Category Archives: reptile

Episode 278: Gender Diverse Animals

Posted on by

Podcast: Play in new window | Download (Duration: 16:51 — 12.7MB)

Subscribe: RSS | More

This week is Connor’s episode, and we’re going to learn about some animals that don’t conform to “typical” gender roles, one way or another.

I’ll be at ConCarolinas this week, from June 3 through 5, including recording a live crossover episode with Arcane Carolinas!

Further reading:

Species of algae with three sexes that all mate in pairs identified in Japanese river

How a microbe chooses among seven sexes

Facultative Parthenogenesis in California Condors

The sparrow with four sexes

Chinstrap penguins make good dads:

Laysan albatrosses make good moms:

Black swans make good dads:

Some rams really like other rams (photo by Henry Holdsworth):

New Mexico whiptail lizards are all females:

California condor females don’t always need a male to produce fertilized eggs:

Clownfish change sex under some circumstances:

The white-throated sparrow essentially has four sexes:

You are awesome (photo by By Eric Rolph)!

Show transcript:

“Hey y’all, this is Connor. Welcome to a very special Pride Month edition of the Strange Animals Podcast.”

This week we have Connor’s episode! We decided to make it the very last episode in our Kickstarter month so that it’s as close to the month of June as possible, because June is Pride Month and our episode is about gender-diverse animals! Don’t worry, parents of very young children, we won’t be discussing mating practices except in very general terms.

Pride month celebrates people’s differences when it comes to gender expression and sexuality. That’s why its symbol is the rainbow, because a rainbow is made up of all different colors the same way there are different kinds of people. Sometimes people get angry when they hear about Pride month because they think there are only two genders, and that those two genders should only behave in certain ways. Pffft. That’s not even true when it comes to animals, and humans are a lot more socially complicated.

For instance, let’s start by talking about a humble creature called algae. If you remember episode 129, about the blurry line between animals and plants, you may remember that algae isn’t actually a plant or an animal. Some species resemble plants more than animals, like kelp, but they’re not actually plants. In July of 2021, scientists in Japan announced that a species of freshwater algae has three sexes: male, female, and bisexual. All three sexes can pair up with any of the others to reproduce and their offspring may be male, female, or bisexual at random.

Even though the algae has been known to science for a long time, no one realized it has three sexes because most of the time, algae reproduces by cloning itself. The research team thinks that a lot of algae species may have three sexes but researchers just haven’t been looking for it.

Yes, I realize that was a weird place to start, but it’s also fascinating! It’s also not even nearly as complicated as a protozoan called Tetrahymena thermophila, which has seven sexes.

Let’s look at a bird next, the penguin. You’ve probably heard of the book And Tango Makes Three, about two male penguins who adopt an egg and raise the baby chick together. For some reason some people get so angry at those penguins! Never trust someone who doesn’t like baby penguins, and never trust someone who thinks animals should act like humans. The events in the book are based on a true story, where two male chinstrap penguins in New York’s Central Park Zoo formed a pair bond and tried to hatch a rock, although they also tried to steal eggs from the other penguins. A zookeeper gave the pair an extra penguin egg to hatch instead.

The most interesting thing about the story is that same-sex couples are common among penguins, in both captivity and in the wild, among both males and females. Since penguins sometimes lay two eggs but most species can only take care of one chick properly, zookeepers often give the extra eggs to same-sex penguin pairs. The adoptive parents are happy to raise a baby together and the baby is more likely to survive and be healthy. Occasionally a same-sex penguin couple will adopt an egg abandoned by its parents.

If you remember episode 263 a few months ago, where we talked about animals that mate for life, you may remember the Laysan albatross. In that episode we learned about a specific Laysan albatross named Wisdom, the oldest wild bird in the world as far as we know. While I was researching Wisdom, I learned something marvelous. As many as 30% of all Laysan albatross pairs are both females. Sometimes one of the females will mate with a male and lay a fertilized egg, and then both females raise the baby as a couple. Sometimes one of the females lays an unfertilized egg that doesn’t hatch. There are many more Laysan albatross females than males, which may be the reason why females form pairs, but it’s perfectly normal behavior. It’s also been a real help to conservationists. Sometimes an albatross pair will nest in an area that’s not safe, like on an airfield. Instead of leaving the egg to be smashed by an airplane, conservationists take the fertilized egg from the unsafe nest and use it to replace the unfertilized egg of a female pair. The egg is safe and the chick has adoptive parents who raise it as their own.

Many other birds develop same-sex pairs too. This is especially common in the black swan, where up to a quarter of pairs are both male. One or both of the males will mate with a female, but after she lays her eggs the males take care of them and the cygnets after they hatch. Cygnets raised by two dads are much more likely to survive than cygnets raised by one mom and one dad. The males are stronger and more aggressive, so they can defend the nest and babies more effectively.

Birds aren’t the only animals that form same-sex pair bonds. Many mammals do too. It’s been documented in the wild in lions, elephants, gorillas, bonobos, dolphins, and many more. In species that don’t typically form pair bonds, homosexual behavior is still pretty common. It’s so common among domestic sheep that shepherds have to take into account the fact that up to 10% of rams prefer to mate with other rams instead of with ewes. Some rams show attraction to both males and females. This happens in wild sheep too, where rams may court other rams the same way they court ewes. Some ewes also show homosexual behavior.

The New Mexico whiptail is a lizard that lives in parts of the southwestern United States and northern Mexico. It can grow over nine inches long, or 23 cm, and is black or brown with yellow racing stripes. It eats insects and is an active, slender lizard that’s common throughout its range. And every single New Mexico whiptail lizard is a female.

The lizards reproduce by a process called parthenogenesis. That basically means an animal reproduces asexually without needing to have its eggs fertilized. The lizards do mate, though, but not with males. Females practice mating behaviors with each other, which researchers think causes a hormone change that allows eggs to develop. Females who don’t mate don’t develop eggs.

Female birds can sometimes reproduce asexually too. It’s been documented in turkeys, chickens, pigeons, finches, and even condors. A study published in late 2021 detailed two instances of parthenogenesis in California condors in a captive breeding program. In both cases the females were housed with their male mates, and in both cases the pairs had produced offspring together before. But in both cases, for some reason the females laid eggs that hatched into chicks that were genetically identical to the mothers. It’s possible parthenogenesis is even more common in birds than researchers thought.

In many species of reptile, whether a baby is a male or female depends completely on how warm its egg gets during incubation. For example, the American alligator. The mother gator builds a nest of plant material and lays her eggs in it. As the plant material decays, it releases heat that keeps the eggs warm. How much heat is generated depends on where the mother alligator builds her nest and what plants she uses, which in turns affects the eggs. If the temperature in the nest is under 86 degrees Fahrenheit, or 30 Celsius, during the first few weeks of incubation, most or all of the eggs will hatch into females. If the temperature is 93 F or 34 C, most or all of the eggs will hatch into males. If the temperature is between the two extremes, there will be a mix of males and females, although usually more females.

