Category Archives: North America

Episode 348: Australopithecus and Gigantopithecus

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Thanks to Anbo for suggesting Australopithecus! We’ll also learn about Gigantopithecus and Bigfoot!

Further reading:

Ancient human relative, Australopithecus sediba, ‘walked like a human, but climbed like an ape’

Human shoulders and elbows first evolved as brakes for climbing apes

You Won’t Believe What Porcupines Eat

Past tropical forest changes drove megafauna and hominin extinctions

An Australopithecus skeleton [photo by Emőke Dénes – kindly granted by the author, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=78612761]:

Show transcript:

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

It’s officially monster month, also known as October, so let’s jump right in with a topic suggested by Anbo! Anbo wanted to learn about Australopithecus, and while we’re at it we’re going to talk about Gigantopithecus and Bigfoot. On our spookiness rating scale of one to five bats, where one bat means it’s not a very spooky episode and five bats means it’s really spooky, this one is going to fall at about two bats, and only because we talk a little bit about the Yeti and Bigfoot at the end.

In 1924 in South Africa, the partial skull of a young primate was discovered. Primates include monkeys and apes along with humans, our very own family tree. This particular fossil was over a million years old and had features that suggested it was an early human ancestor, or otherwise very closely related to humans.

The fossil was named Australopithecus, which means “southern ape.” Since 1924 we’ve discovered more remains, enough that currently, seven species of Australopithecus are recognized. The oldest dates to a bit over 4 million years old and was discovered in eastern Africa.

Australopithecus was probably pretty short compared to most modern humans, although they were probably about the size of modern chimpanzees. A big male might have stood about 4 ½ feet tall, or 1.5 meters. They were bipedal, meaning they would have stood and walked upright all the time. That’s the biggest hint that they were closely related to humans. Other great apes can walk upright if they want, but only humans and our closest ancestors are fully bipedal.

In 2008 a palaeoanthropologist named Lee Rogers Berger took his nine-year-old son Matthew to Malapa Cave in South Africa. Dr. Berger was leading an excavation of the cave and Matthew wanted to see it. While he was there, Matthew noticed something that even his father had overlooked. It turned out to be a collarbone belonging to an Australopithecus boy who lived almost 2 million years ago. Later, Dr Berger’s team uncovered more of the skeleton and determined that the remains belonged to a new species of Australopithecus, which they named Australopithecus sediba. More remains of this species were discovered later, including a beautifully preserved lower back. That discovery was important because it allowed scientists to determine that this species of Australopithecus had already evolved the inward curve in the lower back that humans still have, which helps us walk on two legs more easily. That was a surprise, since A. sediba also still shows features that indicate they could still climb trees like a great ape.

It’s possible that Australopithecus, along with other species of early humans, climbed trees at night to stay safe from predators. In the morning, they climbed down to spend the day mostly on the ground. One study published only a few weeks ago as this episode goes live suggests that the flexible shoulders and elbows that humans share with our great ape cousins originally evolved to help apes climb down from trees safely. Monkeys don’t share our flexible shoulder and elbow joints because they’re much lighter weight than a human or ape, and don’t need as much flexibility to keep from falling while climbing down. Apes and hominins like humans can raise our arms straight up over our heads, and we can straighten our arms out completely flat. Australopithecus could do the same. The study suggests that when another human ancestor, Homo erectus, figured out how to use fire, they stopped needing to climb trees so often. They evolved broader shoulders that allowed them to throw spears and other weapons much more accurately.

Australopithecus probably mostly ate fruit and other plant materials like vegetables and nuts, along with small animals that they could catch fairly easily. This is similar to the diet of many great apes today. The big controversy, though, is whether Australopithecus made and used tools. Their hands would have been more like the hands of a bonobo or chimpanzee, which have a lot of dexterity, but not the really high-level dexterity of modern humans and our closest ancestors. Stone tools have been found in the same areas where Australopithecus fossils have been found, but we don’t have any definitive proof that they made or used the tools. There were other early hominins living in the area who might have made the tools instead.

We also don’t really know what Australopithecus looked like. Some scientists think they had a lot of body hair that would have made them look more like apes than early humans, while some scientists think they had already started losing a lot of body hair and would have looked more human-like as a result.

There’s no question these days that Australopithecus was an early human ancestor. We don’t have very many remains, but we do have several skulls and some nearly complete skeletons, which tells us a lot about how our distant ancestor lived. But we know a lot less about a fossil ape that lived as recently as 350,000 years ago, and it’s become confused with modern stories of Bigfoot.

Gigantopithecus first appears in the fossil record about 2 million years ago. It lived in what is now southern China, although it was probably also present in other parts of Asia. It was first discovered in 1935 when an anthropologist identified two teeth as belonging to an unknown species of ape, and since then scientists have found over a thousand teeth and four jawbones, more properly called mandibles.

The problem is that we don’t have any other Gigantopithecus bones. We don’t have a skull or any parts of the body. All we have are a few mandibles and lots and lots of teeth. The reason we have so many teeth is because Gigantopithecus had massive molars, the biggest of any known species of ape, with a protective layer of enamel that was as much as 6 mm thick. Some of the teeth were almost an inch across, or 22 mm. A lot of the remaining bones were probably eaten by porcupines, and in fact the mandibles discovered show evidence of being gnawed on. This sounds bizarre, but porcupines are well-known to eat old bones along with the shed antlers of deer, which supplies them with important nutrients. The teeth were too hard for the porcupines to eat.

We know that Gigantopithecus was a big ape just from the size of its mandible, but without any other bones we can only guess at how big it really was. It was potentially much bigger and taller than even the biggest gorilla, but maybe it had a great big jaw but short legs and it just sat around and ate plants all the time. We just don’t know.

What we do know is that its massive jaw and teeth were adapted for eating fibrous plant material, not meat. The thick enamel would help protect the teeth from grit and dirt, which suggested it ate tubers and roots that would have had a lot of dirt on them, although its diet was probably more varied. Scientists have even discovered traces of seeds from fruits belonging to the fig family stuck in some of the fossilized teeth, and evidence of tooth cavities that would have resulted from eating a lot of fruit long before toothpaste was invented.

Many scientists thought at first that Gigantopithecus was a human ancestor, but one that grew to gigantic size. It was even thought to be a close relation to Australopithecus. Other scientists argued that Gigantopithecus was more closely related to modern great apes like the orangutan. The debate on where Gigantopithecus should be classified in the ape and human family tree happened to overlap with another debate about a giant ape-like creature, the Yeti of Asia and the Bigfoot of North America.

We talked about the Yeti way back in episode 35, our very first monster month episode in 2017. Expeditions by European explorers to summit Mount Everest, which is on the border between China and Nepal, started in 1921. That first expedition found tracks in the snow resembling a bare human foot at an elevation of 20,000 feet, or 6,100 meters. They realized the tracks were probably made by wolves, with the front and rear tracks overlapping, which only looked human-like after the snow melted enough to obscure the paw pads. Expedition leader Charles Howard-Bury wrote in a London Times article that the expedition’s Sherpa guides claimed the tracks were made by a wild hairy man, but he also made it clear that this was just a superstition. But journalists loved the idea of a mysterious wild man living on Mount Everest. One journalist in particular, Henry Newman, interviewed the guides and specifically asked them about the creature. He wrote a sensational account of the wild man, but he mistranslated their term for it as the abominable snowman.

The word Yeti comes from a Sherpa term yeh-teh, meaning “animal of rocky places,” although it may be related to the term meh-teh, which means man-bear. But the peoples who live in and around the Himalayas belong to different cultures and speak a lot of different languages. There are lots of stories about the hairy wild man of the mountains, and lots of different words to describe the creature of those stories. And the idea of the Yeti that has become popular in Europe and North America doesn’t match up with the local stories. Locals describe the Yeti as brown, black, or even reddish in color, not white, and it doesn’t always have human-like characteristics. Sometimes it’s described as bear-like, panther-like, or just a general monster.

The abominable snowman, or Yeti, became popular in newspaper articles after the 1921 Mount Everest expedition, and it continued to be a topic of interest as expeditions kept attempting to summit the mountain. It wasn’t until May 26, 1953 that the first humans reached the tippy-top of Mount Everest, the New Zealand explorer Edmund Hillary and the Nepali Sherpa climber Tenzing Norgay. Many other successful expeditions followed, including some that were mounted specifically to search for the Yeti.

In the meantime, across the planet in North America, a Canadian schoolteacher and government agent named John W. Burns was collecting reports of hairy wild men and giants from the native peoples in British Columbia. He’s the one who coined the term Sasquatch in 1929. In the 1930s, a man in Washington state in the U.S, which is close to British Columbia, Canada, carved some giant feet out of wood and made tracks with them in a national forest to scare people, leading to a whole spate of big human-like tracks being faked in California and other places. But it wasn’t until 1982 that the hoaxes started to be revealed as the perpetrators got old and decided to clear up the mystery.

But in the 1920s and later, the popularity of the abominable snowman in popular media, giant gorillas like King Kong in the movies, the Yeti expeditions in the Himalayas, the mysterious giant footprints on the west coast of North America, and John Burns’s articles about the Sasquatch all combined to make Bigfoot, a catchall term for any giant human-like monster, a modern legend. People who believed that Bigfoot was a real creature started looking for evidence of its existence beyond footprints and reports of sightings. In 1960, a zoologist writing about a photograph of supposed Yeti tracks taken in 1951 suggested that the Yeti might be related to Gigantopithecus.

On the surface this actually makes sense. The Yeti, AKA the abominable snowman, is reported in the Himalayan Mountains of Asia. The mountain range started forming 40 to 50 million years ago when the Indian tectonic plate crashed into the Eurasian plate very slowly, pushing its way under the Eurasian plate and scrunching the land up into massively huge mountains. It’s still moving, by the way, and the Himalayas get about 5 mm taller every year. The eastern section of the Himalayas isn’t that far from where Gigantopithecus remains have been found in China, and we also know that at many times in the earth’s recent past, eastern Asia and western North America were connected by the land bridge Beringia. Humans and many animals crossed Beringia to reach North America, so why not Gigantopithecus or its descendants? That would explain why Bigfoot is so big, since in 1957 one scientist estimated that Gigantopithecus might have stood up to 12 feet tall, or 3.7 meters.

