Category Archives: reptile

Episode 168: The Longest Lived

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This week let’s take a look at some animals (and other living organisms) that live the longest!

This isn’t Methuselah itself (scientists aren’t saying which tree it is, to keep it safe), but it’s a bristlecone pine:

The Jaya Sri Maha Bodhi, a sacred fig tree in Sri Lanka, planted in 288 BCE by a king:

Some trees of the quaking aspen colony called Pando:

Glass sponges (this one’s called the Venus Flower Basket):

Further reading:

Glass sponge as a living climate archive

Show transcript:

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

This week we’re going to look at the world’s longest lived animals and other organisms. We’re straying into plant territory a little bit here, but I think you’ll agree that this is some fascinating information.

The oldest human whose age we can verify was a French woman who lived to be 122 years old, plus 164 days. Her name was Jeanne Calment and she came from a long-lived family. Her brother lived to the age of 97. Jeanne was born in 1875 and didn’t die until 1997. But the sad thing is, she outlived her entire family. She had a daughter who died of a lung disease called pleurisy at only 36 years old—in fact, on her 36th birthday—and her only grandson died in a car wreck in his late 30s. Jeanne remained healthy physically and mentally until nearly the end of her life, although she had always had poor eyesight.

It’s not all that rare for humans to live past the age of 100, but it is rare for anyone to live to age 110 or beyond. But other animals have average lifespans that are much, much longer than that of humans.

In episode 163 we talked about the Greenland shark, which can live for hundreds of years. The oldest Greenland shark examined was possibly as old as 512 years old, and the sharks may live much longer than that. It’s actually the longest-lived vertebrate known.

No one’s sure which terrestrial vertebrate lives the longest, but it’s probably a tortoise. Giant tortoises are famous for their longevity, routinely living beyond age 100 and sometimes more than 200 years old. The difficulty of verifying a tortoise’s age is that to humans, tortoises all look pretty much alike and we don’t always know exactly when a particular tortoise was hatched. Plus, of course, we know even less about tortoises in the wild than we do ones kept in captivity. But probably the oldest known is an Aldabra giant tortoise that may have been 255 years old when it died in 2006. We talked about giant tortoises in episode 95.

But for the really long-lived creatures, we have to look at the plant world. The oldest individual tree whose age we know for certain is a Great Basin bristlecone pine called Methuselah. Methuselah lives in the Inyo National Forest in the White Mountains in California, which of course is on the west coast of North America. In 1957 a core sample was taken from it and other bristlecone pines that grow in what’s called the ancient bristlecone pine forest. Many trees show growth rings in the trunk that make a pattern that’s easy to count, so the tree’s age is easy to determine as long as you have someone who is patient enough to count all the rings. Well, Methuselah was 4,789 years old in 1957. It probably germinated in 2833 BCE. Other trees in the forest were nearly as old, with at least one possibly older, but the sample from that older tree is lost and no one’s sure where the tree the sample came from is.

Another bristlecone pine, called the Prometheus Tree, germinated even earlier than Methuselah, probably in 2880 BCE, but it’s now dead. A grad student cut it down in 1964, possibly by accident—stories vary and no one actually knows why he cut the tree down. The bristlecone pine is now a protected species.

There are other trees estimated to be as old as Methuselah. This includes a yew in North Wales that may be 5,000 years old and is probably at least 4,000 years old, and a cypress in Iran that’s at least 2,000 years old and possibly 5,000 years old. Sequoyahs from western North America, baobabs from Africa, and kauri trees from New Zealand are all documented to live over a thousand years and possibly many thousands of years.

In at least one case, a sacred fig tree in Sri Lanka, we know exactly when the tree was planted. A Buddhist nun brought a branch of the original sacred fig tree, the one that the Buddha was sitting under when he achieved enlightenment, to Sri Lanka and presented it to King Devanampiya Tissa. He planted the branch in the royal park in 288 BCE, where it grew into a tree which remains in the park to this day, more than 2,000 years later. It’s cared for by Buddhists monks and people come from all over Sri Lanka to visit the tree. If this sounds a little too good to be true, the easiest way to grow a sacred fig is to use a cutting from another tree. The cutting will root and grow into a new tree.

Not all trees are individuals. You may not know this and I didn’t either until recently. Some trees grow as colonies. The most well known tree colony is called Pando, made up of quaking aspens that live in Utah in North America. While the individual trees are only around 130 years old on average, Pando itself has been alive for an estimated 80,000 years. Each tree is a male clone and all the trees are connected by a root system that covers 106 acres, or 43 hectares. Because its root system is so huge and deep, Pando is able to survive forest fires that kill all other trees. Pando’s trees die, but afterwards the roots just send up shoots that grow into new trees. Researchers estimate that it’s been 10,000 years since Pando’s trees actually flowered. Unfortunately, Pando is currently threatened by humans stopping the forest fires that otherwise would kill off rival trees, and threatened by grazing livestock that kill off young trees before they can become established.

Pando isn’t the only quaking aspen colony known, though. There are a number of smaller colonies in western North America. Researchers think it’s an adaptation to frequent forest fires and a semi-arid climate that makes it harder for seedlings to grow. Quaking aspens that live in northeastern North America, where the climate is much wetter, grow from seeds instead of forming colonies.

Other species of tree form colonies too, including a spruce tree in Sweden whose root system dates to nearly 10,000 years ago and a pine colony in Tasmania that is about the same age but with individual trees that are themselves 3,000 years old. Not all long-lived plant colonies are trees, though. A colony of sea grass in the Mediterranean may be as much as 200,000 years old although it may be only 12,000 years old, researchers aren’t sure.

I could go on and on about long-lived plants, but let’s get back to the animals. If the Greenland shark is the longest lived vertebrate known, what’s the longest lived invertebrate? Here’s your reminder that a vertebrate is an animal with some form of spine, while an invertebrate has no spine.

Many invertebrates that live in the ocean have long lifespans. Corals of various kinds can live for thousands of years, for instance. The ocean quahog, a type of clam that lives in the North Atlantic Ocean, grows very slowly compared to other clams. It isn’t fully mature until it’s nearly six years old, and populations that live in cold water can live a long time. Sort of like tree rings, the age of a clam can be determined by counting the growth rings on its shell, and a particular clam dredged up from the coast of Iceland in 2006 was discovered to be 507 years old. Its age was double-checked by carbon-14 dating of the shell, which verified that it was indeed just over 500 years old when it was caught and died. Researchers aren’t sure how long the quahog can live, but it’s a safe bet that there are some alive today that are older than 507 years, possibly a lot older.

But the invertebrate that probably lives the longest is the glass sponge. It’s found throughout the world’s oceans, but is especially common in cold waters of the Northern Pacific and Antarctic. It usually grows up to about a foot tall, or 30 cm, although some species grow larger, and is roughly shaped like a vase. Most species are white or pale in color. In some places the sponges fuse together to form reefs, with the largest found so far 65 feet tall, or 20 meters, and nearly four and a half miles long, or 7 km.

The glass sponge is a simple creature with a lattice-like skeleton made of silica covered with porous tissue. It anchors itself to a rock or the ocean floor, frequently in deep water, and as water flows through the openings in its body, it filters microscopic food out. So it basically lives a very slow, very plant-like existence.

One glass sponge, Monorhaphis chuni, anchors itself to the sea floor with a long basal spicule that looks like a stem. This stem can be over nine feet long, or 3 m. It needs to be long because it lives in deep water where there’s a lot of soft sediment at the bottom. In 1986 the skeleton of a dead Monorhaphis was collected from the East China Sea so it could be studied. Since a glass sponge adds layers of skeleton to its basal spicule every year as it grows, you guessed it, the layers can be counted just like tree rings—although it requires an electron microscope to count since the layers are very small. The sponge was determined to be about 11,000 years old when it died. Researchers are able to determine local ocean temperature changes from year to year by studying the rings, just as tree rings give us information about local climate.

Let’s finish with something called an endolith. An endolith isn’t a particular animal or even a group of related animals. An endolith is an organism that lives inside a rock or other rock-like substance, such as coral. Some are fungi, some lichens, some amoebas, some bacteria, and various other organisms, many of them single-celled and all of them very small if not microscopic. Some live in tiny cracks in a rock, some live in porous rocks that have space between grains of mineral, some bore into the rock. Many are considered extremophiles, living in rocks inside Antarctic permafrost, at the tops of the highest mountains, in the abyssal depths of the oceans, and at least two miles, or 3 km, below the earth’s surface.

Various endoliths live on different minerals, including potassium, sulfur, and iron. Some endoliths even eat other endoliths. We don’t know a whole lot about them, but studies of endoliths found in soil deep beneath the ocean’s floor suggest that they grow extremely slowly. Like, from one generation to the next could be as long as 10,000 years, with the oldest endoliths potentially being millions of years old—even as old as the sediment itself, which dates to 100 million years old.

That is way older than Jeanne Calment and all those trees.

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 a rating and review on Apple Podcasts or wherever you listen to podcasts. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us that way.

Thanks for listening!

Episode 158: Legless Lizards and Other Not-Snakes

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What’s the difference between a snake and a legless lizard? Find out this week and learn about all kinds of interesting reptiles without legs that aren’t actually snakes!

