Category Archives: reptile

Episode 251: Modern Mimics and HIREC

Posted on by

Podcast: Play in new window | Download (Duration: 14:30 — 16.6MB)

Subscribe: RSS | More

Sign up for our mailing list! We also have t-shirts and mugs with our logo!

This week let’s look at some animals that have evolved rapidly to adapt to human-caused environmental pressures. Thanks to Otto and Pranav for their suggestions!

Further reading:

Long-term changes of plumage between urban and rural populations of white-crowned sparrows (Zonotrichia leucophrys)

A light-colored peppered moth (left) and darker-colored peppered moths (right):

Soot is hard to clean off buildings and other items (image from this page):

A white-crowned sparrow in the California countryside:

A (deceased museum specimen being photographed) white-crowned sparrow from the city of San Francisco, CA (taken from the study linked above):

A decorator crab that has attached bits of plastic and other trash to its body (image from this page):

The hermit crab sometimes uses trash instead of shells to hide in:

Show transcript:

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

This week we have two listener suggestions. Otto suggested we learn about camouflage that mimics modern things, and Pranav suggested animals that show rapid evolution due to humans.

We’ve talked about animals that use camouflage in lots of episodes, especially episode 191, Masters of Disguise. If you want to learn more about camouflage itself, that’s a good one to listen to. In addition, rapid evolution due to humans is a hot area of research right now. It even has its own scientific term, human-induced rapid evolutionary change, often shortened to the acronym HIREC.

Let’s start this episode with the story of a humble moth, because it’s a classic example of both HIREC and modern camouflage.

The peppered moth lives throughout much of the northern hemisphere. Its wingspan is a little over 2 inches across, or about 6 centimeters, and its caterpillar looks just like a little twig. Not only that, the caterpillar can change its coloring to match the twigs of the tree it’s on. But it’s not the caterpillars we’re talking about today.

The peppered moth gets its name from the coloring of its wings, which are white with black speckles, like pepper spilled on a plate. The pattern of speckles is unique to each individual, with some moths having more pepper speckles than others. Some moths have so many speckles that they look gray. But in the 19th century, geneticists studying moths in England noticed that the peppered moth seemed to be changing color as a species. Specifically, some of the peppered moths were completely black.

Black peppered moths had never been documented before 1811. They were still rare in the mid-19th century, but by 1900 almost all of the peppered moths in cities in England were black. Scientists noticed this and tried to figure out what was going on.

Pollution is what was going on. The industrial revolution was in full swing, but all those factories and trains and even ordinary houses were burning coal. Burning coal results in soot that’s carried on smoke and settles on everything. If you have a coal fire in your house, your walls and furniture are going to end up dark with soot. My aunt and uncle renovated a house from the late 19th century and had a lot of trouble cleaning soot from the walls and woodwork, even the old curtains that had been in the house. Similarly, when I lived briefly near Pittsburgh, Pennsylvania, there were still a lot of brick and stone buildings that were black from soot, but one beautiful old church had recently been cleaned and it turned out that the stone it was built from was pale gray, not black.

It wasn’t coal soot getting on the moths, though. It was coal soot on the trees where the moths spent most of their time. Most tree trunks are gray, but with all that coal soot in the air, the trees were coated with it and were much darker gray or even black. A light-colored moth that settled on a black tree branch showed up to predators, but a black moth on the same branch was camouflaged. The black moths survived more often to lay eggs while the white or gray moths didn’t, passing on the genetic likelihood that their babies would grow up to be dark-colored instead of light-colored.

It wasn’t just peppered moths that this happened to, either. More than 100 species of moth were documented to be dark gray or black during this time when they were ordinarily much lighter in color. Scientists call this industrial melanism.

Soot is made up of tiny particles that work their way into the crevices of wood and stone and everything else they come in contact with. You can’t just wipe or rinse it off. It’s acidic too and will kill plants, especially lichens that grow on trees, and it even eats away at stone and brick. It’s dangerous to breathe because the tiny particles lodge in your lungs and eventually stop you from being able to absorb oxygen as efficiently. If you’ve heard of the infamous London smog from the olden days, a big contributor to the smog was coal smoke. In 1952 a five-day smog event in London killed an estimated 12,000 people. That led directly to the Clean Air Act of 1956, and these days London doesn’t have that kind of deadly smog anymore.

Once factories and homes switched to electricity, natural gas, or other alternatives to burning coal, and trains switched to diesel fuel, trees stopped being coated with soot. Older trees that had survived were still dark, but young ones grew up with normal colored trunks and branches. Gradually, the black moths became less and less numerous compared to light-colored moths.

Cities in general result in rapid evolution of animals, including how they camouflage themselves. A study published in May of 2021 found that some birds living in cities are developing different colored feathers. Specifically, white-crowned sparrows living in San Francisco, California have much duller, darker feathers on their backs than white-crowned sparrows living outside of the city. Other studies have found that birds in cities sing much louder and at a higher pitch than birds in the countryside, since they have to compete with traffic and other noise.

A Swiss study on the effects of light on ermine moths indicated that while moths who developed from caterpillars collected from the countryside showed a normal attraction to light, moths from caterpillars collected in the city ignored the light. Since moths often die when they collide with electric lights, the city moths who survived to lay eggs were the ones who didn’t fly into a hot lightbulb.

Another study compared the genomes of white-footed mice that live in various parks in New York City with white-footed mice that live in state parks well outside of the city. The mice in city parks showed a lot less genetic diversity, naturally, since those mice are isolated populations. Mice can’t take cabs to visit mice in other parks, much less leave the city for a vacation. But the city mice showed another surprising difference. Their digestive systems have adapted to a much different diet than their country cousins. Some researchers suggest that the city mice may eat more junk food, which people throw away and the mice find, while other researchers think it’s just a difference in the kinds of insects and plants available in city parks for the mice to eat. Either way, it’s a distinct genetic difference that shows how the city mice are evolving to adapt to their urban environments.

Another example is a type of reptile called the crested anole. It’s related to the iguana and is native to the Americas. There are lots of species and subspecies of anole, many of which live on islands and show distinct adaptations to various habitats. The crested anole lives in Puerto Rico and on some nearby islands and grows up to 3 inches long, or 7.5 cm, not counting its long tail. The male is more brightly colored than the female, usually green or brown with darker spots. It’s not related to the chameleon but it is able to change color. It eats small animals, including insects, worms, even other anoles. Anoles are really interesting animals that deserve their own episode one day, so let’s just talk about how the crested anole that lives in cities has adapted to urban life.

One thing the crested anole is known for is its ability to climb right up tree trunks and even perch head-down in a tree. Its toe pads have microscopic scales and hairs that help them adhere to smooth surfaces, something like a gecko’s toes. But there’s a big difference in a tree trunk, no matter how smooth it is, and a pane of glass. Anoles in cities can climb up and down windows and painted walls. Researchers examined the toe pads of city crested anoles and compared them to the toe pads of crested anoles who lived in the countryside. They found that the city anoles had larger toes with more scales, and they even had longer legs. The research team also raced anoles along various surfaces and filmed them in slow motion to study how they were able to maneuver, which sounds like a great day at work.

The crested anoles have only lived in cities for a few decades, so their differences from country anoles evolved very quickly. But not all species of anole can adapt as well and as rapidly as the crested anoles have. Other city anole species don’t show differences from their country cousins.

Human-induced rapid evolutionary change isn’t restricted to cities. Trophy hunters who target the biggest animals with the biggest horns or antlers and leave smaller individuals alone have resulted in only smaller males with smaller horns or antlers surviving to breed. Many populations of bighorn sheep now actually only have small horns. Similarly, elephants have been killed for their tusks for long enough that many elephants are being born without tusks, because tuskless elephants are the ones that survive to breed. Entire populations of some fish species are smaller overall after many generations of being caught with nets, because only the individuals who are small enough to escape the nets survive to breed.

I tried hard to find more examples of animals that camouflage themselves to blend in to human-made items like roads. I’m sure this is happening throughout much of the world, but I couldn’t find any scientific studies about it. If any of you are thinking of going into biology, that might be an interesting field of study. But I did find one other example.

