Category Archives: amphibians

Episode 209: Animals Discovered in 2020

Here’s a 2020 retrospective episode that looks at the bright side of the year! Thanks to Page for the suggestion! Let’s learn about some animals discovered in 2020 (mostly).

Further reading:

Watch This Giant, Eerie, String-Like Sea Creature Hunt for Food in the Indian Ocean

Rare Iridescent Snake Discovered in Vietnam

An intrusive killer scorpion points the way to six new species in Sri Lanka

What may be the longest (colony) animal in the world, a newly discovered siphonophore:

New whale(s) just dropped:

A newly discovered pygmy seahorse:

A newly discovered pipefish is extremely red:

So tiny, so newly discovered, Jonah’s mouse lemur:

The Popa langur looks surprised to learn that it’s now considered a new species of monkey:

The newly rediscovered devil eyed frog. I love him:

The newly discovered Lilliputian frog looks big in this picture but is about the size of one of your fingernails:

This newly discovered snake from Vietnam is iridescent and shiny:

A new giant scorpion was discovered in Sri Lanka and now lives in our nightmares:

The Gollum snakehead was technically discovered in 2019 but we’re going to let that slide:

Show transcript:

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

Very recently, Page suggested the topic “animals discovered in 2020.” Since I was already thinking of doing something like this, I went ahead and bumped his suggestion to the top of the list and here we go!

You’d think that with so many people in the world, there wouldn’t be too many more new animals to discover, especially not big ones. But new scientific discoveries happen all the time! Many are for small organisms, of course, like frogs and insects, but there are still unknown large animals out there. In fact, 503 new animals were officially discovered in 2020. Every single one is so amazing that I had a hard time deciding which ones to highlight. In most cases we don’t know much about these new animals since studying an animal in the wild takes time, but finding the animal in the first place is a good start.

Many of the newly discovered species live in the ocean, especially the deep sea. In April of 2020, a deep-sea expedition off the coast of western Australia spotted several dozen animals new to science, including what may be the longest organism ever recorded. It’s a type of siphonophore, which isn’t precisely a single animal the way that, say, a blue whale is. It’s a colony of tiny animals, called zooids, all clones although they perform different functions so the whole colony can thrive. Some zooids help the colony swim, while others have tiny tentacles that grab prey, and others digest the food and disperse the nutrients to the zooids around it. Many siphonophores emit bioluminescent light to attract prey.

Some siphonophores are small but some can grow quite large. The Portuguese man o’ war, which looks like a floating jellyfish, and which we talked about way back in episode 16, is actually a type of siphonophore. Its stinging tentacles can be 100 feet long, or 30 m. Other siphonophores are long, transparent, gelatinous strings that float through the depths of the sea, snagging tiny animals with their tiny tentacles, and that’s the kind this newly discovered siphonophore is.

The new siphonophore was spotted at a depth of about 2,000 feet, or 625 meters, and was floating in a spiral shape. The scientists estimated that the spiral was about 49 feet in diameter, or 15 meters, and that the outer ring alone was probably 154 feet long, or 47 meters. The entire organism might have measured 390 feet long, or almost 119 meters. It’s been placed into the genus Apolemia although it hasn’t been formally described yet.

Another 2020 discovery off the coast of Australia was an entire coral reef a third of a mile tall, or 500 meters, and almost a mile across, or 1.5 km. It’s part of the Great Barrier Reef but isn’t near the other reefs. A scientific team mapping the seafloor in the area discovered the reef and undoubtedly did a lot of celebrating. I mean, it’s not every day that you find an entirely new coral reef. They were able to 3D map the reef for study and take video too. Best of all, it’s a healthy reef with lots of other animal life living around it.

Another big animal discovered in 2020 is one Patreon subscribers already know about, because we started out the year with an episode all about it. It’s a new whale! In 2018 scientists recording audio of animal life around Mexico’s San Benito Islands in the Pacific Ocean heard a whale call they didn’t recognize. They thought it probably belonged to a type of beaked whale, probably a little-known species called Perrin’s beaked whale.

In late 2020 a team went back to the area specifically to look for Perrin’s beaked whales. They did see three beaked whales and got audio, video, and photographs of them, but they weren’t Perrin’s beaked whales. The whale specialists on the expedition didn’t know what these whales were. They don’t match any species of known cetacean and appear to be a species new to science.

And speaking of new species of whale, guess what. Don’t say chicken butt. You can say whale butt, though, because the discovery of another new whale species was just announced. This one’s a 2021 discovery but there’s no way I was going to wait until next year to talk about it. It lives in the Gulf of Mexico and can grow over 41 feet long, or more than 12 meters. It’s a baleen whale, not a beaked whale, and it was hiding in plain sight. It looks a lot like the Bryde’s whale and was long thought to be a subspecies, but new genetic testing shows that it’s much different. It’s been named Rice’s whale, and unfortunately it’s extremely rare. There may only be around 100 individuals alive. It’s mostly threatened by pollution, especially oil spills like the 2010 Deepwater Horizon oil spill, and by collisions with ships. Hopefully now that scientists know more about it, it can be further protected.

Let’s move on from new gigantic animal discoveries to a much, much smaller one. A new pygmy seahorse was discovered off the coast of South Africa in May 2020. It’s brownish-yellow with pinkish and white markings and is only 20 mm long at most. A dive instructor who had seen the fish but didn’t know what it was told researchers about it and they organized a team to look for it. Its closest known relation lives in southeast Asia almost 5,000 miles away, or 8,000 km. Like other seahorses, it lives in shallow water and uses its flexible tail to hang onto underwater plants, but the area where it lives is full of huge waves rolling in from the ocean. It’s called the Sodwana Pygmy Seahorse after the bay where it was discovered, and officially named Hippocampus nalu. “Nalu” means “here it is” in the local Zulu and Xhosa languages, and it also happens to mean “surging surf” in Hawaiian, and it also happens to be the middle name of the dive instructor who spotted the fish, Savannah Nalu Olivier. Sometimes fate just says “this is the right name.”

A new species of pipefish, which is closely related to the seahorse, was also described in 2020, Stigmatopora harastii. It lives off the coast of New South Wales, Australia and can grow up to 5 ½ inches long, or 14 cm. It was first spotted by scuba divers in 2002. These divers know their fish. It lives among a type of red algae and is the same color red for camouflage. It’s surprising how long it took for scientists to discover it, because it’s not exactly hard to confuse with anything else. Except, you know, algae.

Not all newly discovered animals live in the ocean. In August of 2020 researchers discovered a new mouse lemur in Madagascar. We talked about a different type of mouse lemur in episode 135, that one discovered in 1992 and only growing to 3.6 inches long, or 9 cm, not counting its long tail. The newly discovered Jonah’s mouse lemur is only a little bigger than that. Mouse lemurs are the smallest members of the primate family. They’re also super cute but endangered due to habitat loss.

Another primate discovered in 2020 is one that researchers already knew about for more than a hundred years, but no one realized it was its own species, just like Rice’s whale. In 2020, genetic analysis finally determined that the Popa langur is a new species. It’s a beautiful fuzzy gray monkey with bright white markings around its eyes like spectacles. It lives on an extinct volcano in Myanmar and is critically endangered, with only an estimated 250 individuals left in the wild.

A 2020 expedition to the Bolivian Andes in South America led to the discovery of twenty new species of plant and animal, plus a few re-discoveries of animals that were thought to be extinct. The rediscoveries include a species of satyr butterfly not seen for 98 years, and a frog seen only once before, twenty years ago. The frog is called the devil-eyed frog because of its coloring. It’s purplish or brownish black with red eyes and only grows about an inch long, or 29 mm.

Another frog the team found is one of the smallest frogs in the world. It’s been identified as a frog in the genus Noblella and it only grows about ten mm long. As one article I read pointed out, that’s the size of an aspirin. It’s a mottled brown and black and it lives in tunnels it digs in the leaf litter and moss on the forest floor. It’s being referred to as the Lilliputian frog because of its small size.

In the summer of 2019, a team of scientists surveying the karst forests in northern Vietnam spotted an unusual snake. It was so unusual, in fact, that they knew it had to be new to science. It was dark in color but its small scales shone an iridescent purplish, and it was about 18 inches long, or almost 46 cm. It belongs to a genus referred to as odd-scaled snakes, and we don’t know much about them because they’re so hard to find. They mostly burrow underground or under leaf litter on the forest floor. The new species was described in late 2020.

A new species of giant scorpion was discovered in Sri Lanka in 2020. It lives in the forests of Yala National Park and is nocturnal. The female is jet black while the male has reddish-brown legs, and a big female can grow up to 4 inches long, or a little over 10 cm. It’s called the Yala giant scorpion after the park and is the sixth new scorpion species discovered in the park.