The slow-worm. Not a snake:

Burton’s legless lizard. Not a snake:

The excitable delma. Not a snake:

The Mexican mole lizard. Not a snake or a worm:

The red worm lizard (Amphisbaena alba). Also not a snake or a worm, but honestly, it looks a lot like I imagine the Mongolian death worm to look:

The giant legless skink. Not a snake:

Stacy’s bachia. Not a snake:

Further reading (and this is where I got the Stacy’s bachia picture above):

Bachia lizards–look, no hands!

An Explosive Enigma from Kalmykia—the ‘Other’ Mongolian Death Worm?

Show transcript:

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

A couple of weeks ago we discussed the Mongolian death worm and the possibility that it was an animal called an amphisbaenian, which is a reptile without legs that’s not a snake. But there are lots of other legless reptiles that aren’t snakes. So this week we’re going to learn about legless lizards and their friends.

Researchers have determined that leglessness evolved in reptiles many different times in species that aren’t related, often in species that spend at least part of their time underground. If the legs get in the way of burrowing or other movement, over time individuals born without legs or with much smaller legs end up finding more food than those with legs. That means they’re more likely to reproduce, and their offspring may inherit the trait of no legs or smaller legs.

Some legless lizards look so much like snakes at first glance that it can be hard to tell them apart. The common slow-worm, for instance, lives throughout most of Europe and part of Asia. It grows to about a foot and a half long, or 50 cm, and is brown. It mostly eats slugs and worms so it spends most of its time in damp places or underground. But while it looks superficially like a snake, it’s not a snake. It’s a lizard with no legs. Like some other lizard species, including many legless lizards, it can even drop its tail if it’s threatened and then regrows a little tail stump.

So how can you tell the difference between a legless lizard and a snake? The one big clue is if the reptile blinks. Snakes don’t have eyelids; instead, their eyes are protected by a transparent scale that covers the eye completely. Lizards have eyelids and blink. Legless lizards have a different head shape from snakes too, usually more blocky and less flattened. The tongue is not so much forked as just notched, and shorter and less slender than a snake’s tongue.

Species of one family of legless lizards do sometimes have legs. Honestly, this is almost as confusing as the whole deer and antelope mix-up from episode 116. The family is Pygopodidae and they’re actually most closely related to geckos although they don’t look much like geckos. They look like snakes, and to make things even more complicated, geckos and Pygopodids don’t have eyelids. I know I know, I just said lizards have eyelids but geckos are an exception. Pygopodids don’t have front legs at all, but some do have vestigial hind legs that look more like little flaps than actual legs. They’re sometimes called flap-footed lizards as a result. They live in Australia and New Guinea.

One Pygopodid is Burton’s legless lizard, which does actually have vestigial hind legs. It lives in parts of Australia and Papua New Guinea and is kind of a chunky reptile with a pointed nose. It’s brown or gray, sometimes with long stripes, and can grow to more than three feet long, or one meter. It eats other lizards, especially skinks, but will also sometimes eat small snakes.

Burton’s legless lizard mostly stays in leaf litter in forests. Sometimes it will twitch the end of its tail to attract a lizard, which it then grabs by the neck. It will swallow small lizards whole, but if it’s too big to swallow, it will just hold onto its neck until the lizard suffocates or just gives up out of exhaustion. It can also retract its eyes so they’re less likely to be injured if its prey fights back.

The excitable delma is another pygopodid, this one without any legs at all. It lives in many parts of Australia and can grow nearly two feet long, or 54 cm, but almost half that length is tail. It’s shy and nocturnal, so even though it’s very common, it’s seldom seen. It’s brown or grayish with darker stripes on its head. The reason it’s called the excitable delma is because it uses its long tail to jump, twisting and changing directions as it jumps repeatedly up to six inches off the ground, or 15 cm. It does this to escape from predators but it also sometimes just jumps around for the heck of it, according to observations of excitable delmas in captivity. It can also make a squeaky sound. It likes dry, rocky areas and eats insects.

There are other reptiles that look like snakes but aren’t, in addition to the legless lizards. We talked about the amphisbaenians in the Mongolian animals episode a few weeks ago, and also in episode 10. Amphisbaenians are sometimes called worm lizards because they look less like snakes than they do worms. They’re related to both legless lizards and snakes but lost their legs independently.

The amphisbaenian moves like a worm, not a snake. Its skin is loosely attached to its body so that it can move freely, and it bunches up its skin the way a worm bunches up its body, then extends it to move forward or backward. This kind of action is called peristalsis, by the way. Unlike worms, the amphisbaenian has scales because it’s a reptile, but the scales are often arranged in rings that make it look even more like an earthworm. Many amphisbaenians are pink like many earthworms, too.

Most amphisbaenians live underground their entire lives, hunting worms, insect grubs, and other small animals. In most cases they only come to the surface at night or after a heavy rain. Most have no legs at all, but one family consisting of four species, all of them native to Mexico, has little front legs. One of these species is the Mexican mole lizard, which can grow over a foot long, or more than 30 cm. It mostly eats soft-bodied animals like worms and termites, but it will occasionally eat small lizards. It’s pink and has little black dots for eyes and is actually really cute, but don’t let that fool you. If you are a worm, the Mexican mole lizard is a murder machine. It has sharp little teeth that it uses to bite pieces from its prey instead of swallowing them whole.

All the other known amphisbaenians have no legs at all, and for most species we know very little about them. The red worm lizard, for instance, lives throughout much of western South America and appears to be common, but it lives underground and is hardly ever seen. It’s the largest amphisbaenian known and can grow nearly three feet long, or 85 cm, although it’s only a few inches thick, or around 6 cm. It’s brown, reddish, or yellowish in color with a white belly and has tiny eyes that are barely visible. Its tail is blunt and rounded like other amphisbaenian tails, but its tail is tough enough to withstand bites from predators without being injured. If the red worm lizard feels threatened, it raises its head and tail and bends itself into a U shape so that it looks like it has two heads.

That’s why the amphisbaenian has that name, by the way. In ancient mythology, the amphisbaena was a serpent with a head on each end of its body. It was said to mostly eat ants, and that’s actually a good observation of the real amphisbaenian, which often eats ants, termites, and other insects.

Legless skinks are another group of lizards that either have no legs at all or just little flaps instead of hind legs. The males are the ones with the hind leg flaps, which they use to hold onto the female while mating. Most legless skinks look sort of like amphisbaenians, with a blunt-ended tail that’s sometimes hard to tell from the head, but more snakey than wormy for the most part.

One example is the giant legless skink, which is dark gray or black with no legs, and which lives in South Africa. It grows almost a foot and a half long, or 42 cm, and is a little bit of a chonk. We still don’t know much about it but it probably eats insects and other invertebrates like most legless skinks do.

A while back, Llewelly sent me a link to an article about Stacy’s bachia, a lizard that lives in the tropics of South America. It’s a member of the spectacled lizards, which all have lower eyelids that are transparent. That way the lizard can see even if its eyes are closed. I put a link to the article in the show notes if you want to read it.

Stacy’s bachia usually has no hind legs, although it may have little stubby ones, but it hatches with small front legs. But it spends most of its life burrowing in soil and in leaf litter as it hunts termites, ants, and other small animals, and eventually all its legs wear away to nothing.

Let’s finish with a mystery animal. Kalmykia is a small region of Russia, and the native people of the area are called Kalmyks. The Kalmyks report that there’s an animal that lives in both the steppes and in sand dunes in the desert that looks like a snake but isn’t a snake, which they actually call the short gray snake. It grows around 20 inches long, or 50 cm, and has smooth skin and a tail that’s short and rounded at the end. It has no legs. This report is from zoologist Karl Shuker’s blog, and check the show notes for a link. The person who told him about this animal also says it’s about six to eight inches thick, or up to 20 cm, so if that’s correct it’s even more of a chonk than the giant legless skink.

Kalmykia is west of Kazakhstan, which is west of Mongolia, so there’s always the possibility that this legless animal is related to or the same animal as the Mongolian death worm that we talked about in episode 156. But Kalmykia is actually pretty far away from Mongolia, and the short gray snake is different from the death worm in two important ways. One, reports say it has no bones. If this is true, it must be some kind of invertebrate, not a reptile. It’s also supposed to move like a worm, although remember that the amphisbaenian does too and it’s a reptile.

But the other thing reported about the short gray snake is much weirder than having no bones. Apparently if someone hits the animal in a particular place on its back—presumably with a stick—it EXPLODES. It explodes into goo that spreads for several feet in every direction, or about a meter, leaving nothing else behind.

It’s possible this isn’t a real animal but a folktale, something like American tall tales about the hoop snake that’s supposed to grab its tail in its mouth and roll itself along like a hoop. The hoop snake is not a real animal, in case you were wondering. There’s no way of telling whether the exploding boneless short gray snake is a real animal, a folktale, or reports of more than one real animal that have gotten mixed up in translation. Hopefully someone who lives in Kalmykia will investigate and find out more. In the meantime, don’t hit any animals with sticks. For one thing, that’s mean. For another, it might explode and leave you covered in goo.

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. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us and get twice-monthly bonus episodes.

Thanks for listening!

Episode 135: Smallest of the Large

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This week we’re looking at some very small animals–but not animals that we think of as small. Join us for a horrendously cute episode!