Because climate change has caused an overall increase in temperatures across the world, some already vulnerable reptile populations, especially sea turtles, are hatching almost all males. Conservationists have to dig up the eggs and incubate them at a cooler temperature in captivity, then release the babies into the ocean when they hatch.

Other animals change from male to female or vice versa, depending on circumstances. The clownfish, for example. Clownfish start out life as males but as they grow up, most become females, although only the dominant pair in a colony actually reproduces. Clownfish live in colonies led by the largest, most aggressive female, with the largest, most aggressive male in the group as her mate. If something happens to her, her former mate takes her place, becoming a female in the process. The largest juvenile male then becomes her mate and remains male even though he puts on a growth spurt to mature quickly. If Finding Nemo was scientifically accurate, it would have been a much different movie.

Another group of fish that live around reefs are wrasses, which includes the famous cleaner fish that cleans parasites and dead tissue off of larger fish. Wrasses hatch into both males and females, but the males aren’t the same type of males that can breed. Those develop later. When the dominant breeding male of the group dies, the largest female or the largest non-breeding male then develops into a breeding male. But sometimes a non-breeding male will develop into a female instead.

The term for an animal that changes sex as part of its natural growth process is sequential hermaphroditism. It’s common in fish and crustaceans in particular. Other animals have the reproductive organs of both a male and a female, especially many species of snail, slug, earthworm, sea slug, and some fish. We talked about the mangrove killifish in episode 133, and in that episode I said it was the only known vertebrate hermaphrodite. That’s actually not accurate, although I was close. It’s the only known vertebrate hermaphrodite that can self-fertilize. Almost all mangrove killifish are females, although they also produce sperm to fertilize their own eggs. The eggs hatch into little clones of the mother.

We’ve talked about seahorses before too, especially in episode 130. Seahorse pairs form bonds that last throughout the breeding season. The pair participate in courtship dances and spend most of their time together. When the eggs are ready, the female deposits them in a special brood pouch in the male’s belly, where he fertilizes them. They then embed themselves in the spongy wall of the brood pouch and are nourished not only by the yolk sacs in the eggs, but by the male, who secretes nutrients in the brood pouch. So basically the male is pregnant. The female visits him every day to check on him, usually in the mornings. When the eggs hatch after a few weeks, the male expels the babies from his pouch and they swim away, because when they hatch they are perfectly formed teeny-tiny miniature seahorses.

Let’s finish with a little songbird that’s common throughout eastern North America, the white-throated sparrow. It has a white patch on its throat and a bright yellow spot between the eye and the bill. There are two color morphs, one with black and white stripes on its head, one with brown and tan stripes on its head. Both males and females have these head stripes. The male sings a pretty song that sounds like this:

[white-throated sparrow call]

A 30-year study into white-throated sparrow genetics has revealed some amazing things. The color morphs are due to a genetic difference that affects a lot more than just feather colors. Black morph males are better singers, but they don’t guard their territory as well or take care of their babies as well as brown morphs do. They also aren’t as faithful to their mates as the brown morph males, which are fully monogamous and are diligent about helping take care of their babies. Despite their differences in raising offspring, both morphs are equally successful and equally common.

All this seems to be no big deal on the surface, maybe just pointing to the possibility that the species is in the process of splitting into two species or subspecies. But that’s not the case.

Black morphs always mate with brown morphs. A black morph male will always have a brown morph mate, and vice versa. Genetically, the two morphs are incredibly different—so different, in fact, that they seem to be developing a fully different set of sex chromosomes. In other words, there are male and female black morph birds and male and female brown morph birds that are totally different genetically, but still members of the same species that only ever breed with each other. In essence, the white-throated sparrow has four sexes.

Usually I try to end episodes with something funny, but today I’m going to speak directly to you. Yes, you! If you’re listening to this or reading the transcript, my words are meant just for you. You are an amazing person and I love you. You deserve to be happy. If anyone has ever told you there’s something wrong with the way you are, or the way you wish you were or want to be, they’re wrong. They probably also don’t like penguins, so you don’t have to believe anything they say. If you’ve ever read books by Terry Pratchett, you may recognize this quote: “Be yourself, as hard as you can.”

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 269: Gila Monsters, Basilisks, and Sand Boas, oh my!

Posted on by

Podcast: Play in new window | Download (Duration: 14:34 — 16.8MB)

Subscribe: RSS | More

Thanks to Zachary, Enzo, and Oran for their suggestions this week! Let’s learn about some interesting reptiles!

Happy birthday to Vale! Have a fantastic birthday!!

The magnificent Gila monster:

The Gila monster’s tongue is forked, but not like a snake’s:

The remarkable green basilisk (photo by Ryan Chermel, found at this site):

A striped basilisk has a racing stripe:

I took this photo of a basilisk myself! That’s why it’s a terrible photo! The basilisk is sitting on a branch just above the water, its long tail hanging down:

The desert sand boa:

Show transcript:

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

This week we’re going to learn about three weird and interesting reptiles, with suggestions from Zachary, Enzo, and Oran, including a possible solution to a mystery animal we’ve talked about before!

But first, we have a birthday shoutout! A very happy birthday to Vale! You should probably get anything you want on your birthday, you know? Want a puppy? Sure, it’s your birthday! Want 12 puppies? Okay, birthday! Want to take your 12 puppies on a roadtrip in a fancy racecar? Birthday!

Our first suggestion is from Enzo and Zachary, who both wrote me at different times suggesting an episode about the Gila monster. How I haven’t already covered an animal that has monster right there in its name, I just don’t know.

The Gila monster is a lizard that lives in parts of southwestern North America, in both the United States and Mexico. It can grow up to two feet long, or 60 cm, including its tail. It’s a chonky, slow-moving lizard with osteoderms embedded in its skin that look like little pearls. Only its belly doesn’t have osteoderms. This gives it a beaded appearance, and in fact the four other species in its genus are called beaded lizards. Its tongue is dark blue-black and forks at the tip, but not like a snake’s tongue. It’s more like a long lizard tongue that’s divided at the very end.

The Gila monster varies in color with an attractive pattern of light-colored blotches on a darker background. The background color is dark brown or black, while the lighter color varies from individual to individual, from pink to yellow to orange to red. You may remember what it means when an animal has bright markings that make it stand out. It warns other animals away. That’s right: the Gila monster is venomous!

The Gila monster has modified salivary glands in its lower jaw that contain toxins. Its lower teeth have grooves, and when the lizard needs to inject venom, the venom flows upward through the grooves by capillary force. Since it mostly eats eggs and small animals, scientists think it only uses its venom as a defense. Its venom is surprisingly toxic, although its bite isn’t deadly to healthy adult humans. It is incredibly painful, though. Some people think the Gila monster can spit venom like some species of cobra can, but while this isn’t the case, one thing the Gila monster does do is bite and hold on. It can be really hard to get it to let go.