Some people still think Gigantopithecus was a cousin of Australopithecus, that it walked upright but was huge, and that its descendants are still around today, hiding in remote areas and only glimpsed occasionally. But people who believe such an idea are stuck in the past, because in the last 60 years we’ve learned a whole lot more about Gigantopithecus.

These days, more sophisticated study of Gigantopithecus fossils have allowed scientists to classify it as a great ape ancestor, not an early human. Gigantopithecus was probably most closely related to modern orangutans, in fact, and may have shared a lot of traits with orangutans. It probably could walk upright if it wanted to, but it wasn’t fully bipedal the way humans and human ancestors are. One theory prevalent in 2017 when we talked about the Yeti before was that Gigantopithecus mostly ate bamboo and might have gone extinct when the giant panda started competing with its food sources. This theory has already fallen out of favor, though, and we know that Gigantopithecus was eating a much more varied diet than just bamboo.

We also know that Gigantopithecus lived in tropical broadleaf forests common throughout southern Asia at the time. About a million years ago, though, many of these forests became grasslands. Gigantopithecus probably went extinct as a direct result of its forest home vanishing. It just couldn’t find enough food and shelter on open grasslands, and even though it held on for hundreds of thousands of years, by about 350,000 years ago it had gone extinct. Around 100,000 years ago the forests started reclaiming much of these grasslands, but by then it was too late for Gigantopithecus. Meanwhile, the oldest evidence we have of the land bridge Beringia joining Asia and North America was 70,000 years ago.

There is no evidence that any Gigantopithecus descendant survived to populate the Himalayas or migrated into North America. For that matter, there’s no evidence that Bigfoot actually exists. If a live or dead Bigfoot is discovered and studied by scientists, that would definitely change a lot of things, and would be really, really exciting. But even if that happened, I’m pretty sure we’d find that Bigfoot wasn’t related to Gigantopithecus. Whether it would be related to Australopithecus and us humans is another thing, and that would be pretty awesome. But first, we have to find evidence that isn’t just some footprints in the mud or snow.

Some Bigfoot enthusiasts suggest that the reason we haven’t found any Bigfoot remains is the same reason why we don’t have Gigantopithecus bones, because porcupines eat them. But while porcupines do eat old dry bones they find, they don’t eat fresh bones and they don’t eat all the bones they find. For any bone to fossilize is rare, so the more bones that are around, the more likely that one or more of them will end up preserved as fossils. Bones of modern animals are much easier to find, porcupines or no, but we don’t have any Bigfoot bones. We don’t even have any Bigfoot teeth, which porcupines don’t eat.

Porcupines can be blamed for a lot of things, like chewing on people’s cars and houses, but you can’t blame them for eating up all the evidence for Bigfoot.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 342: Giant Snails and Giant Crabs

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Thanks to Tobey and Anbo for their suggestions this week! We’re going to learn about some giant invertebrates!

Further reading:

The Invasive Giant African Land Snail Has Been Spotted in Florida

A very big shell:

The giant African snail is pretty darn giant [photo from article linked above]:

The largest giant spider crab ever measured, and a person:

Show transcript:

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

This week we’re going to learn about some giant invertebrates, suggested by Tobey and Anbo. Maybe they’re not as big as dinosaurs or whales, but they’re surprisingly big compared to most invertebrates.

Let’s start with Tobey’s suggestion, about a big gastropod. Gastropods include slugs and snails, and while Tobey suggested the African trumpet snail specifically, I couldn’t figure out which species of snail it is. But it did lead me to learning a lot about some really big snails.

The very biggest snail known to be alive today is called the Australian trumpet snail, Syrinx aruanus. This isn’t the kind of snail you’d find in your garden, though. It’s a sea snail that lives in shallow water off the coast of northern Australia, around Papua New Guinea, and other nearby areas. It has a coiled shell that’s referred to as spindle-shaped, because the coils form a point like the spindle of a tower. It’s a pretty common shape for sea snails and you’ve undoubtedly seen this kind of seashell before if you’ve spent any time on the beach. But unless you live in the places where the Australian trumpet lives, you probably haven’t seen a seashell this size. The Australian trumpet’s shell can grow up to three feet long, or 91 cm. Not only is this a huge shell, the snail itself is really heavy. It can weigh as much as 31 lbs, or 14 kg, which is as heavy as a good-sized dog.

The snail eats worms, but not just any old worms. If you remember episode 289, you might remember that Australia is home to the giant beach worm, a polychaete worm that burrows in the sand between high and low tide marks. It can grow as much as 8 feet long, or 2.4 meters, and probably longer. Well, that’s the type of worm the Australian trumpet likes to eat, along with other worms. The snail extends a proboscis into the worm’s burrow to reach the worm, but although I’ve tried to find out how it actually captures the worm in order to eat it, this seems to be a mystery. Like other gastropods, the Australian trumpet eats by scraping pieces of food into its mouth using a radula. That’s a tongue-like structure studded with tiny sharp teeth, and the Australian trumpet has a formidable radula. Some other sea snails, especially cone snails, are able to paralyze or outright kill prey by injecting it with venom via a proboscis, so it’s possible the Australian trumpet does too. The Australian trumpet is related to cone snails, although not very closely.

Obviously, we know very little about the Australian trumpet, even though it’s not hard to find. The trouble is that its an edible snail to humans and humans also really like those big shells and will pay a lot for them. In some areas people have hunted the snail to extinction, but we don’t even know how common it is overall to know if it’s endangered or not.

Tobey may have been referring to the giant African snail, which is probably the largest living land snail known. There are several snails that share the name “giant African snail,” and they’re all big, but the biggest is Lissachatina fulica. It can grow more than 8 inches long, or 20 cm, and its conical shell is usually brown and white with pretty banding in some of the whorls. It looks more like the shell of a sea snail than a land snail, but the shell is incredibly tough.

The giant African snail is an invasive species in many areas. Not only will it eat plants down to nothing, it will also eat stucco and concrete for the minerals they contain. It even eats sand, cardboard, certain rocks, bones, and sometimes other African giant snails, presumably when it runs out of trees and houses to eat. It can spread diseases to plants, animals, and humans, which is a problem since it’s also edible.

Like many snails, the African giant snail is a simultaneous hermaphrodite, meaning it can produce both sperm and eggs. It can’t self-fertilize its own eggs, but after mating a snail can keep any unused sperm alive in its body for up to two years, using it to fertilize eggs during that whole time, and it can lay up to 200 eggs five or six times a year. In other words, it only takes a single snail to produce a wasteland of invasive snails in a very short amount of time.

In June 2023, some African giant snails were found near Miami, Florida and officials placed the whole area under agricultural quarantine. That means no one can move any soil or plants out of the area without permission, since that could cause the snails to spread to other places. Meanwhile, officials are working to eradicate the snails. Other parts of Florida are also under the same quarantine after the snails were found the year before. Sometimes when people go on vacation in the Caribbean they bring back garden plants, without realizing that the soil in the pot contains giant African snail eggs, because the giant African snail is also an invasive species throughout the Caribbean.

Next, Anbo wanted to learn about the giant spider crab, also called the Japanese spider crab because it lives in the Pacific Ocean around Japan. It is indeed a type of crab, which is a crustacean, which is an arthropod, and it has the largest legspan of any arthropod known. Its body can grow 16 inches across, or 40 cm, and it can weigh as much as 42 pounds, or 19 kg, which is almost as big as the biggest lobster. But its legs are really really really long. Really long! It can have a legspan of 12 feet across, or 3.7 meters! That includes the claws at the end of its front legs. Most individual crabs are much smaller, but since crustaceans continue to grow throughout their lives, and the giant spider crab can probably live to be 100 years old, there’s no reason why some crabs couldn’t be even bigger than 12 feet across. Its long legs are delicate, though, and it’s rare to find an old crab that hasn’t had an injury to at least one leg.

The giant spider crab is orange with white spots, sort of like a koi fish but in crab form. Its carapace is also bumpy and spiky. You wouldn’t think a crab this size would need to worry about predators, but it’s actually eaten by large octopuses. The crab sticks small organisms like sponges and kelp to its carapace to help camouflage it.

The giant spider crab is considered a delicacy in some places, which has led to overfishing. It’s now protected in Japan, where people are only allowed to catch the crabs during part of the year. This allows the crabs to safely mate and lay eggs.

There’s another species called the European spider crab that has long legs, but it’s nowhere near the size of the giant spider crab. Its carapace width is barely 8 ½ inches across, or 22 cm, and its legs are about the same length. Remember that the giant spider crab’s legs can be up to six feet long each, or 1.8 meters. While the European spider crab does resemble the giant spider crab in many ways, it’s actually not closely related to it. They two species belong to separate families.

The giant spider crab spends most of its time in deep water, although in mating season it will come into shallower water. It uses its long legs to walk around on the sea floor, searching for food. It’s an omnivore that eats pretty much anything it can find, including plants, dead animals, and algae, but it will also use its claws to open mollusk shells and eat the animals inside. It prefers rocky areas of the sea floor, since its bumpy carapace blends in well among rocks.

Scientists report that the giant spider crab is mostly good-natured, even though it looks scary. Some big aquariums keep giant spider crabs, and the aquarium workers say the same thing. But it does have strong claws, and if it feels threatened it can seriously injure divers. I shouldn’t need to remind you not to pester a crab with a 12-foot legspan.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 341: The Leaf Sheep and the Mold Pig

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Thanks to Murilo and an anonymous listener for their suggestions this week!