Further reading:

The Echinoblog

Further listening:

Animals to the Max episode #75: The Sea Panda (vaquita)

Varmints! episode #49: Hippos

Further watching:

An adorable baby pygmy hippo

The Barbados threadsnake will protecc your fingertip:

Parvulastra will decorate your thumbnail:

Berthe’s mouse lemur will defend this twig:

The bumblebee bat will eat any bugs that come near your finger:

The vaquita, tiny critically endangered porpoise:

The long-tailed planigale is going to steal this ring and wear it as a belt:

He höwl:

A pygmy hippo and its mother will sample this grass:

This Virgin Islands dwarf gecko will spend this dime if it can just pick it up:

Show transcript:

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

I talk a lot about biggest animals on this podcast, so maybe it’s time to look at the very smallest animals. I don’t mean algae or bacteria or things like that, I mean the smallest species of animals that aren’t usually considered especially small.

We’ll start with the smolest snek, the Barbados threadsnake. It only lives on a few islands in the Caribbean, notably Barbados. The very largest individual ever measured was only 4.09 inches long, or 10.4 cm, but most are under four inches long. But it’s an extremely thin snake, not much thicker than a spaghetti noodle.

The Barbados threadsnake mostly eats termites and ant larvae. It spends most of its time in leaf litter or under rocks, hunting for food. The female only lays one single egg, but the baby is relatively large, about half the mother’s length when it hatches.

That’s so cute. Why are small things so cute?

Remember the starfish episode where we talked about the largest starfish? Well, what’s the smallest starfish? That would be Parvulastra parvivipara, which is smaller than a fingernail decoration sticker. It grows to about ten millimeters across and is orangey-yellow in color. It lives on the coast of Tasmania in rock pools between low and high tide, called intertidal rock pools.

If you remember the Mangrove killifish from a few episodes ago, you’ll remember how killifish females are hermaphrodites that produce both eggs and sperm, and usually self-fertilize their eggs to produce tiny clones of themselves. Well, Parvulastra does that too, although like the killifish it probably doesn’t always self-fertilize its eggs. But then it does something interesting for a starfish. Instead of releasing its eggs into the water to develop by themselves, Parvulastra keeps the eggs inside its body. And instead of the eggs hatching into larvae, they hatch into impossibly tiny miniature baby starfish, which the parent keeps inside its body until the baby is big enough to survive safely on its own.

But what do the baby starfish eat while they’re still inside the mother? Well, they eat their SIBLINGS. The larger babies eat the smaller ones, and eventually leave through one of the openings in the parent’s body wall, called gonopores. Researchers theorize that one of the reasons the babies leave the parent is to escape being eaten by its siblings. And yes, occasionally a baby grows so big that it won’t fit through the gonopores. So it just goes on living inside the parent.

Next, let’s look at the smallest primate. The primate order includes humans, apes, monkeys, and a lot of other animals, including lemurs. And the very smallest one is Berthe’s mouse lemur. Its body is only 3.6 inches long on average, or 9.2 cm, with a tail that more than doubles its length. Its fur is yellowish and brownish-red.

Berthe’s mouse lemur was only discovered in 1992. It lives in one tiny area of western Madagascar, where it lives in trees, which means it’s vulnerable to the deforestation going on all over Madagascar and is considered endangered.

It mostly eats insects, but also fruit, flowers, and small animals of various kinds. Its habitat overlaps with another small primate, the gray mouse lemur, but they avoid each other. Madagascar has 24 known mouse lemur species and they all seem to get along well by avoiding each other and eating slightly different diets. Researchers discover new species all the time, including three in 2016.

Last October we had an episode about bats, specifically macrobats that have wingspans as broad as eagles’. But the smallest bat is called the bumblebee bat. It’s also called Kitti’s hog-nosed bat, but bumblebee bat is way cuter. It’s a microbat that lives in western Thailand and southeast Myanmar, and like other microbats it uses echolocation to find and catch flying insects. Its body is only about an inch long, or maybe 30 millimeters, although it has a respectable wingspan of about 6 ½ inches, or 17 cm. It’s reddish-brown in color with a little pig-like snoot, and it only weighs two grams. That’s just a tad more than a single Pringle chip weighs.

Because the bumblebee bat is so rare and lives in such remote areas, we don’t know a whole lot about it. It was only discovered in 1974 and is increasingly endangered due to habitat loss, since it’s only been found in 35 caves in Thailand and 8 in Myanmar, and those are often disturbed by people entering them. The land around the caves is burned every year to clear brush for farming, which affects the bats too.

The bumblebee bat roosts in caves during the day and most of the night, only flying out at dawn and dusk to catch insects. It rarely flies more than about a kilometer from its cave, or a little over half a mile, but it does migrate from one cave to another seasonally. Females give birth to one tiny baby a year. Oh my gosh, tiny baby bats.

So what about whales and dolphins? You know, some of the biggest animals in Earth’s history? Well, the vaquita is a species of porpoise that lives in the Gulf of California, and it only grows about four and a half feet long, or 1.4 meters. Like other porpoises, it uses echolocation to navigate and catch its prey. It eats small fish, squid, crustaceans, and other small animals.

The vaquita is usually solitary and spends very little time at the surface of the water, so it’s hard to spot and not a lot is known about it. It mostly lives in shallow water and it especially likes lagoons with murky water, properly called turbid water, since it attracts more small animals.

Unfortunately, the vaquita is critically endangered, mostly because it often gets trapped in illegal gillnets and drowns. The gillnets are set to catch a different critically endangered animal, a fish called the totoaba. The totoaba is larger than the vaquita and is caught for its swim bladder, which is considered a delicacy in China and is exported on the black market. The vaquita’s total population may be no more than ten animals at this point, fifteen at the most, and the illegal gillnets are still drowning them, so it may be extinct within a few years. A captive breeding plan was tried in 2017, but porpoises don’t do well in captivity and the individuals the group caught all died. Hope isn’t lost, though, because vaquita females are still having healthy babies, and there are conservation groups patrolling the part of the Gulf of California where they live to remove gill nets and chase off fishing boats trying to set more of the nets.

If you want to learn a little more about the vaquita and how to help it, episode 75 of Corbin Maxey’s excellent podcast Animals to the Max is an interview with a vaquita expert. I’ll put a link in the show notes.

Next, let’s talk about an animal that is not in danger of extinction. Please! The long-tailed planigale is doing just fine, a common marsupial from Australia. So, if it’s a marsupial, it must be pretty big—like kangaroos and wallabies. Right? Nope, the long-tailed planigale is the size of a mouse, which it somewhat resembles. It even has a long tail that’s bare of fur. It grows to 2 ½ inches long not counting its tail, or 6.5 cm. It’s brown with longer hind legs than forelegs so it often sits up like a tiny squirrel. Its nose is pointed and it has little round mouse-like ears. But it has a weird skull.

The long-tailed planigale’s skull is flattened—in fact, it’s no more than 4 mm top to bottom. This helps it squeeze into cracks in the dry ground, where it hunts insects and other small animals, and hides from predators.

The pygmy hippopotamus is a real animal, which I did not know until recently. It grows about half the height of the common hippo and only weighs about a quarter as much. It’s just over three feet tall at the shoulder, or 100 cm. It’s black or brown in color and spends most of its time in shallow water, usually rivers. It’s sometimes seen resting in burrows along river banks, but no one’s sure if it digs these burrows or makes use of burrows dug by other animals. It comes out of the water at night to find food. Its nostrils and eyes are smaller than the common hippo’s.

Unlike the common hippo, the pygmy hippo lives in deep forests and as a result, mostly eats ferns, fruit, and various leaves. Common hippos eat more grass and water plants. The pygmy hippo seems to be less aggressive than the common hippo, but it also shares some behaviors with its larger cousins. For instance, the pooping thing. If you haven’t listened to the Varmints! Episode about hippos, you owe it to yourself to do so because it’s hilarious. I’ll put a link in the show notes to that one too. While the hippo poops, it wags its little tail really fast to spread the poop out across a larger distance.

Also like the common hippo, the pygmy hippo secretes a reddish substance that looks like blood. It’s actually called hipposudoric acid, which researchers thinks acts as a sunscreen and an antiseptic. Hippos have delicate skin with almost no hair, so its skin dries out and cracks when it’s out of water too long.

The pygmy hippo is endangered in the wild due to habitat loss and poaching, but fortunately it breeds successfully in zoos and lives a long time, up to about 55 years in captivity. For some reason females are much more likely to be born in captivity, so when a male baby is born it’s a big deal for the captive breeding program. I’ll put a link in the show notes to a video where you can watch a baby pygmy hippo named Sapo and his mother. He’s adorable.

Finally, let’s finish where we started, with another reptile. The smallest lizard is a gecko, although there are a lot of small geckos out there and it’s a toss-up which one is actually smallest on average. Let’s go with the Virgin Islands dwarf gecko, which lives on three of the British Virgin Islands. It’s closely related to the other contender for smallest reptile, the dwarf sphaero from Puerto Rico, which is a nearby island, but while that gecko is just a shade shorter on average, it’s much heavier.

The Virgin Islands dwarf gecko is only 18 mm long not counting its tail, and it weighs .15 grams. A paperclip weighs more than this gecko. It’s brown with darker speckles and a yellow stripe behind the eyes. Females are usually slightly larger than males. Like other geckos, it can lose its tail once and regrow a little stump of a tail.

The Virgin Islands dwarf gecko lives in dry forests and especially likes rocky hills, where it spends a lot of its time hunting for tiny animals under rocks. We don’t know a whole lot about it, but it does seem to be rare and only lives in a few places, so it’s considered endangered. In 2011 some rich guy decided he was going to release a bunch of lemurs from Madagascar onto Moskito Island, one of the islands where the dwarf gecko lives. Every conservationist ever told him oh NO you don’t, rich man, what is your problem? Those lemurs will destroy the island’s delicate ecosystem, drive the dwarf gecko and many other species to extinction, and then die because the habitat is all wrong for lemurs. So Mr. Rich Man said fine, whatever, I’ll take my lemurs and go home. And he did, and the dwarf gecko was saved.