The fossilized remains of a Gila monster relative were discovered in 2007 in Germany, dating to 47 million years ago. The fossils are well preserved and the lizard’s teeth already show evidence of venom canals. The Gila monster is related to monitor lizards, although not closely, and for a long time people thought it was almost the only venomous reptile in the world. These days we know that a whole lot of lizards produce venom, including the Komodo dragon, which is a type of huge monitor lizard.

In 2005, a drug based on a protein found in Gila monster venom was approved for use in humans. It helps manage type 2 diabetes, and while the drug itself is synthetic and not an exact match for the toxin protein, if researchers hadn’t started by studying the toxin, they wouldn’t have come up with the drug.

The Gila monster lives in dry areas with lots of brush and rocks where it can hide. It spends most of its time in a burrow or rock shelter where it’s cooler and the air is relatively moist, and only comes out when it’s hungry or after rain. It eats small animals of various kinds, including insects, frogs, small snakes, mice, and birds, and it will also eat carrion. It especially likes eggs and isn’t picky if the eggs are from birds, snakes, tortoises, or other reptiles. It has a keen sense of smell that helps it find food. During spring and early summer, males wrestle each other to compete for the attention of females. The female lays her eggs in a shallow hole and covers them over with dirt, and the warmth of the sun incubates them.

The Gila monster is increasingly threatened by habitat loss. Moving a Gila monster from a yard or pasture and taking it somewhere else actually doesn’t do any good, because the lizard will just make its way back to its original territory. This is hard on the lizard, because it requires a lot of energy and exposes it to predators and other dangers like cars. It’s better to let it stay where it is. It eats animals like mice and snakes that you probably would rather not have in your yard anyway, and as long as you don’t bother it, it won’t bother you. Also, it’s really pretty.

Next, Oran wants to learn more about the basilisk lizard. We talked about it very briefly in episode 252 and I actually saw two of them in Belize, so they definitely deserve more attention.

The basilisk lives in rainforests from southern Mexico to northern South America. There are four species, and a big male can grow up to three feet long, or 92 cm, including his long tail. The basilisk’s tail is extremely long, in fact—up to 70% of its total length.

Both male and female basilisks have a crest on the back of the head. The male also has a serrated crest on his back and another on his tail that make him look a little bit like a tiny Dimetrodon.

The basilisk is famous for its ability to run across water on its hind legs. The toes on its large hind feet have fringes of skin that give the foot more surface area and trap air bubbles, which is important since its feet plunge down into the water almost as deep as the leg is long. Without the air trapped under its toe fringes, it wouldn’t be running, it would be swimming. It can run about 5 feet per second, or 1.5 meters per second, for about three seconds, depending on its weight. It uses its long tail for balance while it runs.

When a predator chases a basilisk, it rears up on its hind legs and runs toward the nearest water, and when it comes to the water it just keeps on running. The larger and heavier the basilisk is, the sooner it will sink, but it’s also a very good swimmer. If it’s still being pursued in the water, it will swim to the nearest tree and climb it, because it also happens to be a really good climber.

The basilisk can also close its nostrils to keep water and sand out, which is useful because it sometimes burrows into sand to hide. It can also stay underwater for as long as 20 minutes, according to some reports. It will eat pretty much anything it can find, including insects, eggs, small animals like fish and snakes, and plant material, including flowers. It mostly eats insects, though.

Fossil remains of a lizard discovered in Wyoming in 2015 may be an ancestor to modern basilisks. It lived 48 million years ago and probably spent most of its time in trees. It had a bony ridge over its eyes that shaded its eyes from the sun and also made it look angry all the time. It grew about two feet long, or 61 cm., and may have already developed the ability to run on its hind legs. We don’t know if it could run on water, though.

Finally, Zachary also suggested the sand boa. Sand boas are non-venomous snakes that are mostly nocturnal. During the day the sand boa burrows deep enough into sand and dirt that it reaches a cool, relatively moist place to rest. At night it comes out and hunts small animals like rodents. If it feels threatened, it will dig its way into loose soil to hide. It’s a constrictor snake like its giant cousin Boa constrictor, but it’s much smaller and isn’t aggressive toward humans.

Zachary thinks that the sand boa might actually be the animal behind sightings of the Mongolian death worm. We’ve talked about the Mongolian death worm in a few episodes, most recently in episode 156.

The Mongolian death worm was first mentioned in English in a 1926 book about paleontology, but it’s been a legend in Mongolia for a long time. It’s supposed to look like a giant sausage or a cow’s intestine, reddish in color and said to be up to 5 feet long, or 1.5 meters. It mostly lives underground in the western or southern Gobi Desert, but in June and July it surfaces after rain. Anyone who touches the worm is supposed to die painfully, although no one’s sure how exactly it kills people. Some suggestions are that it emits an electric shock or that it spits venom.

Mongolia is in central Asia and is a huge but sparsely populated country. At least one species of sand boa lives in Mongolia, although it’s rare. This is Eryx miliaris, the desert sand boa. Females can grow up to 4 feet long, or 1.2 meters, while males are usually less than half that length. Until recently it was thought to be two separate species, and sometimes you’ll see it called E. tataricus, but that’s now an invalid name.

The desert sand boa is a strong, thick snake with a blunt tail and a head that’s similarly blunt. In other words, like the Mongolian death worm it can be hard to tell at a glance which end is which. Its eyes are small and not very noticeable, just like the death worm. It’s mostly brown in color with some darker and lighter markings, although its pattern can be quite variable. Some individuals have rusty red markings on the neck.

It prefers dry grasslands and will hide in rodent burrows. When it feels threatened, it will coil its tail up and may pretend to bite, but like other sand boas it’s not venomous and is harmless to humans.

At first glance, the desert sand boa doesn’t seem like a very good match with the Mongolian death worm. But in 1983, a group of scientists went searching for the death worm in the Gobi. They were led by a Bulgarian zoologist named Yuri Konstantinovich Gorelov, who had been the primary caretaker of a nature preserve in Mongolia for decades and was familiar with the local animals. The group visited an old herder who had once killed a death worm, and in one of those weird coincidences, while they were talking to the herder, two boys rushed in to say they’d seen a death worm on a nearby hill.

Naturally, Gorelov hurried to the top of the hill, where he found a rodent burrow. Remember that this guy knew every animal that lived in the area, so he had a good idea of what he’d find in the burrow. He stuck his hand into it, which made the boys run off in terror, and pulled out a good-sized sand boa. He draped it around his neck and sauntered back to show it to the old herder, who said that yes, this was exactly the same kind of animal he’d killed years before.