One thing I should mention is that all these scientific expeditions to various countries are almost always undertaken by both local scientists and experts from other places. Any finds are studied by the whole group, resulting papers are written with all members contributing, and any specimens collected will usually end up displayed or stored in a local museum or university. The local scientists get to collaborate with colleagues they might never have met before, while the visiting scientists get the opportunity to learn about local animals from the people who know them best, who also happen to know the best places to eat. Everybody wins!

Let’s finish with an astonishing fish that was technically discovered in 2018 and described in 2019, but was further studied in 2020 and found to be even more extraordinary than anyone had guessed. In 2018, after a bad flood, a man living in the village of Oorakam in Kerala, South India, spotted a fish in a rice paddy. He’d never seen a fish like it before and posted a picture of it on social media. A fish expert saw the picture, realized it was something new, and sent a team to Oorakam to retrieve it before it died or something ate it. It turned out to be a new type of snakehead fish.

There are lots of snakehead species that live in rivers and streams throughout parts of Africa and Asia. But this snakehead, which has been named the Gollum snakehead, lives underground. Specifically, it lives in an aquifer. An aquifer is a layer of water that occurs underground naturally. When rain soaks into the ground, some of it is absorbed by plant roots, some seeps out into streams, and some evaporates into the air; but some of it soaks deeper into the ground. It collects in gravel or sand or fractured rocks, or in porous rocks like sandstone. Sometimes an aquifer carves underground streams through rock, creating caves that no human has ever seen or could ever see, since there’s no entrance to the surface large enough for a person to get through. In this case, the heavy rain and floods in Oorakam had washed the fish out of the aquifer and into the rice paddy.

The Gollum snakehead resembles an eel in shape and grows abound four inches long, or 10 cm. Unlike fish adapted for life in caves, though, it has both eyes and pigment, and is a pale reddish-brown in color. This may indicate that it doesn’t necessarily spend all of its life underground. Aquifers frequently connect to springs, streams, and other aboveground waterways, so the Gollum snakehead may spend part of its life aboveground and part below ground.

When it was first described, the researchers placed the fish in its own genus, but further study in 2020 has revealed that the fish is so different from other snakeheads that it doesn’t just need its own genus, it needs its own family. Members of the newly created family are referred to as dragonfish.

Other snakeheads can breathe air with a structure known as a suprabranchial organ, which acts sort of like a lung, located in the head above the gills. Not only does the Gollum snakehead not have this organ, there’s no sign that it ever had the organ. That suggests that other snakeheads developed the organ later and that the Gollum snakehead is a more basal species. It also has a small swim bladder compared to other snakeheads.

Researchers think that the dragonfish family may have separated from other snakehead species as much as 130 million years ago, before the supercontinent of Gondwana began breaking up into smaller landmasses. One of the chunks that separated from Gondwana probably contained the ancestor of the Gollum snakehead, and that chunk eventually collided very slowly with Asia and became what we now call India.

The Gollum snakehead isn’t the only thing that lives in the aquifer, of course. Lots of other species do too, but it’s almost impossible to study them because they live underground with only tiny openings to the surface. The only time we can study the animals that live there is when they’re washed out of the aquifers by heavy rain. It turns out, in fact, that there’s a second species of dragonfish in the aquifer, closely related to the Gollum snakehead, with a single specimen found after rain.

So, next time you’re outside, think about what might be under the ground you’re walking on. You might be walking above an aquifer with strange unknown animals swimming around in it, animals which may never be seen by humans.

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

Thanks for listening!

Episode 204: Frogs of Many Cheery Colors

Let’s finish off a very weird year and welcome in the new year with a basket of colorful frogs!

The northern leopard frog comes in many color morphs, all of them pretty:

The starry dwarf frog is also pretty and has an orange tummy:

The astonishing turtle frog:


Poison dart frogs are colorful and deadly (blue poison dart frog, golden poison dart frog):

The tomato frog looks like a tomato that is also a frog:

Show transcript:

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

It’s the very last week of 2020, and good riddance. Let’s kick the old year out the back door and welcome in the new year with a basket of pretty frogs. That’s right, we’ve got a frog episode this week!

Let’s start with the northern leopard frog, with thanks to an anonymous reviewer who gave the podcast a really nice five-star review and only signed the review “norhern lepord frong.” I looked that frog up online to see what it looked like, and it’s so pretty, honestly, it’s just the prettiest frog! If you had a basket of northern leopard frogs, they might just look like friendly flowers, because while most are green or brown with darker spots, some are much brighter green with yellow markings, some are dark brown, and some are even pinkish white because of a rare albino trait. Its spots are outlined with yellow or light green and it has two folds of skin that run the length of the body and are sometimes yellow. These folds of skin are called dorsolateral folds and many frogs have them, although they’re not always as easy to spot as in the northern leopard frog.

The northern leopard frog is native to the northern part of North America, especially southern Canada and the northern and western United States. It grows up to 4.5 inches long, or 11.5 cm, measured from snout to vent. As you may recall from previous frog episodes, that’s how frogs are always measured. It basically just means nose to butt. Females are larger than males, which is also the case for most frogs.

It lives anywhere that it can find fresh water, including rivers, streams, creeks, ponds, marshes, even drainage ditches, but it prefers slow-moving or quiet water. As a result, it’s threatened by loss of habitat, pollution, and climate change, all of which affect the water it needs to live, and it’s also threatened by non-native animals and diseases. But while it doesn’t live in as many places as it used to, right now it’s doing fine overall and isn’t considered endangered.

Like most frogs, the northern leopard frog eats insects and any other small animal it can swallow. It has a long sticky tongue that it can shoot out so quickly that even an insect can’t outfly it, but it doesn’t just eat insects. It’s a big frog with a big mouth, and it’s been recorded eating other species of frog, small snakes, small birds, and even a bat. But mostly it eats insects, slugs, snails, and worms. Probably the frog that was documented as catching and eating a bat is famous in the northern leopard frog world, or at least it would be if real life was like the inside of my head and frogs had their own tiny newspapers.

The northern leopard frog was once considered a delicacy, with most frogs’ legs coming from this particular species. It’s also sometimes kept as a pet. It’s mostly nocturnal and semi-aquatic, sometimes called the meadow frog because it will leave the water to hunt for food in grassy areas. It hibernates in winter but is better adapted to cold weather than a lot of frogs are.

There’s also a southern leopard frog that looks very similar to the northern leopard frog but lives farther south, which you probably guessed from the name. It’s also slightly larger than the northern leopard frog, up to five inches long, or 13 cm.

Male leopard frogs, like many other frogs, have special vocal sacs in the throat that allow a male to make a loud call in spring to attract females. Different species of frog have different calls, naturally, and the vocal sacs are shaped differently in every species. The male leopard frog, northern and southern, has two vocal sacs that he fills with air like balloons, which amplifies the sound of his voice and makes it much louder.

This is what a northern leopard frog sounds like:

[frog sound]

Another colorful frog is from India and was only discovered in 2010. A team of scientists surveying the mountains for reptiles and amphibians noticed a teensy frog in the leaf litter one night. Its back was brown with light blue dots that looked like stars in a night sky, but its belly was orange like a sunset. It’s a very pretty frog.

The researchers caught several of the frogs and thought they were pretty but not especially unusual. There are at least 400 known frogs in India and new species are found pretty frequently. The team named it the starry dwarf frog because of the blue dots and its size, less than 20 mm long, or around half an inch. That’s about the size of an adult’s thumbnail.

After the expedition, though, when the team examined the frogs more closely, they realized they had something different from other frogs. It didn’t seem to be related to any other frog species in India or anywhere else. A genetic analysis indicated that the starry dwarf frog is literally not closely related to any frog alive today. For millions of years India was a big island after it separated from Madagascar and Africa but before it collided with mainland Asia, so many species evolved independently from species in other parts of the world. Scientists hope to learn more about the starry dwarf frog to learn more about how other frogs evolved.

Let’s move on to another colorful frog, and a very weird one, the turtle frog. Simon brought this one to my attention, so thank you, Simon! This frog gets its name because it sort of looks like a tiny turtle without a shell.

The turtle frog lives in western Australia in areas that are much dryer than most frog habitats. Its body is bulbous with strong, stubby legs that allow it to burrow into the sand. Generally, when a frog burrows into sand or mud it does so by moving backwards, digging itself deeper with its strong hind legs. But the turtle frog digs forward, using its front legs to dig. Turtles are also forward diggers. Unlike most other frogs, the turtle frog doesn’t have long hind legs that it uses for jumping. It just has short legs in front and back.

It ranges in color from brown to reddish-brown to pink and it grows up to 2 inches long, or 5 cm. Its head is small, rounded, and distinct from the body, like a baby turtle’s head sticking out from its shell–but without a shell, without a beak, and with small black-dot eyes.

Obviously the turtle frog isn’t related to the turtle at all. Turtles are reptiles while frogs are amphibians. The turtle frog has adapted to a semi-arid climate and a diet of termites by evolving the ability to dig deep burrows, some of them almost four feet deep, or 1.2 meters, and the ability to break into termite nests. As a result, its body plan is different from most other frogs.