Further reading:

The ‘sheep’ that can photosynthesize

Meet the ‘mold pigs,’ a new group of invertebrates from 30 million years ago

A leaf sheep:

Shaun the sheep:

A mold pig:

Show transcript:

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

This week let’s learn about two animals that sound like you’d find them on a farm, but they’re much different than their names imply. Thanks to Murilo for suggesting the leaf sheep, which is where we’ll start.

The leaf sheep isn’t a sheep or a leaf. It’s actually a type of sea slug that lives in tropical waters near Japan and throughout much of coastal south Asia. The reason it’s called a leaf sheep is because it actually looks a lot like a tiny cartoon sheep covered with green leaves instead of wool.

Back in episode 215 we talked about the sea bunny, which is another type of sea slug although it’s not closely related to the leaf sheep. The leaf sheep is even smaller than the sea bunny, which can grow up to an inch long, or about 25 mm. The leaf sheep only grows about 10 mm long at most, which explains why it wasn’t discovered until 1993. No one noticed it.

The leaf sheep’s face is white or pale yellow with two tiny black dots for eyes set close together, which kind of makes it look like Shaun the Sheep. It also has two black-tipped protuberances that look like ears, although they’re actually chemoreceptors called rhinophores. The rest of its body is covered with leaf-shaped spines called cerata, which are green and often tipped with pink, white, or black. This helps disguise it as a plant, but there’s another reason why it’s green.

The leaf sheep eats a particular kind of algae called Avrainvillea, which looks like moss or fuzzy carpet. While algae aren’t exactly plants or animals, many do photosynthesize like plants. In other words, they transform sunlight into energy to keep them alive. In order to photosynthesize, a plant or algae uses a special pigment called chlorophyll that makes up part of a chloroplast in its cells, which happens to be green.

The leaf sheep eats the algae, but it doesn’t digest the chloroplasts. Instead, it absorbs them into its own body and uses them for photosynthesis. That way it gets nutrients from eating and digesting algae and it gets extra energy from sunlight. This is a trait shared by other sea slugs in the superorder Sacoglossa. Because they need sunlight for photosynthesis, they live in shallow water, often near coral reefs.

When the leaf sheep’s eggs hatch, the larvae have shells, but as they mature they shed their shells.

This is a good place to talk about cyanobacteria, which was requested ages ago by an anonymous listener. Cyanobacteria mostly live in water and are also called blue-green algae, even though they’re not actually classified as algae. They’re considered bacteria, although not every scientist agrees. Some are unicellular, meaning they just consist of one cell, while others are multicellular like plants and animals, which means they have multiple cells specialized for different functions. Some other cyanobacteria group together in colonies. So basically, cyanobacteria looked at the chart of possible life forms and said, “yes, thanks, we’ll take some of everything.” That’s why it’s so hard to classify them.

Cyanobacteria photosynthesize, and they’ve been doing so for far longer than plants–possibly as much as 2.7 billion years, although scientists think cyanobacteria originally evolved around 3.5 billion years ago. The earth is about 4.5 billion years old and plants didn’t evolve until about 700 million years ago.

Like most plants also do, cyanobacteria produce oxygen as part of the photosynthetic process, and when they started doing so around 2.7 billion years ago, they changed the entire world. Before then, earth’s atmosphere hardly contained any oxygen. If you had a time machine and went back to more than two billion years ago, and you forgot to bring an oxygen tank, you’d instantly suffocate trying to breathe the air. But back then, even though animals and plants didn’t yet exist, the world contained a whole lot of microbial life, and none of it wanted anything to do with oxygen. Oxygen was toxic to the lifeforms that lived then, but cyanobacteria just kept producing it.

Cyanobacteria are tiny, but there were a lot of them. Over the course of about 700 million years, the oxygen added up until other lifeforms started to go extinct, poisoned by all that oxygen in the oceans and air. By two billion years ago, pretty much every lifeform that couldn’t evolve to use or at least tolerate oxygen had gone extinct. So take a deep breath of life-giving oxygen and thank cyanobacteria, which by the way are still around and still producing oxygen. However, they’re still up to their old tricks because they also produce what are called cyanotoxins, which can be deadly.

That brings us to another animal in our imaginary farm, the mold pig. It’s not a pig or a mold, and unlike the leaf sheep and cyanobacteria, it’s extinct. At least, we think it’s extinct.

The mold pig is a microinvertebrate only discovered in 2019. The only reason we know about it at all is because of amber found in the Dominican Republic, on an island in the Caribbean Sea. As we’ve discussed in past episodes, especially episode 108, amber is the fossilized resin of certain types of tree, and sometimes the remains of small animals are found inside. Often these animals are insects, but sometimes even tinier creatures are preserved that we would otherwise probably never know about.

The mold pig was about 100 micrometers long, or .1 millimeter. You’ve probably heard of the tardigrade, or water bear, which we talked about in episode 234, and if so you might think the mold pig was a type of tardigrade just from looking at it, since it looks similar. It had four pairs of legs like tardigrades do, but while scientists think they were related, and that the mold pig was probably also related to mites, it was different enough that it’s been classified in its own genus and may need to belong to its own phylum. Its official name is Sialomorpha.

The mold pig probably ate mold, fungus, and microscopic invertebrates. It lived around 30 million years ago, and right now that’s about all we know about it. There’s a good chance that it still survives somewhere in the world, but it’s so tiny that it’s even easier to overlook than the leaf sheep. Maybe you will be the person who rediscovers its living descendants.

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

Thanks for listening!

Episode 339: The Tully Monster!

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Is it an invertebrate? Is it a vertebrate? It’s the Tully monster!

Further reading:

3D Tully monster probably not related to vertebrates

Has the “Tully monster” mystery finally been solved after 65 years?

Possibly what the Tully monster looked like while alive:

Show transcript:

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

This week we’re going to learn about an ancient creature surrounded by mystery. When I was working on last week’s updates episode, I found some new information about it and intended to include it as an update. Then I realized I was referencing a Patreon episode, which I also reworked into a chapter of the Beyond Bigfoot & Nessie book. So instead, I included the new information in this episode all about the Tully monster.

In 1955, an amateur fossil collector named Francis Tully discovered a really weird fossil. This was in one particular area of Illinois in the United States, roughly in the middle of North America. The fossil was about six inches long, or 15 cm, and Tully thought it resembled a tiny torpedo.

He took the fossil to the Field Museum of Natural History in Chicago in hopes that somebody could tell him what his fossil was. The paleontologists he showed it to had no idea what it was or even what it might be related to. It was described in 1966 and given the name Tullimonstrum, which means Mr. Tully’s monster, which is pretty much what everyone was calling it already.

300 million years ago, in what is now the state of Illinois, a strange animal lived in the shallow sea that covered part of the area. The land that bordered this sea was swampy, with many rivers emptying into the ocean. These river waters carried dead plant materials and mud, which settled to the bottom of the ocean. When an animal died, assuming it wasn’t eaten by something else, its body sank into this soft muddy mess. The bacteria in the mud produced carbon dioxide that combined with iron that was also present in the mud, which formed a mineral called siderite that encased the dead animal. This slowed decay long enough that an impression of the body formed in the mud, and as the centuries passed and the mud became stone, the fossilized body impression was surrounded by a protective ironstone nodule. That’s why we know about the soft-bodied animals from this area, even though soft-bodied animals rarely leave fossil evidence.

So what did this weird animal look like?

The Tully monster was shaped sort of like a slug or a leech, and it had a segmented body. Its eyes were on stalks that jutted out sideways, although the stalks were more of a horizontal bar that grew across the top of the head. The tail end had two vertical fins, which argues that the Tully monster was probably a good swimmer. But at the front of its body it had a long, thin, jointed proboscis that ended in claws or pincers lined with eight tiny tooth-like structures.

It’s easy to assume that the pincers acted as jaws and therefore the proboscis was a mouth on a jointed stalk, but we really don’t know. The Tully monster may have used its proboscis to probe for food in the mud at the bottom of the sea, but because the proboscis had a joint, it probably couldn’t act as a sort of straw. The pincers may have grabbed tiny prey and conveyed it to a mouth that hasn’t been preserved on the specimens we have.

The Tully monster resembles nothing else known, and is so bizarre that researchers aren’t sure where to place it taxonomically. And it wasn’t rare. Paleontologists have since found lots of Tully monster fossils in the Illinois fossil beds, known as the Mazon Creek formation. The Mazon Creek formation is also the source of highly detailed fossils of hundreds of other plant and animal species, including some that have never been found anywhere else.

Scientists have suggested any number of animal groups that the Tully monster might belong to. It might be a type of arthropod, a mollusk, a segmented worm…or it might be a vertebrate. The tiny tooth-like structures in the pincers have been analyzed and some researchers think they were more similar to keratin than chitin. Keratin is a vertebrate protein while chitin is an invertebrate protein.

In 2016 a study argued that pigments in the eyes are arranged the same way as they are in vertebrates, which meant the Tully monster might have been a vertebrate. The problem is that some invertebrates also have these same pigment arrangements, notably cephalopods like octopuses. A 2019 study also looked at the chemical makeup of the fossil eyes, this time with even more advanced equipment—specifically, a synchrotron radiation lightsource, which is a type of particle accelerator. It sounds so science-y. This study suggested that the Tully monster’s eyes had a different chemical makeup than the vertebrates found in the same fossil beds, which means the Tully monster probably wasn’t a vertebrate after all. But it also didn’t match up with known invertebrates from the same fossil beds.

Of course, it might be a deuterostome. The animals in this superphylum develop a nerve cord at some stage of life, usually as an embryo, but may not retain it into adulthood. This includes echinoderms such as sea stars and sea urchins, tunicates like sea squirts, and possibly acorn worms although some scientists disagree. All vertebrates are also members of the superphylum too.