Self-decoration is a type of camouflage I don’t think we’ve talked about before. It’s where an animal decorates its body with items that help it blend in with its surroundings. Some caterpillars will stick little bits of lichen or other plant pieces to their bodies to help them hide, and some invertebrates of various kinds actually pile their own poop on their back as a disguise.

A group of crabs called decorator crabs will stick plants, sponges, and other items to their backs, and different species have preferences as to what items they use. Some species prefer stinging or toxic decorations, such as certain sea anemones which they basically pick up and plant on their backs. Researchers think the sea anemones actually benefit from being used as camouflage, because crabs are messy eaters and the anemones can catch and eat pieces of food that float away from the crab’s mouthparts. A decorator crab’s carapace is often rough in texture with tiny hooks to help things stick to it like Velcro.

Some decorator crabs don’t seek out particular decorations but just make use of whatever small items they find in their local environment. In the past few decades, scientists, divers, and other people who find crabs interesting have noticed more and more decorator crabs using little pieces of trash as decoration. This includes fragments of plastic and pieces of fishing nets.

This is similar to what’s happening with hermit crabs, which we talked about in episode 182. In many places hermit crabs are using trash like bottle caps instead of shells since there’s so much trash on beaches these days. This is your reminder to pick up any trash you find on the beach, but be careful not to cut yourself and also make sure you’re picking up actual trash and not a camouflaged crab.

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

Thanks for listening!

Episode 239: Mystery Crocodiles

Posted on by

Podcast: Play in new window | Download (Duration: 14:27 — 16.5MB)

Subscribe: RSS | More

Sign up for our mailing list! We also have t-shirts and mugs with our logo!

Thanks to Pranav and Max for their suggestions. Let’s learn about some mystery crocodiles (and crocodile mysteries) this week!

Further reading:

Huge prehistoric croc ‘river boss’ prowled waterways

Extinct “horned” crocodile’s ancestry revealed

New species of crocodile discovered in museum collections

Rediscovery of “Lost” Caiman Leads to New Crocodilian Mystery

The Orange Cave-Dwelling Crocodiles

The horned crocodile’s fossil skull:

A baby Apaporis River caiman, looking fierce but cute (picture from link above):

An orange crocodile (later released, picture from link above):

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. We’ve got a crocodile episode this week you can really sink your teeth into. Thanks to Pranav and Max for their suggestions! (Yes, I do have a cold but hopefully I don’t sound too bad. I got a covid test today to make sure it’s just a cold, and it’s just a cold.)

We talked about crododilians in episode 85, so if you want to learn more about the saltwater crocodile or how to tell the American crocodile from the American alligator and so forth, that’s the episode to listen to. This episode is going to talk about mystery crocodiles!

The partial skull of a massive extinct crocodilian discovered in Queensland, Australia over a century ago was finally described in June of 2021. All we have is the partial skull from an animal that lived between 2 and 5 million years ago, but researchers can estimate the size of the whole animal by comparing the dimensions of its skull with its closest living relation. That happens to be an animal called the false gharial that lives on a few islands in South Asia, including Java and Sumatra. It’s the only living member of the subfamily Tomistominae, which used to be common worldwide. The false gharial can grow as long as 16 feet, or 5 meters, but its extinct Australian cousin was much bigger. The new species, Gunggamarandu maunala, may have grown up to 23 feet long, or 7 meters.

A smaller extinct crocodile, called the horned crocodile, lived in Madagascar until only about 1,400 years ago. It grew a little over 16 feet long, or 5 meters. It had two projections at the back of its head that look like horns, although they weren’t actually horns and probably weren’t all that big or noticeable when the crocodile was alive.

Like Gunggamarandu, the horned crocodile’s fossils were discovered almost 150 years ago but only definitively described in 2021. In this case, though, the delay was because no one could decide where the horned crocodile belonged in the crocodilian family tree. The Nile crocodile lives on Madagascar now, and some researchers assumed that the horned crocodile was either a close relation of the Nile croc or its ancestor. Since new evidence points to the Nile crocodile being a fairly recent arrival to the island, that’s not likely, so researchers analyzed the fossil remains and reclassified the horned croc as a member of the dwarf crocodiles in 2007. Finally, though, a research team analyzed the horned croc’s DNA and determined that it belongs in its own genus and is most closely related to the ancestral species of all living crocodiles. This suggests that crocodiles evolved in Africa and spread throughout the world from there.

Researchers aren’t sure what caused the horned croc to go extinct, but it may have been a combination of factors, including a drying climate on Madagascar, the arrival of humans, and the arrival of the Nile crocodile.

Speaking of the Nile crocodile and DNA, a 2011 genetic study of the Nile crocodile resulted in a surprising discovery. The study tested not just DNA samples gathered from 123 living Nile crocodiles but from 57 crocodiles mummified in ancient Egypt. The goal was to see if there were differences between modern crocodiles and ones that lived several thousand years ago, and to determine whether maybe there was a subspecies of Nile crocodile that hadn’t been recognized by science. Instead, they discovered that what was previously known as the Nile crocodile is actually two completely different species!

The Nile croc lives in Africa and is a large, aggressive animal that can grow just over 19 feet long, or almost 6 meters. The West African croc also lives in Africa and is a smaller, less aggressive animal that can grow up to 13 feet long, or 4 meters. Since crocodiles of all species show a lot of variation in size and appearance, no one realized until 2011 that there were two species living near each other. They’re not even all that closely related.

After the finding was published, zoos across the world tested their crocodiles and discovered that a lot of their Nile crocs are actually West African crocs.

Something similar happened more recently, in 2019, when a team of scientists did a genetic study of the New Guinea crocodile. They gathered DNA from 51 museum specimens from 7 different museums, and compared them to living New Guinea crocodiles. They were hoping to determine if there are actually two species of crocodile living in different parts of New Guinea, which had been suspected for a while. It turns out that yes, there are two separate species! Knowing exactly what kinds of animals live in a particular environment helps conservationists protect them properly.

In 1952 a subspecies of the spectacled caiman was discovered by science, called the Apaporis River caiman. It lives in Colombia, South America and is relatively small as crocs go, maybe 8 feet long at most, or 2.5 meters. After that, though, it wasn’t seen again. This was partly due to how remote and hard to navigate its habitat is, and partly due to a dangerous political situation, with rebel forces occupying the jungle where the crocodiles live. A peace treaty signed in 2016 made it safe for scientists to travel to that area at last, and a Colombian biologist named Sergio Balaguera-Reina visited with various indigenous tribes of the area to ask about the Apaporis caiman and learn everything they knew about it.

At night, he and two local people paddled upriver in a canoe and searched for the caimans—and he found lots of them. He caught as many as he could to take DNA samples before releasing them again. When he got home, he tested the DNA and made a surprising discovery. Even though the Apaporis caimans look very different from another subspecies of spectacled caiman found in other parts of South America, their DNA is quite similar. That means the differences, especially the Apaporis caiman’s much narrower snout, are due to selective pressures in its environment. Balaguera-Reina is working on figuring out the causes of the Apaporis caiman’s physical differences.

The Siamese crocodile was once common throughout South Asia, but habitat loss has had a major impact on the species and for a long time it was thought to be extinct in the wild. It grows up to 13 feet long at most, or 4 meters, and is not very aggressive. It’s kept in captivity in crocodile farms, where it’s bred and killed for its meat and skin, but a lot of those farms have multiple species of closely related crocodiles and they can and do interbreed, meaning that the Siamese crocodiles in the farms are most likely hybrid animals.

In 2001 a team of conservationists traveled to Thailand to search for tigers, and one of their camera traps recorded a Siamese crocodile just walking along the river like it was no big deal. The photograph was especially lucky because it shouldn’t have even happened. The camera traps used actual film, not digital cameras which were still expensive and not very good back then. The rolls of film could capture 36 pictures before the film ran out, but the crocodile appeared on the 37th picture. Film is manufactured in long strips, then cut into pieces and rolled up and put in little canisters for a photographer to put in the camera, and the roll is a little longer than it needs to be because the ends have to be anchored in place. This particular strip of film just happened to be long enough to take 37 pictures instead of 36. If it hadn’t been, the conservationists wouldn’t have known the crocodile was still alive.

