Episode 219: The Strange and Mysterious Tarsier



Thanks to Phoebe for suggesting the tarsier, this week’s strange and interesting primate!

Further Reading:

Decoding of tarsier genome reveals ties to humans

Long-lost ‘Furby-like’ Primate Discovered in Indonesia

Tarsiers look like weird alien babies:

A tarsier nomming on a lizard:

A tarsier nomming on an insect:

The pygmy tarsier and someone’s thumb:

There’s probably not much going on in that little brain:

Show Transcript:

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

This week we’re looking at a weird and amazing little primate, but it’s not a monkey or ape. It’s the tarsier, with thanks to Phoebe who suggested it. It’s pronounced tarsiAY or tarsiER and both are correct.

The tarsier is such a little mess that until relatively recently scientists weren’t even completely certain it was a primate. A 2016 genetic study determined for sure that it is indeed a primate even though it differs in many ways from all other primates alive. For instance, it’s a carnivore. Most primates are herbivores and some are omnivores, including humans and chimpanzees, but only the tarsier is an obligate carnivore. That means it has to eat meat and only meat, whether it’s invertebrates, birds, reptiles, or small mammals like rodents.

Scientists divide primates into two groups informally, into wet-noses and dry-noses. Wet-nose doesn’t refer to a nose that’s runny but to a nose that stays moist, like a dog’s nose. This splits along the same lines as simians and prosimians, another way to group primates. Humans and other apes, along with monkeys, are simians, and also dry-noses. If you’re not sure if that’s accurate, just touch the end of your nose. Make sure you’re not standing in the rain or just got out of the bathtub, though. All other primates are wet-noses, and also prosimians, except for the tarsier. The tarsier is sort of in between. It’s grouped with the wet-nose primates, but it turns out to be more closely related to the dry-nose primates than the wet-noses. Also, its nose is actually dry.

One interesting difference between prosimians and simians concerns vitamin C. Vitamin C is found in a lot of foods, but especially in fruit and vegetables. If you don’t have any vitamin C in your diet, you will eventually die of scurvy like an old pirate, so make sure to eat plenty of fruit and vegetables. But most animals don’t need to eat foods containing vitamin C because their bodies already produce the vitamin C they need. Humans, apes, and monkeys have to worry about scurvy but prosimians don’t. But the tarsier does need vitamin C even though it’s a prosimian. A lot of researchers think the tarsier should be grouped with the simians, not prosimians.

The tarsier currently lives only in southeast Asia, mostly on forested islands, although tarsier fossils have been found throughout Asia, Europe, and North America. Genetic studies also indicate it probably started evolving separately from other primates around 55 million years ago in what is now China.

As it happens, we have a fossil that appears to be an early ancestor of the tarsier. Archicebus achilles was discovered in 2003 and studied for an entire decade before it was described in 2013, and it lived about 55 million years ago in what is now central China. It looks a lot like a tiny tarsier, but with smaller eyes that suggest it was active during the day. Its feet were shaped like a monkey’s, though, not like a tarsier’s feet. It probably only weighed about an ounce, or 28 grams. That’s about the same weight as a pencil. It had sharp little teeth and probably ate insects. So far the 2003 specimen is the only one found, but it’s remarkably complete so researchers have been able to learn a lot about it. If I’d been one of the scientists studying it, there is no way I could have waited ten whole years to tell people about it. I’d have studied it for like six months and then thought, “Okay, good enough, HEY EVERYONE LET ME TELL YOU ABOUT THIS COOL ANIMAL.”

The tarsier is nocturnal and has enormous eyes to help it see better in the dark. Its eyes are so big and round, and frankly the tarsier is not the brainiest animal, that its eyes are actually bigger than its brain. The tarsier also has mouse-like ears, long fingers and toes with sucker-like discs at the end to help it grip branches, and an extremely long tail that’s scaly on the underside. It spends almost its whole life in trees, where it climbs and jumps from branch to branch. When it climbs up a tree, it presses its long tail against the trunk to help it balance.

It’s not a big animal, though. A typical tarsier measures about six inches long, or 15 cm, from the top of its little round head to the bottom of its bottom, not counting its tail. Its tail can be almost a foot long, or 25 cm, though, and its hind legs are also extremely long, about as long as the tail. Its body is rounded with short plush fur, usually brown, gray, or dark gold in color.

With its big eyes and chonky body, if you wrapped up a tarsier in a little robe so you can’t see how small its ears are and how long its legs and tail and fingers are, it would kind of look like a miniature baby Yoda guy from that Mandalorian TV show. Someone please do that. Also, it kind of looks like a cute and furry Gollum from the Lord of the Rings movies.

Unlike other primates, the tarsier can turn its head 180 degrees in both directions. Basically it can turn its head like an owl. This is helpful because its eyes are so big it can’t move them. It can only look straight ahead, so it needs to be able to move its head all around instead. This is actually the same for the owl, too.

The tarsier mostly eats insects, but it will eat anything it can catch, including venomous snakes. It doesn’t just eat the meat, though. It eats just about everything, including bones. It has a wide mouth and strong jaws and teeth, and it’s so agile that it’s been observed to jump up and catch a bird as it flies past. Current speculation is that the tarsier gets enough vitamin C from the insects it eats that it doesn’t need to eat fruit, but no one knows for sure yet. Some species of bat can’t synthesize vitamin C in the body and have to get it from their diet, which is made up of insects.

We talked about the tarsier a little in episode 43, about the Chinese ink monkey, and also way back in episode eight, the strange recordings episode, because the tarsier can communicate in infrasound—sounds too high for humans to hear. It has incredibly acute hearing and often hunts by sound alone. Researchers speculate that not only can the tarsier avoid predators by making sounds higher than they can hear, it can also hear many insects that also communicate in infrasound. As an example of how incredibly high-pitched their voices are, the highest sounds humans can hear are measured at 20 kilohertz. The tarsier can make sounds around 70 kh and can hear sounds up to 91 kh.

The tarsier also makes sounds humans can hear. Here’s some audio of a spectral tarsier from Indonesia:

[tarsier sound]

Some species of tarsier are social, some are more solitary. All are shy, though, and they don’t do well in captivity. Unfortunately, because the tarsier is so small and cute and weird-looking, some people want to keep them as pets even though they almost always die quite soon. As a result, not only is the tarsier threatened by habitat loss, it’s also threatened by being captured for the illegal pet trade. Fortunately, conservation efforts are underway to protect the tarsier within large tracts of its natural habitat, which is also beneficial for other animals and plants.

The smallest species is the pygmy tarsier, which is only found in central Sulawesi in Indonesia, in high elevations. It’s four inches long, or 10.5 cm, from head to butt. You measure tarsiers like you measure frogs. It’s basically the size of a mouse but with a really long tail and long legs and big huge round eyes and teeny ears and a taste for the flesh of mortals. Or, rather, insects, since that’s mostly what it eats.

For almost a century people thought the pygmy tarsier was extinct. No one had seen one since 1921. Then in 2000, scientists trapping rats in Indonesia caught a pygmy tarsier. Imagine their surprise! Also, they accidentally killed it so I bet they felt horrible but also elated. It wasn’t until 2008 that some live pygmy tarsiers were spotted by a team of scientists who went looking specifically for them. This wasn’t easy since tarsiers are nocturnal, so they had to hunt for them at night, and because the wet, foggy mountains where the pygmy tarsier lives are really hard for humans to navigate safely. It took the team two months, but they managed to capture three of the tarsiers long enough to put little radio collars on them to track their movements.

One of the things Phoebe wanted to know about tarsiers is if there are any cryptids or mysteries associated with them. You’d think there would be, if only because the tarsier is kind of a creepy-cute animal, but I only managed to find one kinda-sorta tarsier-related cryptid.

According to a 1932 book called Myths and Legends of the Australian Aboriginals, a little red goblin creature lives in trees in some parts of Australia, especially the wild fig tree. It’s called the yara-ma-yha-who and it looks sort of like a frog but sort of like a monitor lizard. It’s bright red and stands around four feet tall, or 1.2 meters, with skinny arms and legs. The ends of its fingers and toes are cup-shaped suckers. Its head is large with a wide frog mouth and no teeth.

When a person comes along, the yara-ma-yha-who drops down from its tree and grabs them by the arm. It uses the suckers on its fingers and toes to drain blood from their arm, then swallows the person whole. Then later it horks them back up, but they’re smaller than before and their skin is starting to turn red. Eventually the person turns into a yara-ma-yha-who, unless they manage to escape in time.

Some cryptozoologists speculate that the yara-ma-yha-who may be based on the tarsier. The tarsier has never lived in Australia, but it does live in relatively nearby islands. Most tarsier species do have toe pads that help them cling to branches, but frogs also have toe pads and frogs are found in Australia. Likewise, by no stretch of the imagination is the tarsier bright red, four feet tall, toothless, or active in the daytime. It’s more likely the legend of the yara-ma-yha-who is inspired by frogs, snakes, monitor lizards, and other Australian animals, not the tarsier. But just to be on the safe side, if you live in Australia you might want to walk around wild fig trees instead of under them.

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 that way.

Thanks for listening!


Episode 218: More Unusual Hoofed Animals



So many interesting hoofed animals in this episode, so many awesome suggestions! Thanks to Page, Elaine, Pranav, Richard E., Richard from NC, and Llewelly!

Further Reading:

Meet the Takin: The Largest Mammal You’ve Never Heard Of

New hope for the elusive okapi, the Congo’s mini giraffe

The Resurrection of the Arabian Oryx

Eucladoceros was not messing around with those antlers:

Megaloceros and Thranduil’s elk in the Hobbit movies. COINCIDENCE?

The stag-moose. What can I say? This thing is AWESOME:

Hoplitomeryx. Can you have too many horns? No, no you cannot:

The gerenuk, still beautiful but freaky-looking:

The golden takin looking beautiful [pic from the article linked above]:

The elusive okapi:

Okapi bums [pic from the article linked above]:

The giraffe being really tall and a baby giraffe being somewhat less tall:

A giraffe exhibiting dwarfism but honestly, he is still plenty tall:

The Arabian oryx is just extra:

The weird, weird tusks of the babirusa. Look closely:

Show Transcript:

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

Back in episode 116, we talked about some amazing hoofed animals. This week we’re going to look at some more amazing hoofed animals that you may have never heard about. Some are extinct but some are running around out there looking awesome even as we speak! Thanks to Page, Elaine, Pranav, Richard E., Richard from NC, and Llewelly for their suggestions! If you’re a Patreon subscriber you may recognize part of the end of the episode as largely from a Patreon episode, by the way.