Look, if you have so much money that you’re making plans to move lemurs halfway across the world because you think it’s a good idea, I can help take some of that money off your hands.

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. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 131: Paleontological Mistakes

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Part of the scientific method involves making mistakes and correcting them. Here are some interesting and sometimes goofy mistakes made by paleontologists through the years, and how the mistakes were corrected.

Iguanodon did not actually look like this (left). It looked like this (right):

Pterosaur did not actually look like this (left). It looked like this (right):

Elasmosaurus did not actually look like this (left). It looked like this (right):

Apatosaurus/brontosaurus did not actually look like this (left). It looked like this (right):

Stegosaurus did not actually look like this (left). It looked like this (right):

Gastornis did not actually look like this (left). It looked like this (right):

Those are Gastornis’s footprints:

Show transcript:

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

Paleontology is the study of fossils, and really it’s only been a discipline for a little over a century. Back in the 19th and early 20th centuries, even experts made major mistakes in preparing and assembling fossil skeletons, and dishonest amateurs made deliberate errors so their fossil animals looked bigger or scarier. Many of these mistakes or hoaxes were displayed in museums, sometimes for decades.

I found so many interesting examples during my research that I decided to split the episode into two. This week we’ll learn about some paleontological mistakes and what the fossil animals really looked like when they were alive. Next week we’ll look at the frauds and hoaxes.

We’ll start with Iguanodon, a dinosaur that lived around 125 million years ago in what is now Europe. It ate plants and was fairly common, with a number of species now known to science. The biggest could grow as much as 43 feet long, or 13 meters. It had teeth that resemble an iguana’s, which is how it gets its name, and a beak probably covered in keratin that it used to clip through tough plants. It probably mostly walked on two legs and browsed from trees, but its front legs were long and it might have spent at least some of its time on all fours. But the most interesting thing about Iguanodon was its hands. Its little finger was slender and usually longer than the others and many researchers think it was used for handling food and other objects. The first finger, which is equivalent to a thumb, wasn’t so much a digit as just a big spike. It’s called a thumb spike and no one’s sure what it was for. It might have been used for defense, but it might also have been used to help dig up plants. Maybe it was used for both. But it was the source of an embarrassing mistake that many paleontologists made for years.

Iguanodon came to the attention of science in 1822 when a medical doctor in Sussex, England found some fossilized teeth. No one was sure what kind of animal the teeth belonged to, although guesses ranged from a crocodile to a rhinoceros. In 1824 the doctor, Gideon Mantell, noted the teeth’s resemblance to iguana teeth, but so big that he estimated Iguanodon must have been almost 60 feet long, or 18 meters. He also thought Iguanodon looked like an iguana.

In 1834 more Iguanodon fossils came to light in a quarry and Mantell bought them. This incomplete skeleton included a thumb spike, but Mantell didn’t know where it belonged. He thought it was a horn, so when he made a drawing of the living animal, he placed the thumb spike on the nose.

And there it stayed, despite other fossils found with the thumb spike in place on the hand, and despite other scientists pointing out that they didn’t think Iguanodon had a horn on its nose. It wasn’t until 1882 that the nose horn vanished for good and Iguanodon started looking more like itself.

Similarly, pterosaurs have been misunderstood since the very beginning, with a lot of frankly ridiculous suggestions made about them. To be fair, they are really strange animals and nothing like any animal living today. The first pterosaur was described in 1784 by an Italian naturalist, but he thought it was a swimming animal and that its wing bones were actually flippers. Zoologist Georges Cuvier pointed out it was a flying reptile in 1801, but the swimming hypothesis wasn’t abandoned for decades after that. Even after the flying part was accepted by other researchers and the general public, many people believed they were related to bats for a remarkably long time. In 1843 one scientist suggested pterosaurs were not only bats, but specifically marsupial bats. (There are no marsupial bats. Bats are placental mammals.) The notion that pterosaurs and bats were related hung around a really long time, right up to the 1930s, although experts had more or less figured it out by then.

Elasmosaurus lived around 80 million years ago and was a type of plesiosaur. We talked about Elasmosaurus in episode 92 about marine reptiles. It wasn’t a dinosaur but it lived at the same time as dinosaurs, and could grow up to 34 feet long, or over 10 meters. It had a very long neck containing 72 vertebrae, a short tail, and four paddle-like legs. These days we know that the neck wasn’t very flexible, but for a long time Elasmosaurus and its relatives were depicted with flexible, serpentine necks. But the real mistake came when it was first discovered.

The first Elasmosaurus fossil was found in Kansas in 1867 and given to Edward Cope, a well-known paleontologist who discovered many fossil species found in North America.

The problem was, Cope was the bitter rival of another well-known paleontologist, Othniel Marsh. The two men were so frantic to publish more descriptions of new animals than the other that it sometimes led to sloppy work. That may have been why, when Cope described Elasmosaurus in 1869, he placed its head at the end of its tail so that it looked like it had a short neck and a really long tail instead of the other way around. The bones were all jumbled together and the jaws had ended up at the wrong end of the skeleton when it was covered over with sediment and the fossilization process began.

Another paleontologist pointed out Cope’s mistake only a few months later. Cope tried to buy up all the copies of the article and reissued a corrected version. But Cope’s nemesis Marsh got hold of a copy of the original article and was absolutely gleeful. He never would let Cope forget his mistake, and in fact it was the final straw in the relationship between the two. Cope and Marsh had started out as friends but their friendship soured, and by 1870 they pretty much loathed each other.

But Marsh made his own mistakes. In 1877 he found a dinosaur he named Apatosaurus, although the specimen was missing a skull. He used the skull of a different dinosaur when he prepared the specimen. Then in 1885 his workers found a similar-looking skeleton with a skull. He named it Brontosaurus.

Guess what. They were the same animal. Marsh was so eager to describe a new dinosaur that Cope hadn’t described yet that he didn’t even notice. But for some reason the name Brontosaurus stuck in pop culture, which is why you probably know what a Brontosaurus was and what it looked like, while you may never have heard of Apatosaurus. The mistake has been corrected and the dinosaur’s official scientific name is Apatosaurus, but Marsh’s Apatosaurus skeleton from 1877 didn’t get the right skull until 1979. The skeleton had been on display with the wrong skull for almost a century, but researchers found the correct skull that had been unearthed in 1910 and stored away.

Apatosaurus lived in North America around 150 million years ago and was enormously long, growing on average 75 feet long from head to tail, or 23 meters. It ate plants, and some researchers suggest that it used its incredibly long tail as a whip to scare predators by cracking the whip and making a loud noise. This sounds absurd but the physiology of the tail’s end supports that it could probably withstand the pressures involved in a whip-crack. The neck was also quite long and researchers are still debating how flexible it was. The reason so much old artwork of Apatosaurus/Brontosaurus shows the animal standing in water eating swamp plants is because scientists used to think it was such a heavy animal that it couldn’t even support its own weight out of the water, much like whales. Not true, of course. It had strong, column-like leg bones that had no trouble supporting its weight on dry land, and it lived on what are referred to as fern savannas. Grass hadn’t yet evolved so the main groundcover was made up of ferns.

The name Brontosaurus has been retained for some Apatosaurus relations, fortunately, because it’s a pretty nifty name. It means thunder lizard.

Marsh is also responsible for the notion that some of the larger dinosaurs, specifically Stegosaurus, had a second brain at the base of their tails. This isn’t actually the case at all. Marsh just couldn’t figure out how such a large animal had such a small brain. Then again, Marsh also thought Stegosaurus’s tail spikes, or thagomizer, belonged on its back while its back plates belonged on its tail.

If you want to learn more about the Stegosaurus, check out episode 107 where we learn about it and Ankylosaurus. It’s too bad a paleontologist named Charles Gilmore couldn’t listen to that episode, because in 1914 he decided the back plates were osteoderms that lay flat on its skin. This was an early idea of Marsh’s that he had rejected early on but which Gilmore liked. Gilmore also thought the thagomizer spikes grew between the back plates so that the Stegosaurus was covered in both big plates like armor with spikes in between the plates.

A man named Henry Fairfield Osborn made a couple of mistakes too. He was the guy who named Oviraptor, which means “egg thief.” That was a reasonable assumption, really, since the first specimen was found in 1923 in a nest of Protoceratops eggs…but the Protoceratops eggs were later found to actually be Oviraptor eggs, and Oviraptor was just taking care of its own nest.

In 1922 Osborn was the president of the American Museum of Natural History when a rancher sent him a fossil tooth he’d found in Nebraska in 1917. Paleontologists often have to extrapolate an entire animal from a single fossil, and teeth are especially useful because they tell so much about an animal. So Osborn examined the tooth carefully and published a paper describing the ape that the tooth came from.

If you remember, though, there are no apes native to the Americas, just monkeys. The media found out about the discovery and wrote articles about the missing link between humans and apes, which was a popular topic back before people fully understood how evolution worked and when so little was known about human ancestry. The papers called the fossil ape the Nebraska man.