A follow-up expedition to look specifically for crocodiles discovered more of them. Since then a captive breeding program was set up, and in 2013 the first hatchlings were released into the wild.

Sometimes when a crocodile is killed, interesting things turn up in its stomach. This is what happened in 2019 when a crocodile farm in Queensland, Australia necropsied one of their saltwater crocs to see what he had died of. The croc was over 15 feet long, or 4.7 meters, and was about 60 years old. When they opened up his stomach, they found a piece of metal and six screws, the kind of metal called an orthopedic plate. It’s used to join two pieces of broken bone or strengthen an injured bone so it won’t break.

Medical devices like this are always etched with a serial number, but the metal was inside the croc’s belly for so long that the serial number was corroded off by stomach acid. This would have taken decades to happen, so the crocodile had to have eaten the metal decades ago, possibly as long as 40 years ago.

The farm contacted the police but so far they haven’t been able to trace what might have happened. The croc wasn’t bred on a farm but had been caught wild. The farm owner sent pictures of the plate to a surgeon, who determined that yes, it was probably from a human, not an animal, and that it looks like a type of plate used in Europe. The farm owner hopes the discovery will one day help solve a missing persons case.

Let’s finish with an interesting discovery in the rainforests of Gabon, a small country on the west coast of central Africa. The Abanda caves in the area are extensive, not very well explored, and full of bats and insects. A man named Olivier Testa, a professional explorer who often leads scientific expeditions into remote areas, heard a rumor about a population of orange [I read this as strange instead of orange and was too lazy to fix it] crocodiles living in the cave system. A lot of people would have just laughed, because everyone knows crocs and other reptiles like hot weather, sunshine, and warm water to hunt in. But when Testa got the opportunity to join an expedition into the cave system in 2010, he remembered the crocodiles.

Guess what they found in the cave. I bet you all guessed correctly. There really were crocodiles in the caves, specifically African dwarf crocodiles, and the biggest ones did look slightly orangey in color. Crocs don’t live in caves, but there they were. The following year the expedition returned, and this time they were there to find out more about the crocs.

A crocodile expert named Matthew Shirley came along, and he figured out why the crocodiles were in the cave. There are an estimated 50,000 bats living in the cave system, so many that the crocodiles could basically just reach up and snap bats off the walls to eat. There are lots of crickets in the cave too, and young crocs eat lots of insects.

As for the orange color of the older crocs, that comes from the water in the cave. Bats have to pee just like every other animal does, and where they roost over the water they pee into the water, naturally. So much bat urine actually has an effect on the water composition, turning it extremely alkaline. This affects the skin color of animals that stay in it for a long time, as the older crocs have.

The cave crocodiles appear to spend the dry season in the caves, eating bats and avoiding humans who hunt crocs. During the rainy season, they emerge from the caves to mate and lay their eggs in rotting vegetation outside.

This is the first population of crocodiles ever found that spends time in caves deliberately. Some researchers speculate that the crocodiles could eventually evolve into a new subspecies of dwarf crocodile that’s especially adapted to the cave system.

You know what we call those? We call them dragons.

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 237: Geckos and Other Arboreal Reptiles

Posted on by

Podcast: Play in new window | Download (Duration: 17:43 — 20.3MB)

Subscribe: RSS | More

Sign up for our mailing list! We also have t-shirts and mugs with our logo!

Thanks to Riley, Richard, and Aiden and Aiden’s unnamed friend for suggestions this week! We’re going to learn about some geckos and other reptiles that live in trees. Thanks also to Llewelly for a small correction about lions. Also, I mispronounced Strophurus–it should be more like Stroff-YOUR-us but I’m too lazy to fix it.

Further reading:

Cancer Clues Found in Gene behind ‘Lemon Frost’ Gecko Color

A chameleon’s feets:

A rare healthy lemon frost domestic leopard gecko (photo taken from article linked above):

An ordinary leopard gecko:

I don’t remember what kind of gecko this is (golden spiny-tailed?) but I love it:

A crested gecko looking surprised:

The green iguana:

A black mamba. Watch out!

Flying snake alert!

The draco lizard with its “wings” extended (male) and the draco lizard with its “wings” folded (female):

A parachute gecko showing how it works:

Show transcript:

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

This week we’re going to learn about some reptiles, specifically reptiles that live in trees. This is a suggestion from Riley, who wanted to hear about arboreal reptiles in general and the crested gecko in particular. Thanks also to my brother Richard, who suggested the dragon-tailed gecko. An anonymous reviewer also suggested the leopard gecko so we’ll learn about that one too. Specifically, the anonymous reviewer said “me and my friend Aiden suggest either red foxes or leopard geckos.” We actually covered the red fox in episode 138, about city animals, and in episode 106, about domestication, but we’ve only mentioned the leopard gecko briefly way back in episode 20.

Arboreal animals have some traits in common, whether they’re reptiles or mammals or something else. In general, an animal that spends most of its time in trees is small and lightweight, either has long legs or very short legs, may have a long tail to help it balance, and may also have various adaptations to its feet to help it maneuver through branches.

This is the case with the chameleon, which is arboreal and has weird feet. Its feet look more like mittens. The feet are called zygodactylous, which means it has two toes pointing forward and two pointing backwards. A lot of birds have feet like this too. Chameleons have other adaptations for arboreal life, like prehensile tails that can twine around a twig to help it keep its balance. The chameleon really deserves its own episode some day, so let’s move on to learn about some geckos.

The biggest gecko known grows up to two feet long, or 60 cm, but most are much smaller. There are more than 1,800 species known and they’re all really interesting and honestly, adorable. They’re mostly nocturnal and eat small animals like insects. About 60% of all gecko species have toe pads that allow them to walk up walls and windows and even across ceilings.

Like many other lizards, most geckos species can drop their tail if a predator attacks. The tail thrashes around on its own for several minutes, distracting the predator so the gecko can escape. The gecko later regrows a little stumpy tail, but it can’t drop it a second time. Many species of gecko store fat in the tail, so it needs that tail. A genus of gecko called the fish-scaled gecko, which lives on Madagascar and nearby islands, has big scales that come loose easily if an animal tries to bite it or if a scientist tries to capture it. The predator gets a mouthful of scales while the gecko runs off. The scales grow back eventually and can be lost again.

Scientists are always interested in animals that can regenerate parts of the body, to learn how that works. A study published in 2017 identified the type of cells that allow the gecko to regrow the part of its spinal cord that’s lost with its tail. In 2018, the same team published their discovery that geckos renew brain cells. This is amazing, since humans and many other animals are born with all the brain cells they’ll ever have, and if something happens to injure the brain, the damage can’t be repaired. Maybe one day people will be able to heal their brains just like the gecko does.

Most species of gecko don’t have eyelids. Instead, the gecko has a protective scale over its eyeball. To remove dust and other debris from the scale, the gecko licks its eyes.

The leopard gecko grows about 11 inches long, or almost 28 cm, and is one of the species that doesn’t have toe pads. That makes it easier to keep in captivity, since it’s less likely to climb out of its terrarium. It’s a handsome lizard that’s yellowish or orangey in color with black spots, but baby leopard geckos actually have black stripes. It’s native to parts of the Middle East and south Asia where it’s mostly hot and dry, and in the wild it spends its day in a burrow and only comes out at night to hunt.

The leopard gecko has been kept as a pet for so long that some people consider it the first truly domesticated lizard. It’s easy to take care of and is usually comfortable around people. Breeders select for brighter colors than are found in wild geckos, including various color and pattern morphs.

One color variety of domestic leopard gecko is called the lemon frost morph, an especially attractive coloration. It’s a pastel yellow with white underneath and brown or black speckles that form broad bands over the lizard’s back. It’s really pretty and when the trait cropped up unexpectedly around 2015, its owner started breeding for the color. Lemon frost babies were rare and incredibly expensive, with people paying up to $2,000 for a single gecko.

Unfortunately, people soon learned that lemon frost geckos were prone to a type of rare skin cancer that affects the iridophores, which are pigment-producing cells. Up to 80% of all lemon frost morphs develop the cancer. Geneticists have discovered that the color morph is due to a single mutation in a single gene, but that the change in that gene also makes the gecko susceptible to cancer. Scientists are now trying to figure out more about how it works in hopes of learning how to prevent skin cancer in humans.