That’s not all that’s different, though. Most frogs lay eggs in water, which hatch into tadpoles that live in the water until they metamorphose into small frogs. The turtle frog doesn’t have that kind of luxury. It doesn’t have a lot of water most of the time, so it hatches into a tiny froglet instead of a tadpole.

The most colorful frogs in the world live in the tropics, especially the poison dart frogs of Central and South America. Poison dart frogs are diurnal, meaning they’re most active during the daytime, and they’re fairly small, with the biggest species growing to no more than about two and a half inches long, or 6 cm. Different species of poison dart frogs are different colors and patterns, ranging from a lovely bright blue to red or yellow. These little frogs need to be brightly colored so that predators know to leave them alone, and the reason they should leave them alone is that poison dart frogs are incredibly toxic.

You may have heard the story that natives of South America would rub the tips of their darts or arrows on these frogs to transfer the frogs’ toxic secretions to the weapons. That’s where the name poison dart frog comes from. That’s sort of true, but not completely true. Not all poison dart frogs were used in this way, just four of the largest species that are especially toxic.

One of these four species is the golden poison dart frog, which lives in the rainforests of Colombia. It’s usually bright yellow with black eyes, although some individuals are a minty green or orange. It looks cheery, but a single frog has enough poison to kill two African elephants, not that it would because it lives in South America and not Africa and the elephants would not try to eat the frog. One frog has enough poison to kill 10 to 20 humans, though, so don’t try to eat one. In fact, don’t even touch it, because poison dart frogs store their poison in skin glands and if a frog feels threatened, it will secrete a tiny amount of the poison. If that poison gets into your body, you will die.

So why do people keep golden poison dart frogs as pets? That would be like having a pet stick of dynamite, right? Actually, it turns out that frogs born in captivity don’t develop the toxins that wild frogs have. Frogs that are captured in the wild and kept in captivity will eventually lose the toxins, although it may take several years. This is because the frog doesn’t manufacture the toxins itself but retains toxins found in some insects it eats, although researchers aren’t sure yet which insect or insects.

The golden poison dart frog lays its eggs on the ground. This sounds weird until you remember that it lives in a rainforest and the ground is covered with dead leaves that are constantly wet from rain. When the eggs hatch into tadpoles, though, they need more than just wet leaves, so the parent frogs squat down and the tadpoles wriggle onto the parents’ backs. They stick there and the parents carry them not to a pond but up into the trees. Water collects in the middle of large leaves of some rainforest tree species, and of course there are always little hollows and holes in tree trunks that can fill with rainwater. The frogs deposit the tadpoles into these little puddles, where the tadpoles eat mosquito larvae and algae. But even then, the parents don’t abandon their babies. Golden poison dart frogs are social animals, not generally a trait you associate with frogs, and they live in little groups of around half a dozen individuals. When the tadpoles finish developing and metamorphose into adult frogs, the parents lead their babies to other golden poison dart frogs so they can join a group.

Finally, our last colorful frog of the episode and the very last animal we’ll cover for 2020 is the tomato frog. As you might have guessed, the tomato frog is red-orange in color. It lives in Madagascar and a big female can grow up to 4 inches long, or 10.5 cm. Males are much smaller and are more yellow than red. But the tomato frog doesn’t use its coloring to hide among tomato plants. Its coloring advertises that it’s toxic, although its toxin is much different from those found in poison dart frogs and not deadly.

The tomato frog mostly eats worms and termites, which it finds by digging around in the leaf litter. It also catches insects with its sticky tongue. It’s not a very good swimmer, surprisingly, and spends most of its time on land or in swampy areas. It’s a mostly nocturnal frog.

If a tomato frog feels threatened, it will puff itself up to appear larger, which also incidentally makes it look even more like a tomato. It will also secrete a sticky white toxin that irritates a predator’s mucus membranes and can cause serious allergic reactions in humans. The toxin is so sticky that it will remain in the predator’s mouth for days. So if you live in Madagascar and have a tomato garden, carefully examine every tomato before you take a bite.

This is what a tomato frog sounds like:

[tomato frog croaking]

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

Thanks for listening!

Episode 172: Temnospondyls

This week let’s go back back back in time to more than 300 million years ago, when amphibian-like animals lived in enormous swamps. Don’t be fooled by the word amphibian: many Temnospondyls were really big!

Further reading:

Palaeos Temnospondyli

Dvinosaurus, three feet long and full of teeth:

And Sclerocephalus, five feet long and full of teeth. This one has a couple of larvae nearby:

Fayella (art by Nix)

Nigerpeton’s astonishing NOSE TEETH:

Mastodonsaurus had nose teeth too and it was way bigger than Nigerpeton, but somehow it just looks goofy instead of cool:

Koolasuchus just looked weird:

The largest Temnospondyl known, Prionosuchus:

Show transcript:

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

This week we’re going back into the past, way before the dinosaurs, to look at an order of animals that resembled modern amphibians but weren’t precisely amphibians, or reptiles, or fish. Let’s look at the Temnospondyls.

During the early Carboniferous period, which lasted from about 360 to 300 million years ago, the ocean levels were high, the climate across much of the world was humid and tropical, and the continents were in the process of smushing together to form a huge landmass called Pangea. Much of the land was flooded with warm, shallow water that created enormous swampy areas full of plants and newly evolved trees. These swampy areas, full of decomposing leaves, eventually became coal and peat beds. As the Carboniferous period continued, the climate turned milder and the sea levels dropped, but while the huge swamps remained, many life forms evolved to take advantage of the various habitats and ecological niches they provided.

The armored fish of the Devonian went extinct, replaced by more modern-looking fish, including sharks and the first freshwater fish. The first conifer trees appeared, land snails, dragonflies and other insects, and the first animals that could survive on land for part of the time. This included the Temnospondyls, a numerous and successful order of animals whose fossils have been found worldwide and appear in the fossil record for more than 200 million years. But most people have never heard of them.

Temnospondyls are grouped in the class Amphibia alongside Lissamphibia, which is the order all living amphibians and their ancestors belong to. But researchers aren’t sure if Temnospondyls gave rise to lissamphibians or if they all died out.

The first Temnospondyl fossils were discovered in the early 19th century and early paleontologists immediately started debating what exactly these strange animals were. It was originally classified as a reptile, but as more fossils came to light, it became clear that these weren’t reptiles. Finally it was classified as a subclass of amphibian called Labyrinthodontia, where it remains today, at least for now.

Temnospondyls do share many traits with modern amphibians. We know that at least some species had a larval form that was completely aquatic, with fossil evidence of gill arches. Some retained external gills into adulthood the way some salamanders do. But they still had a lot in common with their fish ancestors.

Most Temnospondyls had large heads that were broad and flattened in shape, often with a skull that was roughly triangular. The earliest species had relatively small, weak legs and probably spent most of their time in the water, but it wasn’t long before species with stronger legs developed that probably lived mostly on land.

When you think about amphibian relatives, you probably think these animals were small, maybe the size of a bullfrog. But while some Temnospondyls were small, many grew much larger. Some had smooth skin but many had scales, including some species with scales that grew into armor-like plates. Let’s look at some individual species of Temnospondyl and get an idea of how varied they were.

Let’s start with a group of temnospondyls with one of the most confusing names ever, Dvinosauria. That may not sound too confusing, but it’s spelled just like dinosauria but with a V after the D. It lived in the late Permian around 260 million years ago, and its fossils have been found in parts of Russia. It was named not to mess with people who keep seeing dvinosaur and thinking dinosaur, but after the Northern Dvina River.

Dvinosaurs were either semi-aquatic or fully aquatic, depending on the species. The genus Dvinosaurus was pretty typical for aquatic Temnospondyls. It had external gills and was fully aquatic, with small legs but a powerful tail for swimming. It grew over three feet long, or around a meter, and probably looked like a big salamander with a big triangular head. It probably ate fish and other small animals. Like many Temnospondyls, it had extra teeth growing from the roof of its mouth to help it hold onto fish. Some paleontologists think it lurked at the bottom of rivers and streams until it saw a fish or other animal approach, at which point it shot upward and grabbed it.

A typical land Temnospondyl was Sclerocephalus, which lived around 300 million years ago in what is now Germany. We have a lot of Sclerocephalus fossils, which means it was probably a successful animal. It was also big, around five feet long, or 1.5 meters.

Because we have so many Sclerocephalus fossils, we know a lot more about it than we do other Temnospondyls. Its larval form was aquatic and had a long tail to help it swim. As a juvenile it probably had external gills but as it matured, it spent more and more time on land, using its lungs to breathe. Its tail was shorter as an adult because it didn’t need to swim as often. But it did spend time in the water and retained the lateral line system still found in fish and some amphibians, a sensory organ that detects water movements. It also had a pineal eye that a few animals retain today, notably the reptile Tuatara that we talked about way back in episode three. This third eye was at the top of the skull and was probably only sensitive to light rather than being useful for seeing. As in modern animals that still have a pineal eye, it probably helped regulate behaviors according to the length of days.