Then, a few years later, paleontologists went to Nebraska to find the rest of the fossilized ape bones. And while they did find them, they didn’t belong to an ape. The tooth came from a species of extinct peccary. You know, a type of pig relation. Peccaries do evidently have teeth that look a lot like human teeth, which is kind of creepy, plus the fossil tooth was badly weathered. Osborn retracted his identification in 1927.

All this wouldn’t have been a big deal except that people who didn’t believe evolution was real decided that this one relatively small mistake, quickly corrected, meant ALL scientists were ALL wrong FOREVER.

We’ll finish with a bird fossil, a bird you’ve probably never heard of although it’s massive. The first Gastornis fossil was found in the mid-19th century near Paris and described in 1855. More fossils were found soon after, and in the 1870s there were enough Gastornis bones that researchers were able to reconstruct what they thought it looked like, a gigantic crane. They were wrong.

Gastornis was as big as a big moa, over six and a half feet high, or 2 meters. It had a heavy beak and a powerful build that for over a century led many paleontologists to think it was a predator. But these days, we’re pretty sure it only ate tough plant material. Its bill could have crushed nuts but wasn’t the right shape to strip meat from bones, and a carbon isotope study of Gastornis bones indicate that its diet was entirely vegetarian.

Gastornis had vestigial wings that probably weren’t even visible under its body feathers. It was actually related most closely to modern waterfowl like ducks and geese. We have some fossilized Gastornis eggs and they were bigger than ostrich eggs, although they were shaped differently. They were oblong instead of ovoid, about ten inches long, or over 25 cm, but only four inches in diameter, or 10 cm. Only the elephant bird of Madagascar laid bigger eggs. We even have two fossil feather impressions that might be from Gastornis, and some fossil footprints in Washington state that show Gastornis had three toes with blunt claws. The bird went extinct around 40 million years ago.

At about the same time that Gastornis was being described in Europe as a kind of giant wading bird, our old friend Edward Cope found some bird fossils in New Mexico. He described the bird in 1876 as Diatryma gigantea and recognized that it was flightless. Cope’s deadly enemy Othniel Marsh also found a bird’s toe bone and described it as coming from a bird he named Barornis regens in 1894. As more and more fossils were found, however, it became clear that Cope’s and Marsh’s birds were from the same genus, so Barornis was renamed Diatryma.

By then, some paleontologists had already suggested that Diatryma and Gastornis were the same bird. In 1917 a nearly complete skeleton, including the skull, was discovered in Wyoming in the United States, but it didn’t really match up to the 1881 reconstruction of Gastornis.

But in the 1980s, researchers looked at that reconstruction more closely. It turned out that it contained a lot of mistakes. Some of the elements weren’t from birds at all but from fish and reptiles, and some of the broken fossil bones had been lengthened considerably when they were repaired with plaster. A paper published in 1992 highlighted these mistakes, and gradually the use of the term Diatryma was changed over to Gastornis.

So remember, everyone, don’t be afraid to make mistakes. That’s how you get better at things. And for the same reason, don’t make fun of other people who make mistakes. Other people get to learn stuff too. And even if you don’t think you’ve made a mistake, maybe double check to make sure you didn’t accidentally include a fish fossil in your extinct flightless bird reconstruction.

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

Thanks for listening!

Episode 109: Convergent Evolution

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I mention convergent evolution occasionally, but what is it really? This week we learn about what it is and some animals that demonstrate it. Thanks to Richard E. and Llewelly for their suggestions this week! Jaguars and leopards look so similar I’m not 100% sure this picture actually shows one of each:

The adorable sucker-footed bat from Madagascar:

The equally adorable TOTALLY UNRELATED disk-winged bat from South America:

Metriorhynchus looked a lot like a whale even though it was a crocodile ancestor:

Show transcript:

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

This week we’re going to learn about some animals that represent convergent evolution. That’s a term that I mention every so often, so it’s time to really dig into it and see what it’s all about. We’ll start with animals that are fairly closely related, then work our way backwards to those that aren’t related at all.

Basically, when unrelated organisms develop similar form, structure, or functions as each other, that’s called convergent evolution. One simple example is bats and birds. They’re not related, but both can fly using forelimbs that have been modified into wings.

This topic idea was sparked by an idea from Richard E., who suggested an episode about evolution and how it doesn’t “improve” anything, just adapts. That’s an important distinction. Evolution is a reactive force, not a proactive. Sometimes we use terms like advanced to describe certain animals, and primitive to describe others with traits that haven’t changed in a long time. That implies that some animals are “better” than others, or better adapted. In actuality, one trait is not better or worse than another, as long as both traits help the animal survive and thrive. If an animal has traits that haven’t changed in millions of years but it’s still doing well, it’s as adapted as it needs to be. An animal that’s extremely specialized to an environment can sometimes be much more vulnerable to environmental change than a more generalized animal, too.

From a scientific point of view, while it may look like species become more advanced as time goes on, all it means is that a lot of animals have evolved to occupy specific ecological niches. One example Richard gives is the panda, which we talked about in episode 42 about strange bears.

The panda is an extremely specialized animal. It’s a bear that is no longer a carnivore, for one thing, and not only does it not eat meat, or hardly any meat since it will eat small animals and bird eggs when it finds them, it mostly just eats one type of plant. That plant, of course, is bamboo, which is low in nutrients. The panda has adapted in all sorts of ways to be able to digest bamboo, and one of the most obvious adaptations is what looks like a sixth toe on its forefeet. It’s not a toe but a projecting sesamoid bone that acts as a toe and helps the panda grasp bamboo.

But the panda’s sixth toe evolved because of selective pressures, because pandas born with the toe were able to eat more bamboo and were therefore healthier and more likely to have babies than pandas without the toe.

Richard also mentioned the similarities between jaguars and leopards. They are related, but not closely. The jaguar is more closely related to the leopard than to the lion, but the leopard is more closely related to the lion than to the jaguar. That’s not confusing at all. But both cats look very similar, tawny or golden in color with black spots called rosettes, and both frequently demonstrate an all-black coloring called melanism. But the jaguar lives in the Americas while the leopard lives in Asia and parts of Africa. Why do they look so similar?

In this case, a big part of the similarities between jaguars and leopards are that they share a common ancestor that lived around three and a half million years ago. The jaguar migrated from Africa into Europe and then into North America on the land bridge Beringia, while the leopard mostly stayed put but expanded its territory into Asia. New research into feline genetics suggests that the jaguar interbred with lions at some point, which gave it a heavier build and stronger jaws than the leopard.

But leopards and jaguars look very different from other big cats, and very similar to each other. This is where convergent evolution comes in. Leopards and jaguars live in similar habitats, dense forests and jungle where light is dim and filtered through leaves. A spotted animal is harder to see where there’s a lot of dappled shade, and an all-black animal is harder to see when there’s not a lot of light. Melanistic jaguars, those that are all-black, are extremely common, and melanistic leopards are more common in populations living in thicker forests than in populations that live in more open forests with more light.

Leopards and jaguars share a genus, Panthera, which means they’re pretty closely related. But Llewelly suggested we talk about sucker-footed and disk-winged bats, and while they’re both microbats, they’re much less closely related than jaguars and leopards. And they share a really weird adaptation for climbing on smooth leaves.

The sucker-footed bat lives in Madagascar, the big island off the coast of Africa that’s full of lemurs. Madagascar is also home to a tree called the traveler’s palm, although it’s not actually a palm tree. It’s an amazing tree with huge leaves that grow in a fan shape. I don’t mean the tree has a lot of leaves growing in fan shapes, I mean the main part of the tree is one giant fan of enormous leaves. The leaves can be 36 feet long, or 11 meters, and some trees can grow 100 feet high, or 30 meters. It’s supposedly called the traveler’s palm because the fan tends to grow along an east-west line so it gets the most sun, or possibly because the stems catch and hold rainwater that thirsty travelers could drink. Its white flowers are pollinated by ruffed lemurs and it has bright blue seeds. But the traveler’s palm also has extremely smooth leaves, and the sucker-footed bat roosts on the leaves. But the leaves are so slick and smooth that most insects can’t even hold on to them. How does a bat manage it?

As you may have guessed from the name, the sucker-footed bat has little cuplike pieces of skin on its thumb joint and its feet that excrete lots of sweat-like fluid. The bat presses the cups against the leaf and they act just like suction cups, although the main suction comes from wet adhesion. You know how a suction cup holds better if you lick it first? That’s pretty much how it works. Also, hey kids, don’t lick suction cups, they’re dirty. Also don’t drink rainwater out of leaves, that sounds clean but it’s full of dirt and drowned bugs.

The sucker-footed bat roosts head-up instead of hanging upside-down, only one of six species known to roost head-up. It’s about two inches long, or 5 cm, and eats insects. Because it mostly only roosts in the traveler’s palm and is mostly solitary, it doesn’t carry any parasites in its fur or on its skin. Parasites can’t walk across those slick leaves.

The disk-winged bat, meanwhile, lives in the tropical parts of Central and South America. Like the sucker-footed bat, it has cuplike discs made of skin and cartilage on its thumbs and feet that act as suction cups. It roosts head-up in smooth curled-up leaves, generally in small groups. But its suction cups are different from the sucker-footed bat’s. They actually use suction to stay in place, whereas the sucker-footed bat’s suction cups mostly just use wet adhesion from the sweat it produces, with the actual suction being weak and not really necessary.

So let’s back it up some more and look at two animals that have evolved in similar directions that aren’t related. Like crocodiles and whales, or at least a crocodile relative and modern dolphins.

