.

Diplurans also don’t have eyes. They don’t need eyes because they live underground where there’s little or no light. A lot of species are pale in color or lack pigment completely.

Diplurans have been around for something like 350 million years, although we don’t have very many fossil diplurans. But recently, a new species of dipluran was discovered in North America that has raised some interesting questions.

Vancouver Island is a large island on the west coast of Canada, near the city of Vancouver. It’s prone to earthquakes and contains a lot of caves, and last summer, in June of 2018, a party of cavers and scientists explored two of the caves and found a new dipluran, which has been named Haplocampa wagnelli. This dipluran is chunkier than most other known diplurans, with shorter antennae, which researchers think points to a more primitive body plan. Since the dipluran is so different from most other diplurans known, and because the caves where it was found were under a thick ice sheet until around 18,000 years ago, researchers are trying to figure out if it found its way into the caves after the ice sheet melted or if it survived in the caves while they were buried under ice.

Haplocampa seems to be most closely related to a few diplurans found in Asia. Asia was connected to western North America during the Pleistocene when sea levels were much lower, since so much of the world’s water was frozen, so it’s possible the ancestors of Haplocampa migrated from Asia after the ice sheets started to melt but before the Bering Land Bridge was completely submerged. Possibly its eggs were accidentally transported by birds who foraged in leaf litter where its ancestor lived.

A lot of animals that live in caves are only found in one particular cave system. This happens when a species of animal that lives near a cave moves into the cave, either full-time or part-time. As its descendants grow up, they become more and more adapted to cave life, until eventually they couldn’t live outside of the cave. Since there’s no way for them to travel from one cave system to another, they are confined to that single cave. And since caves are largely difficult for humans to explore, that means there are lots and lots and lots of animals unknown to science living out their quiet lives deep within caves where humans have never visited. Every so often a group of adventurous and brave scientists explore a cave and discover new animals, usually with the help of experienced cavers.

Animals that are endemic to a specific cave system are rare to start with and vulnerable to any changes in the cave environment. The Tumbling Creek cave snail is only found in a single stream in Tumbling Creek Cave in Missouri, in the United States. It lives its whole life in the water and is only about 2 millimeters in size, with a pale yellowish shell. When it was first discovered in 1971 it was common. Thirty years later, researchers could only find about forty of the snails due to water pollution.

Caves aren’t very friendly environments. Most of the animals that live in caves are very small as a result. Lots of insects and spiders live in caves, some snails, lots of fish, lots of crustaceans that live in fresh water, like crawdads and amphipods, and some salamanders. But the only mammals and birds that live in caves leave the cave to hunt or forage outside of it, like bats. There just isn’t enough food inside a typical cave to sustain a population of larger animals.

So what do cave animals eat? Obviously they eat each other, but without plants a cave system is definitely lacking in organic matter that can sustain populations of animals. Nutrients enter a cave primarily in two ways. Water flowing into a cave brings nutrients from outside, and animals that mainly live outside but sleep in caves also bring nutrients in. In the case of animals, their poop is a major source of organic material, with dead animals also contributing to the cave’s ecosystem. Bats in particular support a lot of cave animals with their poop, which is called guano, but bears, hyenas, and various other animals, birds, and insects also spend time in caves, either to sleep or to hibernate, and bring nutrients in from outside in one way or another.

There are two birds that spend time in caves, and I’m going to talk about both of them briefly even though technically they don’t live in caves, because they’re so interesting. Both birds are nocturnal and can echolocate like bats. The oilbird lives in parts of northern South America and is related to nightjars. I have a whole episode planned about nightjars and their relatives, but the oilbird is the only one that echolocates (as far as we know). The other bird that echolocates is the swiftlet.

The oilbird nests in caves and also roosts in caves during the day, then flies out at night and eats fruit. Some oilbirds roost in trees during the day instead. Its wings have evolved to allow it to hover and to navigate through tight areas, which helps it fly through caves. It sees well in darkness, with eyes that are arranged more like those of deep-sea fish rather than typical bird eyes.

Several species of swiflet echolocate. These are the birds that make their nests from saliva, and which humans gather to make bird’s nest soup from. They mostly live in Asia. They nest in caves and roost in caves at night, then fly out during the day to catch insects.

Researchers don’t know a lot yet about either bird’s echolocation. It’s audible to human ears, unlike most bat echolocating, and some researchers think it’s less sophisticated than bats’. It’s always possible there are other birds that echolocate, but we don’t know about them yet because maybe we can’t hear their echolocating.