One suggestion is that the Tully monster is related to a type of animal called a conodont. Technically the term conodont refers to its teeth, with the animal itself known as conodontophora, but conodont is easier to say. We know very little about the conodont, since almost the only fossils we have of it are the tiny teeth. We also have eleven body impressions, so we know it was long and skinny like an eel and grew up to 20 inches long, or 50 cm. We also know it had large eyes, a notochord (or primitive spine), and fins on the tail end.

Conodont teeth first appear in the fossil record during the Cambrian, some 525 million years ago. They disappear entirely from the fossil record about 200 million years ago during the Triassic-Jurassic extinction event. But during those 300-some million years they were around, they left a whole lot of tiny fossil teeth, so many that they’re considered an index fossil, which helps scientists determine how old a particular strata of rock is.

When I say tiny teeth, I mean tiny—they’re microfossils usually measured in micrometers, although some of the larger ones were as much as 6 mm long. But they weren’t teeth like modern animal teeth, and the mouth wasn’t like anything we know today.

The conodont’s mouth is called a feeding apparatus by scientists, and it’s very different from what most of us think of as a mouth. This was long before jawed animals evolved some 400 million years ago, and the conodont’s teeth are technically known as conodont elements since they’re not really teeth. There were three types of the conodont elements, meaning they had different shapes and probably different functions.

Some species of conodont may have used the elements to crush prey, but they probably weren’t very strong swimmers so may have mostly eaten very small animals. Some researchers even suggest the conodont used the elements to filter plankton from the water, while others think the conodont might have been parasitic on larger animals, like the sea lamprey is. Conodonts were probably related to hagfish and lampreys and may have looked similar, although not everyone agrees with this classification. Some researchers even think conodonts might have been invertebrates.

Another possibility is that the Tully monster was related to Anomalocarids, which you may remember from the Cambrian explosion episode. Anomalocaris and its relations were arthropods that resemble nothing else alive. It had eyes on stalks, clawed appendages that grew from its front near the mouth, and the rear of its body was segmented with tail fins. Another Cambrian arthropod, Opabinia, had a single flexible feeding proboscis with claws at the end, five eyes on stalks, and a segmented body, so the Tully monster may have been related to it. But we don’t have anything definitive yet one way or another as to what it was related to.

The most recent study on whether the Tully monster was an invertebrate or a vertebrate was published in early 2023 in the journal Nature. The study used high-resolution 3D scanning to examine 153 Tully monster specimens. The scientists determined that the tooth-like structures at the end of the proboscis don’t appear to be keratin, and the Tully monster has segmentation in its head, which is not something found in vertebrates. These and other findings mean that as of now, it looks like the Tully monster was an invertebrate.

However, we still have no idea what kind of invertebrate it might have been. The 2023 study suggests it was either a non-vertebrate chordate or a protostome. Non-vertebrate chordates include hagfish and tunicates, while protostomes include a whole lot of invertebrates, including insects, worms, and mollusks.

The reason all this is important is because there’s a whole lot we don’t know yet about how jawed animals evolved from jawless fish. If the Tully monster really was a vertebrate, it would give us new information about jawless animals. But part of the reason it’s hard to determine where the Tully monster should be placed taxonomically is because of how incredibly weird it is, and that’s exciting too.

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

Thanks for listening!

Episode 338: Updates 6 and an Arboreal Clam!?!

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This week we have our annual updates and corrections episode, and at the end of the episode we’ll learn about a really weird clam I didn’t even think was real at first.

Thanks to Simon and Anbo for sending in some corrections!

Further reading:

Lessons on transparency from the glass frog

Hidden, never-before-seen penguin colony spotted from space

Rare wild asses spotted near China-Mongolia border

Aye-Ayes Use Their Elongated Fingers to Pick Their Nose

Homo sapiens likely arose from multiple closely related populations

Scientists Find Earliest Evidence of Hominins Cooking with Fire

153,000-Year-Old Homo sapiens Footprint Discovered in South Africa

Newly-Discovered Tyrannosaur Species Fills Gap in Lineage Leading to Tyrannosaurus rex

Earth’s First Vertebrate Superpredator Was Shorter and Stouter than Previously Thought

252-Million-Year-Old Insect-Damaged Leaves Reveal First Fossil Evidence of Foliar Nyctinasty

The other paleo diet: Rare discovery of dinosaur remains preserved with its last meal

The Mongolian wild ass:

The giant barb fish [photo from this site]:

Enigmonia aenigmatica, AKA the mangrove jingle shell, on a leaf:

Show transcript:

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

This week is our annual updates and corrections episode, but we’ll also learn about the mangrove jingle shell, a clam that lives in TREES. A quick reminder that this isn’t a comprehensive updates episode, because that would take 100 years to prepare and would be hours and hours long, and I don’t have that kind of time. It’s just whatever caught my eye during the last year that I thought was interesting.

First, we have a few corrections. Anbo emailed me recently with a correction from episode 158. No one else caught this, as far as I can remember. In that episode I said that geckos don’t have eyelids, and for the most part that’s true. But there’s one family of geckos that does have eyelids, Eublepharidae. This includes the leopard gecko, and that lines up with Anbo’s report of having a pet leopard gecko who definitely blinked its eyes. This family of geckos are sometimes even called eyelid geckos. Also, Anbo, I apologize for mispronouncing your name in last week’s episode about shrimp.

After episode 307, about the coquí and glass frogs, Simon pointed out that Hawaii doesn’t actually have any native frogs or amphibians at all. It doesn’t even have any native reptiles unless you count sea snakes and sea turtles. The coqui frog is an invasive species introduced by humans, and because it has no natural predators in Hawaii it has disrupted the native ecosystem in many places, eating all the available insects. Three of the Hawaiian islands remain free of the frogs, and conservationists are working to keep it that way while also figuring out ways to get them off of the other islands. Simon also sent me the chapter of the book he’s working on that talks about island frogs, and I hope the book is published soon because it is so much fun to read!

Speaking of frogs, one week after episode 307, an article about yet another way the glass frog is able to hide from predators was published in Science. When a glass frog is active, its blood is normal, but when it settles down to sleep, the red blood cells in its blood collect in its liver. The liver is covered with teensy guanine crystals that scatter light, which hides the red color from view. That makes the frog look even more green and leaf-like!

We’ve talked about penguins in several episodes, and emperor penguins specifically in episode 78. The emperor penguin lives in Antarctica and is threatened by climate change as the earth’s climate warms and more and more ice melts. We actually don’t know all that much about the emperor penguin because it lives in a part of the world that’s difficult for humans to explore. In December 2022, a geologist named Peter Fretwell was studying satellite photos of Antarctica to measure the loss of sea ice when he noticed something strange. Some of the ice had brown stains.

Dr Fretwell knew exactly what those stains were: emperor penguin poop. When he obtained higher-resolution photos, he was able to zoom in and see the emperor penguins themselves. But this wasn’t a colony he knew about. It was a completely undiscovered colony.

In episode 292 we talked about a mystery animal called the kunga, and in that episode we also talked a lot about domestic and wild donkeys. We didn’t cover the Mongolian wild ass in that one, but it’s very similar to wild asses in other parts of the world. It’s also called the Mongolian khulan. It used to be a lot more widespread than it is now, but these days it only lives in southern Mongolia and northern China. It’s increasingly threatened by habitat loss, climate change, and poaching, even though it’s a protected animal in both Mongolia and China.

In February of 2023, a small herd of eight Mongolian wild asses were spotted along the border of both countries, in a nature reserve. A local herdsman noticed them first and put hay out to make sure the donkeys had enough to eat. The nature reserve has a water station for wild animals to drink from, and has better grazing these days after grassland ecology measures were put into place several years ago.

In episode 233 we talked about the aye-aye of Madagascar, which has weird elongated fingers. Its middle finger is even longer and much thinner than the others, which it uses to pull invertebrates from under tree bark and other tiny crevices. Well, in October of 2022 researchers studying aye-ayes started documenting another use for this long thin finger. The aye-ayes used it to pick their noses. It wasn’t just one aye-aye that wasn’t taught good manners, it was widespread. And I hope you’re not snacking while I tell you this, the aye-aye would then lick its finger clean. Yeah. But the weirdest thing is that the aye-aye’s thin finger is so long that it can potentially reach right through the nose right down into the aye-aye’s throat.

It’s pretty funny and gross, but wondering why some animals pick their noses is a valid scientific question. A lot of apes and monkeys pick their noses, as do humans (not that we admit it most of the time), and now we know aye-ayes do too. The aye-aye is a type of lemur and therefore a primate, but it’s not very closely related to apes and monkeys. Is this just a primate habit or is it only seen in primates because we have fingers that fit into our nostrils? Would all mammals pick their nose if they had fingers that would fit up in there? Sometimes if you have a dried snot stuck in your nose, it’s uncomfortable, but picking your nose can also spread germs if your fingers are dirty. So it’s still a mystery why the aye-aye does it.

A recent article in Nature suggests that Homo sapiens, our own species, may have evolved not from a single species of early human but from the hybridization of several early human species. We already know that humans interbred with Neandertals and Denisovans, but we’re talking about hybridization that happened long before that between hominin species that were even more closely related.

The most genetically diverse population of humans alive today are the Nama people who live in southern Africa, and the reason they’re so genetically diverse is that their ancestors have lived in that part of Africa since humans evolved. Populations that migrated away from the area, whether to different parts of Africa or other parts of the world, had a smaller gene pool to draw from as they moved farther and farther away from where most humans lived.

Now, a new genetic study of modern Nama people has looked at changes in DNA that indicate the ancestry of all humans. The results suggest that before about 120,000 to 135,000 years ago, there was more than one species of human, but that they were all extremely closely related. Since these were all humans, even though they were ancient humans and slightly different genetically, it’s probable that the different groups traded with each other or hunted together, and undoubtedly people from different groups fell in love just the way people do today. Over the generations, all this interbreeding resulted in one genetically stable population of Homo sapiens that has led to modern humans that you see everywhere today. To be clear, as I always point out, no matter where people live or what they look like, all people alive today are genetically human, with only minor variations in our genetic makeup. It’s just that the Nama people still retain a lot of clues about our very distant ancestry that other populations no longer show.