Let’s start with an extinct deer with amazing antlers. Llewelly suggested it, or more accurately replied to a Twitter conversation mentioning it. That counts as a suggestion. It’s been a while but I think the conversation was about the Hobbit movies.

Eucladoceros was a deer the size of a moose but with much weirder antlers. We’re not talking about the Megaloceros, often called the Irish elk, although it was distantly related. Eucladoceros’s antlers were much different. They branched up and out but were spiky like an ordinary deer’s antlers instead of palmate like a moose’s or Megaloceros’s antlers. But they were seriously big, with up to twelve points each and over five and a half feet across, or 1.7 meters. The deer itself stood just under 6 feet tall at the shoulder, or 1.8 meters. It’s often called the bush-antlered deer because the antler’s many points look like the branches of a bush.

Eucladoceros lived in Eurasia but we’re not completely sure when it went extinct or why. We don’t really know that much about it at all, in fact, which is surprising because it was such a big animal. It was one of the earliest deer with branching antlers and it probably went extinct before humans encountered it, but we don’t know that for sure either.

Another deer relation is a gigantic animal called the stag moose that lived at the very end of the Pleistocene, or ice age, until around 13,000 years ago. It probably looked a lot like a huge, muscular deer more than a moose, but had moose-like antlers that grew up to 6 1/2 feet across, or 2 meters. The animal itself stood almost six feet tall at the shoulder, or 1.8 m, which is about the size of the modern moose. It lived in northern North America until melting glaciers allowed other animals to migrate into the area, and the modern moose outcompeted its cousin.

Early deer and deer relations looked a lot different from the deer we’re familiar with today. For instance, Hoplitomeryx. It was a ruminant and therefore related to modern deer, but while it probably looked a lot like a deer, it didn’t have antlers. It had horns. Antlers grow every year from the skull and the animal sheds them later, usually after breeding season. Horns are permanent, usually made of a bony core with a keratin sheath over it.

Hoplitomeryx lived around 11 to 5 million years ago in one small area of Europe. Specifically, it lived on a large island near what is now Italy, although the island is now part of a little peninsula. It probably also lived on other, smaller islands nearby. While some specimens found are quite small, probably due to island dwarfism, some grew as big as the bush-antlered deer, over 5 ½ feet tall, or 1.7 meters.

It had a pair of horns that were shaped like a modern goat’s, that grew from the top of its head and curved backwards. And it had a smaller pair of horns underneath those horns that grew outward. And it had a single horn that was about the same size or bigger and shaped the same as the goat-like horns, but which grew in the middle of the forehead like a really weird unicorn. Also, it had fangs. I am not making this up. It’s sometimes called the five-horned deer for obvious reasons.

We also don’t know much about Hoplitomeryx except that it was really awesome, so let’s move on to our next strange hoofed animal. This one is a suggestion by Page, who wanted to know more about the gerenuk. We talked about it in episode 167 but it’s such an interesting animal that there’s more to learn about it.

The gerenuk is an antelope that lives in East Africa. It’s considered a type of gazelle, although it’s not very closely related to other gazelles. It’s slender with long legs and a long neck, and stands about three feet tall at the shoulder, or 105 cm. The male has a pair of S-shaped, ridged black horns that can grow up to 18 inches long, or 45 cm, while the female doesn’t have horns at all. It’s reddish-brown with a pale belly and a pale stripe down its sides, a short tail, and a white patch around each eye. But as we talked about in episode 167, its legs are extremely thin—so thin that they look like sticks, especially the front legs.

The gerenuk is the only type of antelope that can stand on its hind legs, which it does all the time. It will even use its front legs to pull branches down closer to its mouth while standing on its hind legs. As a result, even though it’s not very big, it can reach leaves that other antelopes can’t. Not only does this mean it can find food where other antelopes can’t, it also means it doesn’t need very much water because it can reach tender leaves with a higher moisture content.

Like many gazelles, the gerenuk marks its territory with scent glands. It has scent glands on its knees, covered with tufts of hair, and scent glands in front of its eyes. So if you see a gerenuk rubbing its knees or face on a branch, that’s why.

Our next hoofed animal is the golden takin, which looks kind of like a musk ox except that it has pale golden fur. But it isn’t a musk ox although it is in the family Bovidae. It’s actually most closely related to sheep but is sometimes referred to as a goat-antelope. It does resemble the mountain goat in some respects, which makes sense because it lives in the Himalayan Mountains in China. As a result, it has a lot of adaptations to intense cold.

It has a thick coat that grows even thicker in winter, with a soft, dense undercoat to trap heat next to the body. It also has large sinus cavities that warm the air it breathes before it reaches the lungs, which means it has a big snoot. Its skin is oily, which acts as a water repellent during rain and snowstorms. In spring it migrates to high elevations, but when winter starts it migrates back down to lower elevations where it’s not quite as cold.

Like the gerenuk, the golden takin will stand on its hind legs to reach leaves, but it has to balance its front legs against something to stay upright. It will eat just about any plant material it can reach, including tree bark, tough evergreen leaves, and bamboo. Yes, bamboo. It sometimes shares the same bamboo forests where pandas live. The golden takin is a strong animal that will sometimes push over small trees so it can eat the leaves. It visits salt licks regularly, and some researchers think it needs the minerals available at salt licks to help neutralize the toxins found in many plants it eats.

Both male and female golden takins have horns, which grow sideways and back from the forehead in a crescent and can be almost three feet long, or 90 cm. It has a compact, muscular build and can stand over four feet tall at its humped shoulder, or around 1.4 m. Baby golden takins are born with dark gold-brown fur that helps camouflage it, but as it ages, it fur grows more and more pale gold. A full-grown golden takin is big enough and strong enough that it doesn’t have many predators. If a bear or wolf threatens it, it can run fast if it needs to or hide in dense underbrush.

Next, let’s learn about an animal requested by both Elaine and Pranav. In the 19th century and earlier, Europeans exploring central Africa kept hearing about an elusive animal that lived deep in the remote forests. It was supposed to be a kind of donkey or zebra, but it was so little-known that some Europeans started calling it the African unicorn because they didn’t even think it existed.

In 1899, a British man named Harry Johnston decided to get to the bottom of the African unicorn mystery. When he asked the Pygmy people about it, they knew exactly what he was talking about and showed him some hoof prints. Like most Europeans at the time, Johnston thought the African unicorn was a zebra, so he was surprised to learn that it had cloven hooves.

The Pygmy people also gave Johnston some strips of skin from the animal, and later he bought two skulls and a complete skin. He sent these to England where the animal was identified as a giraffe relation. It was named Okapia johnstoni, and is known by the name okapi.

The okapi’s discovery by science was as astounding in its way as the coelacanth’s discovery a few decades later. Until it was described in 1901, scientists thought all the giraffe relations had died out long ago. Paleontologists had found fossils that showed how the giraffe evolved from a more antelope-like animal, and suddenly there was a living animal with those same features. It was mind-blowing!

The okapi is the giraffe’s closest living relation, but it doesn’t look much like a giraffe. For one thing, it’s not quite five feet tall at the shoulder, or 1.5 meters, and while it does have a long neck, it’s nothing like as long as a giraffe’s. It looks more like an antelope than a giraffe, at least at first glance. It’s dark reddish-brown with pale gray markings on its face, and its lower legs are white and its rump and upper legs are striped black and white. It also has a tail with a tuft at the end like a giraffe’s. Females are usually larger than males.

The male okapi has a pair of ossicones on his head, but they’re not very long compared to giraffe ossicones. As you may remember, an ossicone is a bony projection from the skull that’s covered with skin and hair. The female has little forehead bumps instead of actual ossicones.

The okapi lives in rainforests in central Africa and is a solitary animal. It has a long tongue like a giraffe which it uses to grab leaves. Its tongue is almost as long as the giraffe’s, up to 18 inches long, or 46 cm, whereas the giraffe’s tongue is 20 inches long, or 56 cm. A female okapi has one calf every two years or so, and in the first month of life, the calf doesn’t defecate at all. Not a single baby okapi poop. Some babies may hold it until they’re ten weeks old. Scientists aren’t sure if this same behavior is found in the wild, since okapis are hard to observe in the wild and most behavioral observations come from captive animals, but the hypothesis is that by not defecating, the baby is less likely to attract the attention of leopards who would smell the poops.

For a long time scientists thought the okapi didn’t make any sounds at all, just some whistles and chuffing sounds. It turns out, though, that a mother okapi communicates with her baby with infrasound, which is below the range of human hearing.

Speaking of giraffes, in March of 2021 a study of the giraffe genome was published, focusing on the giraffe’s adaptations for growing so extremely tall. One interesting discovery is that the giraffe has very little sense of smell although it has excellent eyesight. This makes sense considering that the giraffe’s head is so far above the ground. Most scents left by predators will be on or close to the ground, not high up in the air. The giraffe also doesn’t sleep very much and it shows a lot of genetic adaptations for extremely high blood pressure. It needs that high blood pressure to push blood up its long neck to its brain. Researchers are especially interested in the genetics of blood pressure, since high blood pressure in humans is a serious problem that can lead to all sorts of medical issues.

We’ve talked about giraffes before, especially in episode 50, about the tallest animals. Giraffes have extremely long necks and legs and a big male can stand 19.3 feet high, or 5.88 m, measured at the top of his head. Even a short giraffe is over 14 feet tall, or 4.3 meters. To put that into perspective, the average height of a ceiling in an average home is 8 or 9 feet high, or just over 2.5 meters. This means a giraffe could look into an upstairs window to see if you have any giraffe treats, and not only would it not need to stretch to see in, it would probably need to lower its head.