Metriorhynchids [met-ree-oh-rink-id] were croc relatives that lived around 150 million years ago, about 100 million years before whales and their relatives evolved. Metriorhynchids were marine animals, and while we don’t know a whole lot about them since we don’t have very many fossils, we do know that they grew up to ten feet long, or three meters, and lived in the ocean.

Metriorhynchus ate fish, ammonites, and whatever else it could catch, and it was a fast swimmer. It was streamlined with a long snout, smooth skin instead of armored, and even had a finned tail sort of like a shark’s that probably provided its propulsion through the water. It had four long flippers to help it maneuver.

In other words, in a lot of ways it looked like a dolphin, because it was so well adapted to live in the same environment. Whales and their relations have streamlined shapes, smooth bodies to reduce drag in the water, fluked tails, and flippers. Even the shape of metriorhynchus’s snout mirrors the longer rostrums that some dolphins have evolved to help them catch prey.

Finally, let’s look at convergent evolution between two animals that look totally different, are totally unrelated, but which share one similar feature. If you guessed primates and parrots, you are correct!

Specifically, this is about how the brain manages higher-order processing. In other words, intelligence. Primates, including humans, have an enlarged section of the brain called the pontine nuclei that transfers information between the brain’s cortex and cerebellum, allowing primates to process information in a more sophisticated way than most other mammals studied. But parrots and a lot of other birds are also intelligent, and researchers have recently discovered how their brains do the same thing.

Instead of a big pontine nuclei, birds use a part of the brain called the medial spiriform nucleus that performs the same transfer of information from the cortex and the cerebellum. In intelligent birds like parrots, that part of the brain is very large, five times larger than it is in chickens. I’m sorry, chickens, you’re very pretty birds and taste delicious, but you’re not known for your high-level reasoning abilities.

So convergent evolution is more than just two animals that evolve to look or act similar because they live in the same environment. In fact, there’s so much to convergent evolution that there’s no way I can do more than brush along the surface of the topic in a single episode. It might be a fun topic to revisit now and then.

In the meantime, now you know a little bit about what convergent evolution is. Just remember that if you explain it to a parrot, it’s processing your information with a totally different part of its brain than you are. That’s pretty awesome.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. 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 whatever platform you listen on. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

 

Episode 108: Strange Things Found in Amber

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Thanks to Nicholas for suggesting this week’s episode topic! Lots of strange and fascinating insects and other animals are found trapped in amber. So what is amber, how does it preserve animal parts, and most importantly, what have scientists found in amber?

A millipede preserved in amber, one of 450 millipedes discovered in Myanmar amber. Somebody had to count them:

A newly described insect that got its own order because it’s so weird. Look at that triangular head with giant eyeballs!

A mushroom, a hair, and a tiny phasmid exoskeleton, all caught in amber:

Show transcript:

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

Last month I released an episode about trace fossils, and listener Nicholas wrote me to suggest I also do an episode about amber—specifically, the animals and other items that were trapped in amber and preserved inside it when the amber fossilized. Nicholas also sent me lots of links to really interesting articles!

Amber is the term for fossilized tree resin. If you’ve ever climbed a pine tree and ended up with pine sap all over your hands, which is impossible to get off by just washing your hands and is super sticky and picks up every bit of dirt, you’ll have an idea of what amber starts out as and why it sometimes has insects and other stuff in it. Despite the name pine sap, it’s not actually sap. Sap is the fluid that carries nutrients around to a plant’s cells, sort of like plant blood. Resin is secreted by certain trees and other plants for various reasons, including to protect it from insect damage, to kill fungus, to seal off a broken branch or other injury, and to taste bad so herbivores won’t eat it.

There are different types of amber, because there are different plants that produce resin. We don’t always know what species of plant a particular type of amber comes from, since many are now extinct and can’t be directly studied. Conifer trees evolved around 300 million years ago but became really successful during the Mesozoic around 250 million years ago, spreading throughout the world and dripping resin all over the place. Conifers include pine trees, fir trees, hemlocks, yews, larches, junipers, cedars, redwoods, spruces, and lots of other trees and shrubs that are still widespread today. Some flowering plants, mostly trees, also produce resins. But before conifers evolved and outcompeted them, plants called medullosales lived around the world and produced resin too. Medullosales first appear in the fossil record around 360 million years ago and mostly died out around 298 million years ago. They’re all extinct now.

If your name is Amber, by the way, you are named for fossilized tree resin. That sounds gross, but amber has been prized for millennia as a gemstone. When polished, it can be a gorgeous yellow, gold, or brown, often the color of honey. But some amber is other colors, including red, blue, or green. It all depends on what tree originally produced the resin, its chemical makeup, and how it was fossilized.

So how does the resin fossilize? Sometimes it would drip onto the ground, become buried, and fossilize along with the ground around it. Sometimes the resin-producing tree would fall, become buried, and the resin inside would fossilize along with the wood. Sometimes the resin would drip into water, float to a quiet area or sink to the bottom of the pool or lagoon, and fossilize along with the sand and other sediment that covered it. This is why so much amber is found in the ocean, by the way. Once fossilized, amber floats in salt water—just barely, but enough that on some beaches it’s commonly washed up with the tide. People collect the pieces of amber to polish and sell. Amber can also be burned and often gives off a musky, piney scent that has been used in religious ceremonies.

The reason we’re talking about fossilized plant material in an animal podcast is that amber sometimes has insects or other small animals or animal parts inside it. This happened when it was still resin, which is really sticky. If an ant or bee was in the wrong place at the wrong time, it could be covered with resin and die. Then, if that particular dollop of resin ended up getting protected by sediment at just the right time, instead of weathering away and decaying it might fossilize over millions of years with the ant or bee or whatever inside it. And because the ant or bee was protected from air, water, and bacteria by the resin, and kept in place, the things found in amber are usually mostly intact and include parts of the body that ordinarily never fossilize. It may even help preserve DNA, which ordinarily decays after a matter of thousands of years, although there’s still conflicting evidence about whether this is the case. All this helps researchers study animals that went extinct millions of years ago almost as though those animals were still around.

Substances inside amber are called inclusions, whether they’re something exciting like a spider or just a piece of dirt. Well preserved inclusions, especially pretty ones like flowers, can make the piece of amber extremely valuable. If you want to buy polished amber with an inclusion, though, keep in mind that there are a lot of fakes out there. Make sure to have an expert examine an expensive piece before you spend money on it.

So let’s learn about some insects and other things that have been discovered in amber. I’m going to mention Myanmar repeatedly because it’s a big amber-producing region and the subject of an intensive ongoing study of animals found in the amber. Myanmar is in southeast Asia and was once called Burma.

The oldest organism found in amber are two tiny mites and a fly dated to 230 million years ago. The amber in question is very small, droplets no more than about six millimeters across, found in the Italian Alps. The mites are two different species, both new to science although they have living relations that resemble the ancient mites closely. Both of them ate plants. The fly isn’t as well preserved so researchers aren’t sure what species it was.

A 3 millimeter beetle found in amber dated to 99 million years ago was found in Myanmar. It’s an ancient relative of the modern flat rove beetle that lives under tree bark. But the flat rove beetle lives in South America, with one species from southwestern North America. Comparing the modern beetles with their ancestor gives researchers a closer idea of when the supercontinent Gondwana started to split apart into smaller continents as the landmasses moved slowly across the Earth to their current positions.

The amber found in Myanmar has yielded a lot of interesting information during recent studies. For instance, 450 millipedes! Not all in one piece, of course. The research team used a new type of analysis called micro-CT, which scans the inclusion and creates a highly detailed 3D image which can then be studied without damaging or even touching the amber. This is helpful when the amber pieces are privately owned and only on loan to scientists. Some of the millipede specimens were newly hatched, some fully grown, and include many species new to science.

Another insect found in Myanmar amber dated to 99 million years ago is so unusual that researchers placed it in its own order. To illustrate how rare this is, there are over a million insects described by scientists but they all fit into 31 orders. But now there’s 32 orders. The insect had a triangular head with big bulging eyes, a long flat body, long legs, and no wings. It also had glands on its neck that secreted chemicals that probably helped repel predators. Because of its large eyes and the unusual head shape, it could see almost all the way around it without turning its head. Two specimens of the extinct insect have been found in amber. One of the researchers who described the insect, amber expert and entomologist George Poinar, Jr, said that he thought it looked like an alien’s head so he made a Halloween mask that looked like it. As you do. He said “when I wore the mask when trick-or-treaters came by, it scared the little kids so much I took it off.”

It’s not just insects that are found preserved in amber. One foot and part of a tail from a 100 million year old gecko were found in amber about a dozen years ago. Researchers think the rest of the gecko was probably eaten, possibly by a dinosaur. Even though there isn’t a lot of the gecko to study, there’s enough to determine that it was a genus and species new to science, and that it was probably a juvenile gecko that would have grown up to a foot long if it had lived, or 30 cm. It was only about an inch long when it died, or a bit over two cm. It was stripey and had the same type of toe pads that modern geckos have that allow them to walk up walls.