That doesn’t mean every sighting of a death worm is necessarily a sand boa. I know I’ve said this a million times, but people see what they expect to see. The death worm is a creature of folklore, whether or not it’s based on a real animal. If you hear the story of a dangerous animal that looks like a big reddish worm with no eyes and a head and tail that are hard to distinguish, and you then see a big snake with reddish markings, tiny eyes, and a head and tail that are hard to distinguish, naturally you’ll assume it’s a death worm.

At least some sightings of the death worm are actually sightings of a sand boa. But some death worm sightings might be due to a different type of snake or lizard, or some other animal—maybe even something completely new to science. That’s why it’s important to keep an open mind, even if you’re pretty sure the animal in question is a sand boa. Also, maybe don’t put your bare hand in a rodent burrow.

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 264: Sick, Sad Dinosaurs

Posted on by

Podcast: Play in new window | Download (Duration: 11:05 — 12.7MB)

Subscribe: RSS | More

This week we answer a question you probably didn’t ask, did dinosaurs ever get sick? The answer is yes (or else it would be a super short episode). (Thanks to Llewelly for some corrections!)

A big birthday shout-out to Gwendolyn! Have a great birthday!

The unlocked Patreon episode about green puppies

Further reading:

Researchers discover first evidence indicating dinosaur respiratory infection

Sauro-throat, Part 3: what does Dolly’s disease tell us about sauropods?

Dinosaurs got cancer

Giant Dinosaur Had 2 Tumors on Its Tailbone

Dinosaurs got sick, too–but from what?

cough cough:

Show transcript:

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

This week we have a dinosaur episode, but not one you may expect. We’re going to learn about some dinosaur fossils found with evidence of sickness to answer the question, did dinosaurs get sick? Yes, they did. Otherwise this episode would be about two minutes long.

I know some people get squicked when they hear about illness and disease, so I’ve also unlocked a Patreon episode about puppies that are born green. Don’t worry, the puppies are fine! There’s a link in the show notes so you can click through and listen to the episode on your browser, no login needed.

Before we get to the dinosaurs, we have a birthday shout-out! Happy birthday to Gwendolyn, who is turning two years old this week! Oh my gosh, Gwendolyn, you’re going to learn so many new things this year! I hope you have a wonderful birthday.

And now, the dinosaurs.

Just a few days ago as this episode goes live, researchers announced that they’d found the fossilized remains of a young sauropod dinosaur. It lived around 150 million years ago in what is now the United States, specifically in southwestern Montana. The fossil was nicknamed Dolly by the paleontologists who studied it.

Dolly was a sauropod in the family Diplodocidae, and like other sauropods the Diplodocids all had huge neck vertebrae because their necks were so long. The bones weren’t solid, though, but contained air sacs that made the bones lighter and also connected to the respiratory system. This is the case in birds too. Technically the air sacs in the bones are called pneumatic diverticula, but that’s hard to say so I’m just going to call them air sacs.

When a bird breathes, instead of its lungs inflating and deflating, the air sacs throughout its body and bones inflate and deflate. This pumps fresh air through the lungs and allows the bird to absorb a lot more oxygen with every breath than most mammals can.

The bones of Dolly’s neck had unusual bony protrusions around the spaces where the air sacs once were. When the paleontologists made a CT scan of the protrusions they discovered they were abnormal bone growths that probably resulted from an infection. Sauropods share a common ancestor with birds and researchers think they might have sometimes caught a respiratory illness similar to aspergillosis [asper-jill-OH-sus], a disease common in birds and reptiles today.

Dolly would have had a fever, difficulty breathing, coughing, a sore throat, and other symptoms familiar to us as flu-like or pneumonia-like. Aspergillosis can be fatal in birds, so this respiratory infection might have actually been what killed Dolly. I think we can all agree that the worst symptom to have as a sauropod, whose necks were as much as 30 feet long, or 9 meters, is a sore throat.

That’s not the only indication of illness in a dinosaur fossil, of course. A 2003 paper published in Nature detailed the results of a study where paleontologists scanned 10,000 dinosaur vertebrae from over 700 animals to see if any of them showed tumors. They found 97 individuals that did, all of them from around 70 million years ago and all of them hadrosaurs. Those are the duck-billed dinosaurs that were common in the late Cretaceous in many parts of the world, especially in what is now North America and Asia. Hadrosaurs had flattened snouts that made the skull look like it has a duck bill, but it wasn’t a birdlike bill and hadrosaurs had teeth.

The hadrosaur was a plant-eater and it especially liked to eat conifers. Conifers were really common through most of the Cretaceous and are still around today, including pines, cedars, junipers, hemlocks, redwoods, yews, cypresses, larches, spruces, and more. Most are fast-growing evergreens with scaly or needle-like leaves, and many of them produce resins that are high in toxins to help ward off insects and fungus, and help keep many animals from eating the leaves. Amber is fossilized resin from conifer trees.

Conifer resins contain carcinogenic chemicals, which means that eating enough conifer leaves can increase the risk of developing tumors. Hadrosaurs ate conifers all the time, so it’s not surprising that the 2003 study found a relatively high percentage of hadrosaur vertebrae with tumors. Most of the tumors were small and benign. Only two dinosaurs showed evidence of cancerous tumors. Most confusing to the researchers is that the tumors are mostly in the hadrosaurs’ tail vertebrae.

A more recent study, from 2016, found two tiny tumors on one vertebra from a titanosaur. It lived 90 million years ago in what is now Brazil in South America. Titanosaurs are some of the largest sauropods known, including one species that was 85 feet long, or 26 meters, but the tumors were only about 8 millimeters across and were benign. This was the first study that found a tumor in a dinosaur that wasn’t a hadrosaur, although they’ve been found in fossils of other animals like mosasaurs and ancient crocodiles.

A study published in 2020 found advanced cancer in the leg bone of a centrosaurus too. Centrosaurus was a ceratopsian dinosaur that lived in the late Cretaceous in what is now Canada. It had a single horn on its nose, two smaller horns over its eyes, and a frill at the back of its head that was decorated with two more small hook-like horns. It lived in herds and ate plants. The individual with the cancerous leg bone would have had trouble running or even walking on its bad leg, but it didn’t die of cancer or predation. Instead, researchers think it drowned in a flood along with the rest of its herd. This means it was protected by its herd and able to live a normal life despite its disease. In fact, when the centrosaurus bone was first discovered, researchers thought it just showed a healed fracture.

That’s the case for a disease seen in some theropod dinosaurs, specifically tyrannosaurids, including Tyrannosaurus rex. Even Sue the T. rex shows evidence of this disease and researchers think it might have been wide-spread among tyrannosaurids. Initially paleontologists thought it was the result of bite wounds from other dinosaurs, but a 2009 study presented evidence that the lesions seen in many tyrannosaurid skulls were due to a parasitic infection similar to that found in some birds today.