This is what oilbirds sound like. The clicking noises are the echolocation calls.

[oilbird calls]

Cave fish are especially interesting. There isn’t one kind of cave fish but hundreds, mostly evolved from ordinary fish species that ended up in a cave’s water system and stayed. Sometimes the species of fish that gave rise to cave fish are still around, living outside the cave, but most cave fish species have evolved so much that they’re no longer very closely related to their outside ancestors.

Cave fish are considered extremophiles and they tend to have similar characteristics. They usually have no pigment, no scales, and often have no eyes at all, or tiny eyes that no longer function. They’re usually only a few inches long, or maybe 10 cm, and have low metabolic rates. They typically eat anything they can find.

Some cave fish have evolved in unusual ways to better fit their specific habitats. The cave angel fish lives in a single large cave system in Thailand, in fast-moving water. It’s about an inch long, or not quite 3 cm, and gets its name from its four broad fins, which look feathery like angel wings.

It was discovered in 1985 but it wasn’t until 2016 that researchers verified a persistent rumor about the fish, which is that it can WALK on its fins. It has a robust pelvis and vertebral column, and strong fin muscles that allow it to climb rocks to navigate waterfalls.

Other fish navigate waterfalls and other obstacles by squirming and wriggling, using their fins to push them along. But the cave angel fish walks like a salamander. Scientists are studying the way it walks to learn more about how the ancestors of four-legged animals evolved.

The largest cave dwelling animal is the blind cave eel, which grows up to 16 inches long, or 40 cm, although it’s very slender. Since it appears pink due to a lack of pigment in its skin and it has no eyes or fins, it looks a lot like a really long worm. But it’s actually a fish. Not much is known about it, but it’s widespread throughout western Australia and is sometimes found in wells. It lives in caves or underground waterways that are connected to the ocean.

The first insect that was recognized as living only in caves is a beetle called Leptodirus hochenwartii. It was discovered in 1831 deep in a cave in Slovenia, and researchers of the time found it so intriguing that they invented a whole new discipline to study it and other cave animals, known as biospeleology.

Leptodirus has some interesting adaptations to cave living. It has no wings and no eyes, its antennae and legs are long, but the real surprise is its body. Its head is small and the thorax, the middle section of an insect, is slender. But the abdomen is relatively large and round, and the insect uses it to store moist air. Caves tend to be humid environments and Leptodirus has evolved to need plenty of moisture in the air it breathes. But some parts of a cave can be dry, so not only does Leptodirus keep a supply of breathable air in its abdomen, its antennae can sense humidity levels with a receptor called the Hamann organ.

Some spiders live in caves and like other cave dwellers, they’ve evolved to look strange compared to ordinary spiders. The cave robber spider was only discovered in 2010 in a few caves in Oregon. Researchers suspect there are more species of cave robber spider in other cave systems that haven’t been explored yet by scientists.

The cave robber spider is so different from other spiders that it’s been placed in its own family, Trogloraptoridae, which means cave robber. It has hook-like claws on the ends of its legs which it probably uses to capture prey. It spins small, simple webs on the roofs of caves and researchers think it probably hangs upside down from its web and grabs its prey as it passes by. But since no one knows what the cave robber spider eats, it’s anyone’s guess. Researchers have even tried raising the spider in captivity to learn more about it, but it wouldn’t eat any of the insects or other small invertebrates it was offered as food. It starved to death without ever eating anything, so it’s possible it only eats specific prey. It’s a yellowish-brown spider with two rows of teeth, called serrula in spiders, which researchers say is unique among spiders.

It’s also pretty big for a cave dweller. Its body is up to 10 millimeters long, or about a third of an inch, and it has a legspan of about 3 inches, or 7.6 cm. But it’s very shy and rare, and of course it’s not going to hurt you. It literally wouldn’t even hurt a fly to keep itself from starving.

One of the scientists who discovered the spider and is studying it, Charles Griswold, points out that there are stories in the area of giant spiders living in caves. He suggests the cave robber spider might be the source of the stories, since a three inch spider looks much bigger when it’s hanging down from the roof of a cave right in your face, with hooked claws.