To remind everyone how awesome out distant ancestors were, here’s one new finding of how ancient humans lived. We know that early humans and Neandertals were cooking their food at least 170,000 years ago, but recently archaeologists found the remains of an early hominin settlement in what is now Israel where people were cooking fish 780,000 years ago. There were different species of fish remains found along with the remains of cooking fires, and some of the fish are ones that have since gone extinct. One was a carp-like fish called the giant barb that could grow 10 feet long, or 3 meters.

In other ancient human news, the oldest human footprint was discovered recently in South Africa. You’d think that we would have lots of ancient human footprints, but that’s actually not the case when it comes to footprints more than 50,000 years old. There are only 14 human footprints older than that, although there are older footprints found made by ancestors of modern humans. The newly discovered footprint dates to 153,000 years ago.

It wouldn’t be an updates episode without mentioning Tyrannosaurus rex. In late 2022 a newly discovered tyrannosaurid was described. It lived about 76 million years ago in what is now Montana in the United States, and while it wasn’t as big as T. rex, it was still plenty big. It probably stood about seven feet high at the hip, or a little over 2 meters, and might have been 30 feet long, or 9 meters. It probably wasn’t a direct ancestor of T. rex, just a closely related cousin, although we don’t know for sure yet. It’s called Daspletosaurus wilsoni and it shows some traits that are found in older Tyrannosaur relations but some that were more modern at the time.

Dunkleosteus is one of a number of huge armored fish that lived in the Devonian period, about 360 million years ago. We talked about it way back in episode 33, back in 2017, and at that time paleontologists thought Dunkleosteus terrelli might have grown over 30 feet long, or 9 meters. It had a heavily armored head but its skeleton was made of cartilage like a shark’s, and cartilage doesn’t generally fossilize, so while we have well-preserved head plates, we don’t know much about the rest of its body.

With the publication in early 2023 of a new study about dunkleosteus’s size, we’re pretty sure that 30 feet was a huge overestimation. It was probably less than half that length, maybe up to 13 feet long, or almost 4 meters. Previous size estimates used sharks as size models, but dunkleosteus would have been shaped more like a tuna. Maybe you think of tuna as a fish that makes a yummy sandwich, but tuna are actually huge and powerful predators that can grow up to 10 feet long, or 3 meters. Tuna are also much heavier and bigger around than sharks, and that was probably true for dunkleosteus too. The study’s lead even says dunkleosteus was built like a wrecking ball, and points out that it was probably the biggest animal alive at the time. I’m also happy to report that people have started calling it chunk-a-dunk.

We talked about trace fossils in episode 103. Scientists can learn a lot from trace fossils, which is a broad term that encompasses things like footprints, burrows, poops, and even toothmarks. Recently a new study looked at insect damage on leaves dating back 252 million years and learned something really interesting. Some modern plants fold up their leaves at night, called foliar nyctinasty, which is sometimes referred to as sleeping. The plant isn’t asleep in the same way that an animal falls asleep, but “sleeping” is a lot easier to say than foliar nyctinasty. Researchers didn’t know if folding leaves at night was a modern trait or if it’s been around for a long time in some plants. Lots of fossilized leaves are folded over, but we can’t tell if that happened after the leaf fell off its plant or after the plant died.

Then a team of paleontologists from China and Sweden studying insect damage to leaves noticed that some leaves had identical damage on both sides, exactly as though the leaf had been folded and an insect had eaten right through it. That’s something that happens in modern plants when they’re asleep and the leaves are folded closed.

The team looked at fossilized leaves from a group of trees called gigantopterids, which lived between 300 and 250 million years ago. They’re extinct now but were advanced plants at the time, some of the earliest flowering plants. They also happen to have really big leaves that often show insect damage. The team determined that the trees probably did fold their leaves while sleeping.

In episode 151 we talked about fossils found with other fossils inside them. Basically it’s when a fossil is so well preserved that the contents of the dead animal’s digestive system are preserved. This is incredibly rare, naturally, but recently a new one was discovered.

Microraptor was a dinosaur that was only about the size of a modern crow, one of the smallest dinosaurs, and it probably looked a lot like a weird bird. It could fly, although probably not very well compared to modern birds, and in addition to front legs that were modified to form wings, its back legs also had long feathers to form a second set of wings.

Several exceptionally well preserved Microraptor fossils have been discovered in China, some of them with parts of their last meals in the stomach area, including a fish, a bird, and a lizard, so we knew they were generalist predators when it came to what they would eat. Now we have another Microraptor fossil with the fossilized foot of a mammal in the place where the dinosaur’s stomach once was. So we know that Microraptor ate mammals as well as anything else it could catch, although we don’t know what kind of mammal this particular leg belonged to. It may be a new species.

Let’s finish with the mangrove jingle shell. I’ve had it on the list for a long time with a lot of question marks after it. It’s a clam that lives in trees, and I actually thought it might be an animal made up for an April fool’s joke. But no, it’s a real clam that really does live in trees.

The mangrove jingle shell lives on the mangrove tree. Mangroves are adapted to live in brackish water, meaning a mixture of fresh and salt water, or even fully salt water. They mostly live in tropical or subtropical climates along coasts, and especially like to live in waterways where there’s a tide. The tide brings freshly oxygenated water to its roots. A mangrove tree needs oxygen to survive just like animals do, but it has trouble getting enough through its roots when they’re underwater. Its root system is extensive and complicated, with special types of roots that help it stay upright when the tide goes out and special roots called pneumatophores, which stick up above the water or soil and act as straws, allowing the tree to absorb plenty of oxygen from the air even when the rest of the root system is underwater. These pneumatophores are sometimes called knees, but different species of mangrove have different pneumatophore shapes and sizes.

One interesting thing about the mangrove tree is that its seeds actually sprout while they’re still attached to the parent tree. When it’s big enough, the seedling drops off its tree into the water and can float around for a long time before it finds somewhere to root. If can even survive drying out for a year or more.

The mangrove jingle shell clam lives in tropical areas of the Indo-Pacific Ocean, and is found throughout much of coastal southeast Asia all the way down to parts of Australia. It grows a little over one inch long, or 3 cm, and like other clams it finds a place to anchor itself so that water flows past it all the time and it can filter tiny food particles from the water. It especially likes intertidal areas, which happens to be the same area that mangroves especially like.

Larval jingle shells can swim, but they need to find somewhere solid to anchor themselves as they mature. When a larva finds a mangrove root, it attaches itself and grows a domed shell. If it finds a mangrove leaf, since mangrove branches often trail into the water, it attaches itself to the underside and grows a flatter shell. Clams attached to leaves are lighter in color than clams attached to roots or branches. Fortunately, the mangrove is an evergreen tree that doesn’t drop its leaves every year.

So there you have it. Arboreal clams! Not a hoax or an April fool’s joke.

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

Thanks for listening!

Episode 334: Piranha!

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Thanks to David for this week’s suggestion, the piranha!

Further reading:

Florida wildlife officer’s fish seizure nibbles at illegal piranha sales

How Teddy Roosevelt Turned Piranhas into Ferocious Maneaters

The beautiful butterfly peacock bass (not a piranha):

The red-bellied piranha (By H. Zell – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=82557603):

Chompy chompy teeth:

Show transcript:

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

This week we’re covering a type of fish that I absolutely cannot believe we haven’t talked about before. It’s the piranha! Thanks to David for telling me on Mastodon about a piranha incident that led to me realizing we don’t have an episode about it yet.

David’s incident is something that happened in Florida in 2009. In October of that year, a 14-year-old boy named Jake was fishing in a retention pond in West Palm Beach, Florida, which he did a lot. He’d caught all kinds of unusual fish in the pond, including a butterfly peacock bass, which is yellow, green, or even orange in color with three black stripes on its back. It can grow well over two feet long, or 74 cm. The peacock bass is native to tropical areas of South America but was deliberately introduced to Florida in 1984 to prey on other invasive species. This actually worked, and because the fish can’t survive if the water gets too cold, it can’t spread very far.

But on this particular October day in 2009, Jake caught a fish that no one wanted to find in Florida, a red-bellied piranha! The teenager took the fish to his dad, who called the Florida Fish and Wildlife Conservation Commission. A wildlife biologist investigated and caught another piranha in the same pond the following week.

That was enough of a problem that wildlife officials decided to poison the entire 4-acre pond rather than risk having piranhas become naturalized in Florida. The poison killed every single fish in the pond, including at least one other piranha, although it was a poison that quickly broke down into nontoxic compounds. The pond was later restocked with bluegills and other native fish.

The reason that Florida wildlife officials would rather kill all the fish in a big pond rather than let any piranhas live is that Florida is very similar to the piranha’s native habitat in South America. Florida already has enough issues with invasive species like the Burmese python, cane toad, lionfish, and giant land snail without adding another fish that’s famous for its sharp teeth and voracious appetite. If the piranha became established in Florida, it could drive all kinds of native fish and other animals to extinction very quickly.

This has actually happened in parts of China, where red-bellied piranha were first found in the wild in 1990 and have since spread throughout much of South China. In some waterways, up to half of the native fish have disappeared after piranha and other invasive species became established.

But wait, you may be thinking, what about the danger to humans? Aren’t piranhas incredibly dangerous to swimmers?

The red-bellied piranha is the species that most people think is dangerous to people. We’ve all heard the stories and maybe seen movies where a pack of piranha attack someone swimming along, and within minutes all that’s left of them is a skeleton. But it may not surprise you to learn that those stories are fake, but they’re widespread for an unusual reason.