We even know exactly what Sclerocephalus ate, because we have fossilized stomach contents in a few cases. It ate fish and amphibians and sometimes smaller Sclerocephaluses, and was probably an opportunistic predator. Like other Temnospondyls it had teeth on its palate, three pairs in its case that grew from the roof of its mouth.

A less typical temnospondyl was the genus Fayella, which lived in what is now Oklahoma in the United States and lived around 270 million years ago, in the early Permian. It grew to about four feet long, or 1.15 meters, and had unusually long legs for a Temnospondyl. It also had a smaller head in proportion to its body compared to most Temnospondyls, and was more lightly built. As a result, it looked more like a reptile or an early synapsid, which as you may remember from episode 119 were proto-mammals that looked like weird reptiles. Researchers think Fayella could run much faster than other Temnospondyls could, which didn’t so much help it catch prey as evade hunting synapsids.

Nigerpeton looked more like your average Temnospondyl, mostly. It lived in what is now the African country of Niger, around 250 million years ago. It was only discovered in the early 2000s and we still don’t have very many fossils so we don’t know exactly how big it was. But its skull was two feet long, or 60 cm, so it was definitely a big animal. It probably looked a lot like a crocodile in many ways, including a long, heavy snout with lots of teeth. Lots of teeth. LOTS of teeth. As with other Temnospondyls, it ate fish and other small, wriggly animals, and to help it catch those fish it had ordinary teeth and extra teeth that grew from the top of the mouth and the lower jaw. Basically it just had a mouthful of teeth. This is true for many Temnospondyls, but Nigerpeton took that one step too far. Two of its extra teeth are referred to as tusks, because they grew upward from the lower jaw, pierced through the roof of the mouth, and emerged from the top of the nose about where you’d expect nostrils to be in a modern animal. Instead of nostrils, NOSE TEETH. Actually, the nostrils were behind the nose teeth. We don’t know enough about Nigerpeton to know what it used these tusks for, but it sure looked cool.

Nigerpeton wasn’t the only Temnospondyl with tusks that emerged from the top of the nose when its mouth was closed. Others had it too, including one of the first Temnospondyls discovered, Mastodonsaurus. Mastodonsaurus was a successful genus of Temnospondyls that lived from about 247 million years ago to 201 million years ago in what is now Europe. Despite its name, Mastodonsaurus was neither a mastodon nor a dinosaur. It was big, though—one species grew up to 20 feet long, or 6 meters. Like other Temnospondyls it had a big head and a somewhat short tail. It also had legs that were small and weak, which suggests it was mostly if not completely aquatic, and it ate fish and other small animals.

The most recently living Temnospondyl, which went extinct around 120 million years ago, lived in what is now Australia. Koolasuchus lived in fast-moving streams and filled the same ecological niche as crocodiles, which eventually replaced it after it went extinct. But it didn’t look anything like a crocodile. It had the typical big head of a Temnospondyl, in this case broad and rounded with a blunt nose, but with what are called tabular horns that projected from the rear of the skull, which gave its head a triangular appearance. Plus, it probably grew up to 16 feet long, or 5 meters. But its body was relatively slender compared to the chonky head, which made it look kind of like a really really big tadpole.

We’ll finish with the largest species of Temnospondyl known, Prionosuchus. It lived between 299 and 272 million years ago in what is now Brazil, and while it didn’t look much like a modern crocodile, it filled the same ecological niche. It had relatively small legs and a big head like most Temnospondyls, but its snout was slender and elongated like a ghavial’s. It was an aquatic animal and was probably an ambush predator that mostly ate fish.

While we don’t know exactly how big Prionosuchus could grow since we don’t have any complete specimens, the largest skull found measured 5.2 feet long, or 1.6 meters. That’s just the skull. Researchers estimate the animal was 30 feet long, or 9 meters, when it was alive.

But although Prionosuchus was amphibious like other temnospondyls, it retained a lot of features from its fish ancestors. Basically, it looked something like the biggest salamander you could imagine, but with jaws and teeth like a ghavial’s, but inside it was more fish than amphibian. It’s no wonder paleontologists have been trying to figure Temnospondyls out for almost two centuries.

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

Thanks for listening!

Episode 170: Spinosaurus

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

Further reading:

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

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

Further watching:

A good video about the new findings

Spinosaurus’s updated look:

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

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

Show transcript:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Thanks for listening!

Episode 148: Gastric Brooding and Other Frogs

Thanks for Merike for suggesting the gastric brooding frog and to Hally for suggesting newly-discovered frogs!!

The Gastric brooding frog:

Darwin’s frog, round boi:

The Surinam toad carries her eggs and tadpoles in the skin of her back:

Kermit the frog and a newly discovered glass frog:

Show transcript:

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

This week we have another fantastic listener suggestion, about frogs! Merike is a herpetologist from Estonia, who suggested the gastric brooding frog, and another listener, Hally, also wanted to learn about some of the new frog species discovered recently.

The gastric brooding frog is native to eastern Australia, specifically Queensland. There are two species, and both of them live in creeks in separate rainforests. The habitat is specific and small, and unfortunately both species went extinct less than forty years ago. Researchers aren’t sure why they went extinct, but it was probably due to pollution and habitat loss.

The gastric brooding frog was a slender frog, with the northern gastric brooding frog being about three inches long, or about 8 cm, while the southern gastric brooding frog was about half that size. Females were larger than males. It was grey or brown-gray in color with some darker and lighter patches on the back with a lighter belly. During the day it spent most of its time at the water’s edge, hidden in leaf litter or among rocks, although it generally only fully came out of the water when it was raining. It ate insects and may have hibernated in winter.

As you may have guessed from its name, the gastric brooding frog had a unique way of taking care of its eggs. After the eggs were fertilized, the female would actually swallow the eggs and keep them in her stomach while they developed. Even after the eggs hatched into tadpoles, they stayed in the mother’s stomach. As they grew larger, the stomach also grew larger, until it pretty much filled up the mother’s insides, to the point where she couldn’t even use her lungs to breathe. Fortunately many frogs, including the gastric brooding frog, can absorb a certain amount of oxygen through the skin. Finally the tadpoles metamorphosed into little frogs, at which point the mother regurgitated one or a few of them at a time, or sometimes all of them at once if she felt threatened.

So how did the mother keep from digesting her own eggs or tadpoles? How did she eat when her stomach was full of babies? How did the babies eat?

The jelly around the gastric brooding frog’s eggs contained prostaglandin E2, also called PGE2, which causes the stomach to stop producing hydrochloric acid. That’s a digestive acid, so once the eggs were inside the stomach, the stomach basically stopped stomaching. There is some speculation that the first eggs the mother frog swallowed actually got digested, but then the acid production stopped and the rest of the eggs remained. Once the eggs hatched, the tadpoles also produced PGE2 in the mucus in their gills.

The tadpoles continued to live off the yolk sac from their eggs as they developed, and in fact their mouths weren’t even connected to their gut yet. As for the mother, she just didn’t eat until the babies were developed and released into the water on their own, which took about six weeks.

The gastric brooding frog is the only frog known to raise its babies this way, but other frog species have interesting variations of the usual way frogs reproduce. Most female frogs lay their eggs, and then the male fertilizes them. But about a dozen species of frog have developed internal fertilization, where the female retains the eggs in her body until the male fertilizes them. The tailed frog from California in the United States, in North America, gets its name from a structure that looks like a tail, but is actually an extension of the cloaca. That’s the opening used for both excretion and reproduction. Only males have the tail, and it works like a penis to fertilize the female’s eggs without her needing to lay the eggs first. Once they’re fertilized, she can choose just the right spot to lay the eggs.

Another weird way frogs take care of their eggs is something that Darwin’s frog does. Darwin’s frog lives in Chile and Argentina in South America, and grows to a little over an inch long, or 3 cm. It has a pointy snout that gives its head a wedge  shape something like a leaf, which helps keep it camouflaged on the forest floor. The female lays her eggs in damp leaf litter, and after the male fertilizes them he guards them for several weeks. When they start to move as they develop, the male swallows them—but instead of his stomach, he stores them in his vocal sac. That’s the expandable sac in the frog’s throat that males use to make their croaking sounds by filling the sac with air.

The eggs hatch into tadpoles, which the male carries around as they grow. They live off their egg yolks, but they also eat secretions from the lining of the vocal sac. Once the tadpoles metamorphose into little frogs, they hop out of the male’s mouth and are on their own. Until then, the male doesn’t eat.