Let’s finish with a remarkable cave fish known as the devil’s hole pupfish. Devil’s hole is a geothermal pool inside a cavern in the Amargosa Desert in Nevada, which is in the southwestern United States. It’s not far from Death Valley. The cavern is more than 500 feet deep, or 150 meters, with water that stays at about 92 degrees Fahrenheit, or 33 degrees Celsius. There’s a single small opening into the cavern at the surface, which geologists estimate opened about 60,000 years ago. The cavern and cave system are more than half a million years old.

The geothermal pool is home to the devils hole pupfish, which is barely an inch long, or 25 millimeters, and looks pretty ordinary. It mostly stays around the opening to the surface, where there’s a limestone shelf just below the water’s surface that measures about 6 ½ by 13 feet, or 2 by 4 meters. While the pupfish does swim deeper into the cavern at times, it mostly eats algae that live on and around the shelf, and tiny animals that live within the algae. It also depends on the shelf for laying eggs and spawning.

So the shelf is really important. But it’s also really small and close to the surface. It can only support so many pupfish, so the average devil’s hole pupfish population is about 200 or 300 fish, although this fluctuates naturally depending on many factors. In the 1960s, a farming corporation drilled wells in the area and pumped water out for irrigation, and the water in devil’s hole started to drop and drop. Devil’s hole is part of Death Valley National Monument, and conservationists were well aware of how fragile the pupfish’s environment was. As the water level dropped, threatening to expose the limestone shelf that the pupfish depended on for their entire lives, conservation groups sued to stop the pumping of groundwater in the area. After a series of court cases that went all the way up to the Supreme Court, the water rights were acknowledged to be part of the national monument status. Pumping of groundwater was limited and the pupfish was saved.

The water level in devil’s hole is monitored daily, which has led to a lot of information about how the water is affected by seismic events. Earthquakes as far away as Alaska, Japan, and South America have all affected the water level.

Researchers aren’t sure how long the pupfish have lived in devil’s hole. Some researchers think they’ve been there for 20,000 years, others think it’s more like a few hundred. Researchers aren’t sure how such a small population of fish has stayed healthy for so long, since such a restricted number of individuals should be so inbred they’re no longer viable. The most recent genetic analysis of the pupfish suggests they became isolated from other pupfish species in the area less than a thousand years ago. But if that’s the case, no one’s sure how they got into devil’s hole in the first place. Flooding of the area hasn’t happened in the last thousand years.

Because the pupfish’s habitat is so fragile, the U.S. Fish and Wildlife Service has moved some of the fish into captive populations that mimic the fish’s original habitat. It’s nice to think that these tiny silvery-blue fish with big eyes have so many people working to keep them safe.

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

Thanks for listening!

Episode 120: Hybrid Animals

If you’re a subscriber on Patreon, you may recognize some of the information in this episode, but I’ve updated it and added a whole bunch. Thanks to Pranav for the topic suggestion!

A cama, llama/camel hybrid:

A swoose, swan/goose hybrid:

Motty the Asian/African elephant hybrid and his mother:

A zorse, zebra/horse hybrid:

Show transcript:

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

This week we’ve got another listener suggestion. Pranav really really wants me to do an episode about hybrid animals, but I’ve been dragging my feet on it because I actually already did an episode on the topic back in 2017—but only for Patreon subscribers. It wasn’t my best episode so for various reasons I’d decided not to unlock it. But Pranav really really wants to learn about hybrids! So I’ve taken part of the Patreon episode and added a lot of newer information to it to bring it up to date and make it more interesting.

The term for an animal with parents of different species is hybrid. Crossbreed is also a common term, although technically a crossbred animal is one with parents of the same species but different breeds, like a labradoodle is a crossbreed of a Labrador and a poodle. Both parents are domestic dogs.

A mule, on the other hand, is a hybrid between a horse and a donkey, specifically a mare and a jack, which is what a male donkey is called. The offspring of a stallion and a lady donkey, known as a jenny, is a hinny.

So why can a horse and a donkey breed while, for instance, a possum and a rat can’t? The two species must belong to the same family, and with very few exceptions, they must also belong to the same genus. The genus is indicated in an animal’s scientific name. Equus caballus is a horse and Equus africanus is a donkey, while a Labrador and a poodle are both Canis familiaris, or Canis lupus familiaris depending on who you ask. The Virginia opossum is Didelphis virginiana while the brown rat is Rattus norvegicus. They’re not even slightly related, although superficially they look alike.