The infection is called trichomonosis and is especially common in pigeons, where it’s called canker, and birds of prey, where it’s called frounce. Other birds can catch it too and it can decimate songbird populations. It’s due to a parasite that only affects birds, so you can’t catch it from a sick bird. If you have a birdfeeder or birdbath in your yard, it’s a good idea to give it a good scrub every so often and let it dry out thoroughly before putting it out again in a different area. The parasite is spread from bird to bird and causes lesions in the mouth and throat that can eventually cause the bird to die. 

Researchers think trichomonosis in tyrannosaurids was spread not only between individuals when fighting, but the parasite might have been present in other dinosaurs that tyrannosaurids typically killed and ate. The parasite might not have caused symptoms in other dinosaurs, but when a tyrannosaurid was infected, the parasite completed its life cycle in its host. Other researchers think tyrannosaurids practiced cannibalism, which would also spread the parasite. The parasite actually feeds on the infected animal’s jawbone, causing erosive lesions in the mouth and throat which can stop a bird from being able to swallow, so researchers think many tyrannosaurids died of it the same way birds do.

A 2011 study of a reptile called Labidosaurus, which lived about 275 million years ago in the midwestern United States, showed a bacterial infection in the jaw bone that was the equivalent to an abscessed tooth. Labidosaurus grew about a foot long, or 30 cm, and looked like a lizard with a wide head. It lived long before dinosaurs evolved. This specimen is the first fossil ever found that shows a bacterial infection in a land-dwelling animal. The reptile had bitten something that caused it to lose two teeth, and as the injury healed over, bacteria were trapped inside the jaw. This led to a bad bone infection that was still active when the animal died, although researchers aren’t sure if the infection caused the animal’s death or not.

Most diseases don’t leave any evidence in bones, so we don’t have a fossil record of them. Since all animals get sick sometimes, it’s certain that dinosaurs had various diseases too. Next time you get a sore throat, just be glad that your throat isn’t as long as a sauropod’s.

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 262: Animals Discovered in 2021

Posted on by

Podcast: Play in new window | Download (Duration: 14:49 — 17.2MB)

Subscribe: RSS | More

It’s the second annual discoveries episode! Lots of animals new to science were described in 2021 so let’s find out about some of them.

Further reading:

First description of a new octopus species without using a scalpel

Marine Biologists Discover New Species of Octopus

Bleating or screaming? Two new, very loud, frog species described in eastern Australia

Meet the freaky fanged frog from the Philippines

New alpine moth solves a 180-year-old mystery

Meet the latest member of Hokie Nation, a newly discovered millipede that lives at Virginia Tech

Fourteen new species of shrew found on Indonesian island

New beautiful, dragon-like species of lizard discovered in the Tropical Andes

Newly discovered whale species—introducing Ramari’s beaked whale (Mesoplodon eueu)!

Scientists describe a new Himalayan snake species found via Instagram

The emperor dumbo octopus (deceased):

The star octopus:

New frog just dropped (that’s actually the robust bleating tree frog, already known):

The slender bleating tree frog:

The screaming tree frog:

The Mindoro fanged frog:

Some frogs do have lil bitty fangs:

The hidden Alpine moth, mystery solver:

The Hokie twisted-claw millipede:

One of 14 new species of shrew:

The snake picture that led to a discovery:

Show transcript:

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

This episode marks our 5th year anniversary! I also finally got the ebook download codes sent to everyone who backed the Kickstarter at that level. The paperback and hardback books will hopefully be ready for me to order by the end of February and I can get them mailed out to backers as soon as humanly possible. Then I’ll focus on the audiobook! A few Kickstarter backers still haven’t responded to the survey, either with their mailing address for a physical book or for names and birthdays for the birthday shout-outs, so if that’s you, please get that information to me!

Anyway, happy birthday to Strange Animals Podcast and let’s learn about some animals new to science in 2021!

It’s easy to think that with all the animals already known, and all the people in the world, surely there aren’t very many new animals that haven’t been discovered yet. But the world is a really big place and parts of it, especially the oceans, have hardly been explored by scientists.

It can be confusing to talk about when an animal was discovered because there are multiple parts to a scientific discovery. The first part is actually finding an animal that the field scientists think might be new to science. Then they have to study the animal and compare it to known animals to determine whether it can be considered a new species or subspecies. Then they ultimately need to publish an official scientific description and give the new animal a scientific name. This process often takes years.

That’s what happened with the emperor dumbo octopus, which was first discovered in 2016. Only one individual was captured by a deep-sea rover and unfortunately it didn’t survive being brought to the surface. Instead of dissecting the body to study the internal organs, because it’s so rare, the research team decided to make a detailed 3D scan of the octopus’s body instead and see if that gave them enough information.

They approached a German medical center that specializes in brain and neurological issues, who agreed to make a scan of the octopus. It turned out that the scan was so detailed and clear that it actually worked better than dissection, plus it was non-invasive so the preserved octopus body is still intact and can be studied by other scientists. Not only that, the scan is available online for other scientists to study without them having to travel to Germany.

The emperor dumbo octopus grows around a foot long, or 30 cm, and has large fins on the sides of its mantle that look like elephant ears. There are 45 species of dumbo octopus known and obviously, more are still being discovered. They’re all deep-sea octopuses. This one was found near the sea floor almost 2.5 miles below the surface, or 4,000 meters. It was described in April of 2021 as Grimpoteuthis imperator.

Oh, and here’s a small correction from the octopus episode from a few years ago. When I was talking about different ways of pluralizing the word octopus, I mispronounced the word octopodes. It’s oc-TOP-uh-deez, not oc-tuh-podes.

Another octopus discovered in 2021 is called the star octopus that has a mantle length up to 7 inches long, or 18 cm. It lives off the southwestern coast of Australia in shallow water and is very common. It’s even caught by a local sustainable fishery. The problem is that it looks very similar to another common octopus, the gloomy octopus. The main difference is that the gloomy octopus is mostly gray or brown with rusty-red on its arms, while the star octopus is more of a yellowy-brown in color. Since individual octopuses show a lot of variation in coloration and pattern, no one noticed the difference until a recent genetic study of gloomy octopuses. The star octopus was described in November 2021 as Octopus djinda, where “djinda” is the word for star in the Nyoongar language of the area.

A study of the bleating tree frog in eastern Australia also led to a new discovery. The bleating tree frog is an incredibly loud little frog, but an analysis of sound recordings revealed that not all the calls were from the same type of frog. In fact, in addition to the bleating tree frog, there are two other really loud frog species in the same area. They look very similar but genetically they’re separate species. The two new species were described in November 2021 as the screaming tree frog and the slender bleating tree frog.