But in 2015, a team of biologists surveying the animals in the Murchison Falls National Park in Uganda, which is in eastern Africa, noticed a male giraffe that had much shorter legs than usual. They nicknamed him Gimli after one of the dwarf characters from Lord of the Rings, and estimated his height as just over nine feet tall, or about 2.8 meters. Gimli would not be able to peek into an upstairs window, but he was still a fully grown giraffe.

Since dwarfism affects the length of an animal’s limbs, it was obvious that Gimli was actually a dwarf giraffe, the first ever documented.

Then, in 2018, a different team of scientists found a different giraffe in a different place, Namibia in southwest Africa, who was fully grown but also had short legs. He was also a male, nicknamed Nigel, and was hanging around with some other giraffes on a private farm. The farmer had seen Nigel plenty of times over several years. Nigel’s height was estimated at 8 ½ feet tall, or 2.6 meters.

In animals, dwarfism can result from inbreeding, which is sometimes done on purpose by humans trying to breed cute pets. It also just sometimes happens, a random mutation that affects growth hormones. In the wild, an animal with unusually short legs usually doesn’t live very long. Either it can’t run fast enough to escape a predator or it can’t run fast enough to catch prey. Both Gimli and Nigel appear healthy, though, and even a short giraffe is still a large animal that can kick and run pretty fast.

Next, Richard from North Carolina suggested the Arabian oryx, and it is a beautiful and amazing hoofed animal. It’s a large antelope and used to live throughout the Middle East, but by the 1930s, habitat loss and hunting had restricted it to the desert in northwestern Saudi Arabia. Then oil company employees and Arabian princes both discovered the fun that is to be had when you have a car and a machine gun and can just drive around shooting everything you see. Such fun, driving animals to extinction, I’m being sarcastic of course. The last few Arabian oryx survived to 1972, but they were effectively extinct decades before then.

But. Zoos to the rescue. The Arabian oryx is a beautiful animal that does well in captivity, so lots of zoos had them on display. In 1960 conservationists realized they had to act fast if the oryx wasn’t going to go extinct completely, and they started a captive-breeding project called Operation Oryx at the Phoenix Zoo in Arizona, which is in the southwestern United States. They managed to capture three of the remaining wild animals and added to the herd with captive-bred oryxes donated by other zoos.

Operation Oryx was such a success that in only twenty years they were able to reintroduce oryx into the wild. Currently there are an estimated 1,200 oryxes in the wild with another 7,000 or so in zoos and conservation centers around the world. It’s still vulnerable, but it’s not extinct.

The oryx is white with dark brown or black markings, including dark legs and a pair of long, straight, slender black horns. Both males and females have these horns, which can grow up to two and a half feet long, or 75 cm. Since the oryx itself only stands a little over three feet high at the shoulder, or 1 meter, the horns are sometimes longer than the animal is tall. The oryx lives in small herds of mixed males and females, which travel widely in their desert habitat to find food and water. During the hot part of the day, the oryx digs a shallow nest under a tree or bush to lie in. It also has a short tufted tail. I just noticed the tail in a picture I’m looking at. It’s so cute.

In the last weird hoofed animals episode, we ended with a pig relation, so we’re going to end this episode with a pig relation too. Richard E. suggested the babirusa, and you definitely need to know about this weird piggy.

The babirusa is native to four islands in Indonesia. It’s related to pigs, but researchers think it split off from other pigs early on because of how different it is. Females have only one pair of teats, for instance, and usually only one piglet is born at a time, sometimes two. Females make a nest of branches to give birth in.

The babirusa also lacks the little bone in the snout that helps most pig species root. The babirusa only roots in very soft mud, but sometimes it digs for roots with its hooves. It eats plants of all kinds, including cracking nuts with its strong jaws, and will eat insect larvae, fruit, mushrooms, and even occasionally fish and small animals when it can catch them. Unlike most pigs, the babirusa is good at standing on its hind legs to reach branches, much like deer, which is why it’s sometimes called the deer-pig. Its stomach is more like a sheep’s than a pig’s, with two sacs that help it digest fibrous plant material, and it has relatively long, slender legs compared to most pigs.

Most pigs have tusks of some kind, but the babirusa’s are really weird. At first glance they’re just surprisingly long tusks that curve up and back, but when you look closer, you see that the upper pair actually grows up through the top of the snout.

The babirusa boar has two pairs of tusks, which are overgrown canine teeth. The lower pair jut out from the mouth the way most pig tusks do. The upper pair are the weird ones. Before a male babirusa is born, the tooth sockets for its upper canines are normal, but gradually they twist around and the teeth grow upward instead of down. They grow right up through the snout, piercing the skin, and then continue to grow up to 17 inches long, or 43 cm, curving backwards toward the head. In at least one case, a tusk has grown so long it’s actually pierced the boar’s skull.

For a long time researchers assumed males used their tusks to fight, but males fight by rearing on their hind legs and kicking each other with their forehooves. Then researchers decided the tusks were actually for defense during fights, to keep a boar from getting its face kicked. But the tusks aren’t actually very strong and don’t appear to be used for much of anything. Most likely, it’s just a display for females.

The babirusa does well in captivity, even becoming quite tame. Many zoos keep them, which is a good thing because they’re becoming more and more endangered as their island habitats are taken over by farming and development.

So that’s it for the second episode about strange hoofed animals. I guarantee you that we’re going to have a third because there are so many.

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 that way.

Thanks for listening!


Episode 217: Three (Small) Mystery Animals



This week we’re going to look at three small mystery animals! Well, the mysteries are small. The animals are not particularly small.

Further Reading:

Long-Extinct Gibbon Found Inside Tomb of Chinese Emperor’s Grandmother

Ancient Egypt’s Mona Lisa? An elaborately drawn extinct goose, of course

A case of mistaken identity for Australia’s extinct big bird

Bones of a mystery gibbon found in a noblewoman’s tomb:

Gibbons painted about a thousand years ago by artist Yi Yuanji:

A couple of gibbons at MAX FLUFF:

The mystery goose painting (left) compared with a modern version of the painting (middle) and a red-breasted goose (right):

All the geese from the painting:

A red-breasted goose, not historically known from Egypt:

The mystery bird rock art:

An emu (with babies):

Genyornis compared to a human:

Genyornis leg bones compared to emu leg bones (right), but on left is a comparison of a so-called Genyornis (actually not) egg and an emu egg:

A couple of megapodes in their egg field:

Show transcript:

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

We’re long overdue for an episode about a mystery animal, so this week let’s look at not one, not two, but three mysteries! They’re all small scientific mysteries, not big spooky ones, but I think you’ll find them interesting.

We’ll start at an archaeological dig in China. In 2004, archaeologists excavated a noblewoman’s tomb in northwestern China, which they dated to about 2,200 to 2,300 years old. The tomb might have been for a woman called Lady Xia, who was the grandmother of the first emperor of China. So, kind of a big deal.

The archaeologists discovered twelve pits in the tomb, and each pit contained the skeletons of various animals, some of them domesticated animals but some of them wild. Having a private menagerie was a status symbol back then, as it sometimes has been in other cultures around the world. In pit #12, they found remains of a leopard, a black bear, a crane, a lynx, and a type of small ape called a gibbon.

The gibbon remains were a surprise, because today all species of gibbon in China live only in the very southern areas and are critically endangered by habitat loss and hunting. Either a gibbon had been transported hundreds of miles over difficult terrain 2,300 years ago, or gibbons lived in the area.

Gibbons are small apes and there are 16 species alive today. They all live in southern Asia. We talked about the siamang in episode 76, and the siamang is a type of gibbon. Many gibbons, including the siamang, have inflatable resonant chambers in the throat to amplify their calls, but all gibbons make loud, often musical sounds to communicate with each other. They spend most of the time in treetops and mostly eat fruit, along with other plant material.

Because this part of northwestern China is subtropical, and because it’s been so long since the animals died, the skeletons aren’t complete. The only gibbon bones left were part of a cranium and mandible. Obviously, scientists had to be careful with the bones and couldn’t run any tests that might damage them. They made a 3D scan of the bones and used the scan to compare the gibbon’s skull and jaw with those of living species of gibbon, to determine what species it was.

It turned out that not only was it a species unknown to science, it was different enough from other gibbons that it belonged in its own genus.

According to experts in Chinese history and literature, gibbons were considered noble animals that often appeared in paintings and poetry. Various species of gibbon lived throughout much of China until around the 14th century. After the 14th century, though, habitat loss and hunting drove the gibbons farther south until now there are almost no gibbons left in China. Lady Xia’s pet gibbon is the first species known that definitely went extinct in the modern era, which makes it even more important that the gibbons still alive today are protected along with their habitats.

Speaking of ancient paintings of animals, 4,600 years ago, an artist made a painting of some geese for a tomb in Egypt. The painting is five feet long, or 1.5 meters, and is a fragment of a larger wall decoration that has been lost. It’s called the “Meidum Geese.” It’s a lovely painting and the geese are incredibly lifelike—so lifelike, in fact, that it should be easy to identify them.

But maybe not quite so easy after all.

There are three species of geese in the painting. Two are probably the graylag goose and the greater white-fronted goose. The third looks similar to the red-breasted goose, but there are enough differences that researchers aren’t sure. No red-breasted goose remains have ever been found in Egypt; it only lives in Europe and Asia.

It’s quite likely that the mystery goose is an extinct species. Other animal species depicted in Egyptian art are extinct now, even though they were common when the art was made. Egypt’s climate is much dryer than it was thousands of years ago, so naturally there were different animals back then even if you don’t factor in human activity like hunting.

The painting was discovered in 1871. One Italian archaeologist named Francesco Tiradritti claims it’s a hoax, painted by one of the curators at the Cairo Museum back when it was first found. One of the reasons he thinks it’s a hoax is that the red-breasted goose isn’t known in Egypt. This isn’t a very good argument to me. First of all, the goose doesn’t exactly match the red-breasted goose, while a hoaxer would probably work from a model or a picture to get the details right. Second of all, a hoaxer would probably have been careful to only include goose species that are known to live in Egypt. Tiradritti’s argument basically seems to be that the Meidum geese are too good and therefore could only possibly be painted by someone who had trained in Italy. In reality, though, ancient people of all cultures were perfectly capable of being masterful artists even though they were not European.