The Surinam toad is a species of frog. Remember that all toads are frogs but not all frogs are toads. It lives in wetlands and forests in northern South America, and has a radically different way of keeping its eggs safe. The Surinam toad is a flattened, broad toad that can grow up to 8 inches long, or 20 cm, and looks a lot like a dead leaf. It lives in slow-moving water. Unlike other frogs it doesn’t have a tongue, so instead of catching insects with its sticky tongue, it grabs them with its hands. It’s sometimes called the star-fingered toad because its long, thin fingers have tiny star-shaped appendages that help it catch prey. Instead of croaking, male Surinam toads make a clicking noise by moving a small bone in the throat back and forth.

When the female is ready to lay her eggs, a male clasps her around the middle like most frogs do while mating. But instead of just releasing her eggs and letting the male release sperm to fertilize them, the female makes a sort of flipping movement in the water as she releases a few eggs at a time. The male fertilizes them, then presses them onto her back. The skin of the female’s back grows up over the eggs, embedding them in the skin in little pockets. When the tadpoles hatch they stay in these little pockets as they develop. They only leave when they’ve metamorphosed into tiny toads, at which point they emerge and live on their own. The mother then sheds the layer of skin on her back where her babies lived.

A frog described in 2014 that lives in parts of South Asia gives birth to tadpoles instead of laying eggs. It’s a species of fanged frog, which are frogs that do actually have teeth unlike most frogs. Limnonectes larvaepartus grows about 1 ½ inches long, or just under 4 cm. The eggs are fertilized internally, but instead of laying them the female keeps them in her oviducts until they hatch. They remain inside her until they no longer have any yolk left to nourish them, at which point the mother releases them into a slow-moving stream.

Lots of other interesting frogs have been discovered recently. A new frog discovered in southern India in 2018 was recently determined to be a member of its own genus. It’s called the narrow-mouthed frog and had gone unnoticed even though it lives in an area that’s been extensively explored by scientists. It only comes out into the open for less than one week out of the year during the short breeding season, and the rest of the time it hides. Obviously, we don’t know much about it yet.

In 2016 in the same area as the narrow-mouthed frog, researchers discovered a new species of frog with a tadpole that burrows through sand. It’s a member of the Indian dancing frog family, and not only do the tadpoles burrow through wet sand at the bottom of streams, they have ribs that help them move around more easily. Tadpoles are usually just squidges without bones. Dancing frogs get that name because the males wave their feet to attract females during mating season.

There are so many recently discovered frog species that it’s hard to know which ones to highlight. You know, like the new glass frog from Costa Rica described in 2015 that honestly looks just like Kermit the Frog, if Kermit had a translucent belly that showed his organs. Scientists don’t know why glass frogs have no pigmentation at all on their bellies. Or the three tiny frog species discovered in Madagascar and described earlier in 2019, all of them smaller than your thumbnail, that belong to a new genus, Mini. Their scientific names are therefore Mini mum, Mini scule, and Mini ature. The three are related to one of Madagascar’s biggest frogs, which grows over four inches long, or 10.5 cm, as opposed to the Mini frogs which top out at about 15 mm long. Hally sent me an article about eleven new species of frog discovered recently in the Andes, including the multicolored rain frog. It’s sometimes yellow, sometimes brown, sometimes green, speckled, splotched, spotted–so variable that at first scientists thought they were different related species. All eleven of the Andes frogs lay their eggs on land, and instead of hatching into tadpoles the eggs hatch into tiny froglets.

Frogs and other amphibians are sensitive to environmental change, which means a lot of species have either recently gone extinct or are critically endangered. Habitat loss and an amphibian fungal disease that has spread around the world are also making things hard for frogs and their relations. Scientists have been working hard lately to find species that are rare, suspected to be extinct, or are unknown to science, to learn about them while we can and do our best to preserve the species, either in the wild or in captivity. There are even multiple genetic resource banks, or biobanks, to preserve genetic material of frogs and other animals so that future scientists might be able to clone them.

There’s always the possibility that the gastric brooding frog isn’t actually extinct. The southern gastric brooding frog hasn’t been seen since at least 1981 despite extensive searches, though, with the last captive individual dying in 1983. The northern gastric brooding frog was only discovered in 1984 but hasn’t been seen since 1985.

But even if there aren’t any left in the wild, all hope isn’t lost. The gastric brooding frog is a good candidate for de-extinction, and cloning has actually been successful to a limited degree already. In 2013 a living embryo was produced from preserved genetic material, although it didn’t survive. Researchers are still working to clone the frogs and keep them alive. With luck the attempt will be successful, and not only can a population of the frogs be kept in captivity, they can be reintroduced to their former habitat one day.

You can find Strange Animals Podcast online at That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 136: Smallest of the Small

Last week we learned about the smallest species of animals not typically thought of as small, like snakes and cetaceans. This week let’s look at some of the tiniest animals in the world, the smallest of the small!

Further watching:

A short video about jerboas. Really interesting and well-made!

A button quail:

Baby button quails are the size of BEES:

Kinglets are teeny birds even when grown up. Left, the golden-crowned kinglet. Right, the goldcrest. These birds MAY BE RELATED, you think?

The pale-billed flowerpecker, also teeny and with a cute name:

Moving on from birds, the pygmy jerboa is one of the smallest rodents in the world:

The Etruscan pygmy shrew is even tinier, probably the smallest known mammal alive today. Shown here with friend/lunch:

The Western pygmy blue butterfly is probably the smallest butterfly known:

But the pygmy sorrel moth is even smaller. Right: red marks left behind on a sorrel leaf eaten by its larvae:

One of the world’s teeniest frogs:

Show transcript:

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

Last week we learned about the smallest species of animals that aren’t typically thought of as small. But this week let’s learn about the smallest of the small animals. It’s like saying they’re the cutest of the cute animals. We’ll start with the bigger ones and get smaller and smaller as we go.

Let’s start with a bird. The smallest bird is the bee hummingbird, which we’ve talked about before. But there’s another bird that’s really small, the button quail. It’s about the size of a sparrow.

The button quail isn’t actually a quail, but it looks like one due to convergent evolution. There are a number of species in parts of Asia and Africa and throughout Australia. It generally lives in grasslands and is actually more closely related to shore and ocean birds like sandpipers and gulls than to actual quails, but it’s not very closely related to any other living birds. It can fly but it mostly doesn’t. Instead it depends on its coloring to hide it in the grass where it lives. It’s mostly brown with darker and lighter speckled markings, relatively large feet, and a little stubby nothing of a tail. It mostly eats seeds and other plant parts as well as insects and other invertebrates.

The button quail is especially interesting because the female is more brightly colored than the male, although not by much. In some species the female may have bright white markings, in some their speckled markings are crisper than the males. The female is the one who calls to attract a male and who defends her territory from other females. The female even has a special bulb in her throat that she can inflate with air to make a loud booming call.

The male incubates the eggs and takes care of the chicks when they hatch. Baby button quails are fuzzy and active like domestic chicken babies but they’re only about the size of a bumblebee. In many species, as soon as the female has laid her eggs, she leaves them and the male and goes on to attract another male for her next clutch of eggs.

People sometimes keep button quails as pets, specifically a species called the painted buttonquail or the Chinese painted quail. It’s about five inches long, or 12 cm. The female has black and white stripes on her face and throat. The birds can become quite tame and can live several years.

Button quails make a lot of different noises. This is what a button quail sounds like:

[button quail calls]

One of the smallest birds in the world that isn’t a hummingbird is the kinglet, with several species that live in North America and Eurasia. The goldcrest is a type of kinglet and the smallest European bird. It’s only 3.3 inches long, or 8.5 cm, although some individuals are larger. It looks a lot like the North American bird the golden-crowned kinglet, which is just a shade smaller at 3.1 inches, or 8 cm. Both species have a golden patch on the top of the head. The male also has an orangey spot in the middle of the golden patch. Both live in coniferous forests and eat insects and spiders.

Because kinglets are so small and active, they can starve to death quickly—in only an hour in some cases. Females lay up to 12 eggs at a time. TWELVE EGGS. That is a lot of eggs. The nest is too small to hold a dozen eggs in one layer so they end up in a pile. The female keeps all of them warm by pushing her legs down into the pile of eggs. Since her legs have a lot of blood vessels near the surface, they’re much warmer than most birds’ legs.

When the babies hatch, they stay in a pile. The ones on the top of the pile get fed first, naturally, but then they burrow down into the pile and push their siblings up toward the top. They’re not just being nice, though, since birds in the bottom of the pile stay warmer.

This is what a golden-crowned kinglet sounds like:

[bird call]

The pale-billed flowerpecker is even smaller than the kinglets and are among the smallest birds in Asia. It lives in parts of India and nearby areas and mostly eats berries, although it also eats flower nectar. It grows to only 3 inches long, or 8 cm, and is plain brownish-green in color with a short tail and shiny black eyes. It lives in forests but often visits gardens. It doesn’t lay a dozen eggs at a time, just an ordinary two or three.