This is what the slender bleating tree frog sounds like:

[frog call]

This is what the screaming tree frog sounds like:

[another frog call]

Another newly discovered frog hiding in plain sight is the Mindoro fanged frog, found on Mindoro Island in the Philippines. It looks identical to the Acanth’s fanged frog on another island but its mating call is slightly different. That prompted scientists to use both acoustic tests of its calls and genetic tests of both frogs to determine that they are indeed separate species.

Lots of insects were discovered last year too. One of those, the hidden alpine moth, ended up solving a 180-year-old scientific mystery that no one even realized was a mystery.

The moth was actually discovered in the 1990s by researchers who were pretty sure it was a new species. It’s a diurnal moth, meaning it’s active during the day, and it lives throughout parts of the Alps. Its wingspan is up to 16mm and it’s mostly brown and silver.

Before they could describe it as a new species and give it a scientific name, the scientists had to make absolutely sure it hadn’t already been named. There are around 5,000 species of moth known to science that live in the Alps, many of them rare. The researchers narrowed it down finally to six little-known species, any one of which might turn out to be the same moth as the one they’d found.

Then they had to find specimens of those six species collected by earlier scientists, which meant hunting through the collections of different museums throughout Europe. Museums never have all their items on display at any given time. There’s always a lot of stuff in storage waiting for further study, and the larger a museum, the more stuff in storage it has. Finding one specific little moth can be difficult.

Finally, though, the scientists got all six of the other moth species together. When they sat down to examine and compare them to their new moth, they got a real surprise.

All six moths were actually the same species of moth, Dichrorampha alpestrana, described in 1843. They’d all been misidentified as new species and given new names over the last century and a half. But the new moth was different and at long last, in July 2021, it was named Dichrorampha velata. And those other six species were stricken from the record! Denied!

You don’t necessarily need to travel to remote places to find an animal new to science. A professor of taxonomy at Virginia Tech, a college in the eastern United States, turned over a rock by the campus’s duck pond and discovered a new species of millipede. It’s about three quarters of an inch long, or 2 cm, and is mostly a dark maroon in color. It’s called the Hokie twisted-claw millipede.

Meanwhile, on the other side of the world on the island of Sulawesi, a team of scientists discovered FOURTEEN different species of shrew, all described in one paper at the end of December 2021. Fourteen! It’s the largest number of new mammals described at the same time since 1931. The inventory of shrews living on Sulawesi took about a decade so it’s not like they found them all at once, but it was still confusing trying to figure out what animal belonged to a known species and what animal might belong to a new species. Sulawesi already had 7 known species of shrew and now it has 21 in all.

Shrews are small mammals that mostly eat insects and are most closely related to moles and hedgehogs. Once you add the 14 new species, there are 461 known species of shrew living in the world, and odds are good there are more just waiting to be discovered. Probably not on Sulawesi, though. I think they got them all this time.

In South America, researchers in central Peru found a new species of wood lizard that they were finally able to describe in September 2021 after extensive field studies. It’s called the Feiruz wood lizard and it lives in the tropical Andes in forested areas near the Huallaga River. It’s related to iguanas and has a spiny crest down its neck and the upper part of its back. The females are usually a soft brown or green but males are brighter and vary in color from green to orangey-brown to gray, and males also have spots on their sides.

The Feiruz wood lizard’s habitat is fragmented and increasingly threatened by development, although some of the lizards do live in a national park. Researchers have also found a lot of other animals and plants new to science in the area, so hopefully it can be protected soon.

So far, all the animals we’ve talked about have been small. What about big animals? Well, in October 2021 a new whale was described. Is that big enough for you? It’s not even the same new whale we talked about in last year’s discoveries episode.

The new whale is called Mesoplodon eueu, or Ramari’s beaked whale. It’s been known about for a while but scientists thought it was a population of True’s beaked whale that lives in the Indian Ocean instead of the Atlantic.

When a dead whale washed ashore on the South Island of New Zealand in 2011, it was initially identified as a True’s beaked whale. A Mātauranga Māori whale expert named Ramari Stewart wasn’t so sure, though. She thought it looked different than a True’s beaked whale. She got together with marine biologist Emma Carroll to study the whale and compare it to True’s beaked whale, which took a while since we don’t actually know very much about True’s beaked whale either.

The end result, though, is that the new whale is indeed a new species. It grows around 18 feet long, or 5.5 meters, and probably lives in the open ocean where it dives deeply to find food.

We could go on and on because so many animals were discovered last year, but let’s finish with a fun one from India. In June of 2020, a graduate student named Virender Bhardwaj was stuck at home during lockdowns. He was able to go on walks, so he took pictures of interesting things he saw and posted them online. One day he posted a picture of a common local snake called the kukri snake.

A herpetologist at India’s National Centre for Biological Sciences noticed the picture and immediately suspected it wasn’t a known species of kukri snake. He contacted Bhardwaj to see where he’d found the snake, and by the end of the month Bhardwaj had managed to catch two of them. Genetic analysis was delayed because of the lockdowns, but they described it in December of 2021 as the Churah Valley kukri snake.

The new snake is stripey and grows over a foot long, or 30 cm. It probably mostly eats eggs.

It just goes to show, no matter where you live, you might be the one to find a new species of animal. Learn all you can about your local animals so that if you see one that doesn’t quite match what you expect, you can take pictures and contact an expert. Maybe next year I’ll be talking about your discovery.

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 255: Reptiles with Something Extra

Posted on by

Podcast: Play in new window | Download (Duration: 12:13 — 13.9MB)

Subscribe: RSS | More

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

Thanks to Ethan and Simon this week for their suggestions! This week we’re looking at some extinct reptiles that each have a little something extra (and unexpected).

Further reading:

Two Extinct Flying Reptiles Compared

Cretaceous ‘Four-Limbed Snake’ Turns Out To Be Long-Bodied Lizard

Kuehneosaurids may have resembled big Draco lizards although they weren’t related:

Big turtle:

Purussaurus was big enough to eat even really big turtles (from Prehistoric Wildlife):

Meiolania had a pointy head and a pointy tail:

Not a snake with legs after all:

Show transcript:

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

This week we’ll learn about an extinct reptile suggested by Ethan, some extinct turtles suggested by Simon, and an extinct snake that might not be a snake at all. All these animals had physical details you wouldn’t expect, as we’ll see.

First, though, a reminder that I have five Kickstarter backers who haven’t sent me their birthday shout-out names and birthdays yet! I sent messages to them last month and haven’t heard back, so if you backed the Kickstarter and added on the birthday shout-out, but never got the opportunity to send me your names and birthdays, please message me as soon as possible! The shout-outs start in January!

So, on to the extinct reptiles that each have something a little extra. Let’s start with Ethan’s suggestion, the kuehneosaurids. Kuehneosaurus, kuehneosuchus, and their relations lived around 225 million years ago in what is now England. The first dinosaurs lived around the same time but kuehneosaurids weren’t dinosaurs. They were lizard-like reptiles that grew about two feet long, or 70 cm, including a long tail, and probably lived in trees and ate insects. Oh, and they had wings.