Other experts have rebutted Tiradritti’s claim and point out that he’s not an art historian and that many actual art historians have studied the Meidum geese and declared them genuine. Not only that, but scenes carved in other tombs seem to depict the same types of geese that are in the painting.

Speaking of geese and artwork, let’s move on to our final mystery animal. This one’s complicated, because it’s not just one mystery, it’s two.

Ancient artwork sometimes gives scientists useful information about when and where an animal lived and what it looked like. Sometimes, though, the artwork reveals more mysteries than it solves. For instance, some rock art found in Australia’s Northern Territory.

The art depicts two birds with long goose-like necks, drawn with a pigment called red ochre. It’s sort of a rusty color. The birds have legs that are about as long as the neck, and small heads with short, blunt bills.

At first the archaeologists studying the site thought the art depicted emus. Then they took a closer look and realized the details were wrong for emus, but they did match a different bird. Genyornis newtoni was distantly related to modern ducks and geese, but was flightless and really big. It stood seven feet tall, or over two meters. It had strong but relatively short legs, a goose-like neck, tiny wings, and a short, blunt bill. It probably ate fruit and small animals.

The finding excited the palaeontologists, because Genyornis was supposed to have gone extinct around 45,000 years ago. That meant that if the art really did depict the bird, the art had to be that old too.

The reason that researchers dated the extinction of Genyornis to about 45,000 years ago is because that’s when its eggshells stop being found, even though until then they were fairly common in ancient sand dunes.

But something didn’t add up. Genyornis was a little taller but six times heavier than the emu, but its eggs were no larger than an emu’s egg. A 2016 study suggested that the eggshells identified as Genyornis eggs were actually from a completely different bird, specifically a type of megapode.

Megapodes are birds that live in Australia and some nearby islands, including New Guinea. In fact, I think we’ll learn about some megapodes in an upcoming episode about more weird New Guinea birds. One interesting thing about megapodes is the way they incubate their eggs. Instead of keeping the eggs warm by sitting on them, megapodes build nest mounds. Most make a big mound of leaves and other vegetation, because as vegetation decays, it releases heat. The female lays her eggs on the mound and the male guards and tends the eggs, placing more leaves over them as needed or sometimes removing it to keep the eggs from getting too hot. Other megapodes lay their eggs in warm sand or even in volcanic areas where the ground stays warm. In other words, it makes sense that lots of these old eggshells would be found in what were once sand dunes, since the eggs were most likely buried in the sand to start with. Researchers think the sand dune eggs belonged to an extinct species of megapode called the giant malleefowl.

So that’s one mystery solved, but it leaves us with other mysteries. When did the Genyornis actually go extinct? How old is the rock art and does it really depict Genyornis?

Since its discovery around 2010, the so-called Genyornis rock art has been carefully studied. Geologists have determined the age of the rock face where the painting appears, and it’s not nearly as old as 45,000 years. Right about 13,800 years ago, a rock overhang collapsed, exposing a rock surface. Then some people came along and decided that rock surface would be the perfect place to paint two birds. So the painting can’t be any older than that.

A close analysis of the painting shows that there’s more than meets the eye, too. The initial painting was of a person with animal characteristics, called an anthropomorph, and at some point later someone painted the birds over it. The painting also contains the image of a barbed spear piercing one of the birds. So whatever the birds are, they were birds that people hunted.

Meanwhile, other experts were studying Genyornis. The current determination is that it went extinct around 25,000 or 30,000 years ago.

So we have rock art that cannot be older than a tad under 14,000 years old, but it appears to be art of a bird that went extinct at least 25,000 years ago. What’s going on?

It’s probable that Genyornis actually lived a lot more recently than 25,000 years ago. Scientists can only make determinations of when an animal went extinct by the fossils and subfossil remains they find or don’t find. There aren’t a lot of Genyornis fossils to start with, but the ones we do have mostly come from the same area where the rock art was found.

If the rock art really is of Genyornis, and it does seem to be, then people were most likely hunting Genyornis less than 14,000 years ago and possibly much more recently. Hopefully soon researchers will find more recent evidence so we can get a better idea of when it really went extinct and why.

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 216: Gentle Giant Sharks



Let’s learn about some of the biggest sharks in the sea–but not sharks that want to eat you!

Further reading:

‘Winged’ eagle shark soared through oceans 93 million years ago

Manta-like planktivorous sharks in Late Cretaceous oceans

Before giant plankton-eating sharks, there were giant plankton-eating sharks

An artist’s impression of the eagle shark (Aquilolamna milarcae):

Manta rays:

A manta ray with its mouth closed and cephalic fins rolled up:

Pseudomegachasma’s tooth sitting on someone’s thumbnail (left, photo by E.V. Popov) and a Megachasma (megamouth) tooth on someone’s fingers (right):

The megamouth shark. I wonder where its name came from?

The basking shark, also with a mega mouth:

The whale shark:

Leedsichthys problematicus (not a shark):

Show transcript:

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

This week we’re going to look at some huge, weird sharks, but they’re not what you may expect when you hear the word shark. Welcome to the strange world of giant filter feeders!

This episode is inspired by an article in the brand new issue of Science, which you may have heard about online. A new species of shark is described in that issue, called the eagle shark because of the shape of its pectoral fins. They’re long and slender like wings.

The fossil was discovered in 2012 in northeastern Mexico, but not by paleontologists. It came to light in a limestone quarry, where apparently a quarry worker found it. What happened to it at that point isn’t clear, but it was put up for sale. The problem is that Mexico naturally wants fossils found in Mexico to stay in Mexico, and the authors of the study are not Mexican. One of the authors has a history of shady dealings with fossil smugglers too. On the other hand, the fossil has made its way back to Mexico at last and will soon be on display at a new museum in Nuevo León.

Fossils from this quarry are often extremely well preserved, and the eagle shark is no exception. Sharks don’t fossilize well since a shark’s skeleton is made of cartilage except for its teeth, but not only is the eagle shark’s skeleton well preserved, we even have an impression of its soft tissue.

The eagle shark was just slightly shorter than 5 ½ feet long, or 1.65 meters. Its tail looks like an ordinary shark tail but that’s the only ordinary thing about it. The head is short and wide, without the long snout that most sharks have, it doesn’t appear to have dorsal or pelvic fins, and its pectoral fins, as I mentioned a minute ago, are really long. How long? From the tip of one pectoral fin to the other measures 6.2 feet, or 1.9 meters. That’s longer than the whole body.

Researchers think the eagle shark was a filter feeder. Its mouth would have been wide to engulf more water, which it then filtered through gill rakers or some other structure that separated tiny animals from the water. It expelled the water through its gills and swallowed the food.

The eagle shark would have been a relatively slow swimmer. It glided through the water, possibly flapping its long fins slowly in a method called suspension feeding, sometimes called underwater flight. If this makes you think of manta rays, you are exactly correct. The eagle shark occupied the same ecological niche that manta rays do today, and the similarities in body form are due to convergent evolution. Rays and sharks are closely related, but the eagle shark and the manta ray evolved suspension feeding separately. In fact, the eagle shark lived 93 million years ago, 30 million years before the first manta remains appear in the fossil record.

The eagle shark lived in the Western Interior Seaway, a shallow sea that stretched from what is now the Gulf of Mexico straight up through the middle of North America. Because it’s the only specimen found so far, we don’t know when it went extinct, but researchers suspect it died out 65 million years ago at the same time as the non-avian dinosaurs. We also don’t have any preserved teeth, which makes it hard to determine what sharks it was most closely related to. Hopefully more specimens will turn up soon.

Now that we’ve mentioned the manta ray, let’s talk about it briefly even though it’s not a shark. It is big, though, and it’s a filter feeder. If you’ve never seen one before, they’re hard to describe. If it had gone extinct before humans started looking at fossils scientifically, we’d be as astounded by it as we are about the eagle shark—maybe even moreso because it’s so much bigger. Its body is sort of diamond-shaped, with a blunt head and short tail, but elongated fins that are broad at the base but end in drawn-out points.

Manta rays are measured in width, sometimes called a wingspan since their long fins resemble wings that allow it to fly underwater. There are two species of manta ray, and even the smaller one has a wingspan of 18 feet, or 5.5 meters. The larger species can grow 23 feet across, or 7 meters. Some other rays are filter feeders too, all of them closely related to the manta.

The manta ray lives in warm oceans, where it eats zooplankton. Its mouth is wide and when it’s feeding it moves forward with its mouth open, letting water flow into the mouth and through the gills. Gill rakers collect tiny food, which the manta ray swallows. It has a pair of fins on either side of the mouth that are sometimes called horns, but which are properly called cephalic fins. Cephalic just means “on the head.” These fins help direct water into the mouth. When a manta ray isn’t feeding, it closes its mouth just like any other shark, folding its shallow jaw shut. For years I thought it closed its mouth by folding the cephalic fins over it, but that’s not the case, although it does roll the fins up into little points. The manta ray is mostly black with a white belly, but some individuals have white markings on the back and black speckles and splotches underneath. We talked about some mysteries associated with its coloring in episode 96.

The eagle shark isn’t the only filter feeding shark. The earliest known is Pseudomegachasma, the false megamouth, which lived around 100 million years ago. It was only described in 2015 after some tiny shark teeth were found in Russia. The teeth looked like those of the modern megamouth shark, although they’re probably not related. The teeth are only a few millimeters long but that’s the same size as teeth from the megamouth shark, and the megamouth grows 18 feet long, or 5.5 m.

Despite its size, the megamouth shark wasn’t discovered until 1976, and it was only found by complete chance. On November 15 of that year, a U.S. Navy research ship off the coast of Hawaii pulled up its sea anchors. Sea anchors aren’t like the anchors you may be thinking of, the big metal ones that drop to the ocean’s bottom to keep a ship stationary. A sea anchor is more like an underwater parachute for ships. It’s attached to the ship with a long rope on one end, and opens up just like a parachute underwater. The tip of the parachute has another rope attached with a float on top. When the navy ship brought up its sea anchors, an unlucky shark was tangled up in one of them. The shark was over 14 ½ feet long, or 4 ½ m, and didn’t look like any shark anyone had ever seen.