Another foot, this one from a frog, was discovered in more of the Myanmar amber that’s the subject of ongoing studies. It was a tiny juvenile frog that lived in a tropical forest around 100 million years ago. It’s only the third frog ever found in amber, and is by far the oldest in addition to being the best preserved. Its skull, forelegs, part of its backbone, and the partial hind leg and foot are all preserved, together with a beetle. The problem is, some of the details researchers need to determine what kind of frog it is are missing, like the pelvis. They have just enough information to tantalize them since what they can see indicates that it might be related to some species of toad that live in temperate climates today, but not enough to tell for sure. You know they have to be tearing their hair out in frustration. Hopefully they’ll find another frog with all the bits and pieces they need.

Another surprise from the Myanmar amber is a baby snake only about two inches long, or 5 cm. At first researchers thought it was yet another millipede—I mean, when you’ve found 450 millipedes in amber you probably start to think everything is a millipede—but a scan determined that it was way different. It’s well preserved and even shows some features that modern snakes no longer have, like V-shaped bone spurs on the tail vertebrae that probably helped with stability when snakes first evolved to be limbless. Unfortunately the specimen is missing its skull.

Only one salamander has been found in amber, and it came from a surprising place. The amber was mined from the mountains of the Dominican Republic, which is in the Caribbean near Haiti. But there are no salamanders in the Caribbean today. The salamander in amber dates to around 25 million years ago and proves that salamanders did once live in the Caribbean. Not only that, the amber itself comes from an extinct tree that’s related to a tree native to East Africa. The salamander was a tiny juvenile that fell into a glob of resin after a predator bit one of its legs off. So, you know, it was doomed either way. Poor little salamander.

One really exciting discovery is part of an actual dinosaur tail trapped in amber. It came from a juvenile dinosaur that a scientist found at a market in Myanmar in 2015. The seller thought the tail was a plant, because—you’ll like this—it’s covered in FEATHERS that looked like bits of leaf. It’s dated to 99 million years ago. The feathers were chestnut brown on the tail’s upper surface and white underneath. They’re also very different from modern bird feathers. Researchers aren’t sure which dinosaur species the tail is from, but they do note that the dinosaur died, probably because it couldn’t get free from the resin. It wasn’t like some modern lizards that can drop their tails to escape predators.

Lida Xing, the same researcher who acquired the dinosaur tail in amber also managed to buy a bird in amber in the same Myanmar amber market. Only a few birds have been found in amber and they sell for ridiculous amounts of money—like half a million dollars—to private collectors. As a result, they’re rarely studied. Fortunately, Lida Xing was able to buy the bird in amber and it’s been studied ever since. It’s a young bird that was partially weathered away and squished after it died. It’s about 2 ½ inches long, or 6 cm, and is a type of primitive bird that went extinct at the same time as the non-avian dinosaurs 66 million years ago. It was dark brown and had teeth and clawed fingers on its wings, although both the beak and the finger-wings are missing from the specimen.

Sometimes marine or freshwater organisms are found in amber. For a long time no one understood how this happened, but in 2007 a team of researchers conducted a simple study to find out how it worked. One of the researchers owned some swampy property in central Florida. The team went there and cut pieces out of some pine trees growing in the swamp. Resin flowed from the trees’ injuries, down the trunk, and into the water. The researchers then collected the resin from the water and took it to a lab to examine it. They found water beetles, nematodes, small freshwater crustaceans, mites, even bacteria found in swampy water, all stuck in the blobs of resin. In other words, it’s not a bit unusual for water animals to get caught in resin. The unusual part is when they’re preserved in the resin long enough for the resin to fossilize into amber, and then the really rare part is when they’re found by a human who understands what they’re looking at and realizes it’s important.

Some of the most useful information preserved in amber concerns animal behavior. For instance, the recent discovery of a tick wrapped in spider silk. Spiders don’t usually eat ticks, but occasionally they do, and this tick in amber had been wrapped up in spider silk to immobilize it. Researchers aren’t sure whether the spider planned to eat the tick or was just stopping it from tearing up its web. Either way, it fell out of the web and plopped right into resin, which fossilized and was then found around 100 million years later. From this little piece of amber, we have direct evidence of a spider wrapping up its prey the same way they do today.

Another example is dated to 130 million years ago, when some green lacewing eggs hatched and the larvae and eggs were trapped in resin almost immediately. The green lacewing is a type of flying insect that’s still around today, although the ones found in resin are a species new to science. Since the babies were covered in resin during the act of hatching, researchers have learned a lot about how they emerged from the eggs.

There’s even a piece of amber dated to around 100 million years ago, also found in Myanmar, that shows a dragonfly with a missing head, together with the foot and tail of a tiny lizard. Researchers think the lizard may have caught the dragonfly and decapitated it to kill it, but before it could eat it, both predator and prey were trapped in resin. It’s too bad we don’t have the lizard’s head, because it would be really awesome if it had the dragonfly’s head in its mouth.

Some pieces of amber tell a story like this, like a photograph from millions of years ago. About 50 million years ago near what is now the Baltic Sea, a small mammal, possibly a rodent, bit a mushroom off at its base. A tiny insect, specifically a phasmid, or walking stick, was feeding on the mushroom and jumped away. All this happened just as a blob of resin dropped on the scene. The mammal fled, leaving behind a hair. The insect was trapped but was able to wriggle out of its exoskeleton in an early molt and escape, leaving its exoskeleton behind. The mushroom did nothing, because it was a mushroom. That particular phasmid species is now extinct, as is the mushroom species. Researchers don’t know much about the mammal. They know that the exoskeleton was literally shed moments before it was enveloped in resin because it still shows tiny filaments that would have crumbled away otherwise.

Even more dramatically, another piece of amber, again from Myanmar and about 100 million years old, shows a spider in the act of attacking a wasp. Both the spider, a bristly orb-weaver, and the parasitic wasp are still around today.

Other things are also preserved in amber, from pollen and plant spores to feathers and spiderwebs. It’s mined and gathered in various parts of the world for jewelry, so new amazing specimens could be discovered any day.

I could literally just keep going with this episode for hours talking about what’s been found so far, but I have to stop somewhere so I’ll leave you with one last amber inclusion.

It’s another strange insect new to science, also found in Myanmar amber dated to about 100 million years ago. It was tiny but really weird-looking. Researchers have been referring to it as a unicorn fly because it had a sort of horn sticking up from the top of its head that had three eyes at its tip. Researchers think its specialized horn with eyes on it gave it an advantage when flowers were tiny, as they were back in the early Cretaceous when it lived. Flowering plants had only recently emerged and were diversifying rapidly. It probably ate pollen and nectar. But when flowers evolved to be larger, it lost its evolutionary advantage and went extinct. It also had tiny mandibles that meant it could only eat very small particles of food, long legs, and weirdly shaped antennae.

The unicorn fly was described by our friend George Poinar, who described the weird insect with the triangular head too. And true to form, Dr. Poinar is up to his same tricks. He’s reported as saying that he was “thinking of making some masks based on it for Halloween.”

George, no! The children are frightened! Stop making Halloween masks!

One note about listener suggestions. I’ve been getting a lot of them lately, which is awesome, but I don’t necessarily use the suggestions in order. Which one I pick out for the next episode depends on a lot of things, including how much time I have for research, what strikes me as neat on any given day, and whether I can work a suggestion in to a planned episode about a larger topic. But I promise I do keep all suggestions in a list, and I will eventually get to them all! I’m always delighted to get more, too, so don’t feel like I’m telling you not to send any. Some of the best episodes I’ve done have been from listener suggestions, about animals I’d never heard of before.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

 

Episode 099: Island Life

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Those of us in the northern hemisphere are thinking a lot about island life right about now, where it’s warm and sunny. But there are islands everywhere, not just the tropics, and the animals on islands often evolve to look strange and different from their mainland cousins. Thanks to Richard E. and Lucy for their suggestions this week!

A fossa:

A tamaraw, miniature water buffalo:

A Socotra starling, my new favorite bird:

Adorable little Galapagos penguin:

A dragonblood tree, good grief!

A blue baboon. It’s not a baboon but it is blue:

A ground dragon:

Further listening:

The unlocked Patreon bonus episode about vampire finches on the Galapagos Islands

Show transcript:

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

In a lot of episodes, we talk about animals from islands like the Galapagos and the Canaries. There’s a reason why islands give rise to strange animals. This week we’ll focus on island life—how island habitats lead to unique animals and how introduced animals can destroy an entire island ecosystem in a matter of a few years. Massive thanks to listener Richard E., who suggested the topics of introduced animals and island life!

Islands, of course, are surrounded by water and isolated from larger landmasses as a result. Some are close to the mainland so it’s easy for animals to swim or float across to the island. In cold areas, animals can sometimes walk across ice to islands. But other islands are more remote, or used to be close to the mainland but were pushed farther away by tectonic forces.

Once a piece of land is cut off from the mainland, the animals and plants on that piece of land start to evolve independently of the larger population of animals and plants on the mainland. If the island is isolated enough that potential predators can’t get to it, the animals already living on the island start to adapt to life with no or few predators. As a result, they may appear tame when humans arrive.

And that is where the problems start. Humans don’t just arrive alone. We bring other animals with us, either on purpose, like dogs, cats, and livestock, or by accident, like rats and mice. And these animals, along with humans, can destroy an entire island habitat really easily.

I’ll use one of Richard’s examples, since it’s a good one and not one you’d think of when thinking of islands. The red squirrel is native to Europe and parts of Asia, but it also lives in the UK and Ireland. It’s usually red-brown in color, although some populations can be brown, gray, or even black. The belly is white. It has long ear tufts and a poofy tail. It lives in trees and eats seeds, nuts, berries, fungi, and occasionally eggs or baby birds.