They weren’t technically wings but extended ribs. Kuehneosaurus’s wings weren’t all that big, although they were big enough that they could act as a parachute if the animal fell or jumped from a branch. Kuehneosuchus’s wings were much longer. In a study published in 2008, a team of scientists built models of kuehneosuchus and tested them in a wind tunnel used for aerospace engineering. It turned out to be quite stable in the air and could probably glide very well.

We don’t know a whole lot about the kuehneosaurids because we haven’t found all that many fossils. We’re not even sure if the two species are closely related or not. We’re not even sure they’re not the same species. Individuals of both were uncovered in caves near Bristol in the 1950s, and some researchers speculate they were males and females of the same species. Despite the difference in wings, otherwise they’re extremely similar in a lot of ways.

Generally, researchers compare the kuehneosaurids to modern Draco lizards, which we talked about in episode 237, even though they’re not related. Draco lizards are much smaller, only about 8 inches long including the tail, or 20 cm, and live throughout much of southeastern Asia. They have elongated ribs that they use to glide efficiently from tree to tree, and they eat insects. Draco lizards can fold their wings down and extend them, which isn’t something the kuehneosaurids appear to have been able to do.

Next, let’s look at Simon’s turtles. Stupendemys geographicus lived a lot more recently than the kuehneosaurids, only about 6 million years ago in northern South America. It was a freshwater turtle the size of a car: 13 feet long, or 4 meters. As if that wasn’t impressive enough, the males also had horns—but not on their heads. The male Stupendemys had projections on its shell, one on either side of its neck, that pointed forward and were probably covered with keratin sheaths to make them sharper and stronger. Males used these horns to fight each other, and we know because some of Stupendemys’s living relations do the same thing, although no living species actually have horns like Stupendemys. They’re called side-necked turtles and most live in South America, although they were once much more widespread.

Stupendemys probably grew to such a huge size because there were so many huge predators in its habitat. It lived in slow-moving rivers and wetlands, where it probably spent a lot of time at the river’s bottom eating plants, worms, crustaceans, and anything else it could find. It was too big and heavy to move very fast, but a full-grown turtle was a really big mouthful even for the biggest predator in the rivers at the time, Purussaurus.

Purussaurus was a genus of caiman, related to crocodiles, that might have grown up to 41 feet long, or 12.5 meters. We don’t know for sure since the only Purussaurus fossils found so far are skulls. It ate anything it could catch, and we even have Stupendemys fossils with tooth marks that show that Purussaurus sometimes ate giant turtles too. One Stupendemys fossil has a 2-inch, or 5 cm, crocodile tooth embedded in it.

Stupendemys is the largest freshwater turtle known and the second-largest turtle that ever lived. Only Archelon was bigger, up to about 15 feet long, or 4.6 meters. Archelon was a marine turtle that lived around 70 million years ago. We talked about it in episode 75.

Simon also told me about another turtle genus, Meiolania, which lived in what is now Australia and parts of Asia around 15 million years ago. It might even have remained in some areas as recently as 11,000 years ago. The shell, or carapace, of the largest species grew over 6.5 feet long, or 2 meters. Even the smallest species had a carapace over 2 feet long, or about 70 cm. Since the fossils of smaller species have only been found on islands, researchers think the small size may have been due to island dwarfism. It probably lived on land and ate plants. It also had horns, but not on its shell. These horns were actually on its head, although they aren’t technically horns.

The horn-like projections pointed sideways and its tail also had spikes at its end. That meant it couldn’t pull its head under its shell to protect it like most other turtles can, but on the other hand, anything that tried to bite its head or tail would get a painful mouthful of spikes.

We don’t know a whole lot about Meiolania, including if it’s related to living species of turtle. When the first fossils were found, early paleontologists thought they were lizards, not turtles. What we do know, though, is that people ate them. Bones of some species appear in the middens, or trash sites, of ancient people in Australia, and there’s evidence that they were hunted to extinction within a few hundred years after humans settled where the turtles lived. That would also explain why the island-dwelling species seemed to have lived longer than the mainland species, since people didn’t live on the islands where they’ve been found.

Finally, we’ll finish with Tetrapodophis amplectus, leading to the philosophical question about whether a snake with legs is really a snake. That’s the same question researchers were asking themselves too until very recently. Tetrapodophis was only described in 2015 and was initially determined to be an early snake that had four legs.

Tetrapodophis lived around 120 million years ago in what is now Brazil in South America. It grew about a foot long, or 30 cm, and had a slender, elongated body with small but well-developed legs. Is it a lizard with snake-like characteristics or an early snake that hadn’t completely lost its legs yet?

It had hooked teeth and we know it ate small animals because one specimen actually has the fossilized remains of its last meal in its fossilized digestive system. Initially researchers thought it might have been a burrowing animal, using its small legs to help it grab onto items and push itself forward.

The type specimen was a complete skeleton, which is really rare. Unfortunately it was illegally exported and the paleontologist who described the species didn’t bother to at least invite a Brazilian paleontologist to study the Brazilian fossil. He was also incredibly rude when asked about it so I’m not going to give you his name, but he seems to be a really sketchy guy, which is too bad.

He also made some mistakes that might not have been mistakes. If a person is dishonest in one area, they’re probably dishonest in other areas too. When he described Tetrapodophis, he mischaracterized some aspects of its anatomy to make it seem more snake-like. A new study published in November 2021 corrects those mistakes and determines that instead of being a flashy exciting snake with legs, Tetrapodophis was most likely just a small member of the lizard family Dolichosauridae. I’m happy to report, by the way, that one of the lead authors of the new study is named Tiago Simões, a paleontologist from Brazil.

Dolichosaurs were marine lizards with small legs and snake-like bodies and were actually pretty closely related to mosasaurs. You know, the marine reptiles that lived at the same time as dinosaurs and could grow more than 50 feet long in some species, or 15 meters.

There’s some controversy in the mosasaur camp too, because some researchers think mosasaurs were most closely related to snakes while others think they were most closely related to monitor lizards. It just goes to show that scientific knowledge is forever growing and adapting to new information as it comes to light, but that answers aren’t always clear.

What is clear is that extinct reptiles are awesome, but you probably already knew that.

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 252: Mini Rex

Posted on by

Podcast: Play in new window | Download (Duration: 11:30 — 13.2MB)

Subscribe: RSS | More

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

Thanks to Zachary for suggesting this topic! Let’s learn about some sightings of what look like miniature theropod dinosaurs running around in the American Southwest!