Back in 1913, the former U.S. President Teddy Roosevelt, who we talked about in episode 284 about the teddy bear, took part in an expedition to the Amazon basin in South America. The expedition was arranged by the Brazilian government, who invited Roosevelt along.

The expedition planned to explore the headwaters of the Amazon and it did, at great peril. Three people died and almost everyone got sick from malaria or some other disease, including Roosevelt, who got a cut on his leg that became badly infected. One of the three people who died was murdered by another expedition member, and instead of taking the murderer home to face justice, they just…left him in the jungle, a looooooooong way from anywhere or anyone.

Anyway, one of the things Roosevelt saw early on in the trip was something he told everyone about later, in gruesome detail. You’ve probably heard about it too. The local dignitaries took Roosevelt and the other expedition members on a tour of their town, showing things off, as people do all over the world when they have important visitors. They also showed how ferocious the local piranhas were by driving a cow into the water. A pack of piranhas attacked the cow, and within minutes it was nothing but a skeleton, just like in the movies!

But wait, you’re probably thinking again, I just said that was all fake! Did it really happen? It did, but not the way it sounds. The whole cruel spectacle was arranged ahead of time by the local dignitaries. They had people capture piranhas from miles away and bring them to one section of the river, where they were penned in with a net and not given any food for days. By the time the cow was driven into the makeshift pen, the piranhas were starving and desperate. Under normal circumstances, they would have never attacked the cow.

The red-bellied piranha and its relations are actually mild-mannered fish who only want to eat small fish, snails, insects, and other tiny animals, along with fruit and leaves. It will also sometimes eat dead animals it finds, which has led to people assuming piranhas killed someone swimming in the water when actually the person drowned and the piranhas just, you know, cleaned things up a little.

The red-bellied piranha can grow up to 20 inches long, or 50 cm, and is usually silvery-gray in color with black markings and a reddish belly. It does have big sharp teeth, but so do lots of other fish. Most importantly, the piranha doesn’t hunt in packs. It hunts individually most of the time, but it may stay in a school with other piranhas to help it avoid predators. If a caiman or something decides it wants a piranha snack, any given individual fish in a school is likely to escape the caiman, whereas a fish by itself has a much higher chance of being grabbed and eaten.

The piranha communicates with other piranha by sound. Fish aren’t usually famous for making noise, but the piranha can use its swim bladder as a resonant chamber. It uses special muscles to make a low-pitched drumming sound, usually to warn another piranha away from whatever food it’s found.

Aquarium enthusiasts sometimes keep piranha as pets, but they need special care. A piranha won’t eat meat that’s going bad, so it has to have fresh meat or live animals it can catch, and some animals can make the piranha sick, like goldfish. It’s also a messy eater, so its water will get yucky very quickly and has to be continually changed. And, of course, in some places people aren’t allowed to own piranha at all. You know, places like Florida.

The red-bellied piranha is the largest living species, but 8 to 10 million years ago a species named Megapiranha could grow as much as four feet long, or 1.27 meters. If you’d lived back then, you might have needed to be a little more careful where you swam.

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

Thanks for listening!

Episode 333: Robins and Ravens

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Thanks to Liesbet, Simon, and Thea for their suggestions this week! Let’s learn about some birds!

Further reading:

Blue Tits and Milk Bottle Tops

Ravens parallel great apes in flexible planning for tool-use and bartering

Further watching:

A Raven Calling [this is a great video of a raven making all sorts of interesting sounds–I only used a tiny clip of it in the episode but it’s worth watching the whole thing]

The European robin:

The American robin and a worm that is having a very bad day:

A blue tit [photo By © Francis C. Franklin / CC-BY-SA-3.0, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=37675470]:

A blue tit about to get the cap off that milk bottle [photo from link above]:

The Eastern bluebird:

A raven:

An American crow:

Show transcript:

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

This week we have suggestions from Liesbet, Simon, and Thea, who suggested some relatively common birds that you may already think you know all about, but there’s lots to learn about them!

We’ll start with Liesbet’s suggestion, about the European robin and bluebird, and while we’re at it we’ll learn about the American robin and bluebird. The European and American birds are completely different species. The reason they have the same names is because when Europeans first started paying attention to the birds of North America, they needed names for the birds. The native peoples had names for them, of course, but the Europeans wanted names in a language they understood, so in a lot of cases they just borrowed names already in use at home.

Let’s start with the robin, which we also talked about way back in episode 81.

The European robin is a little bitty bird, only around 5 inches long, or 13 cm, with a brown back, streaked gray or buff belly, and orange face and breast. It has a short black bill and round black eyes. It eats insects, worms, berries, and seeds. The eggs are pale brown with reddish speckles.

It lives throughout much of Eurasia, but robins in Britain tend to be fairly tame, probably because they were traditionally considered beneficial in Britain and Ireland, so farmers and gardeners wouldn’t hurt them. In other parts of Europe they were hunted and are much more shy. European robins are also common on Christmas cards in Britain and Ireland, possibly because in the olden days, postmen used to wear red jackets. The postmen started to be called robins as a result, and since postmen bring Christmas cards, the bird robin became linked with card delivery and finally just ended up on the Christmas cards. Plus, their orange markings are cheerful in winter.

This is what the European robin sounds like:

[robin song]

The American robin is a type of thrush. It lives year-round in most of the United States and parts of Mexico, spends summers in much of Canada, and winters in parts of Mexico. It’s very different from the European robin. The European robin is tiny and round and adorable, while the American robin is big and always looks kind of angry. It grows around 10 inches long, or 25 cm. It’s dark gray on its back, with a rusty red breast, white undertail coverts, and a long yellow bill. It also has white markings around its eyes. Young birds are speckled. It mostly eats insects, worms, and berries.

If you see a bird on the ground, running quickly and then stopping, it’s probably a robin. Mostly the robin hunts bugs by sight, but it has good hearing and can actually hear worms moving around underground. You can sometimes see a robin with its head cocked, listening for a worm, before pouncing and pulling it out of the ground, just like in a cartoon.

American robin eggs are a light teal blue, so common and well-known that robin’s-egg-blue is a typical description of that particular color. In the spring after eggs hatch, the mother robin will carry the eggshells away from the nest to drop them, so predators won’t see the shells and know there’s a nest nearby. That’s why you’ll sometimes see half a robin eggshell on the sidewalk. It doesn’t mean something bad happened to the baby, just that the mother bird is doing her job. Both parents feed the chicks, and the parents also carry off the babies’ droppings to scatter them away from the nest.

This is what an American robin’s song sounds like.

[robin song]

Liesbet also wanted to learn about the European bluebird, more commonly called the Eurasian blue tit. We haven’t talked about it or the American bluebird before, even though they’re both beautiful birds.

The blue tit lives throughout Europe and parts of western Asia. It grows around 4 and a half inches long, or 12 cm, and has a bright blue crown on its head with blue on its wings, tail, and back. Its face is mostly white but it has a black streak that crosses its eye and a black ring around its neck. In fact, if you’re familiar with the blue jay of North America, the blue tit looks a lot like a miniature blue jay. It even has a little bit of a crest that it can raise and lower.

Because it eats a lot of insects and other small invertebrates, along with some seeds, the blue tit is an acrobatic bird. It will hang upside down from a twig to reach a caterpillar on the underside of a leaf, that sort of thing. It will also peel bits of bark away from a tree trunk to find tiny insects and spiders hiding underneath it. This habit leads it to sometimes peel bits off of people’s houses, like the putty that holds windowpanes in place. It also once led to the blue tit learning a surprising way to find food, and to learn about that, we have to learn a little bit about how people in the olden days got their milk if they didn’t own cows.

Back in the early 20th century, people used to get milk delivered every morning by a milkman. Refrigerators and ice boxes weren’t common like they are today, and most people didn’t have a way to keep milk cold. That meant it would go bad very quickly, so people would just order how much milk they needed in one day and when they got up in the morning, the milkman would have left the milk and other dairy products on the doorstep for the family.

The milk was always whole milk, also called full-fat, and as it sat in its bottles on the doorstep waiting for the family to wake up and bring the milk in, the cream would separate and rise to the top of the milk. Cream is just the fattiest, richest part of the milk. These days milk is processed differently so even if you buy whole milk, the cream won’t separate from it, and most milk sold today has already had most of the cream separated out. That’s why skim milk is called that, because the cream has been skimmed off the top. It’s sold separately as heavy whipping cream or mixed with milk as half-and-half. But back in the olden days, if you wanted to make whipped cream or clotted cream or some other recipe that calls for cream, you’d just skim the cream off yourself to use it.

The problem is, cream is so rich and full of protein that other animals learned to rob milk bottles, especially the blue tit. Birds can’t digest milk, naturally, since only mammals produce milk and are adapted to digest it, and even most adult mammals have trouble digesting milk. But cream contains a lot less lactose than the milk itself, and lactose is the type of sugar in milk that can cause stomach upset in adults. Blue tits learned that if they peeled the little foil cap off a milk bottle, they could get at the cream, and it became such a widespread behavior that each generation of blue tits became more adapted to digest cream.

These days, of course, most people buy their milk at the grocery store. The blue tits have had to go back to eating bugs and seeds.

This is what a blue tit sounds like:

[blue tit song]

The bluebird is a North American bird that also eats insects and other small invertebrates, along with berries and seeds. It grows around 7 inches long, or 18 cm. There are three species, the eastern bluebird and western bluebird, which look similar with bright blue above and white underneath with rusty red breast, and the mountain bluebird, which is blue almost all over and lives in mountainous areas of western North America. The bluebird is a type of thrush, meaning that it’s actually related to the American robin and used to be called the blue robin.

The bluebird spends a lot of its time sitting on a branch and watching for insects in the grass below. When it spots a grasshopper or beetle or spider or even a snail, it will drop down from its branch to grab it. It prefers open grasslands with trees or brush it can perch in, so it’s common around farmland. The mountain bluebird hunts like this too, but it doesn’t always bother to perch and will just hover above the ground until it spots a bug.