If the hybrid’s parents are from species with different numbers of chromosomes, hybrid males will almost always be sterile. You can’t cross two mules to get more mules, for instance, because male mules can’t make babies. Female mules are sometimes fertile but very rarely conceive. Horses have 64 chromosomes while donkeys have 62. Mules end up with 63. Hinnies are much rarer than mules because if the female of a pair of related species has fewer pairs of chromosomes than the male, it’s less likely that any offspring will result.

More closely related species can have fertile offspring. Killer bees, for instance, are hybrids of a European honeybee and an African honeybee. The two are actually subspecies of the honeybee, Apis mellifera, so it’s less like creating a hybrid and more like crossing a Labrador and a poodle to get an adorable happy pup with curly hair. It seemed like a really good idea. The result was supposed to be a tropical bee that would produce more honey. What actually happened was killer bees. Which do actually kill people. Hundreds of people, in fact, since they escaped into the wild in 1957 and started spreading throughout the Americas.

When animals hybridize even though they aren’t of the same genus, it’s called an intergeneric hybrid. That’s the case with sheep and goats. While sheep and goats are related on the subfamily level, they belong to separate genuses. Sheep have 54 chromosomes while goats have 60. That’s enough of a difference that most hybrid babies don’t survive long enough to be born alive, but it does happen occasionally. Usually the babies have 57 chromosomes, and sometimes the babies survive and even prove to be fertile when crossed with either a goat or a sheep. So that’s weird.

Just because someone wants to find out what you get when you cross, say, a sheep and a goat, doesn’t mean the sheep and goat in question are willing to make that effort. The less closely related the two animals are, the less interested they are in mating. Occasionally hybrids are produced by artificial insemination, or rarely by genetic manipulation of embryos, although genetic manipulation technically results in a chimera, not a hybrid.

Another intergeneric hybrid is a cross between a male camel and a female llama. In this case it’s accomplished by artificial insemination and has only produced a handful of living babies, called camas. Researchers were hoping to produce a camel-sized animal with a llama’s more cooperative temperament, but camas turn out to act like camels. So basically they’re just camels that aren’t as big or strong as camels.

In the 1970s, Chester Zoo in Cheshire in the UK kept a female Asian elephant and a male African elephant together in the same enclosure. The pair mated but no one thought they could produce a hybrid calf, since Asian elephants and African elephants aren’t that closely related. They’re another pair of animals that don’t share a genus. But a calf named Mottie was born in 1978. Surprise!

Many hybrids resemble one or the other of their parents. Motty was a fascinating blend of both. He had five toenails on his forefeet and four on the hind feet like his mom. African savannah elephants like his dad have four front toenails and three hind toenails. But he had longer legs and bigger ears than an Asian elephant. His trunk was wrinkled like his dad’s, but had only one digit at the tip like his mom’s. African elephants have two digits at the tip of their trunks. Even the shape of Motty’s head and back were a mixture of his parents’ characteristics.

So why would anyone want to cross species to get a hybrid? I mean, you might end up with killer bees.

A lot of times hybrids show what is known as hybrid vigor. This is more common in hybrid plants, but some hybrid animals combine the best features of their parents. Mules, for instance, have more stamina than horses and are stronger than donkeys. A hybrid of a domestic cow and an American bison is called a beefalo, which is bred to produce leaner meat in an animal that is better for the environment than a cow but easier to handle than a bison. But a lot of times, hybrids are the result of human ignorance, such as keeping related animals together without realizing babies might result, or human curiosity. We just want to see what might happen.

Unfortunately, for every healthy mule-like hybrid, there’s an unhealthy, malformed, or stillborn animal from parents who should have never produced offspring. Motty the elephant was premature and died of infection when he was only eleven days old, probably because his immune system was weakened due to his hybridized genetics.

Lions, tigers, leopards, and other big cats can all interbreed, but the resulting babies sometimes have unusual health issues. When a male lion and a female tiger breed, the resulting babies are known as ligers, and ligers are enormous. They’re much bigger and heavier than both their parents. This sounds neat, but it happens because of a genetic anomaly that means the animals just grow and grow much faster and longer than a normal tiger or lion cub. This puts stress on the body and can lead to health problems. Ligers can sometimes weigh over 1200 pounds, or over 550 kg, and grow up to 12 feet long, or 3.6 meters, bigger than a full-grown tiger or lion. The offspring of a puma and a leopard, often called a pumapard, has the opposite problem, with cubs usually inheriting a form of dwarfism. The cubs are only half the size of the parents.