The shark was hauled on board and the navy consulted marine biologists around the country. No one knew what the shark was. It wasn’t just new to science, it was radically different from all other sharks known. Since then, only about 100 megamouth sharks have ever been sighted, so very little is known about it even now.

The megamouth is dark brown in color with a white belly, a wide head and body, and a large, wide mouth. The inside of its lower lip is a pale silvery color that reflects light, although researchers aren’t sure if it acts as a lure for the tiny plankton it eats, or if it’s a way for megamouths to identify each other. It’s sluggish and spends most of its time in deep water, although it comes closer to the surface at night.

The basking shark is even bigger than the megamouth. It can grow up to 36 feet long, or 11 meters. It’s so big it’s sometimes mistaken for the great white shark, but it has a humongous wide mouth and unusually long gill slits, and, of course, its teeth are teensy. It’s usually dark brown or black, white underneath, and while it spends a lot of its time feeding at the surface of the ocean, in cold weather it spends most of its time in deep water. In summer, basking sharks gather in small groups to breed, and sometimes will engage in slow, ponderous courtship dances that involve swimming in circles nose to tail.

But the biggest filter feeder shark alive today, and possibly alive ever, is the whale shark. It gets its name because it is literally as large as some whales. It can grow up to 62 feet long, or 18.8 meters, and potentially longer.

The whale shark is remarkably pretty. It’s dark gray with a white belly, and its body is covered with little white or pale gray spots that look like stars on a night sky. Its mouth is extremely large and wide, and its small eyes are low on the head and point downward. Not only can it retract its eyeballs into their sockets, the eyeballs actually have little armored denticles to protect them from damage. The body also has denticles, plus the whale shark’s skin is six inches thick, or 15 cm.

The whale shark lives in warm water and migrates long distances. It mostly feeds near the surface although it sometimes dives deeply to find plankton. It filters water differently from the megamouth and basking sharks, which use gill rakers. The whale shark has sieve-like filter pads instead. The whale shark doesn’t need to move to feed, either. It can gulp water into its mouth by opening and closing its jaws, unlike the other living filter feeders we’ve talked about so far.

We talked about the whale shark a lot in episode 87, if you want to know more about it.

All these sharks are completely harmless to humans, but unfortunately humans are dangerous to the sharks. Even though they’re all protected, they’re vulnerable to getting tangled in nets, killed by ships running over them, and killed by poachers.

One interesting thing about these three massive filter feeding sharks is their teeth. They all have tiny teeth, but the mystery is why they have teeth at all. Their teeth aren’t just tiny, they have a LOT of teeth, more than ordinary sharks do. It’s the same for the filter feeding rays. They have hundreds of teensy teeth that the animals don’t use for anything, as far as researchers can tell. One theory is that the babies may use their teeth before they’re born. All of the living filter feeders we’ve talked about, including manta rays, give birth to live pups instead of laying eggs. The eggs are retained in the mother’s body while they grow, and she can have numerous babies growing at different stages of development at the same time. The babies have to eat something while they’re developing, once the yolk in the egg is depleted, and unlike mammals, fish don’t nourish their babies through umbilical cords. Some researchers think the growing sharks eat the mother’s unfertilized eggs, and to do that they need teeth to grab hold of slippery eggs. That still doesn’t explain why adults retain the teeth and even replace them throughout their lives just like other sharks. Since all of the filter feeders have teeth although they’re not related, the teeth must confer some benefit.

So, why are these filter feeders so enormous? Many baleen whales are enormous too, and baleen whales are also filter feeders. Naturally, filter feeders need large mouths so they can take in more water and filter more food out of it. As a species evolves a larger mouth, it also evolves a larger body, and this has some useful side effects. A large animal retains heat even if it’s not actually warm-blooded. A giant fish can live comfortably in cold water as a result. Filter feeding also requires much less effort than chasing other animals, so a giant filter feeder has plenty of energy for a relatively low intake of food. And, of course, the larger an animal is, the fewer predators it has because there aren’t all that many giant predators. At a certain point, an adult giant animal literally has no predators. Nothing attacks an adult blue whale, not even the biggest shark living today. Even a really big great white shark isn’t going to bite a blue whale. The blue whale would just bump the shark out of the way and probably go, “HEY, STOP IT, THAT TICKLES.” The exception, of course, is humans, who used to kill blue whales, but you know what I mean.

Let’s finish with a filter feeder that isn’t a shark. It’s not even closely related to sharks. It’s a ray-finned fish that lived around 165 million years ago, Leedsichthys problematicus. Despite not being related to sharks and being a member of what are called bony fish, its skeleton is partially made of cartilage, so fossilized specimens are incomplete, which is why it was named problematicus. Because the fragmented fossils are a problem. I’m genuinely not making this up to crack a dad joke, that’s exactly why it got its name. One specimen is made up of 1,133 pieces, disarticulated. That means the pieces are all jumbled up. Worst puzzle ever. Remains of Leedsichthys have been found in Europe and South America.

As a result, we’re not completely sure how big Leedsichthys was. The most widely accepted length is 50 feet long, or 16 meters. If that’s anywhere near correct, it would make it the largest ray-finned fish that ever lived, as far as we know. It might have been much larger than that, though, possibly as long as 65 feet, or 20 meters.

Leedsichthys had a big head with a mouth that could open extremely wide, which shouldn’t surprise you. Its gills had gill rakers that it used to filter plankton from the water. And we’re coming back around to where we started, because like the eagle shark, Leedsichthys had long, narrow pectoral fins. Some palaeontologists think it had a pair of smaller pelvic fins right behind the pectoral fins instead of near the tail, but other palaeontologists think it had no pelvic fins at all. Because we don’t have a complete specimen, there’s still a lot we don’t know about Leedsichthys.

The first Leedsichthys specimen was found in 1886 in a loam pit in England, by a man whose last name was Leeds, if you’re wondering where that part of the name came from. A geologist examined the remains and concluded that they were part of (wait for it) a type of stegosaur called Omosaurus. Two years later the famous early palaeontologist Othniel Marsh examined the fossils, probably rolled his eyes, and identified them as parts of a really big fish skull.

In 1899, more fossils turned up in the same loam pits and were bought by the University of Cambridge. IA palaeontologist examined them and determined that they were (wait for it) the tail spikes of Omosaurus. Leeds pointed out that nope, they were dorsal fin rays of a giant fish, which by that time had been named Leedsichthys problematicus.

In 1982, some amateur palaeontologists excavated some fossils in Germany, but they were also initially identified as a type of stegosaur—not Omosaurus this time, though. Lexovisaurus. I guess this particular giant fish really has been a giant problem.

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 215: The Cutest Invertebrates



Thanks to Lorenzo and Page for suggestions used in this week’s episode, and a belated thanks to Ethan for last week’s episode! Let’s learn about some of the cutest invertebrates out there!

Further reading:

Photosynthesis-like process found in insects

Mystery of the Venezuelan Poodle Moth

Further viewing:

Dr. Arthur Anker’s photos from his Venezuela trip, including the poodle moth

The pea aphid, red morph and regular green

So many ladybugs:

The sea bunny is a real animal, but it’s not a real bunny:

A larval sea bunny is SO TINY that fingertip looks like it’s the size of a BUILDING:

The bobtail squid not hiding (left) and hiding (right):

The bobtail squid is SO CUTE I MIGHT DIE:

The Venezuelan poodle moth:

Not a Venezuelan poodle moth–it’s a female muslin moth from Eurasia:

Not a Venezuelan poodle moth–it’s a silkworm moth from Asia:

The dot-lined white moth:

Show transcript:

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

This week I promised we’d cover a cute, happy animal to make up for last week’s extinction event episode, but instead of mammals let’s look at some cute invertebrates! One of them is even a mystery animal. Thanks to Page and Lorenzo for suggesting two of the animals we’re going to cover today!

We’ll start with Lorenzo’s suggestion, the pea aphid. Years and years ago I spent a slow day at work making a list of cute foods with a coworker, and peas were at the top of the list. Blueberries were second and I don’t remember the rest of the list. Generally, cuteness depended on how small the food was and how round. Aphids are really small and peas are round, so the pea aphid has to be adorable.

The pea aphid, however, is not round. It’s shaped sort of like a tiny pale-green teardrop with long legs, long antennae, and teeny black dots for eyes. It’s actually kind of big for an aphid, not that that’s saying much since it only grows 4 mm long at most. It’s called the pea aphid because it likes to live on pea plants, although it’s also happy on plants related to peas, such as beans, clover, and alfalfa. Cute as it is, farmers and gardeners do not like the pea aphid because it eats the sap of the plants it lives on, which can weaken the plant and can spread plant diseases.

During most of the year, all pea aphids are females. Each adult produces eggs that don’t need to be fertilized to hatch, but instead of laying her eggs like most insects, they develop inside her and she gives birth to live babies, all of them female. An aphid can have up to 12 babies a day, called nymphs, and the nymphs grow up in about a week or a little longer. Then they too start having babies. Even though lots of other insects and other animals eat aphids, as you can see, they will always be numerous.

As the summer turns to fall and the days become shorter, some of the baby aphids are born with wings. Some are also born male, and sometimes the males also have wings, although they might not have mouths. These males and winged females mate and the females fly off to lay their eggs on clover and alfalfa plants, assuming they aren’t already on clover or alfalfa plants. The eggs don’t hatch until spring, and all the resulting nymphs are female.

Sometimes winged females are born if the plants where the aphids live get too crowded. The winged females can fly away and find new plants.

If you’ve ever had a garden, you’re probably familiar with aphids. They spend most of the time on the undersides of leaves, drinking sap through specialized mouthparts called stylets. You may also have noticed that when you try to smush the aphids, all of them immediately drop to the ground. This protects them not just from being smooshed by a gardener’s thumb, but from being eaten along with the leaves when a deer or other animal browses on the plants where they live.

Sometimes, instead of being leaf green, pea aphids are a pale reddish color. This is called the red morph. Red morph pea aphids are more likely to live on certain plants while the ordinary green pea aphids are more likely to live on others, although many times you can find both varieties on a single plant.