Further reading:

All About Birds: Wild Turkey

A collared lizard running (photo by Joe McDonald from this page):

Basilisks running:

A female wild turkey:

A male wild turkey (note the tuft of hair-like feathers sticking forward, called a beard) (picture from this page):

Show transcript:

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

Thanks to Zachary for his email a while back that helped shape this episode. Zachary has kept a lot of different kinds of pets, which we had a nice conversation about, and one of the reptiles he’s kept as a pet is in this episode. I’ll reveal which one at the end.

But first, a small correction, maybe. Paul from the awesome podcast Varmints! messaged me to point out that the word spelled A-N-O-L-E is pronounced a-NOLL, not a-NO-lee. I’d looked it up before I recorded so that confused me, so I looked it up again and it turns out that both pronunciations are used in different places and both are correct. So if you’ve always heard it a-NOLL, you’re fine, but now I can’t decide which pronunciation I should use.

This week we’re going to learn about an interesting mystery of the American southwest. Even though non-avian dinosaurs went extinct 66 million years ago, occasionally someone spots what they think is a little dinosaur running along on its hind legs. They’re sometimes called mini rexes.

Many reports come from the American southwest, especially Colorado, Arizona, and Texas. For instance, in the late 1960s two teenaged brothers were looking for arrowheads near their home in Dove Creek, Colorado when they were startled by an animal running away from them at high speed. The boys said it looked like a miniature dinosaur, only about 14 inches tall, or 35 centimeters. It was kicking up so much dust as it ran on its hind legs that the boys had trouble making out details. They did note that it seemed to be brown and possibly had a row of spines running down its back, maybe even two rows of spines, similar to an iguana’s. It had long hind legs and shorter front legs that it held out in front of it as it ran.

The animal left behind three-toed footprints that the boys followed until they disappeared into some brush. The boys were familiar with turkey footprints but these were different, with the toes closer together and no rear-pointing toe prints.

In April 1996, in Cortez, Colorado, a woman saw an animal run past her house on its hind legs, seemingly from a nearby pond. It was greenish-gray and stood about 3.5 feet tall, or about a meter. It had a long neck and long, tapering tail. She didn’t notice its front legs but its hind legs had muscular thighs but were thinner below the hock joint.

One night in July 2001, a woman and her grown daughter were driving near Yellow Jacket, Colorado when they noticed an animal at the edge of the road. At first the driver thought it was a small deer and slammed on the brakes so she wouldn’t hit it, but when it darted across the road both women were shocked to see what looked like a small dinosaur pass through the headlight beams of the car. They reported it was about 3 feet tall, or 91 centimeters, and that it had no feathers or fur. Its legs were thin and long, while its arms were tiny and held out in front of its body. It had a slender neck, a small head, and a long tapering tail.

The witnesses in both the 1996 sighting and the 2001 sighting noted that the animal they saw ran gracefully. They also all agreed that the animals’ skin appeared smooth.

Lots of dinosaurs used to walk on their hind legs, but the reptiles living today are all four-footed. There are a few lizards that run on their hind legs occasionally, though, and one of them lives in the American southwest. The collared lizard, also called the mountain boomer, will run on its hind legs to escape predators. Females are usually light brown while males have a blue-green body and light brown head. The name collared lizard comes from the two black stripes both males and females show around their necks, with a white stripe in between. During breeding season, in early summer, females also have orange spots along their sides.

The collared lizard can run up to 16 miles an hour, or 26 kilometers per hour, for short bursts on its hind legs. It uses its long tail for balance as it runs, and its hind legs are three times the length of its front legs. This makes it a good jumper too. It mostly eats insects but will occasionally eat berries, small snakes, and even other lizards. It hibernates in winter in rock crevices.

While the teenaged boys probably saw a collared lizard in the 1960s, the other two sightings we just covered sound much different. The collared lizard typically only grows up to 14 inches long, or 35 centimeters, including its long tail.

A few other lizards are known to run on their hind legs, such as the basilisk that lives in rainforests of Central and South America. It’s famous for its ability to run across water on its hind legs. It’s much larger than the collared lizard, up to 2.5 feet long, or 76 centimeters, including its long tail. It holds its front legs out to its sides when running on its hind legs, and the toes on its hind feet have flaps of skin that help stop it from sinking. It has a crest on its head, and the male also has crests on his back and tail. It can be brown or green in color.

The basilisk is sometimes kept as an exotic pet. In 1981 in New Kensington, Pennsylvania, four boys playing along some railroad tracks saw a green lizard that they thought was a baby dinosaur. It was 2 feet long, or 61 centimeters, and had a crest and an extremely long tail. It ran away on its hind legs but one of the boys, who was 11 years old, managed to catch it. It startled him by squealing and he dropped it again, and this time it got away. It sounds like an escaped pet basilisk.

But let’s go back to our mini rex sightings from 1996 and 2001, the ones of dinosaur-like animals running gracefully on their hind legs with a long neck and long tail. These don’t sound like lizards at all. When lizards run on their hind legs, they don’t look much like how we imagine a tiny raptor dinosaur would look. They appear awkward while running, with their arms sticking out and their heads pointing more or less upward. While all the lizards known that can run on their hind legs have long tails, they all have relatively short necks.

There’s another type of animal that’s closely related to the dinosaurs, though, and every single one walks on its hind legs. That’s right: birds! All the birds alive today are descended from dinosaurs whose front legs evolved for flight. Even flightless birds are well adapted to walk on two legs.

Let’s look at the details of those two sightings again. Both were of animals estimated as about three feet tall or a little taller, or up to about a meter, with long neck, small head, long tapering tail held above the ground, and long, strong legs that were nevertheless thin. Both also appeared smooth. In one of the sightings, the front legs were tiny and held forward; in the other, the witness didn’t notice the front legs.

My suggestion is that in these two sightings, at least, the witnesses saw a particular kind of bird, a wild turkey. That may sound ridiculous if you’re thinking of a male turkey displaying his feathers, but most of the time turkeys don’t look round and poofy. Most of the time, in fact, the wild turkey’s feathers are sleek and its tail is an ordinary-looking long, skinny bird tail instead of a dramatic fan. Its feathers are mostly brown and black, the upper part of its long neck is bare of feathers, as is its small head, and its legs are long and strong but relatively thin. It also typically stands 3 to 3.5 feet tall, or up to about a meter, although some big males can stand over 4 feet tall, or 1.2 meters. As for the front legs seen by witnesses in 2001, a full-grown male turkey has a tuft of long, hair-like feathers growing from the middle of his breast, called a beard. It sticks out from the rest of the feathers and might look like tiny arms if you were already convinced you were looking at a dinosaur instead of a bird.

That’s not to say that all mini-rex sightings are of turkeys, of course, but some of them probably are. The wild turkey lives throughout much of the United States, including most of Colorado. Since birds are the closest animals we have to dinosaurs these days, though, that’s still pretty neat.

Finally, the reptile Zachary kept as a pet was the collared lizard. I didn’t want to say so at the beginning and potentially spoil part of the mystery for some people!

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 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!