The savannah cat is now accepted as a domestic cat breed by some organizations, but it was first developed in 1986 by crossing a female domestic cat and a male serval. The serval is a wild cat from Africa with large ears, long legs, and a spotted and striped coat pattern. It’s a little larger than a domestic cat and is sometimes kept as an exotic pet, although it’s not domesticated. The hybrid babies inherited their mother’s domesticated nature and turned out to be mostly sociable with humans, although some are less tame. But while Savannah cats are pretty, the kittens of a serval and domestic cat are often stillborn or premature, and many male offspring are infertile. Savannah cats are also prone to certain health issues, especially heart problems. Some areas have banned savannah cats since they’re not considered fully domesticated.

The more closely related the parents, the more likely a hybrid baby will result, and the more likely it will be healthy. Many wolf-like canids can and do easily hybridize with other wolf-like canids, since they have 78 chromosomes in the same arrangement and are closely related. Offspring are usually fertile. The wolf-like canids include wolves, domestic dogs, coyotes, jackals, and dholes. Where the ranges of these various species overlap in the wild, hybrids are not uncommon. But canids that are less closely related to the wolf-like canids, like foxes and raccoon dogs, can’t and don’t hybridize with their cousins.

Some whales will hybridize in the wild, including the fin whale and the blue whale, which are closely related. Dolphins of different species sometimes hybridize when they’re kept together in captivity, such as the false killer whale and the bottlenose dolphin. The resulting babies don’t usually live very long. Occasionally dolphins also hybridize in the wild too. In 2017 a hybrid baby of a rough-toothed dolphin and a melon-headed whale, which is actually a species of dolphin, was spotted off the coast of Hawaii. Researchers were able to get a small tissue sample from the young hybrid to DNA test, which confirmed its parentage. The melon-headed whale mother was also spotted with her calf in a pod of rough-toothed dolphins.

Birds also sometimes hybridize in the wild. This happens occasionally where the range of two closely related species overlap. Since the resulting babies may look very different from both their parents, this makes bird-watching even more challenging. Some warbler species hybridize so often that the hybrid offspring are well-known to birders, such as Brewster’s warbler and Lawrence’s warbler. These two birds are both offspring of a golden-winged warbler and a blue-winged warbler mate, with the appearance different depending on which traits the babies inherit from which parent.

Occasionally a domestic chicken will mate with a wild pheasant and produce babies, since chickens and pheasants are related. Very rarely, a swan and goose will mate and produce babies, although the babies don’t usually survive very long. One swan-goose hybrid that did survive was hatched in 2004 in Dorset in the UK, with a mute swan mother and a domestic goose father. The baby was referred to as a swoose and it was the only of the offspring to survive. It looks like a goose but with a longer, more swan-like neck and head.

If you’ve listened to episode 25, part one of the humans episode, you’ll recall that human DNA contains traces of DNA from our extinct cousins, including Neandertals. If Neandertals were still around, we could undoubtedly produce hybrids with them. But what about our living cousins, the other great apes? Humans are closely related to chimpanzees, but could a human produce a hybrid with a chimp? It’s possible but very unlikely. We belong to different genuses and have different numbers of chromosomes, not to mention the enormous ethical issues involved.

Let’s finish up with my favorite hybrid animal, the zebroid. This is a term for any hybrid where one parent is a zebra and the other parent is a horse, a donkey, or a pony, which also leads to the terms zorse, zedonk, and zony. These all crack me up, especially zedonk.

Zebroids are usually at least partially striped, frequently on the legs and neck but sometimes all over. The mane may stand up like a zebra’s or fall over the neck like a horse’s. The zebroid is adorable because of the stripes, but it’s also ornery and can be aggressive. There goes my dream of having a stripy horse.

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

Thanks for listening!

Episode 119: Before the Dinosaurs

What kinds of animals lived before dinosaurs evolved? What did they evolve into? Let’s find out!

Dimetrodon! Not a dinosaur! Not even actually a reptile:

Cotylorhynchus had a teeny head. I am not even exaggerating:

Moschops had a big thick skull:

Lisowicia was the size of an elephant but looked like…well, not like an elephant:

Show transcript:

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

Lots of people know about dinosaurs. Dinosaurs are really interesting. But do you know what animals lived before dinosaurs evolved? Let’s find out.

If you’ve heard of dimetrodon, you may think it’s just another dinosaur. It’s the animal that looks sort of like a huge lizard with a sail-like frill down its back. But not only was dimetrodon not a dinosaur, it went extinct 40 million years before the first dinosaur evolved.