The red coloration of red morph pea aphids is due to larger quantities of a chemical called carotenoid [kerOTenoid] in its body. All pea aphids contain carotenoids, though, and it’s not just used for coloration. Research suggests that the carotenoids absorb sunlight and produce energy that the aphid can use. It’s a limited form of photosynthesis—you know, that thing that only plants do.

Not only that, the pea aphid produces the carotenoids in its body. Every other animal that needs carotenoids absorbs them from plants it eats, with the possible exception of a type of mite. The genetic sequence that allows the pea aphid to make its own carotenoids originally came from fungi. Somehow the aphid captured the genetic material from fungi, probably after eating it, and passed those genes down to its descendants. This is called lateral gene transfer and scientists aren’t sure exactly how it works or how common it is.

Pea aphids also contain beneficial bacteria that produce nutrients it needs that it doesn’t get from the sap it eats. The aphids can’t live without the bacteria, and the bacteria can’t survive outside of the aphids.

Even though the pea aphid is really common just about everywhere these days, it’s actually an invasive species in most places. It’s native to temperate parts of Eurasia but has spread to the rest of the world on cultivated plants. For small infestations of aphids, some people release certain species of ladybugs into their gardens, because many ladybugs love eating aphids.

Ladybugs, of course, are another cute invertebrate, specifically a family of beetles. They’re also small and round, although not as small as aphids. A typical ladybug grows about 10 mm long at most. Depending on the species, a ladybug can be red, orange, yellow, or brown, usually with black spots but sometimes with black stripes, or it may be mostly black with red or yellow spots. Most eat tiny insects and other animals, but some species eat plant material.

The ladybug’s bright coloring warns birds and other predators that it contains a toxin that makes it taste nasty. This even affects humans. I mean, obviously don’t eat ladybugs, but sometimes if there are ladybugs on grapes used to make wine, and the ladybugs end up crushed along with the grapes in a wine press, the whole batch of wine will end up tasting bad. It’s called ladybird taint so winemakers try to make sure any ladybugs are removed from the grapes before they’re crushed.

In many cultures around the world, ladybugs are supposed to bring good luck. In some places, if you see a ladybug you should make a wish. We’ve talked about ladybugs before, most recently in episode 203, so let’s move on to our next cute invertebrate.

This one lives in the ocean. It’s called the sea bunny or sea rabbit, a type of nudribranch [noodi-bronk] that lives along the coastline of the Indian Ocean, especially in tropical waters. Nudibranchs are a type of mollusk that are sometimes called sea slugs. Many are brightly colored with beautiful patterns. Compared to some, the sea bunny is a little on the plain side. It’s white, yellow, or rarely green, with tiny brown or black speckles. It looks fuzzy because it’s covered in little protuberances that it uses to sense the world around it, as well as longer, thinner fibers called spicules. It also has two larger black-tipped protuberances that look for all the world like little bunny ears, although they’re actually chemoreceptors called rhinophores. It really is amazing how much the sea bunny actually resembles a little white bunny with dark speckles, which would make it cute right there, because bunnies are cute, but it’s also really small. It barely grows an inch long, or 2.5 cm.

Like other nudibranchs, the sea bunny is a hermaphrodite, which means it produces both eggs and sperm, although it can’t fertilize its own eggs. When it finds a potential mate, they both perform a little courtship dance to decide if they like each other. After mating, both lay strings of eggs in a spiral pattern. The eggs hatch into larvae that are free-swimming, although the adults crawl along the ocean floor looking for small animals to eat. Some nudibranch larvae have small coiled shells like snails, which they shed when they metamorphose into an adult, but the sea bunny hatches into a teeny-tiny miniature sea bunny.

Cute as it is, don’t pet a sea bunny! It’s toxic! One of the things that sea bunnies especially like to eat are sponges, and many sponges contain toxins. The sea bunny absorbs these toxins to protect it from predators. Even its eggs are toxic.

Next we’ll talk about another intensely cute marine animal, the bobtail squid. It’s only a few inches long, or up to 8 cm at most, with a rounded mantle and short little arms. Small and round, the hallmarks of cuteness. It’s also sometimes called the dumpling squid, which is extra cute and potentially delicious. Basically, it’s no longer than your thumb and smaller around than a golf ball.

The bobtail squid lives along the coast of the Pacific Ocean and parts of the Atlantic and Indian oceans, and it’s not just one species. It’s an entire order containing around 70 species. The oceans are full of adorable little squids.

The bobtail squid has a symbiotic relationship with a type of bacteria, much like the pea aphid and its beneficial bacteria, but in the bobtail squid’s case, the bacteria don’t provide nutrients, they provide light. The bacteria are bioluminescent and help the squid hide from predators. You may be thinking, “Wait a minute, how does it help the squid hide to be lit up from within like a tiny squid-shaped lamp?” but that just proves that you’re a land animal and not a water animal. If you’re a big fish on the hunt for yummy bobtail squid to eat, you’re probably hiding in deep water where the squid can’t see you in the darkness, looking up for the telltale shadowy outline of a squid against the surface of the water. Day or night, the water’s surface is much brighter than the water underneath it because it’s reflecting sun, moon, or starlight, but if the squid is glowing faintly, instead of showing up as a dark shape against the brighter surface, it blends in. The light only shines downward and the squid adjusts it to be brighter or dimmer to match the amount of light shining on the water.

The bobtail squid is mostly nocturnal and will hide in the sand during the day or if it feels threatened, using its arms to pull sand over its body. All squids have large eyes, but the bobtail squid’s eyes are especially large in comparison to its small body, which makes it even cuter. It eats small animals and especially likes shrimp. It can also change colors to blend in with its surroundings and communicate with other squid.

Let’s finish with Page’s suggestion, the Venezuelan poodle moth. I was going to start the episode with this one because it’s so fuzzy and cute, but when I started research I realized that there’s a mystery associated with this insect. I like to end episodes with a mystery if I can. I want to keep everyone guessing.

In late 2008 and early 2009, a zoologist named Arthur Anker was in southeastern Venezuela in South America, and photographed a fuzzy white moth he found. He didn’t know what it was so he labeled it as a poodle moth when he posted the picture online. I’ve put a link in the show notes to all the photos he posted from his trip, including the poodle moth, and they’re absolutely gorgeous. He has a lot of moth photos but the poodle moth was the one that went viral in 2012.

There are other cute, fuzzy moths that sometimes get called poodle moths, such as the silkworm moth. Silkworm moths are native to Asia and are one of the few domesticated insects in the world, together with the honeybee. If you’ve ever had a silk shirt, that silk probably came from the domestic silkworm, which has been raised for at least 5,000 years in China and other places.

Silk comes from the cocoons the silkworm moth larva spins. Each cocoon can contain up to a mile of silk fiber, or 1.6 km, in one long, thin thread. The problem is, to harvest the silk properly, you have to kill the silkworm inside, usually by throwing the cocoon into boiling water. If the silkworm is allowed to mature, it releases enzymes to break down the silk so it can get out of the cocoon, and that weakens any fabric made from the silk. You can get silk made from cocoons of silkworms that weren’t killed, though, sometimes collected from wild moths.

Domestic silkworm moths have been bred so that they don’t produce pigments, since that means the silk won’t have any pigments either and can be dyed more easily. Domestic silkworms differ from their wild relatives in other ways too. Their cocoons are bigger, they no longer have any fear of predators, and they can no longer fly because their wings are too small for their bodies. The moth is covered in short white hairs that make it look fuzzy and cute, with black eyes. The larvae eat the leaves of the white mulberry tree or related trees, but adult moths don’t eat at all and don’t even have functional mouths.

So the silkworm moth is definitely a cute invertebrate, but what’s going on with the Venezuelan poodle moth? What’s the big mystery?

Well, no one knows what species it is. Some people have even accused Dr. Anker of making it up completely. Considering how many thousands of moths live in Venezuela, and how many new moth species are discovered every year, it’s likely that the poodle moth is new to science. The trouble is that no one has seen it since. Anker wasn’t on a collecting trip and he didn’t realize the poodle moth might be something new to science, so he just took a picture of it and left it alone.

The best guess by entomologists who’ve examined the picture is that the poodle moth is a member of the genus Artace, possibly a close relation of the dot-lined white moth. The dot-lined white moth is white and fuzzy with tiny black dots on its wings. It mostly lives in the southeastern United States but there have been sightings in Colombia, which is a country in South America just west of Venezuela.

There are other fuzzy white moths in the world that are known to science, including the muslin moth that’s equally small and cute. Female muslin moths are white and fuzzy with some gray or brownish-gray speckles on the wings, while male muslin moths are dark gray and fuzzy with black speckles on the wings. They live mostly in Eurasia.

Hopefully soon a scientist can find and capture a Venezuelan poodle moth and solve the mystery once and for all. Hopefully that scientist will also take lots of pictures so we can verify that it’s just as cute as it looks in its first picture.

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 214: Armored Fish and the Late Devonian Mass Extinctions



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

Further reading:

Titanichthys: Devonian-Period Armored Fish was Suspension Feeder

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

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

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

Pteraspis: NOSE HORN FISH:

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

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

Show transcript:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Thanks for listening!


Episode 213: More Honeybees, But Stingless



Thanks to Nicholas for this week’s suggestion! Let’s learn about the Australian stingless bee and its relatives!

Listen to BewilderBeasts if you want more fun, family-friendly animal facts!

Further reading/watching:

Australian Stingless Bees

Women Work to Save Native Bees of Mexico (I really recommend the short video embedded on this page! It’s utterly charming!)

House of the Royal Lady Bee: Maya revive native bees and ancient beekeeping

A Maya beekeeper’s hut and some Central/South American stingless bees (pictures from the last link, above):

Stingless bees build their combs in a spiral shape:

An Australian stingless bee collecting nectar and pollen:

Show transcript:

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

Last year Nicholas emailed me with a correction to episode 183 and a suggestion. In that episode I said that only honeybees make honey, but Nicholas pointed out that the Australian stingless bee also makes honey. In fact, he keeps some of these bees himself! So let’s learn about Tetragonula carbonaria and its close relations, as well as some other interesting bee information!