The dragon-tailed gecko is one name for the golden spiny-tailed gecko, one of twenty species in the genus Strophurus. All Strophurus geckos are from Australia and they all spend most of their lives in trees and shrubs. Unlike other geckos, Strophurus geckos don’t drop their tails when threatened. Instead, they have a unique way of deterring predators. A Strophurus gecko can squirt an incredibly smelly liquid from tiny pores in its tail. If it feels threatened, instead of dropping its tail, it will raise its tail up and wave it back and forth as a warning. It also opens its mouth to reveal a bright yellow or blue lining, which alerts the potential predator that this is not a lizard it wants to mess with. If that doesn’t scare the predator away, it will squirt liquid at its face. The liquid is sticky and smells horrible, and if it gets in an animal’s eyes it can cause eye irritation.

Strophurus geckos grow up to 5 inches long, or 13 cm, and species may look very different from each other. Some are drab and spiny, some are smooth and brighter in color. The dragon-tailed gecko has a broad reddish or golden stripe down the top of its tail.

The crested gecko is native to a collection of remote Pacific islands called New Caledonia. It can grow more than 10 inches long, or 25 cm. It has tiny spines above its eyes that look like eyelashes and more spines in two rows down its back, like a tiny dragon. It can be brown, reddish, orange, yellow, or gray, with various colored spots, which has made it a popular pet. These days all pet crested geckos were bred in captivity, since it’s now protected in the wild.

The crested gecko spends most of its time in trees, and not only does it have adhesive toe pads, it also has tiny claws. Most geckos don’t have claws. It can drop its tail like other geckos, but it doesn’t grow back. This doesn’t seem to bother the gecko, though.

The crested gecko was discovered by science in 1866, but wasn’t seen after that in so long that people thought it was extinct. Then it was rediscovered in 1994, so hurrah for the crested gecko!

Let’s move on from geckos to some other arboreal reptiles. A lot of reptiles live mostly in trees, and not all of them are small. The green iguana, for instance. It’s native to southern Mexico into parts of South America but has been introduced in many other places in the Americas, where it’s often considered an invasive species. In warm weather it lives in trees, although it will climb down to the ground in cool, rainy weather, and it can grow up to six and a half feet long, or 2m.

Although the iguana can be really long, most of its length is tail. It has an incredibly long tail for its size. It’s not that heavy, either, with the biggest green iguana ever weighed only a little more than 20 lbs, or 9.1 kg. Most are much lighter. It has long legs and long toes with claws, which makes it a good climber. It uses its tail to balance. It’s usually a drab olive-green or brown in color, although babies are brighter green with reddish spots and some adults are more orange in color. The tail is patterned with broad stripes. It has spines along its back and down its chin, and males develop a large dewlap that hangs down under the neck.

Although the iguana looks like a small dragon, it eats leaves, flowers, fruit, and other plant material, although it will also sometimes eat a grasshopper or snail and even bird eggs every so often. Many people keep green iguanas as pets, but they can be hard to keep healthy in captivity.

Another big reptile that lives in trees is the black mamba, a snake that lives in parts of Africa. It’s a slender snake that can be black in color, but that’s actually rare. The name black mamba comes from the inside of the snake’s mouth, which is black. When it feels threatened, it will raise its head high and open its mouth as a threat display. It can even flatten its neck to look like a hood like some cobras do. You really don’t want to see this threat display, because the black mamba’s venom is deadly and it’s an aggressive snake. Without treatment and antivenin, someone who is bitten can die within 45 minutes.

The mamba’s body can be gray, gray-green, brown, or brownish-yellow. It can grow nearly 15 feet long, or 4.5 meters, which makes it the second-longest venomous snake in the world, after the king cobra that we talked about in our Q&A episode last week.

The black mamba mostly lives in open forests and savannas, and it’s equally at home on the ground and in trees. It hides in termite mounds or in holes in trees at night, then comes out in the morning to warm up in the sunshine. Then it goes hunting, usually for small animals like rodents but also for larger ones like the rock hyrax. The rock hyrax can grow almost two feet long, or 50 cm, and looks kind of like a big rodent even though it’s not a rodent. It’s actually most closely related to the elephant. The black mamba will sneak up on a hyrax, bite it quickly, and then just wait until it dies to swallow it whole. The mamba also hunts birds and bats, which is why it spends so much time in the trees.

Some reptiles are so well adapted to living in trees that they can glide from tree to tree, like the flying snakes we talked about in episode 56. Flying snakes live in southeast Asia, and of course they can’t really fly. A flying snake has ridged scales on its belly that help it climb trees, and when it wants to move from one tree to another, it can flatten its body by flaring its ribs. This gives it more surface area to catch air, like a long skinny Frisbee. It’s been measured as gliding as far as 100 meters, or 109 yards, which is just a little longer than an American football field.

The largest species of flying snake, the golden tree snake, can grow over four feet long, or 1.3 meters. It’s striped black, gold, and yellow although some may be green and black. It eats small animals it finds in trees, including frogs, birds, bats, and lizards. It’s venomous, but its venom is weak and not dangerous to humans.

Many lizards can glide too, including the draco lizard. The draco lizard is common throughout much of southeast Asia and spends almost its whole life in trees, eating insects like ants and termites. It’s a small, slender lizard that only grows about 8 inches long at most, or 20 cm, and that includes its very long tail. Many gliding animals, like the flying squirrel, have gliding membranes called patagia that stretch from the front legs to the back legs, but the draco lizard is different. It has greatly elongated ribs that it can extend like wings, and the skin between the ribs acts as a patagium. This skin is usually yellow or brown so that the lizard looks like a falling leaf when it’s gliding.

The male draco also has a brightly colored dewlap under its chin that it can extend to attract a mate. When a female is ready to lay her eggs, she climbs down from her tree, finds some soil that’s soft enough for her to stick her head into to make a little hole, and then lays her eggs in the hole and covers them with dirt to hide them.

The draco lizard is beautiful and looks like a tiny dragon, and I want one to live in my garden and every time I go out to water my plants or pull weeds, I want it to fly down and ride around on my shoulder.

To bring us full circle, some geckos can also glide using thin membranes of skin around their body, legs, tail, and toes that act as patagia. They’re called parachute geckos, which is just perfect.

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 236: Updates 4 and a Mystery Snake!

Posted on by

Podcast: Play in new window | Download (Duration: 17:33 — 19.4MB)

Subscribe: RSS | More

Sign up for our mailing list! We also have t-shirts and mugs with our logo!

It’s our fourth annual updates and corrections episode! I’ve already had to make a correction to this episode!

Further reading:

Cassowary, a rare emu-like bird, attacks and kills Florida man, officials say

The dog Bunny’s Facebook page

3D printed replicas reveal swimming capabilities of ancient cephalopods

Enormous ancient fish discovered by accident

A rare observation of a vampire bat adopting an unrelated pup

Pandemic paleo: A wayward skull, at-home fossil analyses, a first for Antarctic amphibians

Neanderthals and Homo sapiens used identical Nubian technology

Entire genome from Pestera Muierii 1 sequenced

Animal Species Named from Photos

Cryptophidion, named from photos:

The sunbeam snake showing off that iridescence:

Show transcript:

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

 

It’s our fourth annual updates and corrections episode, and to keep it especially interesting we’ll also learn about a mystery snake. Make sure to check the show notes for lots of links if you want to learn more about these updates.

 

First, we have a small correction from episode 222. G emailed with a link about a Florida man who was killed by a cassowary in 2019, so cassowaries continue to be dangerous.

 

We also have a correction from episode 188, about the hyena. I called hyenas canids at one point, and although they resemble canids like dogs and wolves, they’re not canids at all. In fact, they’re more closely related to cats than dogs. Thanks to Bal for the correction!

 

In response to the talking animals episode, Merike told about a dog who uses computer buttons to communicate. The dog is called Bunny and she’s completely adorable. I’ll link to her facebook page. I have my doubts that she’s actually communicating the way it looks like she is. She’s obviously a clever dog but I don’t think she understands the English language so well that she can choose verbs like “is” from her list of words. I think she’s probably mostly taking unconscious cues from her owner. But I would be happy to be proven wrong.