Dimetrodon lived almost 300 million years ago and was a synapsid. Synapsid is a catchall term for a group of animals with both reptilian and mammalian characteristics, also sometimes called proto-mammals. The term synapsid also includes mammals, so yes, you are related to dimetrodon verrrrrrry distantly. You are more closely related to dimetrodon than you are to any dinosaur, let’s put it that way.  Dimetrodon was an early synapsid, which are referred to as pelycosaurs.

The largest species of dimetrodon grew up to 15 feet long, or 4.6 meters, with some probably growing even larger. It had serrated teeth, a long tail, short legs, and a massive sail on its back. The sail is formed from neural spines, which are basically just really long prongs of bone growing from the vertebrae. The spines were connected with webbing, although possibly not all the way to the tip of the spines. Ever since the first fossil remains of dimetrodon were discovered in 1878, scientists have been trying to figure out what the sail was for.

For a long time the most popular theory was that the sail helped with thermoregulation. That is, it helped dimetrodon stay warm in cool weather and cool in warm weather by absorbing sunshine or releasing heat, depending on where dimetrodon was. If dimetrodon was chilly, it would angle its body so that lots of sunlight reached its sail, but if dimetrodon was hot, it would find a patch of shade or turn its body so that minimal sunlight reached its sail, allowing the blood vessels covering the sail to release heat into the atmosphere.

This is a pretty good guess, since many modern animals use something similar to help regulate body temperature. That’s why African elephants have such large ears. But more recent studies of dimetrodon’s sail show that it didn’t have a lot of blood vessels, as it would if it was for thermoregulation. These days paleontologists suggest the sails may have mostly been for display. Different species had differently shaped sails, and there’s some evidence that male and female dimetrodons of the same species may have had differently shaped sails too. It’s possible the sails were brightly colored or patterned during the breeding season.

But dimetrodon wasn’t the only early synapsid with a sail. Secodontosaurus had one too and resembled dimetrodon in many ways, including having a long tail and short legs. But where dimetrodon was chunky with a massive skull, secodontosaurus was much more slender with long, narrow jaws. It may have eaten fish. It probably grew up to nine feet long, or 2.7 meters, and it lived around 275 million years ago. It was related to dimetrodon, but paleontologists aren’t sure how closely it was related.

The largest pelycosaur, or early synapsid, was cotylorhynchus [ko-tillo-rinkus], which lived around 275 million years ago in what is now North America. It was a weird-looking animal. Weird, weird weird. Seriously, it was very strange. It grew to almost twenty feet long, or 6 meters, with a barrel-shaped body, great big legs, and a long tail. But its neck was very short and its head was tiny.

Some researchers think cotylorhynchus lived in the water. Its forefeet may have been paddle-shaped. It ate plants, which is why its body was so big, since it needed room to hold lots of plants while they digested. It may have dug for roots as well, since its forefeet had long claws. Weird as it was, if you think of it as shaped sort of like a giant tortoise, its small head and big body make more sense.

Dimetrodon and other pelycosaurs lived in the early Permian era. By the mid-Permian, a group of synapsids called therapsids started evolving to become more mammal-like. The legs of therapsids were positioned more beneath the body instead of sprouting out from the sides, which is the difference between a dog’s body and a lizard’s body. This allowed therapsids to run more efficiently and breathe more efficiently when moving fast.

We know that at least some of these early therapsids had fur because paleontologists have found coprolites, which as you recall are fossilized poops, with fur embedded in them. Since this was long before mammals evolved, it had to be therapsids with fur. In fact, it was the therapsids that eventually evolved into mammals, so technically you are also a therapsid.

Therapsids were probably warm-blooded and probably had whiskers. But they wouldn’t have looked like mammals today. They probably resembled reptiles in a lot of ways, especially early therapsids. The tails of many therapsids would have looked like reptile tails, long, thick, and pointed. The heads would have looked much more like a lizard head than a mammal head, with no external ears.

Some therapsids would have looked really weird. For instance, moschops [mo-shops], which lived around 260 million years ago in what is now southern Africa. Moschops was a type of therapsid that ate plants, and it was massively built. It was around 8 feet long, or 2.5 meters, and had a thick skull and short snout with strong jaw muscles. The back sloped downward from the shoulders to a short tail. Its relatively short legs were sturdy to hold up the weight of the broad and massive body. The front legs were much farther apart than the hind legs. Its teeth were strong but not sharp; instead, they had chisel-like edges that helped it bite through tough vegetation.