This is what an eastern bluebird sounds like:

[bluebird song]

Next, Simon and Thea wanted to learn about crows and ravens. The raven is another bird we covered a long time ago, in episode 112. I had a really bad cold the week of that episode and not only did I sound awful, I didn’t do a very good job with my research. I’m glad to revisit the topic and correct a few mistakes.

Crows and ravens look similar and are closely related, with both belonging to the genus Corvus. There are lots of species and subspecies of both, but let’s talk specifically about the American crow since it’s closely related to the hooded crow and the carrion crow found throughout Europe and Asia. Likewise, we’ll talk about the common raven since it’s found throughout much of the northern hemisphere.

The American crow can grow up to about 20 inches long, or 50 cm, with a wingspan over 3 feet across, or about a meter. Meanwhile, the common raven has a wingspan of up to 5 feet across, or 1.5 meters, and can grow up to 26 inches long, or 67 cm. Both are glossy black all over with large, heavy bills and long legs.

Crows and ravens both mate for life. Crows in particular are devoted family birds, with the grown young of a pair often staying to help their parents raise the next nest.

Both crows and ravens are omnivores, which means they eat pretty much anything. They will eat roadkill and other carrion, fruit and grain, insects, small animals, other birds, and eggs. They’re also extremely smart, which means a crow or raven can figure out how to get into trash cans and other containers to find food that humans think is secure.

Both also sometimes make and use tools, especially sticks that they use to dig out insects in places where their beaks can’t reach. But ravens in particular show a lot of tool use. Ravens sometimes throw pinecones or rocks at people who approach too close to their nests, and will even use sticks to stab at attacking owls. A few ravens have been observed to hold big pieces of bark in their feet while flying in strong winds, and they use the bark as a sort of rudder to help them maneuver. Other cognitive studies of ravens show that they have sophisticated and flexible problem-solving abilities where they can plan at least one step ahead, similar to great apes. Other corvids show similar abilities.

The raven can imitate other animals and birds, even machinery, in addition to making all sorts of calls. It can even imitate human speech. 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.

Ravens also communicate non-vocally with other ravens. A raven will use its beak to point with, the way humans will point with a finger. They’ll also hold something and wave it to get another raven’s attention, which hasn’t been observed in any other animal besides apes.

The raven is much larger and heavier than a crow, and you can also distinguish a crow from a raven by their calls. This is what an American crow sounds like:

[crow call]

And this is what a raven sounds like:

[raven call]

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

Thanks for listening!

Episode 332: Hunting Partners and Mutualism

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Thanks to Vaughn and Jan for their suggestions this week! We’re going to learn about mutualism of various types.

Further reading:

The odd couple: spider-frog mutualism in the Amazon rainforest

What Birds, Coyotes, and Badgers Know About Teamwork

Octopuses punch fishes during collaborative interspecific hunting events

An Emotional Support Dog Is the Only Thing That Chills Out a Cheetah

Buddies [picture from the first link above]:

The honeyguide bird:

Cheetahs and dogs can be friends:

Show transcript:

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

This week we’re going to learn about a topic that I’ve been wanting to cover for a long time, mutualism. It’s a broad topic so we won’t try to cover everything about it in this episode, just give an overview with some examples. Vaughn suggested symbiotic behavior ages ago, and Jan gave me a great example of this, also ages ago, so thanks to both of them!

Mutualism is similar to other terms, including symbiosis, often referred to as “a symbiotic relationship.” I’m using mutualism as a general term, but if you want to learn more you’ll quickly find that there are lots of terms referring to different interspecies relationships. Basically we’re talking about two unrelated organisms interacting in a way that’s beneficial to both. This is different from commensalism, where one organism benefits and the other doesn’t but also isn’t harmed, and parasitism, where one organism benefits and the other is harmed.

We’ll start with the suggestion from Jan, who alerted me to this awesome pair of animals. Many different species have developed this relationship, but we’ll take as our specific example the dotted humming frog that lives in parts of western South America.

The dotted humming frog is a tiny nocturnal frog that barely grows more than half an inch long from snout to vent, or about 2 cm. It lives in swamps and lowland forests and spends most of the day in a burrow underground. It comes out at night to hunt insects, especially ants. It really loves ants and is considered an ant specialist. That may be why the dotted humming frog has a commensal relationship with a spider, the Colombian lesserblack tarantula.

The tarantula is a lot bigger than the frog, with its body alone almost 3 inches long, or 7 cm. Its legspan can be as much as 8 and a half inches across, or 22 cm. It’s also nocturnal and spends the day in its burrow, coming out at night to hunt insects and other small animals, although not ants. It’s after bigger prey, including small frogs. But it doesn’t eat the dotted humming frog. One or even more of the frogs actually lives in the same burrow as the tarantula and they come out to hunt in the evenings at the same time as their spider roommate.

So what’s going on? Obviously the frog gains protection from predators by buddying up with a tarantula, but why doesn’t the tarantula just eat the frog? Scientists aren’t sure, but the best guess is that the frog protects the spider’s eggs from ants. Ants like to eat invertebrate eggs, but the dotted humming frog likes to eat ants, and as it happens the female Colombian lesserblack tarantula is especially maternal. She lays about 100 eggs and carries them around in an egg sac. When the babies hatch, they live with their mother for up to a year, sharing food and burrow space.

This particular tarantula also gets along with another species of frog that also eats a lot of ants. Researchers think the spiders distinguish the frogs by smell. The ant-eating frogs apparently smell like friends, or at least useful roommates, while all other frogs smell like food. Or, of course, it’s possible that the ant-eating frogs smell and taste bad to the spider. Either way, both the frogs and the tarantulas benefit from the relationship–and this pairing of tiny frogs and big spiders is one that’s actually quite common throughout the world.

Mutualism is everywhere, from insects gathering nectar to eat while pollenating flowers at the same time, to cleaner fish eating parasites from bigger fish, to birds eating fruit and pooping out seeds that then germinate with a little extra fertilizer. Many mutualistic relationships aren’t obvious to us as humans until we’ve done a lot of careful observations, which is why it’s so important to protect not just a particular species of animal but its entire ecosystem. We don’t always know what other animals and plants that animal depends on to survive, and vice versa.

Sometimes an individual animal will work together with an individual of another species to find food. This may not happen all the time, just when circumstances are right. Sometimes, for example, a coyote will pair up with a badger to hunt. The coyote is closely related to wolves and can run really fast, while the American badger can dig really fast. Both are native to North America. They also both really like to eat prairie dogs, a type of rodent that can run really fast and lives in a burrow. Some prairie dog tunnels can extend more than 30 feet, or 10 meters, with multiple exits. The badger can dig into the burrow and if the prairie dog leaves through one of the exits, the coyote chases after it. When one of the predators catches the prairie dog, they don’t share the meal but they will often continue to hunt together until both are able to eat.

Other animals hunt together too. Moray eels will sometime pair up with a fish called the grouper in a similar way as the coyote and badger. The grouper is a fast swimmer while the eel can wriggle into crevices in rocks or coral. The grouper will swim up to the eel and shake its head rapidly to initiate a hunt, and if the grouper has seen a prey item disappear into a crevice, it will lead the eel to the crevice and shake its head at it again.

Groupers also sometimes pair up with octopuses to hunt together, as will some other species of fish. Like the eel, the octopus can enter crevices to chase an animal that’s trying to hide. But the octopus isn’t always a good hunting partner, because if the grouper catches a fish, sometimes the octopus will punch the grouper and steal its fish. Not cool, octopus.

Birds have mutualistic relationships too, including the honeyguide that lives in parts of Africa and Asia. It’s a little perching bird that’s mostly gray and white or brown and white, with the males of some species having yellow markings. It eats insects, spiders, and other invertebrates, and it especially likes bee larvae. But it’s just a little bird and can’t break open wild honeybee hives by itself.

Some species of honeyguide that live in Africa have figured out that humans can break open beehives. When the honeyguide bird finds a beehive, it will fly around until it hears the local people’s hunting calls. The bird will then respond with a distinct call of its own, alerting the people, and will guide them to the beehive. This has been going on for thousands of years. The humans gather the honey, the honeyguide feasts on the bee larvae and wax, and everyone has a good day except the bees.

The honeyguide is also supposed to guide the honey badger to beehives, but there’s no definitive evidence that this actually happens. Honey badgers do like to eat honey and bee larvae, though, and when a honey badger breaks open a beehive, honeyguides and other birds will wait until it’s eaten what it wants and will then pick through the wreckage for any food the badger missed. But the honeyguide might lead the honey badger to the hive, we just don’t know for sure.

Humans sometimes even help other animals into a commensal relationship. Vaughn gave me an example of a cheetah in a zoo who became best friends with a dog. This hasn’t just happened once, it’s happened lots of times because zookeepers have found that it helps cheetahs kept in captivity. Cheetahs are social animals but sometimes a zoo doesn’t have a good companion for a cheetah cub. The cub could be in danger from older, unrelated cheetahs, but a cheetah all on its own is prone to anxiety. It’s so important for a cheetah to have a sibling that if a mother cheetah only has one cub, or if all but one cub dies, a lot of times she’ll abandon the single cub. If this happens in the wild, it’s sad, but if it happens in captivity the zoo needs to help the cub.

To do this, the zoo will pair the cub with a puppy of a sociable, large breed of dog, such as a Labrador or golden retriever. The cub and the puppy grow up together. The cheetah has a mellow friend who helps alleviate its anxiety, and the dog has a friend who’s really good at playing chase.

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

Thanks for listening!

Episode 328: Giant Ants

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Thanks to Richard from NC for suggesting Titanomyrma!

Further reading:

‘Giant’ ant fossil raises questions about ancient Arctic migrations

A fossilized queen Titanomyrma ant with a rufous hummingbird (stuffed) for scale:

Show transcript:

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

This week we have a suggestion from Richard from North Carolina, who sent me an article about an extinct giant ant called Titanomyrma. This episode is short, but I think you’ll find it interesting.