 

Following up from our recent deep-sea squid episode, a team of paleontologists studying ancient cephalopods 3-D printed some replicas of what the animals would have looked like while alive. Then they took the models into a swimming pool and other water sources to study how their shells affected the way they could move through the water. They discovered that a type of cephalopod with a straight shell, called an orthocone, probably mostly moved up and down in the water to find food and could have moved extremely fast in an upward or downward direction. A type of cephalopod with a spiral shaped shell, called a torticone, also spun slightly as it moved around. The same team has previously worked with 3-D models of ammonoids, which we talked about in episode 86. The models don’t just look like the living animals, they have the same center of balance and other details, worked out mathematically.

 

Speaking of ancient animals, a collector in London bought a fossil found in Morocco thinking it was part of a pterodactyl skull. When the collector asked a palaeontologist to identify it, it turned out to be a fossilized coelacanth lung. The collector donated the fossil for further study, and the palaeontologist, David Martill, worked with a Brazilian coelacanth expert, Paulo Brito, to examine the fossil.

 

The fossil dates to the Cretaceous, about 66 million years ago, and is bigger than any coelacanth lung ever found. Modern coelacanths grow a little over six feet long at most, or 2 meters, but the estimated length of this Coelacanth is some 16 ½ feet, or 5 meters. The fossil is being donated to a university in Morocco.

 

We talked about vampire bats way back in episode 11, and I love bats and especially vampire bats so I try to keep an eye on new findings about them. Everyone thinks vampire bats are scary and creepy, but they’re actually social, friendly animals who don’t mean to spread rabies and other diseases to the animals they bite. It just happens.

 

Vampire bats live in colonies and researchers have long known that if a female dies, her close relations will often take care of her surviving baby. Now we have evidence that at least sometimes, the adoptive mother isn’t necessarily related to the birth mother. It’s from a recently published article based on a study done in 2019.

 

A team researching how unrelated vampire bats form social bonds captured 23 common vampire bats from three different colonies and put them together in a new roost where their interactions could be recorded by surveillance cameras. One particular pair of females, nicknamed Lilith and BD, became good friends. They groomed each other frequently and shared food. If you remember from episode 11, vampire bats share food by regurgitating some of the blood they drank earlier so the other bat can lap it up. Since vampire bats can starve to death in only a few nights if they can’t find blood, having friends who will share food is important.

 

During the study, Lilith gave birth to a baby, but shortly afterwards she started getting sick. She had trouble getting enough food and couldn’t groom or take care of her baby as well as a mother bat should. Her friend BD helped out, grooming the baby, sharing food with Lilith, and eventually even nursing the baby when Lilith got too sick to produce milk. After Lilith died, BD adopted the baby as though it was her own. By the time the study ended, BD was still caring for the baby bat.

 

We talked about spiders in the Antarctic in episode 221, and mentioned that Antarctica hasn’t always been a frozen wasteland of ice and snow. In a new study of fossils found in Antarctica, published in May of 2021, the first Antarctic amphibian skull has been identified. It lived in the early Triassic, not long after the end-Permian mass extinction 252 million years ago. It’s been named Micropholis stowi and is a new species of temnospondyl that was previously only known from South Africa. The skull, along with other fossils from four individuals, was discovered in the Transantarctic Mountains in 2017 and 2018, and the research team studied them from home during the 2020 pandemic lockdowns.

 

In news about humans and our extinct close relations, a new finding shows that Neanderthals and humans used the same type of tools. Researchers studied a child’s tooth and some stone tools, all found in a cave in the mountains of Palestine, and determined that the tooth was from a Neanderthal child, not a human. The tooth was discovered in 1928 but was in a private collection until recently, so no one had been able to study it before now. The tools are a specific type developed in Africa that have only been found associated with humans before. Not only that, but until this finding, there was no evidence that Neandertals ever lived so far south.

 

The child is estimated to have been about nine or ten years old, which is the age when you’re likely to lose a baby tooth as your adult teeth start growing in. I like to think about the child sitting next to their Mom or Dad, who were either creating new tools or using ones they’d already made to do something like cut up food for that evening’s dinner. Maybe the child was supposed to be helping, and they were, but they had a loose tooth and kept giving it a twist now and then, trying to get it to come out. Then, finally, out it popped and bounced onto the cave floor, where it was lost for the next 60,000 years.

 

Researchers have just announced that they’ve sequenced the genetic profile of a woman who lived in what is now Romania about 35,000 years ago. Judging from her skull shape and what is known about ancient humans in Europe, the team had assumed she would be rather restricted in her genetic diversity but that she would show more Neanderthal ancestry than modern humans have. Instead, they were surprised to find that the woman had much more genetic diversity than modern humans but no more Neanderthal genes than most human populations have these days.

 

This was a surprise because modern humans whose prehistoric ancestors migrated out of Africa show much less genetic diversity than modern humans whose ancestors stayed in Africa until modern times. Researchers have always thought there was a genetic bottleneck at some point during or not long after groups of humans migrated out of Africa around 80,000 years ago. Lots of suggestions have been made about what might have caused the bottleneck, including disease, natural disaster, or just the general hardship of living somewhere where humans had never lived before. A genetic bottleneck happens when a limited number of individuals survive long enough to reproduce—in other words, in this case, if so many people die before they have children that there are hardly any children left to grow up and have children of their own. To show in the general population as it does, the bottleneck has to be widespread.

 

Now researchers think the genetic bottleneck happened much later than 80,000 years ago, probably during the last ice age. Humans living in Europe and Asia, where the ice age was severe, would have had trouble finding food and staying warm.

 

I’m getting close to finishing the Strange Animals Podcast book, which I’ll talk about a little more in our Q&A episode later this week. It’s a collection of the best mystery animals we’ve covered on the podcast, along with some new mystery animals, and I’m working hard to update my research. If you remember back in episode 83, about mystery big cats, we discussed the Barbary lion, which was thought to be an extinct subspecies of lion that might not actually be extinct. Well, when I looked into it to see if any new information had turned up, I found more than I expected. I rewrote those paragraphs from episode 83 and I’ll read them here as an update:

 

Lions live mostly in Africa these days, but were once common throughout southern Asia and even parts of southern Europe. There even used to be a species called the American lion, which once lived throughout North and South America. It only went extinct around 11,000 years ago. The American lion is the largest species of lion ever known, about a quarter larger than modern African lions. It probably stood almost 4 feet tall at the shoulder, or 1.2 meters. Rock art and pieces of skin preserved in South American caves indicate that its coat was reddish instead of golden. It lived in open grasslands like modern lions and even in cold areas.

 

Much more recently, the Barbary lion lived in northern Africa until it was hunted to extinction in the area. The Barbary lion was the one that battled gladiators in ancient Rome and was hunted by pharaohs in ancient Egypt. It was a big lion with a dark mane, and was thought to be a separate subspecies of lion until genetic analysis revealed in 2006 that it wasn’t actually different from Panthera leo leo.

 

The last wild Barbary lion was sighted in 1956, but the forest where it was seen was destroyed two years later. The lions in a few zoos, especially in Ethiopia and Morocco, are descended from Barbary lions kept in royal menageries for centuries.

 

Lions are well known to live on the savanna despite the term king of the jungle, but they do occasionally live in open forests and sometimes in actual jungles. In 2012 a lioness was spotted in a protected rainforest in Ethiopia, and locals say the lions pass through the reserve every year during the dry season. That rainforest is also one of the few places left in the world where wild coffee plants grow. So, you know, extra reason to keep it as safe as possible.

 

Finally, we’ll finish with a mystery snake. In 1968, during the Vietnam War, the United States Naval Medical Research Unit discovered a small snake in central Vietnam. It was unusual enough that they decided to save it for snake experts to look at later, but things don’t always go to plan during wartime. The specimen disappeared somewhere along the line. Fortunately, there were photographs.

 

The photos eventually made their way to some biologists, and in 1994 a paper describing the snake as a new species was published by Wallach and Jones. They based their description on the photos, which were good enough that they could determine details like the number of scales on the head and jaw. They named it Cryptophidion annamense and suggested it was a burrowing snake based on its characteristics.