Moschops had such a thick skull that many researchers think it fought other moschopses by butting heads. The small brain was extremely well protected by a skull that was as much as 6 inches thick, or 15 cm, and new research shows that the head was usually held forward instead of up. This makes sense in a grazing animal, and would also make sense if males were butting heads to impress potential mates, or if individuals fought over territory or food. If moschops did butt heads, it’s possible that it lived in groups with a certain amount of social organization.

Toward the end of the Permian, a group of therapsids called dicynodonts became widespread and lived well into the Triassic era. Dicynodonts were probably warm-blooded, probably had fur or hair, and some may have had feet that were more paw-like than reptilian, with fleshy pads. But while all these features are mammalian, most dicynodonts had a horny beak like a turtle and either no teeth at all, or only a pair of teeth in the front of the jaw that grew like tusks. Some paleontologists think only males had these tusks. Most dicynodonts were herbivorous and some dug burrows.

About 250 million years ago, there was a mass extinction event called the Permian-Triassic extinction, or sometimes just the Great Dying. Researchers aren’t sure what caused it, but like the later extinction that ended the dinosaurs, it may have been caused initially by a massive meteor impact that sent the earth’s climate into a tailspin. 96% of all marine species went extinct and 70% of land animals. This was the event that led to the rise of the dinosaurs ultimately. But some therapsids survived.

The biggest dicynodont evolved after the great dying and it was the size of an elephant. Lisowicia lived in what is now Poland around 230 million years ago, but it was probably more widespread than that sounds. We only have a single specimen of lisowicia that was discovered in south Poland in 2008. It probably stood 8 ½ feet high, or 2.6 meters. All four of its legs were positioned under the body like modern mammals, whereas most dicynodonts were similar to moschops, where the hind legs were under the body and the forelegs were more widely spaced and sprawling. But it probably didn’t look much like a modern mammal beyond that. Its head would probably have looked quite reptilian since it had a horny beak like other dicynodonts. Its tail was short.

Dicynodonts went extinct by the late Triassic, but the related cynodonts persisted. Cynodonts are the direct ancestors of mammals. You are definitely also considered a cynodont. The first cynodonts evolved in the late Permian and had a lot of traits that are still retained by mammals, such as fur, whiskers, warm-bloodedness, and teeth that are differentiated into different types like molars and incisors. They also developed what’s called a secondary palate, or as we call it, the roof of the mouth. All mammals still have this feature, which allows us to breathe and chew at the same time. But cynodonts also still probably laid eggs. Eventually cynodonts developed into monotremes like the platypus and echidna, which many researchers consider to retain many cynodont features.

Probably the largest cynodont was cynognathus, which lived around 240 million years ago. Cynognathus was a predator that grew almost four feet long, or 1.2 meters, not counting its long tail. It was widespread throughout the southern hemisphere, with cynognathus fossils of various species found in modern-day southern Africa, South America, and Antarctica. It had already evolved the secondary palate, and its head and jaws were both long and wide, with sharp teeth.

Because cynodonts lived alongside dinosaurs for millions of years, they evolved into animals that were generally quite small, no larger than a rat, and frequently nocturnal. But they were still incredibly successful, spreading out across the world and evolving into animals that looked more and more like mammals that we’d recognize today. The haramiyids were probably insectivores and lived in trees, with some species able to glide like flying squirrels or the colugo. Many cynodonts lived in large shared burrows, suggesting increasingly complex social behavior.

But not all early mammals were tiny and ran away from dinosaurs. Repenomamus [re-penno-may-mus] lived around 125 million years ago and grew over three feet long, or 1 meter. In shape, it somewhat resembled a badger with a long tail. We know it ate small animals, including hatchling dinosaurs, because fossil remains of a baby psittacosaurus [sit-acko-saurus] was found in the stomach area of a fossil repenomamus. The psittacosaurus remains were in chunks, which suggests that repenomamus had bitten it into pieces to swallow it.

Repenomamus was considered a Eutriconodont, a type of early mammal, but the eutriconodonts went extinct at about the same time as the dinosaurs.

But by then, the therapsids were fully evolved into what we have termed mammals. And they were poised to take over. Or, I should say, we mammals were poised to take over. And we have.

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

Thanks for listening!