Stingless bees don’t just live in Australia. Different species live in parts of Australia, Africa, Asia, and Central and South America. Most produce honey, although not very much of it compared to the European honeybee. They don’t sting but some species will bite.

Stingless bees are much smaller than European honeybees. Some look more like a flying ant than a bee unless you look closely. A stingless bee worker only grows around 4 mm long, while a European honeybee worker grows about 15 mm long. Different species have different markings, but Tetragonula carbonaria, which is sometimes called the sugarbag bee, is black all over.

Stingless bees have a lot in common with honeybees, which makes sense because they’re closely related. The stingless bee lives in a social colony with a caste structure of the queen who stays home and lays eggs, male drones that mate with new queens, and infertile female workers. Young worker bees keep the hive clean and take care of the brood, or developing larvae, while older worker bees are the ones who fly out and forage for pollen and nectar. While stingless bees only have one queen laying eggs at any given time, some species will have a few backup queens in case of an emergency. These backup queens don’t produce eggs because they only mate with the drones if the reigning queen dies.

In a few species of stingless bee, there’s actually another caste in addition to the ordinary queen, drone, and worker. It’s the soldier caste. Soldier bee larvae get extra food, and they grow to be larger and stronger than other bees to help them guard the colony, especially the hive entrance. Before the stingless bee soldier castes were discovered, no one realized that any bees ever had soldiers, although some ant and termite species have them.

The stingless bee builds a nest in tree cavities, preferably in the tops of large trees because that keeps the hive warm and protected. It’s a tropical bee so it needs to stay warm. If any insect or other small animal gets into the hive, the bees can’t sting it because as their name implies, they don’t have working stingers. Instead, they swarm the intruder and attempt to smother it with anything they can find, including wax, resin, and mud.

The stingless bee builds honeycombs, but they’re spiral shaped. They’re made from beeswax mixed with resin that the worker bees collect from certain plants. The combs can be yellow like ordinary honeycombs, or they can be black, brown, or reddish. The word honeycomb isn’t actually accurate because it’s not where the bees store honey. The honey is stored in large chambers in the nest called honeypots. The combs are properly called brood combs because they’re used for baby bees. Worker bees fill the cells about three-quarters full of honey and pollen and the queen lays one egg in each cell. The workers then cap the cell. When the egg hatches, the bee larva has plenty of nutritious honey and pollen to eat. Once the larva has metamorphosed into an adult bee, it chews a hole through the cell’s cap and emerges.

If you’re wondering whether you can eat the honey of the sugarbag bee, yes! It’s runnier than ordinary honey but it smells wonderful and according to Nicholas, it has a tangy citrusy flavor. It sounds really good. Stingless bees don’t produce nearly as much honey as European honeybees, though, which makes sense since honeybees have been selectively bred over centuries to produce more honey than the hive could possibly need. The beekeeper takes the extra to eat, but naturally leaves plenty for the hive to live on.

People in Australia only started keeping stingless bees around the early 1980s, but it’s growing more and more popular. Since the bees are native to Australia, they’re much better for the environment than the European honeybee. They’re also incredibly good at pollinating crops, and if the weather’s warm enough, they’ll happily pollinate year round. A lot of people who keep stingless bees don’t even bother to harvest the honey, just use the bees as pollinators and as weird pets.

Before European honeybees became popular all over the world, many cultures kept stingless bees. This includes the ancient Maya, who kept stingless bees for their honey and wax. There was even a god associated with the bees, and the bees themselves were called “royal lady bees.” They look like tiny honeybees with striped abdomens, but their eyes are blue. It’s a forest bee that will pollinate flowers growing at the tops of tall trees as well as low-growing flowers, which is good for the environment and helps the native trees in particular.

Some modern Maya still keep stingless bees, but so few traditional beekeepers are left that the stingless bees in the Yucatan are endangered. Fortunately, a women’s collective in the area has started teaching local women how to keep the bees. The new beekeepers can sell honey on the gourmet market for extra money, and the bees have help competing with introduced European honeybees. It’s also a source of local pride to have royal lady bees around again.

When a stingless bee worker finds flowers producing a lot of nectar, she marks the area with pheromones. Other bees from her nest detect the pheromones and arrive to help harvest all the nectar and pollen. Pheromones are chemicals that correspond to scents, and although humans can’t detect them, bees have a really sensitive sense of smell. Their sense of smell is so good, in fact, that people in Croatia have trained European honeybees to find a particular scent for a surprising purpose.

Croatia is a country near Italy on the Adriatic Sea, and while it’s an independent country now, its independence only came after a whole lot of fighting. During the war, soldiers hid landmines all over the country and now, decades later, no one remembers where they are. There may be as many as 90,000 mines in the country, and they’re still deadly if a person or animal steps on one.

Obviously, Croatia needs to disarm the landmines—but finding them is the hard part. That’s where the bees come in.

The bees in question are ordinary European honeybees. Scientists train the bees by mixing nectar with tiny traces of the chemical signature of TNT. The bees quickly learn to associate TNT with food, and the scientists follow the bees with drones to see where they go.

I learned about these bomb-sniffing bees from a podcast called BewilderBeasts, which I highly recommend. There’s a promo for it at the end of this episode and I’ll put a link in the show notes. BewilderBeasts’s logo and their first episode both feature the bomb-sniffing bees.

Let’s finish with some interesting folklore associated with honeybees. Many bee-keeping cultures across the world have a superstition that you have to tell the bees about important events in the family. In English it’s literally called “telling the bees.” If you don’t, the bees may swarm and leave you. Some cultures especially stress that the bees must be told about the death of the beekeeper, and that they need to be invited to the funeral too or at least given cake or wine from the service afterwards.

This particular superstition ties into the association with bees and honey with the afterlife. In ancient Egypt and many other cultures across Asia and Europe, honey was a funerary gift for the dead, and tombs were sometimes decorated with images of bees and beehives. Honey isn’t just good to eat, it’s been used as a medicine for millennia and as an ingredient in skin cream and other cosmetics, so it has always been valuable. Every single bee-keeping culture in the world—literally every single one—gives religious significance to honey to some degree or another.

Humans all agree: honey is good, bees are good, and bee-keeping is worth the effort.

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

Thanks for listening!


Episode 212: The River of Giants



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

Further reading:

King of the River of Giants

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

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

Not actually a pancake crocodile:

A model of Aegisuchus and some modern humans:

Show transcript:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Thanks for listening!


Episode 211: The Magnificent Fin Whale



This week let’s venture into the ocean and learn about the fin whale!

Further reading:

The songs of fin whales offer new avenue for seismic studies of the oceanic crust

Fin whales’ big gulp

The fin whale can hold a whole lot of water in its mouth (illustration from the second article linked above):

A fin whale underwater. Look at that massive tail. That’s pure muscle:

A fin whale above water. It’s like a torpedo:

Show transcript:

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

It’s been too long since we had an episode about whales. Yes, okay, two weeks ago we talked about a couple of newly discovered whales, but I want to really learn about a particular whale. So this week, let’s look at the fin whale.

The fin whale is a baleen whale that’s only a little less enormous than the blue whale. The longest fin whale ever reliably measured was 85 feet long, or just a hair shy of 26 meters, but there are reports of fin whales that are almost 90 feet long, or a bit over 27 meters. An average American school bus is half that length, so a fin whale is as long as two school buses. Even a newborn fin whale calf is enormous, as much as 21 feet long, or 6.5 meters. Females are on average larger than males.

It’s a long, slender whale that’s sometimes called “the greyhound of the sea,” because it’s also really fast. It can swim up to 29 mph, or 46 km/hour, and possibly faster. If that doesn’t sound too fast, consider that the Olympic gold-medal swimmer Michael Phelps topped out at about 4.7 miles per hour, or 7.6 km/h.

Like other baleen whales, the fin whale has a pair of blowholes instead of just one. On its underside, it has up to 100 grooves that extend from its chin down to its belly button. Yes, whales have belly buttons. They’re placental mammals, and all mammals have belly buttons because that’s where the umbilical cord is attached when a developing baby is in its mother’s womb. I don’t know what a whale’s belly button looks like. Also, the proper term for belly button is navel, and if you’re wondering, that’s where navel oranges get their name, because they have that weird thing on one end that looks like a belly button. It’s not, though. I don’t know what it is. You’ll have to find a podcast called Strange Plants to explain it.

Anyway, the grooves on the fin whale’s underside act as pleats, or accordion folds. Other baleen whales have these pleats too. A baleen whale eats tiny animals that it filters out of the water through its baleen plates, which are keratin structures in its mouth that take the place of teeth. The baleen is tough but thin and hangs down from the upper jaw. It’s white and looks sort of like a bunch of bristles at the end of a broom. The whale opens its mouth wide while lunging forward or downward, which fills its huge mouth with astounding amounts of water. As water enters the mouth, the skin stretches to hold even more, until the grooves completely flatten out. The water it can hold in its mouth is about equal to the size of a school bus.

Technically, though, a lot of that water isn’t in the whale’s mouth. It’s in a big pocket between the body wall and the blubber underneath the skin. The ballooning out of the pocket stretches the nerves in the mouth and tongue to more than twice their length, and then the nerves have to fold back up tightly after the water is pushed out. The nerves fold in a complicated double layer to minimize damage during all this stretching.

After the whale fills its mouth with water, it closes its jaws, pushing its enormous tongue up, and forces all that water out through the baleen. Any tiny animals like krill, copepods, small squid, small fish, and so on, get trapped in the baleen. It can then swallow all that food and open its mouth for another big bite. Even more amazing, this whole operation, from opening its mouth to swallowing the food, only takes six to ten seconds.

Because it only eats small animals, the fin whale’s esophagus (which is the inside part of the throat) is actually quite narrow considering what a huge animal it is. In other words, it could not possibly swallow a human, in case you were worried. I was worried. If you did end up in a fin whale’s mouth, it would just spit you back out.

Baleen whales have a sensory organ on the chin that’s found in no other animal. It’s about the size of a grapefruit and situated between the tips of the jaws. It probably helps the whale determine how much potential food is in the water, which saves it from wasting time and energy gulping in water and filtering it out when there’s nothing much to eat.