 

Other biologists thought Cryptophidion wasn’t a new species of snake at all. In 1996 a pair of scientists published a paper arguing that it was just a sunbeam snake. The sunbeam snake is native to Southeast Asia, including Vietnam, and can grow over 4 feet long, or 1.3 meters. It’s chocolate-brown or purplish-brown but has iridescent scales that give it a rainbow sheen in sunshine. It’s a constricting snake, meaning it squeezes the breath out of its prey to kill it, but it only eats small animals like frogs, mice, and other snakes. It’s nocturnal and spends a lot of its time burrowing in mud to find food.

 

Wallach and Jones, along with other scientists, argued that there were too many differences between the sunbeam snake and Cryptophidion for them to be the same species. But without a physical specimen to examine, no one can say for sure if the snake is new to science or not. If you live in or near Vietnam and find snakes interesting, you might be the one to solve this mystery.

 

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

 

Thanks for listening!

Episode 228: Monkey Lizards and Weird Turtle…Things

Posted on by

Podcast: Play in new window | Download (Duration: 14:27 — 15.0MB)

Subscribe: RSS | More

Sign up for our mailing list!

We have a merch store now too!

Thanks to Ethan for this week’s topic, two weird animals that developed after the Great Dying we talked about last week!

Further reading:

Monkey Lizards of the Triassic

Placodonts: The Bizarre ‘Walrus-Turtles’ of the Triassic

Drepanosaurus (without a head since we haven’t found a skull yet, but with that massive front claw):

Drepanosaurus’s tail claw:

Hypuronector had a leaf-like tail:

Placodus was a big round-bodied swimmer:

Some placodonts [art by Darren Naish, found at the second article linked above]:

Henodus was the oddball placodont that probably ate plant material:

Show transcript:

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

 

Last week we talked about the end-Permian mass extinction, also called the Great Dying. This week let’s follow up with a couple of weird and interesting animals that evolved once things got back to normal on Earth. Thanks to Ethan who suggested both animals.

 

The great dying marks the end of the Permian and the beginning of the Triassic period, which lasted from about 251 million years ago to 201 million years ago. In those 50 million years, life rebounded rapidly and many animals evolved that we’re familiar with today. But some animals from the Triassic are ones you’ve probably never heard of.

 

We’ll start with a reptile called the drepanosaur. Drepranosaurs are also sometimes called monkey lizards for reasons that will soon become clear. Paleontologists only discovered the first drepanosaur in 1980, Drepanosaurus, and within a few years they recognized a whole new family, Drepanosauridae, to fit that first discovery and subsequent closely related specimens. Drepanosaurs were weird little reptiles that probably looked like lizards in many ways, although they weren’t lizards.

 

How weird was Drepanosaurus? Very weird. Very, very weird.

 

It was obviously a climbing animal that probably spent all of its life in the treetops. It had lots of adaptations to life in trees, such as hind feet where all the toes pointed in the same direction and were somewhat curved, sort of like a spider monkey’s hand. That would help it get a good grip on branches. But those hind feet aren’t why it’s called the monkey lizard.

 

Drepanosaurus and its relatives are called monkey lizards because of their tails. Many monkeys have prehensile tails, which act as a fifth limb and help keep the monkey stable in a tree by curling around branches and hanging on. Drepanosaurus had something similar. Instead of being mobile from side to side like most reptile tails, Drepanosaurus’s tail could mostly only curve downward. Modern chameleons have an even more pronounced downward-curving tail that helps them climb. But the chameleon’s tail is still just a tail. The end of Drepanosaurus’s tail had several modified caudal bones that were probably exposed through the skin. Those modified bones acted as a claw to help the animal grab onto tree trunks and branches. So Drepanosaurus had claws on its front feet, claws on its hind feet, and a claw on its tail. It’s sort of like having five feet.

 

As if that wasn’t weird enough, let’s talk about those claws on the front feet. It had five toes on each foot, and four of them had ordinary claws. They were sharp but fairly small, about what you’d expect from an animal that grew about 19 inches long at most, or 50 cm. But the second toe on each foot, which corresponds to the pointer finger on a human hand, had a much bigger claw. MUCH BIGGER CLAW. It was as big as its whole hand! Most researchers think it used the claw to dig into rotting wood, insect nests, and bark to find insects and other small animals to eat.

 

But that’s not all. Drepanosaurus also had a structure called a supraneural bone at the base of its neck, made up of fused vertebrae, that would have made it look like it had a little hunch on its shoulders. While we don’t have a skull of Drepanosaurus, since we only have three specimens so far, this structure is also present in other drepanosaur species where we do have the neck and head, and they all have fairly long, slender necks and birdlike skulls with large eyes. It’s possible that the supraneural bone was the attachment site for special muscles that helped Drepanosaurus extend its neck very quickly to grab insects and other small animals.

 

Drepanosaurs in general shared many of the traits seen in Drepanosaurus, although with some differences. Many drepanosaurs had opposing toes on the feet that would help them grasp branches and twigs more securely. Most don’t have the giant claw on the front feet although most do have the tail claw. But one monkey lizard doesn’t live up to its name at all.

 

A little drepanosaur called Hypuronector limnaios, which only grew about five inches long, or 12 cm, had a much different tail from its relations. Its tail didn’t curve downward at all—in fact, it stuck up behind it and was probably not very flexible. Not only was the tail longer than the body and head together, it had long points growing down from the vertebrae, called haemal arches, which made the tail extremely large top to bottom but flattened from side to side.

 

In other words, its tail looked like a leaf. The drepanosaur could cling to a branch with its tail sticking up, and any nearby predators would probably think it was just another leaf growing from the branch, especially if the tail was covered in green skin. Some researchers speculate that it could have used its tail as a sail to glide from branch to branch too, or it might have acted as a parachute if it had to jump from a branch to escape a predator. Hypuronector’s front legs were longer than its hind legs, unlike other drepanosaurs, which suggests it might have had a flap of skin that helped it glide.

 

Drepanosaur fossils have been found in parts of the United States and western Europe, but were probably more widespread than that. We still don’t know a whole lot about them, so every new specimen that’s found can give paleontologists lots of new information. Most drepanosaurs resembled weird chameleons with birdlike heads, but they weren’t related to birds or chameleons. We don’t actually know what they were closely related to.

 

Ethan also suggested placodonts, another reptile that evolved in the Triassic. Don’t confuse them with placoderms, the armored fish that went extinct in the great dying. The “placo” part of both words means tablet or plate. Therefore, placoderms have skin—that’s the “derm” part—covered in plates, while placodonts have flattened teeth, because the “dont” part refers to teeth. That’s why you get braces on your teeth at the orthodontist but you go to the dermatologist for skin problems.

 

What did placodonts do with their flattened teeth? They used them to crush the shells of shellfish and crustaceans. From that you can infer that they were marine reptiles, and you would be right. The earlier species had big round bodies with heavy bones, which helped them dive to the ocean floor to find food. They lived in shallow coastal waters and had large flattened ribs that helped protect them from injury if currents pushed them into rocks. While the teeth in the back of the mouth were flattened to crush shells, the teeth in the very front of the mouth were sharp and pointed forward to grab prey.

 

One of the most common early placodonts was Placodus [PLAK-oh-dus], which grew nearly six and a half feet long, or 2 meters. Its long tail was flattened laterally to help it swim and it probably had webbed toes. Since its legs were small and relatively weak considering how heavy its body was, it probably couldn’t get around very well on land, so it would have stayed close to the water. It probably looked kind of like the modern marine iguana, which we talked about in episode 92, but with longer jaws. On the other hand, unlike the marine iguana, placodus had a third eye.

 

THIRD EYE ALERT! If you remember way back in episode 3, where we talked about the tuatara, we learned a little bit about the parietal eye, or third eye. Parietal eyes are found on the top of a few animals’ heads, including the tuatara, but they aren’t the same as ordinary eyes. They’re very small photoreceptive eyes that can only sense light and dark. In Placodus’s case, researchers think that ability helped it figure out which way was up more easily when it was underwater. If you’ve ever been knocked down by a wave you’ll understand how easy it is to get disoriented underwater.