We’ve talked about ants in previous episodes, most recently episode 185. Most ant colonies consist of a single queen ant who lays all the eggs for her colony, seasonally hatched males with wings who fly off as soon as they’re grown, and worker ants. The worker ants are all female but don’t lay eggs. Army ants have another caste, the soldier ant, which are much larger than the worker ants and have big heads and strong, sharp mandibles. In many species of ant, the worker ants are further divided into castes that are specialized for specific tasks.

The biggest species of ant alive today is probably the giant Amazonian ant. The workers can grow over 1.2 inches long, or more than 3 cm, which is huge for an ant. It lives in South America in small colonies, usually containing less than 100 workers, and unlike most ants it doesn’t have a queen. Instead, one of the workers mates with a male and lays eggs for the colony. The giant Amazonian ant can sting and its sting contains venom that causes intense pain for up to two days. Fortunately, you will probably never encounter these giant ants, and even if you do they’re not very aggressive.

Another contender for the biggest species of ant alive today is the Dorylus genus of army ants, also called driver ants, which we talked about in episode 185. It lives in Africa in colonies that have millions of members, and the queen is the largest ant known. A queen army ant can measure 2.4 inches long, or 63 millimeters, but worker ants are much smaller.

Around 50 million years ago, giant ants related to modern driver ants lived in both Europe and North America. The genus is Titanomyrma and three species are known so far, found in Germany, England, Canada, and the American states of Tennessee and Wyoming.

The Wyoming ant fossil was discovered years ago and donated to the Denver Museum of Nature and Science, where it was stored in a drawer and forgotten about. In 2011 a curator found it and showed it to a paleoentomologist named Bruce Archibald. Dr. Archibald recognized it immediately as a fossilized queen ant even though it was the size of a hummingbird. He also realized it was very similar to a type of giant ant that once lived in Germany.

The German discovery was the first Titanomyrma species discovered, and it’s also the biggest known so far. The queen Titanomyrma gigantea grew up to 2.8 inches long, or 7 centimeters. Males grew up to 1.2 inches long, or 3 cm. The fossilized queen ants found have wings, with a wingspan of over 6 inches, or 16 cm. The other two known species are generally smaller, although still pretty darn big for ants.While they’re not that much bigger than the living Dorylus queens, most of the size of a queen Dorylus ant comes from her enlarged abdomen. Titanomyrma ants were just plain big all over.

Titanomyrma didn’t have a stinger, so it’s possible it used its mandibles to inflict bites, the way modern army ants do. It might also have sprayed formic acid at potential predators, as some ants do today.

The biggest ants alive today all live in tropical areas, so researchers thought Titanomyrma probably did too. During the Eocene, the world was overall quite warm and parts of Europe were tropical. The northern hemisphere supercontinent Laurasia was in the process of breaking up, but Europe and North America were still connected by the Arctic. Even though the Arctic was a lot warmer 50 million years ago than it is now, it was still too cold for a tropical ant. If Titanomyrma couldn’t survive in cold weather, how did it spread from one continent to another when it had to go through the Arctic?

There were warming periods during the Eocene that lasted a few hundred thousand years at a time, so researchers thought the ants probably migrated through the Arctic while it was warmer than usual. Then, in early 2023, a fossilized Titanomyrma queen ant was discovered in Canada. Because the rock it was preserved in has been distorted over the years, we can’t be certain how big the ant actually was. What we do know, though, is that the ant lived in a mountainous area that could get quite chilly, very different from the tropical climate scientists thought the giant ants needed.

As a result of the new finding, researchers are reconsidering whether the giant ants that lived 50 million years ago were really all that similar to modern giant ants. Just because the biggest ants alive today require tropical climates doesn’t mean that ancient giant ants did.

Hopefully more giant ant fossils will turn up soon, so we can learn more about where they lived, how they lived, and precisely how big they could get.

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

Thanks for listening!

Episode 327: The Humble Marmot

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Thanks to Dean for suggesting this week’s topic, the marmot!

Thanks also to Al-Ka-Lines Studio for the beautiful bat pin! You should definitely visit their online shop, because all their jewelry is hand-made by the two of them.

Further reading:

The secret to longevity? Ask a yellow-bellied marmot

The yellow-bellied marmot doing a sit [By Inklein, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2675916]:

A groundhog keeping an eye out for danger:

Show transcript:

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

This week we’re going to have a short little episode about a short little animal suggested by Dean, although I don’t know if Dean is short and/or little. Probably not. The name Dean makes me think of a tall person, probably someone who plays sports and can run really fast, so basically completely unlike a marmot. Dean suggested the marmot, specifically the yellow-bellied marmot.

Before we get started, two quick notes. First, thanks so much to Kathi and Alex of Al-Ka-Lines Studio for the gorgeous bat pin! They make hand-crafted leather jewelry and while they usually sell wholesale to shops, I checked with Kathi to see if it was okay to link to their shop and they said that yes, they sometimes sell to individuals too. I’ve put a link in the show notes in case you’re interested in seeing what they have for sale. They recently started listening to the podcast in order from the first episode and so far they’re not sick of my voice yet.

Second, I’ll be at Furry Weekend Atlanta this coming weekend, assuming you’re listening to this episode when it comes out on May 8, 2023. If you’re going to be there too, let me know and we can meet up. I went to way too many conventions last year so this one and Dragon Con at the end of August are the only ones I have planned this year, and I’m not on any programming on either. I just plan to look at people’s amazing costumes and attend interesting panels and have fun dancing in the evenings. Also, I’ll probably eat a lot of pizza.

Now, on to the marmots!

If you live in North America, you may have seen a marmot without realizing it. I didn’t realize that the groundhogs that are pretty common where I live in the eastern United States are a type of marmot. Similarly, if you live in the western part of North America, especially in mountainous areas, you may have seen the yellow-bellied marmot. Other species of marmot live in Asia, Europe, and other parts of North America. One interesting thing is that the groundhog of eastern North America is actually more closely related to the marmots of Europe and Asia than it is to the other North American marmot species.

Marmots are big rodents related to squirrels, and in fact they’re considered a type of ground squirrel along with the closely related chipmunks and prairie dogs. They dig burrows and mostly eat plant material, and can grow quite large. The largest species is probably the Olympic marmot that only lives in the state of Washington in the Pacific Northwest of North America, which can weigh up to 18 lbs, or 8 kg. That’s its summer weight, though, when it’s had time to eat lots of food. All marmots hibernate and during that time they survive on the fat reserves they build up in warm weather. Basically all marmots are about the size of a cat, but they’re big chonks with short legs, short tails, little round ears, and a blunt muzzle. Its thick fur makes it look even larger than it really is.

The yellow-bellied marmot mostly lives in higher elevations and, like all marmots, it’s well adapted to cold weather. It’s a social animal that lives in small colonies and spends most of its time underground when it’s not out finding food. It’s mostly brown with yellowish markings underneath and a spot of white between its eyes. It usually digs its burrow among rocks and can have multiple burrows in its territory, so if it spots a predator it doesn’t have far to run to get safely underground. It digs an especially deep burrow to hibernate in, sometimes as much as 23 feet deep, or 7 meters. Since it spends as much as eight months hibernating every year, it needs to stay comfortable. It lines its sleeping chamber with dried leaves and even digs a little side burrow that acts as a latrine.

In a study released in March of 2022, a team of scientists studying yellow-bellied marmots discovered that when it hibernates, an adult marmot’s body basically stops aging. The marmot exhibits true hibernation where its body temperature drops almost to the air temperature and its breathing and heart rate slow dramatically. It will hibernate for a week or two, wake up slightly for about a day so it can stretch and rearrange itself more comfortably, and then will go back into hibernation for another few weeks. This goes on for almost three-quarters of the year and during that time, the yellow-bellied marmot doesn’t eat or drink anything. It just lives off its fat reserves, and because its metabolic rate is so low it hardly uses any energy on any given day, only burning about a gram of fat. A small paperclip weighs about a gram, to give you a comparison. As a side effect, the marmot basically only ages during the summer when it’s active. The scientists think this may be the case for all animals that hibernate.

Like other marmots, the yellow-bellied marmot starts its mating season as soon as it emerges from hibernation around May. Males may have several mates and they all live together with him. Females give birth to around four babies during the summer, which like kittens and puppies are born without fur and with their eyes still sealed shut. They stay in the mother’s nesting burrow for the next six weeks, at which point they can see and have grown fur, so they can go outside with their mother. The babies stay with their mother for up to two years.

Most marmot species are social like the yellow-bellied marmot, but the groundhog is different. It’s mostly solitary, although it’s still part of a complex social network of all the groundhogs in a particular area, and sometimes it will share a burrow with other groundhogs. It also prefers lower elevations while most marmots prefer high elevations. It lives throughout most of the eastern United States and throughout much of Canada.

Because the marmot is a relatively big, common animal, it’s an important food source for many animals. Bears will sniff out marmot burrows and dig them open, and badgers, foxes, coyotes, and mountain lions eat lots of marmots in North America. In Europe and Asia, marmots are frequently eaten by foxes, wolves, snow leopards, and hawks. People will eat them too. In parts of Mongolia where marmots are common, it’s been a food source for thousands of years, traditionally prepared on special occasions by putting hot stones into the dead animal’s body cavity and letting the heat cook the meat slowly. But the marmot can carry diseases that humans can catch, including the plague, so these days a dead goat is often used instead of a marmot.

After I learned this, I naturally got distracted and started reading about other traditional Mongolian foods, and now I suddenly remember that I haven’t eaten anything today but trail mix and toast. So I’ll leave you with a final marmot fact. When a marmot sees a predator, it will whistle to warn other marmots, and the whistle sounds like this:

[marmot whistle]

Now I’m going to go make myself dinner. But it won’t be marmot.

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