This is what a pale-billed flowerpecker sounds like. These are some teeny sounds from teeny birds:

[bird call]

There are several rodents that are considered the smallest rodent, but we’re only going to learn about one of them today, the pygmy jerboa. On average it’s only 1.7 inches long, or 4.4 cm, not counting its extremely long tail.

The pygmy jerboa lives in the deserts of Pakistan and possibly in nearby areas too. It has very long hind legs and very short front legs so it hops like a tiny kangaroo, using its long tail as a way to balance and maneuver at high speeds. Its tail is twice as long as its body. Its large hind feet and the end of its tail are very furry to give it more surface area so it can easily maneuver through loose sand.

It mostly eats seeds and leaves, and it gets all the moisture it needs from the food it eats. It’s nocturnal and spends its days in the burrow it usually digs under bushes. Like many other tiny animals, when it rests it slows its metabolism drastically so it won’t starve to death while it’s asleep. Life is rough for tiny animals.

We don’t know a whole lot about the pygmy jerboa except that it’s endangered due to habitat loss, so let’s move on to an even smaller mammal.

The Etruscan shrew grows to about 1.6 inches long, or 4 cm, on average, not counting its short tail. The tail is about a third of the length of its body. It lives in southern Europe, parts of Asia, parts of the Arabian Peninsula, and northern Africa and prefers warm, moist climates. It’s the same size and weight as the bumblebee bat we talked about last week, so it’s one of the smallest mammals known.

The Etruscan pygmy shrew is pale brown with a lighter colored belly, a long nose, and short whiskers around its mouth that it uses to help it find its prey. It’s incredibly active and makes clicking noises almost constantly, as a way to alert other shrews that it’s there and is willing to defend its territory. It makes its nest among rocks and in the abandoned burrows of other animals.

Like the kinglets and other highly active, tiny animals, it has to eat a lot to keep its metabolism going—up to twice its own weight in food every day. It can also enter a torpid state where it reduces its body temperature and metabolism the same way the pygmy jerboa does, in order to not starve while it sleeps. But the Etruscan shrew doesn’t rest very often.

It mostly eats insects and other invertebrates like earthworms, but it will eat anything it can kill. This includes lizards, small rodents, and frogs. It especially likes grasshoppers and crickets, which are often as large as it is. In order to kill prey its own size, the shrew is incredibly fast. If you remember episode 82 where we talked about the star-nosed mole, the Etruscan shrew primarily hunts by touch and can react in barely 25 milliseconds when it touches something it wants to eat. It takes something like 300 milliseconds for a human to blink their eyes, if that gives you an idea of how fast the shrew is. It can touch a cricket and kill it in less time than it takes to blink.

So that’s as small as mammals get, as far as we know. What’s the smallest amphibian?

Well, it’s really, really small. The smallest known frog is only 7.7 mm long. Paedophryne amauensis isn’t just the smallest frog, it’s the smallest vertebrate known. It was only discovered in 2009 in Papua New Guinea.

It sounds like an insect and lives in the damp leaf litter on the forest floor, and it’s dark brown and black in color to blend in with dead leaves, so it was hard to find. Researchers only found it by using sensitive microphones to triangulate on its call, then quickly scooping up lots of leaf litter and stuffing it into plastic bags so anything living in the leaves couldn’t escape. Its eggs hatch into tiny froglets instead of tadpoles.

The tiniest frog is just about the same length as the tiniest fish, the stout infantfish that lives in a few coral reefs near Australia, including the Great Barrier Reef. It also grows 7.7 mm long on average, although females are typically longer and it can grow as much as 10 mm long. But the smallest known fish is the male of an anglerfish species that only grow 6.2 mm long. This doesn’t really count, though, since females grow up to two inches long, or 50 mm. Like other deep-sea anglerfish species, when a male of Photocorynus spiniceps finds a female, he bites her and stays there. Eventually his mouth actually fuses to her body and he lives the rest of his life as a sort of parasitic extension of the female. He supplies her with sperm to fertilize her eggs before she lays them, and she supplies him with nutrition and oxygen since he’s basically part of her body at that point. A female can have more than one male fused to her.

So, we seem to have reached the smallest vertebrates. What about the smallest insects and other invertebrates?

Butterflies are generally pretty small, but the smallest butterfly known is really, really small. The Western pygmy blue butterfly only has a wingspan of 20 mm at most but usually more like 12 mm across. That’s less than an inch. It lives in western North America and parts of the middle east, and has even been found on Hawaii. Its wings are a pretty coppery brown color with rows of black and white spots. It likes deserts and waste places where you wouldn’t expect to find anything as delicate as a tiny butterfly. Its caterpillars eat various types of weed plants.

That is pretty much it. There’s not much to this tiny butterfly. The real mystery is why it’s called the western pygmy blue when it’s not actually blue.

Compared to the smallest moth known, the western pygmy blue butterfly is a giant. The smallest moth is the pygmy sorrel moth and its wingspan is barely four millimeters. Its wings shade from silvery with a metallic bronze tint to purply with a white stripe, and gray along the ends. It’s really pretty but so tiny that it’s hard to spot. It lives in much of Europe and its larvae leave distinctive spiral shapes on sorrel leaves as it eats.

We’ll come back to insects in a minute or two, but let’s look at a few snails first. The smallest land snail is the Borneo snail. Its shell is only .7 of a mm high. It was only discovered in 2015. We don’t know a lot of about it yet, but it probably eats bacterial film growing on limestone in caves. So far researchers haven’t even found a living Borneo snail, though, just its shells.

The smallest water snail is even smaller than the Borneo snail. It’s from North America and its shell is only half a millimeter across at the most. Some individuals are only .3 mm across. Ammonicera minortalis lives in shallow water off the coast of southern Florida and around Cuba and other islands in that area. And that’s pretty much all we know about it. It’s a lot easier to study bigger animals just because they’re easier to find.

Small as that is, on average the smallest beetle is smaller than the smallest snail. It’s a type of featherwing beetle only described in 1999, and on average it’s .338 mm long. So far it’s only been found in Central America and it eats fungus. It’s yellowish-brown in color but that doesn’t really matter because it’s so small that you need a magnifying glass to really see it.

Once you start dividing millimeters, you’re getting into ridiculously tiny territory. But the smallest insect is a type of wasp known as a fairyfly. Kikiki huna is so small it’s measured in micrometers, sometimes called microns, and is smaller than some single-celled organisms. It’s only 150 micrometers long, which is shorter than an ordinary piece of printer paper is thick. It’s been found on Hawaii, Costa Rica, and Trinidad but it probably lives in other places but just hasn’t been found yet. Some researchers suspect that it’s as small as a flying animal can become without losing the ability to fly under its own power instead of just floating on the wind.

At this point anything smaller than Kikiki huna and its close relatives are made up largely of bacteria, which are frankly not as cute or as interesting as, say, button quail. So let’s finish with what may be the very smallest living organism ever found. Or it may not be. Because researchers are literally not even sure if the nanobe is even alive.

In 1996 researchers found what looked like filiments growing among rock samples collected from wells off the Australian coast. Some of them were only 20 nanometers in diameter. To put that into perspective, a nanometer is one billionth of a meter. That’s billion with a B. It’s one thousandth of a micrometer. A nanobe is a tenth of the size of the smallest known bacteria.

The researchers weren’t sure what they’d found so they did a lot of tests. They thought they might have discovered a new kind of crystal, but when they stained the nanobes with a type of dye that binds to DNA, the results indicated the nanobes might be living organisms. But no DNA has been successfully recovered from nanobes.

There’s still a lot of research to be done to determine what they are and if they’re actually alive, though. The main problem is that nanobes appear to be too small to contain all the things that living organisms need. But they do resemble fungi in some ways, just much, much smaller. If nanobes are alive, they’re extremely different from any living animal ever known and presumably live and reproduce in ways completely unlike all other life.

But here’s an interesting note. In 1996 researchers found structures inside a meteorite from Mars that look a lot like nanobes.

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

Thanks for listening!

Episode 112: The Bullfrog and the Raven

I am sick and sound like a frog, or possibly a raven, so here’s a croaky episode about both!

Thanks to Corbin Maxey of Animals to the Max and Simon for their suggestions!

A bullfrog:

A common raven:

A baby raven:

NOT a baby raven (it’s probably a corncrake):

Show transcript:

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

Guess who has a cold! That’s right, I do! If this is the first episode you’ve ever listened to, I promise I don’t ordinarily sound like this.

Because my voice is such a mess, let’s have a short episode this week and learn about two animals that sound kind of like I do right now: the bullfrog and the raven. Thanks to Corbin Maxey of the great podcast Animals to the Max who suggested frogs, and friend of the pod Simon who suggested ravens, both of them in response to my complaining on Twitter that I had a sore throat. Little did they know what I would sound like a few days after that tweet!