 

Placodus and other early placodonts had a ridge of bony scutes on the back to help protect it from predators. In later placodonts those scutes were bigger and bigger until they were more like armor, which added weight to the body and meant that the bones didn’t have to be so dense. This meant that instead of having barrel-like bodies, later placodonts were a little more streamlined. Their bodies were more flattened than round, but still broad across with big plates protecting the back. Their legs were more like flippers.

 

Does this make you think of something? Something like a sea turtle?

 

Later placodonts looked a lot like turtles, a classic case of convergent evolution because they weren’t related to turtles at all. If you saw Placochelys, for instance, you’d probably just think it was a weird sea turtle, unless you got a really close look at it. It grew about three feet long, or 90 cm, with a triangular head, a knobby shell, and flippers with clawed toes at the ends. It had a beak like a turtle’s instead of Placodus’s forward-pointing teeth, but unlike a turtle it also had teeth in the back of the mouth. These were still big flat teeth used for crushing shellfish, but like other placodonts the upper teeth grew from the palate, or the roof of the mouth.

 

Other placodonts would have looked strange to us, like Psephoderma. It grew up to six feet long, or 180 cm, and instead of a single turtle shell, it had two shells. One covered its body from the back of the head down to the pelvis. The other covered its pelvis and was smaller. It had a long tail and a pointy nose.

 

At least one placodont didn’t live in the ocean and didn’t eat shellfish and crustaceans. Henodus grew about three feet long, or one meter, and lived in brackish water or possibly freshwater. Its shell was twice as broad as it was long. It also had a lower shell, or plastron, on its belly. Its nose was short and squared-off and it had a turtle-like beak, and instead of teeth it had denticles on the sides of its jaws. Some researchers think it was a filter feeder, filtering tiny animals from the water through the denticles, while other researchers think it may have eaten water plants. It might have done both.

 

There’s a lot we don’t know about placodonts. We don’t know if they laid eggs or gave birth to live young, and we don’t know what exactly they ate. Obviously their teeth were best suited to crushing shells, but we don’t actually know what kind of shellfish they preferred or if they only ate crustaceans or something else. Placodont remains have been found in Europe, the Middle East, and China, but they were probably more widespread than that. During the Triassic, as the supercontinent Pangaea broke up, it created lots of shallow oceans and island chains that would have been ideal for placodonts.

 

Unfortunately for the placodonts, as the landmasses moved farther apart over millions of years, the shallow seas became deeper. Populations would have become isolated from each other. Eventually placodonts went extinct, probably by a combination of habitat loss and competition from other animals as dinosaurs and their relatives spread throughout the world.

 

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, and don’t forget to join our mailing list. There’s a link in the show notes.

 

Thanks for listening!

Episode 223: The Elephantnose Fish and the Burmese Star Tortoise

Posted on by

Podcast: Play in new window | Download (Duration: 12:19 — 12.7MB)

Subscribe: RSS | More

Sign up for our mailing list!

This week let’s learn about an amazing little fish and an awesome tortoise! All the pictures here were taken by ME at the Tennessee Aquarium in Chattanooga!

Further Reading:

Star tortoise makes meteoric comeback

The astonishing elephantnose fish:

Burmese star tortoises:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. I’m fully vaccinated now so I’m able to go out and about cautiously, still wearing a mask of course, and this weekend I went to the Tennessee Aquarium in Chattanooga. I had a fantastic time and saw lots and lots of amazing fish and other animals! If you ever get a chance to visit, it’s definitely worth it.

When I got home, I kept thinking about one particular fish. I wanted to learn more about it. So I decided to make an episode about that fish and another animal I saw at the aquarium.

The fish that captivated me so much is called the elephantnose fish. I’d never seen anything like it. The one I saw was about the length of my hand, dark gray or black in color, and looked like a pretty ordinary fish except for the proboscis that gives it its name. The fish has a flexible projection from its nose that it was using to probe around in the gravel at the bottom of its river habitat.

I should mention that the Tennessee Aquarium has enormous displays, beautifully designed to mimic the animals’ natural habitat and give them plenty of room to move around. There’s one tidal animals display in the ocean side of the aquarium where the water sloshes through and around rocks to mimic the tide. It’s fascinating to watch the fish in that exhibit stay pretty much motionless despite the water’s movement, because that’s what they’re adapted for. So there’s plenty of opportunities to see an animal’s behavior.

Anyway, I took lots of pictures of the elephantnose fish and when I got home, I started researching it. It turns out that it’s way more interesting even than I thought!

It lives in rivers and other freshwater in central Africa and grows up to 9 inches long, or 23 cm. That’s according to the info display next to the exhibit. The display also said the fish was a species called Peter’s elephantnose fish, although it’s possible they have more than one species on display. There are a lot of elephantnose fish, more properly called mormyrids or freshwater elephantfish, and many of them have this interesting proboscis.

The proboscis isn’t actually a nose like an elephant’s trunk. It’s technically a modified chin and mouth, called the Schnauzenorgan. The elephantnose fish mostly eats small worms and insect larvae, and it especially loves mosquito larvae.

The elephantnose fish uses electroreception to navigate the muddy waters where it lives and find food. Its whole body, and especially its Schnauzenorgan, is covered with electrocyte cells that can detect tiny electrical pulses. If you remember way back in episode ten, about electric animals, many animals can sense the weak bioelectrical fields that other animals generate in their nerves and muscles. It’s especially common in fish since water conducts electricity much better than air does. But the elephantnose fish also generates a stronger electric field of its own, which it uses as a sort of sonar. It generates the field in special electric organs in its tail, and as it moves around in the water, the electric field comes in contact with other things—plants, rocks, other fish, and so on. It’s not strong enough to give an animal a shock, but it’s strong enough for the elephantnose fish to easily sense changes in its environment. The fish can tell what it’s near because its electrical field interacts differently with different things. A rock, for instance, doesn’t conduct electricity so the fish probably senses it as a blank spot in its electrical field, while a plant may conduct electricity even better than water and therefore changes the shape of the fish’s electrical field in a particular way. But it doesn’t generate its bioelectric field all the time. It can control when it discharges pulses of electricity the same way a dolphin can control when it sends out pulses of sound. If the fish feels threatened, maybe by another elephantnose fish nosing in on its territory, it will pulse much faster so it can keep tabs on what the other fish is doing—plus, of course, the other elephantnose fish can sense its pulses and can interpret how aggressive the first fish is. Female elephantnose fish generate a slightly different electrical field than males, which allows males and females to find each other to spawn.

You may be thinking about all this and wondering how the elephantnose fish can sense the tiny bioelectric charges of its tiny prey over its own electric field. Its electric field is much stronger than that of a teensy worm hiding in the mud, after all. It would be like trying to hear a bird chirping outside through a closed window while someone is playing music really loudly in the room you’re in. It turns out that the elephantnose fish is able to filter out its own electrical field so it can sense other things—but at the same time it’s still able to navigate using its electrical field.

The elephantnose fish needs a large brain to interpret all these complicated bioelectrical signals, and it has a brain to body size ratio equivalent to birds and possibly equivalent to primates. It’s not a social fish, and intelligence seems to develop from complex social interactions, although the fish is considered pretty intelligent. I mean, generally fish are not masterminds, so it’s not hard to be considered an intelligent fish, but the elephantnose fish has the brainpower to pull it off.

The elephantnose fish lives along the bottom of rivers and ponds, usually murky ones, and is mostly nocturnal. For a long time researchers thought it probably couldn’t see very well. It turns out, though, that it sees extremely well. Its retina is made up of cup-shaped cells that act like tiny mirrors, reflecting light and concentrating it so it can see better even in low light.

The elephantnose fish is a popular pet, but it is hard to keep. You have to really know what you’re doing and have a really big aquarium that’s set up just right. The males are aggressive toward each other and while the fish isn’t threatened in the wild, from what I could find out it has never bred in captivity.

Speaking of breeding in captivity, our other animal this week isn’t a fish but a reptile. It’s called the Burmese star tortoise and unlike the elephantnose fish, it’s critically threatened in the wild. It also doesn’t have a Schauzenorgan and instead just has a short little snub nose and lives on land in dry forests in Myanmar. It’s basically the opposite of the elephantnose fish.