The fin whale looks a lot like the blue whale and the two species are closely related, so much so that they sometimes interbreed and produce hybrid babies. It usually lives in small groups of up to around 10 individuals and a female fin whale has one baby every two or three years. It probably migrates seasonally to new feeding grounds, but we don’t actually know a whole lot about where it goes and whether all fin whales migrate.

Fin whales have extremely loud vocalizations, but most humans would barely be able to hear them, or wouldn’t be able to hear them at all, because they’re at the very bottom or below the range of sounds that the human ear can detect. The calls can be up to 188 decibels, a measure of loudness, which may be the loudest sounds made by any animal alive today. Technically the blue whale is louder, at 190 decibels, but on average the fin whale is louder. In comparison, a jet plane taking off is measured at 150 decibels. Of course, sound through water is different from sound through air, because water is much denser. A better comparison is with an offshore drill rig at 185 decibels or a supertanker ship at 190 decibels. The fin whale is about as loud as both, although of course the fin whale doesn’t make those noises all the time like drill rigs and ships do. The male fin whale makes short pulses of sound that last a second or two in specific patterns, which he repeats sometimes for days. Since the sounds travel long distances underwater, researchers think a female can hear a male’s calls and follow the sound so she can find him to mate. Of course, this means that females may have trouble finding a male these days since the ocean is full of noise from human-made things like offshore drill rigs and supertanker ships.

The fin whale is not only one of the loudest animals known, its vocalizations are among the lowest in frequency of any animal ever recorded. It turns out that this combination has a surprising benefit to human knowledge in a very specific way.

In an article published in Science just a few days ago as this episode goes live in February of 2021, a team of scientists discovered that fin whale vocalizations can help with seismic imaging of the oceanic crust.

The oceanic crust isn’t just the sea floor but what the earth below the sea floor is made up of. Scientists measure the reflections of a sound wave, and since sound waves travel at different speeds through different materials, and bounce off various types of rocks and other structures at different speeds and angles, the reflections can tell us a lot. Scientists use sensitive seismometers on the ocean floor to read the reflections. The problem is how to get the sound wave in the first place. Researchers usually use a giant air gun to make sound waves, but not only can this be dangerous to ocean life because it’s so loud, it’s also expensive and can’t be used in all areas.

But the fin whale does almost as good a job as an air gun. A pair of researchers studying earthquakes off the Oregon coast in North America noticed that when fin whales were around, their seismometers picked up extra signals. They figured out that the signals were actually from the fin whales’ vocalizations, and were surprised to find that the reflections matched those from the air gun sound waves. As an added benefit, the researchers could pinpoint exactly where each whale was since its signals were picked up by multiple seismometers.

Fin whale vocalizations are at the perfect frequency and strength for sound waves to travel through the ocean floor and be picked up by the seismometers. Best of all, fin whales live throughout almost all of the world’s oceans, including places where air guns can’t be used. Researchers just have to put the seismometers in place and the whales produce as many sound waves as the scientists need.

Because the fin whale makes such low-frequency noises, its hearing is different from other animals’. Big as a fin whale is, the low-frequency vocalizations it makes actually form a sound wave that’s longer than its body, which means the whale actually can’t hear it through its ears. But for a long time, scientists weren’t sure how the fin whale and other big baleen whales could hear those sounds.

Then, in 2003, a fin whale beached in California and died despite attempts to save it. Scientists were allowed to collect the body for research, and they took the head to an X-ray CT scanner designed for rocket motors to get a 3D image they could study. It turns out that the fin whale’s skull has acoustic properties that makes it sensitive to low frequency sounds and actually amplifies the sound waves as the bones of the skull vibrate. So fin whales hear each other with their skull bones instead of their ears.

Absolutely nothing can top that amazing fact, so that’s the end of this episode.

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 210: The Mysterious Lightbulb Lizard



Does the Shreve’s lightbulb lizard really emit light? (Hint: sort of.) Let’s find out!

Further reading:

The Lightbulb Lizard of Benjamin Shreve

Shreve’s lightbulb lizard, looking pretty ordinary really:

A web-footed gecko in moonlight:

A Jamaican gray anole showing off his dewlap:

Show Transcript:

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

This week let’s learn about an interesting reptile with a mystery that’s mostly solved, but still really weird. It’s called Shreve’s lightbulb lizard.

The story of this little lizard starts in 1937, when zoologist Ivan Sanderson was collecting freshwater crabs on a mountaintop in Trinidad. They were probably mountain crabs, also called the manicou crab, which is actually a pretty astonishing animal on its own. It’s a freshwater crab that doesn’t need to migrate to the ocean to release its eggs into the water. Instead, the female carries her eggs in a pouch in her abdomen. The eggs hatch into miniature crabs instead of larvae, and they stay in her pouch until they’re old enough to strike out on their own.

The mountains of Trinidad are made of limestone, which means they’re full of caves, and Sanderson was reportedly catching crabs in an underground pool or stream. He noticed a flash of light in the darkness and naturally went to find what had made it. All he found was a little lizard hiding under a ledge. It looked kind of like a brown skink and was pretty boring, but when the lizard turned its head, Sanderson saw a flash of dotted light down both its sides. When he caught the lizard and examined it while it was sitting in his hand, it flashed its lights again.

Sanderson knew he’d found something extraordinary, because lizards don’t bioluminesce. We still don’t know of any terrestrial vertebrate that emits light. Lots and lots of marine animals do, and some terrestrial invertebrates like lightning bugs and glow-worms, but no terrestrial vertebrates.

Sanderson took the lizard back to his camp, where he and his team observed it in different situations to see if it would light up again. They moved it to warmer areas and colder ones, made loud noises nearby, even tickled it, and they did indeed see it light up a few times. The light came from a row of tiny eyespots along its sides, from its neck to its hips. It had one row of these spots on each side, and each spot looked like a tiny white bead. The greenish-yellow flashes of light seemed to shine through the spots, as Sanderson said, like “the portals on a ship.”

Sanderson sent the lizard to The British Museum in London where another zoologist studied it and discovered that it was actually a known species, but apparently very rare. Only two specimens had ever been caught, one a juvenile and one an adult female. The lizard Sanderson caught was male, and it turns out that only adult males have these little eyespots. Sanderson later caught seven more of the lizards.

Let’s jump forward a bit and get a better idea of what these lizards look like. Shreve’s lightbulb lizard grows around 5 inches long at most, or 13 cm, not counting its long tail. It has short legs, a pointy nose, and broad, flat scales on its back and sides. It’s mostly brown in color. It lives in high elevations in the Caribbean island of Trinidad and Tobago, which is just off the coast of Venezuela in South America. It prefers cool climates, unlike most reptiles, and while it turns out that it’s not actually very rare, it’s also hard to study because it lives in such remote areas, so we don’t know much about it. It may be nocturnal and it may be semi-aquatic. It certainly lives along mountain streams, where it eats insects and other small animals.

Now, we have mentioned Ivan Sanderson a number of times in past episodes, and you may remember me sounding pretty skeptical about some of his cryptozoological claims. But Sanderson was a zoologist with a good reputation as a field scientist, and more importantly, he wasn’t the only one who saw the lizard light up.

The British Museum zoologist, H.W. Parker, who studied the first lizard Sanderson found, was actually the scientist who had originally discovered the lizard a few years before. He was very interested in the little portholes along the male lizard’s sides and studied them carefully. But he couldn’t find anything about them that indicated how they lit up. Each tiny eyespot consisted of a transparent center spot with a ring of black skin around it. The eyespots did not contain glowing bacteria, specialized nerve endings, ducts, reflecting structures, or anything else that he could think of that might cause a flash of light.

Other zoologists examined the so-called lightbulb lizard over the next few decades and none of them saw it emit light either. By 1960 no one believed it was bioluminescent.

I’m taking most of my information from a blog post by Dr Karl Shuker, a zoologist who writes a lot about cryptozoological mysteries. If you want to read his article, there’s a link in the show notes. Shuker was the one who got some modern scientists interested in the lightbulb lizard again, and there’ve been some recent studies. The lizard has been reclassified several times recently and its current name is Oreosaurus shrevei. Oreosaurus is spelled Oreo-saurus and it may be pronounced that way, and while I would like to think that the name comes from the white-appearing center of the eyespot with black pigment around it like an Oreo cookie, the name Oreosaurus is older than the cookie and as far as I can tell it means mountain lizard.

Some experiments conducted in the early 2000s finally figured out just what is going on with the lightbulb lizard. Sanderson was right: he and his colleagues really did see light coming from the eyespots. But it’s reflected light, not light emitted by the lizard itself. The white dots in the middle of the eyespots are reflective at some angles. Not only that, but when the lizard feels threatened, the skin around the white dots becomes even darker, which makes the reflection seem brighter. It’s partly optical illusion, partly just optics.

The big question now is why the lightbulb lizard has these reflective spots at all. The female doesn’t have them. That suggests that the male uses them in some way to attract a mate, but we don’t know.

While I was researching this episode, I kept coming across mentions of other lizards named lightbulb lizards. They’re all related to Shreve’s lightbulb lizard and I suspect the name got popular after Sanderson’s findings, which he published in a book of his nature travels called Caribbean Treasure. As far as I can find, none of the other lightbulb lizards have these reflective eyespots. Many are burrowing reptiles and they all have short legs and look a lot like skinks.

Meanwhile, in glowing lizard news, scientists discovered in 2018 that chameleons glow fluorescent under ultraviolet light. Even their bones are fluorescent. A lizard called the web-footed gecko, which lives in the desert in Namibia, Africa, has translucent markings on its sides and around its eyes. In daylight the markings don’t show, but in moonlight they glow neon green due to special pigment cells called iridophores. Iridophores are found in cephalopods and other marine animals, but they’ve never been seen before in land animals. Male Jamaican gray anoles have a colorful throat decoration called a dewlap that they extend to attract a mate, and the skin is translucent so that when sunlight passes through it, the colors glow brightly.

All these findings are only a few years old, so obviously we’re only just learning about all the different ways that lizards use light to their advantage. I wouldn’t be a bit surprised if a genuinely bioluminescent lizard was discovered eventually. So when you’re outside at night, don’t assume that every little flash of light is a firefly.

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!