Let’s start with the bullfrog. The American bullfrog is a species of frog. You probably figured that out without me needing to tell you. It originally only lived in eastern North America, but it’s been introduced in many other parts of the world. The reason it’s been introduced elsewhere is that it’s raised as food—specifically, it’s raised for its hind legs, which are considered a delicacy. It’s also sometimes kept as a pet. Sometimes it escapes from captivity and sometimes it’s just released into the wild by people who don’t know any better. In many places it’s become an invasive species that outcompetes native amphibians.

The bullfrog is a big, heavy frog. It can grow up to eight inches long from nose to butt, or 20 cm, but the hind legs are much longer. It can also be up to 1.8 pounds in weight, or 800 grams. Because the bullfrog has such long, strong legs, it can jump up to ten times the length of its own body.

The bullfrog is olive green in color, sometimes with darker blotches or stripes. The belly is pale and the lower part of the nose along the upper edge of the mouth is often bright green. Males usually have yellow throats, or technically yellow gular sacs. This is the sac the male inflates in order to make his loud croak.

Male bullfrogs have territories in swampy areas that they defend from other males, but the territories aren’t very large, maybe 20 feet apart from each other at most, or 6 meters. The males tend to move around and gather in groups during the breeding season, though, which is usually spring and early summer. The males croak loudly to attract females, and sometimes wrestle each other to show who’s stronger.

The female bullfrog lays her eggs in shallow water with plenty of plant cover. If the temperature isn’t too warm or too cold, the eggs hatch in about five days into tadpoles. The tadpoles have gills and teeth, although at first they don’t use their teeth for anything. They eat algae and other tiny food at first, and as they grow bigger, they start catching larger food.

In warmer climates, the tadpole starts to metamorphose into a frog in a few months. In colder climates, the tadpole can take up to three years to grow into a frog.

A full-grown bullfrog will eat anything it can swallow, not just insects. It’ll eat mice and other rodents, bats, birds, other amphibians, crawdads, snails, fish, and small reptiles. It uses its long sticky tongue to catch its prey, then clamps its jaws shut so the prey can’t escape. If part of the prey is sticking out of its mouth, like a tail or leg, the frog uses its thumbs to cram the bits in. If the prey won’t quit struggling, the frog may jump into the water and swim around until the animal drowns. They should call them sharkfrogs, not bullfrogs.

A lot of animals eat bullfrogs, though, like alligators and various snakes, birds like herons and kingfishers, and river otters. I have personally seen a snapping turtle attack a bullfrog. That was creepy. Sometimes when something attacks a bullfrog, it will actually scream. This sometimes startles the predator enough that it lets go, and the bullfrog can escape. Bullfrogs show some resistance to snake venom too.

The bullfrog gets its name from its voice, not its size. It sounds like this:

[bullfrog croaking]

Next, hopefully I will not lose my voice before I finish talking about the raven. There are a number of different raven species but they all look similar. They’re big black birds with heavy bills and deep, raspy voices. They look like a buff crow. We’ll talk about the common raven today, which lives throughout the northern hemisphere: that means North America, Greenland, and most of Eurasia.

The common raven can grow up to 26 inches long, from bill to tail, or 67 cm, with a wingspan over four feet wide, or 150 cm. Its feathers are glossy black, with purplish or blue iridescence in sunlight. Young ravens look similar but are not as glossy. Sometimes you’ll see a picture online of a little black poof of a baby bird labeled as a baby crow or raven, but that’s a mistake. Baby ravens have sleek feathers, not downy feathers. I’ll put pictures in the show notes so you can see the difference.

The raven is an omnivore, which means it pretty much eats anything it can get. It will eat roadkill and other carrion, fruit and grain, insects, small animals, other birds, and eggs. It’s also extremely smart, which means it can figure out how to get into trash cans and other containers to find food humans think it secure. If a raven finds a good supply of food, it will call other ravens to join in the feast. This usually happens when a younger raven finds food and calls its friends, even if the food source is being guarded by a mated pair of adult ravens. Those pesky kids.

Ravens mate for life, but younger birds who haven’t paired off usually live in flocks. They’re devoted family birds, with grown young of a pair sometimes hanging around to help their parents raise the next nest. The raven lives a long time, up to 21 years in the wild and over 40 years in captivity.

The only animals that eat ravens are large owls and eagles, and even that’s rare. Ravens are big enough, strong enough, and smart enough to defend themselves.

Ravens are extremely intelligent birds. Research suggests that they may even have something approaching an actual language. They can certainly reason and deceive each other, and demonstrate empathy in their interactions with other ravens. They also use tools to help get food, and are well known to play with items, sometimes making toys out of twigs or other items to play with as a group. Young ravens in particular are curious and will steal shiny things.

Ravens can imitate other animals and birds, even machinery, in addition to making all sorts of calls. It can even imitate human speech much like parrots. If a raven finds a dead animal but isn’t strong enough to open the carcass to get at the meat, it may imitate a wolf or fox to attract the animal to the carcass. The wolf or fox will open the carcass, and even after it eats as much as it wants, there’s plenty left for the raven.

But ravens also communicate nonvocally with other ravens. A raven will use its beak to point with the way humans will point with a finger. Incidentally, dogs understand what pointing means, but wolves don’t. Just throwing that in there. They’ll also hold something and wave it to get another raven’s attention, which hasn’t been observed in any other animal or bird besides apes.

I will soon be reduced to communicating nonvocally if I don’t stop and rest my voice. So I’ll shut up and let you listen to a real raven:

[raven sound]

You can find Strange Animals Podcast online at blah blah blah I’m not saying it this week. My throat hurts.

Thanks for listening! Next week hopefully I’ll be all better and sound like a human again instead of like a frog or a raven.

Episode 104: Tiger Salamanders

Thanks to Connor who suggested this week’s topic, tiger salamanders! Not only do we learn all about the Eastern tiger salamander and the banded tiger salamander, we also learn where asbestos comes from AND IT’S NOT EVEN LIKE I GOT OFF TOPIC, I SWEAR

The Eastern tiger salamander:

The barred tiger salamander:

A baby tiger salamander:


Show transcript:

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

This week we’ll learn about an animal suggested by listener Connor that’s been waiting on the ideas list for way too long. Thanks, Connor! Sorry it took me so long to get to your suggestion!

So, Connor suggested that we cover “tiger salamanders’ cannibalism and how salamanders were once believed to be fire-related.” That sentence gives us a lot to unpack.

First let’s find out what a tiger salamander is. It gets its name because it’s stripey, or at least has blotches that can look sort of like stripes. It may be yellow and black or green and black. It grows up to 14 inches long, or 36 cm, which is pretty darn big for a salamander. Smaller tiger salamanders mostly eat insects and worms, but the bigger ones will naturally eat bigger prey, including frogs.

Like all salamanders, the tiger salamander is an amphibian. That means it’s cold-blooded with a low metabolic rate, with delicate skin that needs to stay damp. Like other salamanders, it doesn’t have claws, it does have a tail, and its body is long compared to its short legs. Basically a salamander usually looks like a wet lizard. But salamanders actually have more in common with frogs than with lizards, since frogs are also amphibians.

While the tiger salamander can swim just fine, it spends most of its adult life on land. It catches insects by shooting its sticky tongue at them just like frogs do. And just like a frog, the tiger salamander’s eyes protrude like bumps on its head, and it retracts its eyeballs when it swallows to help force the food down its throat. This is fascinating, but you might want to take a moment to be glad you don’t have to do this every time you swallow a bite of food.

The tiger salamander, like most other amphibians, secretes mucus that helps its skin stay moist and tastes nasty to predators. The tiger salamander doesn’t appear to actually be toxic, though. It mostly lives in burrows it digs near water, and while it’s common throughout much of eastern North America, it’s not seen very often because it’s shy and because it prefers ponds in higher elevations such as mountains.

A female lays her eggs on the leaves of water plants in ponds or other standing water. The eggs hatch into larvae which have external gills and a fin that runs down its back and tail to help it swim. At first the larva looks a little bit like a tadpole, but it grows legs soon after hatching. As a larva, it eats aquatic insects and tiny freshwater crustaceans like amphipods. How soon it metamorphoses into an adult salamander depends on where it lives. Tiger salamanders that live in more northerly areas where summer is short will metamorphose quickly. Tiger salamanders that live in warmer climates stay larvae longer. And in areas where the water is better suited to gathering food than the land is, the larvae may not fully metamorphose at all and will live in the water their whole lives. The term for a fully adult salamander that still retains its external gills and lives in the water is neotene, and it’s pretty common in salamanders of various species.

The tiger salamander is actually closely related to the axolotl, more properly pronounced ash-alotl. I learned that from the Varmints! podcast. Most axolotls are neotenic. On the rare occasion that an axolotl metamorphoses into its adult form, it actually looks a lot like a tiger salamander.