It gets the name star tortoise because of its pretty shell markings that look sort of like stars. It can grow up to a foot long, or 30 cm, and eats grass, fruit, and other plant material, but will also eat mushrooms, insects, and snails. It has a steeply domed carapace, the proper name for its shell, with big bumps on it. It lives in central Myanmar in south Asia, but by the late 1990s it was almost extinct in the wild. The tortoise was eaten by locals, but mostly it was captured and sold as a pet or as a medicine ingredient even though it’s a tortoise, not a medicine. This was despite the tortoise being a protected species in the country.

Conservationists realized they had to act fast before this lovely tortoise went extinct. In 2004, authorities caught smugglers with 175 of the tortoises, so Myanmar’s conservation group created tortoise breeding facilities within three of the country’s wildlife sanctuaries. They consulted zoo veterinarians and tortoise experts from all over the world to make sure the rescued tortoises were as happy and healthy as possible. The first captive-bred Burmese star tortoise babies had only been hatched the year before, since it’s hard to breed in captivity.

Each sanctuary has guards that protect it from anyone who wants to sneak in and steal the animals to sell, and 150 of the tortoises have little radio trackers attached to their shells so conservationists can keep an eye on exactly where they are. They go out and check on the tagged tortoises every other week.

Since 2004, over 16,000 Burmese star tortoises have hatched in captivity and about a thousand have been returned to the wild. They’d release more into the wild, but the conservationists are worried that poachers would collect them to sell. The country of Myanmar is in a long-running civil war, unfortunately, and that makes it hard for the people living there to concentrate on conservation. Their main goal is just to stay safe. Hopefully things will get better soon for the people of Myanmar, and when they do, the tortoises will be waiting.

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 212: The River of Giants

Posted on by

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

Subscribe: RSS | More

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

Further reading:

King of the River of Giants

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

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

Not actually a pancake crocodile:

A model of Aegisuchus and some modern humans:

Show transcript:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Thanks for listening!

Episode 210: The Mysterious Lightbulb Lizard

Posted on by

Podcast: Play in new window | Download (Duration: 10:19 — 10.6MB)

Subscribe: RSS | More

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!

Episode 209: Animals Discovered in 2020

Posted on by

Podcast: Play in new window | Download (Duration: 18:31 — 19.4MB)

Subscribe: RSS | More

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

Further reading:

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

Rare Iridescent Snake Discovered in Vietnam

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

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

New whale(s) just dropped:

A newly discovered pygmy seahorse:

A newly discovered pipefish is extremely red:

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

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

The newly rediscovered devil eyed frog. I love him:

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

This newly discovered snake from Vietnam is iridescent and shiny:

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

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

Show transcript:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, or just want a sticker, email us at 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 207: The Dire Wolf!

Posted on by

Podcast: Play in new window | Download (Duration: 9:58 — 10.3MB)

Subscribe: RSS | More

This week we’re on the cutting edge of science, learning about the brand new genetic study of dire wolves that rearranges everything we know about the dire wolf and other canids! Also, a bonus turtle update.

Further reading:

Dire Wolves Were Not Really Wolves, Genetic Clues Reveal

An artist’s rendition of dire wolves and grey wolves fighting over a bison carcass (art by Mauricio Anton):

The pig-nosed face of the Hoan Kiem turtle, AKA Yangtze giant softshell turtle, AKA Swinhoe’s softshell turtle:

Show transcript:

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

You may have heard the news this past week about the new study about dire wolves. I thought it would make a great topic for an episode, and we’ll also have a quick update about a rare turtle that’s been in the news lately too.

Dire wolves show up pretty often in movies and TV shows and video games and books, because as far as anyone knew until very recently, the dire wolf was an extra big wolf that lived in North America during the Pleistocene until it went extinct around 13,000 years ago. Researchers assumed it was a close cousin of the modern grey wolf.

Well, in a brand new study published in Nature literally less than a week ago as this episode goes live, we now have results of a genetic study of dire wolf remains. The results give us surprising new information not just about the dire wolf, but about many other canids.

The study started in 2016, when an archaeologist, Angela Perri, who specializes in the history of human and animal interactions, wanted to learn more about the dire wolf. She went around the United States to visit university collections and museums with dire wolf remains, and took the samples she collected to geneticist Kieren Mitchell. Perri, Mitchell, and their team managed to sequence DNA from five dire wolves that lived between 50,000 and 13,000 years ago.

Then the team compared the dire wolf genome to those of other canids, including the grey wolf and coyote, two species of African wolf, two species of jackal, and the dhole, among others. To their surprise, the dire wolf’s closest relation wasn’t the grey wolf. It was the jackals, both from Africa, but even they weren’t very closely related.

It turns out that 5.7 million years ago, the shared ancestor of dire wolves and many other canids lived in Eurasia. At this point sea levels were low enough that the Bering land bridge, also called Beringia, connected the very eastern part of Asia to the very western part of North America. One population of this canid migrated into North America while the rest of the population stayed in Asia. The two populations evolved separately until the North America population developed into what we now call dire wolves. Meanwhile, the Eurasian population developed into many of the modern species we know today, and eventually migrated into North America too.

By the time the gray wolf populated North America, the dire wolf was so distantly related to it that even when their territories overlapped, they avoided each other and didn’t interbreed. We’ve talked about canids in many previous episodes, including how readily they interbreed with each other, so for the dire wolf to remain genetically isolated, it was obviously not closely related at all to other canids at this point.

The dire wolf looked a lot like a grey wolf, but researchers now think that was due more to convergent evolution than to its relationship with wolves. Both lived in the same habitats: plains, grasslands, and forests. The dire wolf was slightly taller on average than the modern grey wolf, which can grow a little over three feet tall at the shoulder, or 97 cm, but it was much heavier and more solidly built. It wouldn’t have been able to run nearly as fast, but it could attack and kill larger animals. Its head was larger in proportion than the grey wolf’s and it had massive teeth that were adapted to crush bigger bones.

The dire wolf lived throughout North America and even migrated into South America and back into east Asia. It preferred open lowlands and its most important prey animal was probably the horse, although it also ate ground sloths, camels, bison, and many others. It probably also scavenged dead animals and probably hunted as a pack.

Researchers think the dire wolf went extinct due to a combination of factors, including increased competition with grey wolves and maybe with humans, climate change, and the extinction of the megaherbivores that made up its diet. It will probably be reclassified into a different genus, Aenocyon, instead of staying in its current genus, Canis.

Before this study, most researchers thought that the ancestor of North American canids evolved in Eurasia, but had already migrated into North America before developing into dire wolves, grey wolves, coyotes, and other canid species. But now the history of canids has changed a lot. From what we now know, pending further study, the dire wolf was the only canid in North America for millions of years. Grey wolves, coyotes, and their relations are relative newcomers. It’s an exciting time for scientists studying ice age megafauna. Hopefully we’ll learn more soon as more studies are conducted into the dire wolf’s history.

Next, let’s look briefly at a type of turtle that’s been in the news lately too. Swinhoe’s softshell turtle is considered the most endangered turtle in the world. In early 2019 there were only two individuals known, a male and a female, but they had never bred despite being kept together in captivity. Then the female died in April of that year. No females meant no eggs, no baby turtles, no more Swinhoe’s softshell turtle. The species would be extinct.

But in October of 2020, researchers found a female Swinhoe’s softshell turtle in the wild! Not only that, they spotted what they think is a male turtle in the same lake, and found evidence of what may possibly be a third turtle nearby.

Swinhoe’s softshell turtle is also known as the Yangtze giant softshell turtle and used to be found in many lakes and rivers in Asia. Unfortunately, people killed it for its meat and dug up its eggs to eat, and pollution and habitat loss also killed off many of the turtles. This is the same turtle we talked about in episode 68, the Hoan Kiem turtle of Vietnam. It’s probably the largest freshwater turtle in the world, and the largest one ever measured weighed 546 lbs, or 247.5 kg. It can grow over three feet long, or 100 cm.

The newly discovered wild turtles are being monitored carefully to make sure they’re healthy, their environment is clean and safe, and to see if the female lays eggs this spring. The female was captured briefly, just long enough to take blood samples and verify that she was healthy. Then they released her back into the lake. Fingers crossed that she hatches some baby turtles soon!

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!