Unfortunately, the tiger salamander carries diseases that can kill frogs, reptiles, fish, and even other amphibians, even though the tiger salamander is usually not affected. The tiger salamander is also a popular pet, but since many pet tiger salamanders were caught in the wild, be careful that you’re not introducing diseases that might kill your other amphibians, reptile, or fish pets. While the tiger salamander is doing just fine in the wild and isn’t protected, it’s always better to buy pets from people who bred the salamanders and can guarantee they’re disease free. Likewise, if you’re someone who likes to fish, don’t use tiger salamander larvae as bait. Researchers think this is the main way the diseases carried by tiger salamanders spread.

So all this information about tiger salamanders is interesting, but it’s also pretty normal for salamanders. What does Connor mean by cannibalism in tiger salamanders?

The tiger salamander we’ve just learned about is actually called the Eastern tiger salamander. Until recently the barred tiger salamander was considered a subspecies of the Eastern tiger salamander, although now it’s considered a separate species. It looks and acts pretty much just like the Eastern tiger salamander but it lives in the western areas of North America. The main difference between the two species is that the barred tiger salamander is not quite as big, and it isn’t as common. The adults are illegal to sell in most American states, although it’s legal to keep them as pets.

But there is one main difference about the barred tiger salamander, and it’s something that only happens in some populations, usually ones in dry areas where ponds are more likely to dry up and larvae need to metamorphose quickly as a result. A few weeks after they hatch, some of the larvae develop large teeth and wider heads. Then they start eating other tiger salamander larvae. Researchers have found that a cannibal tiger salamander won’t eat tiger salamanders it’s related to, and the hypothesis is that it recognizes the scent of its brothers and sisters.

Researchers think most tiger salamanders don’t become cannibals because doing so increases the risk that it will be affected by the diseases tiger salamanders carry. By eating salamanders that are competing for the same resources its siblings need to grow up quickly, the cannibal salamanders help their siblings and may sacrifice themselves by risking disease as a result.

Forget what I said about being glad you don’t have to retract your eyeballs every time you swallow. Just be glad you’re not a tiger salamander at all.

Connor also mentioned the old belief that salamanders lived in fire. How the heck did that belief come about? Salamanders are wet little amphibians that mostly live in water.

It’s been a belief for literally thousands of years. It’s mentioned in the Talmud, in Pliny the Elder’s writings, and in bestiaries. Where did it start?

The main hypothesis is that because some salamanders hibernate in rotting logs, the only time most people would see a salamander would be when they tossed firewood into a fire. The salamander, rudely awakened from its winter home, would slither out of the fire, protected from the heat for a very brief time by its damp skin. There’s actually a species of salamander common throughout Europe called the fire salamander. So that sounds plausible. Older legends refer to the salamander actually being able to put fires out with its cold body or breath. Since salamanders are cold-blooded and damp, they do feel cold to the touch even on relatively warm days.

One traditional writer thought all this was pish-posh, though. Marco Polo himself, who traveled widely in Asia starting in 1271, wrote, “Everybody must be aware that it can be no animal’s nature to live in fire.” He was right, of course. Nothing lives in fire. But by the time Marco Polo lived, there was a certain amount of confusion regarding a type of cloth that was fire-resistant. It was called salamander wool and was supposed to be woven from hairs harvested from salamanders—which is a real trick, considering only mammals have hair.

Marco Polo met a man from Turkey who procured the fibers that were called salamander wool. But they didn’t come from an animal at all. He had to dig for them. I’ll quote from a translation of Marco Polo’s writing:

“He said that the way they got them was by digging in that mountain till they found a certain vein. The substance of this vein was then taken and crushed, and when so treated it divides as it were into fibres of wool, which they set forth to dry. When dry, these fibres were pounded in a great copper mortar, and then washed, so as to remove all the earth and to leave only the fibres like fibres of wool. These were then spun, and made into napkins. When first made these napkins are not very white, but by putting them into the fire for a while they come out as white as snow. And so again whenever they become dirty they are bleached by being put in the fire.

“Now this, and nought else, is the truth about the Salamander, and the people of the country all say the same. Any other account of the matter is fabulous nonsense.”

This actually sounds even more confusing than fire salamanders. What the heck is this cloth, what are those fibers, are they really fireproof, and if so, why hasn’t anyone these days heard of it?

Well, we have, we just don’t realize it. That stuff is called asbestos.

I always thought asbestos was a modern material, but it’s natural, a type of silicate mineral that’s been mined for well over 4,000 years. It’s actually any of six different types of mineral that grow in fibrous crystals. Just like Marco Polo reported, after pounding and cleaning, you’re left with fibers that really are fire, heat, and electricity resistant. As a result, it became more and more common in the late 19th century when it was used in building insulation, electrical insulation, and even mixed with concrete. And just as Marco Polo reported, it was still spun into thread and woven into fabric that was often made into items used around the house, like hot pads for picking up pans from the oven, ironing board covers, and even artificial snow used for Christmas decorations.

Of course, we know now that breathing in bits of silica is really, really bad for the lungs. The dangers of working with asbestos had already started to be known as early as 1899, when asbestos miners started having lung problems and dying young. The more asbestos was studied, the more dangerous doctors realized it was—but since it was so useful, and the effects of asbestos damage on the lungs usually took years and years to manifest, businesses continued to ignore the warnings. Asbestos was even used in cigarette filters during the 1950s, as if smoking wasn’t already bad enough.

These days, most uses of asbestos have been banned around the world, but if you’ve seen those TV commercials asking if you or someone you know suffers from mesothelioma, and you might be entitled to compensation, that’s a disease caused by breathing in asbestos dust. Some industries still use asbestos.

It sounds like asbestos being called salamander wool was named not because people literally thought they were made from hairs harvested from salamanders but because asbestos cloth resisted fire and heat the way salamanders were supposed to. These days chefs use a really hot grill called a salamander to sear meats and other foods, which is named after the folkloric animal, but no one believes it has anything to do with real salamanders. At least, I hope not. Then again, there are pictures of salamanders in medieval bestiaries showing salamanders with hair, which argues that at least some people really truly believed that asbestos came from salamanders.

Because tiger salamanders are large and not endangered, they’re good subjects for study. Researchers have learned some surprising things by studying the behavior and physiology of tiger salamanders. For instance, salamanders in general have legs that haven’t changed that much from those of the first four-legged animals, or tetrapods. Researchers study the way tiger salamanders walk to learn more about how early tetrapods evolved. And yes, this research did involve filming tiger salamanders walking on a tiny treadmill.

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Thanks for listening!

Bonus! Reticulated siren discovered!

BREAKING NEWS, EVERYONE! A new giant salamander has been discovered, right here in the southern United States! It was only formally described YESTERDAY if you’re listening to this the night it goes live, assuming I manage to get it finished and uploaded before Friday morning. I should have put this together yesterday but didn’t think about it until today. Today being Thursday.

We’re talking about the reticulated siren, also called the leopard eel although it’s not an eel. It’s also not a leopard. There are three species of siren alive today, including the reticulated. Reticulated means spotted or mottled, if you were wondering. Sirens look a lot like eels except that instead of fins they have tiny vestigial forelegs and external gills. They have no hind limbs at all.

The greater siren lives in wetlands near the Atlantic coast of North America, specifically in the southern coastal states like Alabama and Florida. It grows over three feet long, or 97 cm, and is usually dark greenish or gray with tiny green or yellow dots along its sides. It eats water insects, mollusks, and occasionally plants. The lesser siren is very similar to the greater siren but doesn’t grow as big, and lives throughout much of the eastern United States and northeastern Mexico.

The reticulated siren is almost the size of the greater siren, and is gray-green and covered with a maze of spots. Its head is relatively small and its gill branches are large. It’s only been found in southern Alabama and the Florida panhandle.

The first reticulated sirens known to science were actually caught in the 1970s in Alabama, but although those three specimens were preserved and held in a museum for study, it wasn’t formally described. Another reticulated siren wasn’t found until 2009, when a herpetologist, David Steen, caught one while trapping water snakes and turtles in Florida.

Steen and biologist Sean Graham worked together to find more. It took them five years to trap three more specimens in a pond in Florida. After lots of study, including DNA analysis, they determined they had found a new species.

Now that we know the reticulated siren is a species of its own, researchers like Steen and Graham are working to find out more about it. They suspect it’s rare since it’s been so hard to find, and that means it needs to be protected. The wetlands where it lives are constantly in danger of being drained and filled in to make way for houses, Walmarts, parking lots, and other things we should put somewhere else and leave the wetlands alone.

Sirens are fully aquatic, specifically living in swamps, ponds, and boggy areas with a lot of vegetation they can hide in. If a siren’s pond dries up, it can burrow into the mud and aestivate in a cocoon of slime and sloughed-off skin, sometimes for a year or two until water returns to the area. But we don’t yet know if the reticulated siren can do this too.

That’s it for our breaking news update. We’ll be back on Monday morning as usual with an episode about strange reptiles.

Thanks for listening!