But remember, Ireland and the UK are islands. And in the 1870s, someone thought it would be really great to import eastern gray squirrels from North America and release them in parks in the UK. In Ireland, in 1911 someone gave a bunch of gray squirrels as a wedding gift, which is not a great gift, honestly, and they got loose because of course they did. They’re squirrels.

Grey squirrels are larger than red squirrels and don’t have ear tufts. They eat the same foods red squirrels do. They also carry a disease called squirrel parapoxvirus that doesn’t bother them but which kills red squirrels. The population of red squirrels has dropped substantially as introduced gray squirrel populations climb in the UK and Ireland. The red squirrel is now protected, with conservation efforts in place that are making a difference. But that just goes to show how easy it is to lose even a well-established species on large islands when an outside species is introduced.

On islands, especially smaller islands, small animals tend to grow larger overall and big animals tend to grow smaller overall. This is called Foster’s rule. It comes about partly because there are fewer predators but limited resources. Small animals don’t need to hide as carefully from predators, large animals may not be able to get enough to eat, but medium-sized animals are able to survive short famines without starving and can take advantage of some resources smaller or larger animals couldn’t use.

One example of island gigantism is the fossa, a predator from Madagascar. If you’ve seen the Madagascar movies, you might remember the fossa as a scary predator that looks something like a big cat. Well, the fossa is a real animal, but it’s not related to cats. It’s related to the mongoose, which is a weasel-like animal, but the fossa is generally much larger than a mongoose. It grows some five feet long, or 1.5 meters, including its tail, although its legs are short compared to those of a similarly-sized cat. It spends a lot of time in trees, where it uses its long tail to help it balance. It’s reddish-brown with a paler belly and eats lemurs and other mammals, birds, insects, crabs, lizards, and even fruit.

An example of island dwarfism is the tamaraw from the island of Mindoro in the Philippines, also called a Mindoro dwarf buffalo. It looks like its close relative, the water buffalo, but is much smaller, only about three and a half feet tall at the shoulder, or 105 cm. It’s like a pocket-sized water buffalo. It has V-shaped horns and is black with some white markings on the legs. It prefers to live in mountainous forested areas with water nearby, and it eats grass, young bamboo shoots, and wild sugarcane. It’s a solitary, shy animal.

Famously, Charles Darwin worked out the theory of evolution after examining the differences in finches living on the various Galapagos Islands. He had actually already started thinking along these lines before he’d really examined the finches, but they supported his ideas and helped him work out the details. Basically, as Darwin eventually determined, a type of finch had colonized the islands at some point in the far distant past. Each island had slightly different ecology, so although the finches could fly, over the years populations living on separate islands began to adapt to better fit the resources available on those islands. For instance, the large ground finch has developed a short, heavy bill to crack nuts, while the closely related vampire ground finch has a thinner, sharper bill that it uses to eat insects, seeds, and the BLOOD OF OTHER BIRDS. I am totally not making this up. In fact, I covered the vampire finch in a patreon bonus episode earlier this year. It’s already unlocked for anyone to listen to, so if you haven’t listened to it and want to, I’ll put a link in the show notes.

Remember that squirrel disease I mentioned earlier? There’s a bird disease called avipoxvirus, or avian pox, that has affected the Galapagos finches since 1898. Researchers think it was probably spread by humans who brought infected domestic birds with them on ships. Fortunately, it hasn’t driven any finches or other birds to extinction.

Another problem brought to the Galapagos Islands by humans, this one spread more recently by tourist boats, is a parasitic nest fly that kills baby birds. Researchers have started leaving cotton balls treated with a mild insecticide where the flies are known to attack endangered finches. The parent finches use the cotton balls to line their nests, which helps protect the babies once they hatch. The nest flies lay their eggs in the nests, and the larvae bite babies and mother birds and drink their blood, which can kill the babies. So far the treatment has helped reduce the number of larvae that hatch.

There’s another bird that lives on the Galapagos that is unique to the islands, and that’s the Galapagos penguin. Thanks to Lucy, who suggested it as a topic, and a shout-out to Lucy’s sister Willa too!

Lucy also wanted to hear about King and Gentoo penguins, so let’s start with them. Both species mostly nest on islands.

The King penguin is almost as big as the Emperor penguin and looks very similar, not surprising since they’re closely related. It stands over three feet tall, or 100 cm. It eats small fish, squid, and krill. Females lay one egg at a time and after the egg hatches, the baby spends its first month or so of life sitting on one parent’s feet while the other parent forages. After that both parents leave the baby in a communal nest, called a crèche, while both go foraging. A young king penguin won’t be able to fish for itself until it’s more than a year old.

The Gentoo penguin lives off the southern tip of South America, and it’s almost as tall as the king penguin, but it’s not closely related to the king and emperor penguins. The Gentoo penguin has a reddish bill and a white stripe on its head above its eyes. The female usually lays two eggs in a nest made of round stones. Gentoo penguins value good nesting stones, and a male may court a female by offering her high-quality stones. Sometimes he has stolen those good stones from other penguin nests. Watch out, ladies. The Gentoo penguin eats krill and other small crustaceans for the bulk of the diet, and also eats fish and squid.

So that gives us a sort of baseline of ordinary penguins to compare to the Galapagos penguin. All other penguins all live in the southern hemisphere, usually not all that far from Antarctica. Part of the Galapagos Islands are in the northern hemisphere, although just barely. Penguins are adapted to severe cold, so how do Galapagos penguins thrive near the equator? As it happens, the waters around the Galapagos are actually quite cold, with various oceanic currents bringing cold water north from the Antarctic and bringing cold water from the depths to the surface in the area. Unlike other penguin species, which often travel widely to find food, the Galapagos penguin stays near the islands where the water is comfortably cool and there’s enough food. On hot days, penguins go into the water to stay cool.

The Galapagos penguin is only about 19 inches tall, or 49 cm. It’s almost the smallest penguin and is definitely the rarest penguin, with only about 1,000 breeding pairs. It mates for life and females lay one or two eggs, making sure to lay eggs in the shade so they won’t get too hot in the sun. If both eggs hatch, the weaker baby usually dies as the parents concentrate on feeding the stronger one. Then again, in good years, grown babies who have moved out of the nest may continue to beg their parents for food and sometimes get fed. I know some people like that. In addition to ordinary predators like seals and hawks, the Galapagos penguin is also vulnerable to introduced predators like cats.

We’ve talked a lot about the Galapagos Islands, but every island has its own unique ecosystem. For example, the island of Socotra lies in the Arabian Sea off the coast of Yemen. It’s only 82 miles long, or 132 km, and 31 miles wide, or 50 km. There are three other, smaller islands nearby. It’s been so isolated for so long that even its trees are bizarre-looking, like the dragon’s blood tree that has dense branches with leaves sticking up at the very top so that it looks like grass growing on top of a weird tree-shaped cliff. The tree also has red sap that has been traditionally used as a dye or varnish.

Humans have lived on the Socotra for 2,000 years, so many endemic species have gone extinct due to habitat loss, hunting, and competition or predation by introduced animals like cats and cattle. But there are still a lot of unusual animals that are found nowhere else in the world. The island has only one native mammal species, a bat, and no amphibians, but it has lots of reptiles and some birds found nowhere else in the world. For instance, the Socotra starling. It’s a large, beautiful songbird with a black body and soft gray head and neck, a heavy black bill, and a black eye with a thin white eye ring. It eats insects and fruit. Socotra is also surrounded by coral reefs with lots of unique fish and crabs.

One interesting animal that lives on Socotra Island is called the blue baboon. But it’s not a baboon or any other kind of primate. It’s not even a mammal. It’s a tarantula, and it’s beautiful! It’s a lovely indigo blue in color with white hairs on the abdomen and the top joints of the legs. Its legspan is about five inches across, or 12 cm, and males are smaller than females. Unlike most other tarantula species, it tolerates others instead of being solitary, so people often keep them as pets. Fortunately, it’s become so popular in captivity that there are lots of captive-bred blue baboons readily available, so the market for illegally collected wild specimens has diminished.

I’ve talked a lot about how animals in island habitats can be driven to extinction very easily, but there are success stories too. For instance, the island of Redonda. It’s a tiny island in the Caribbean, only about a mile long, or 1.6 km, with no source of fresh water and land that’s basically just rock. For centuries no one bothered Redonda because no one wanted to live there, but in the late 19th century it was mined for bird guano, or bird poop, which was used as fertilizer. This went on until 1914, and then in 1929 a hurricane destroyed what was left of the mining equipment. The few people who lived there left, but there were still rats and feral goats that ate everything they could find.

Redonda might have become a wasteland with nothing but rats, goats, and a few birds, but an ambitious conservation effort is paying off. First, the rats and goats were trapped and removed from the island. The rats were mostly killed, but the goats were taken to nearby Antigua where they’ve found homes. Then—and this is important—people left the island alone. Without introduced species and without human interference, the population of endemic animals have begun to rebound. Native plants and trees have started growing back. Rare seabirds nest there again. Instead of a big rock, the island now appears green again.

And the population of lizards on the island is rebounding like crazy. In just a year, the number of ground dragons has almost doubled. Ground dragons are lizards only found on the island. They’re shiny black with long tails and eat pretty much anything they can catch, including young ground dragons.

Sometimes all it takes for nature to be set right is to just leave it alone to do what it does best. Sometimes humans have to help by restoring keystone species to a habitat. This has happened with giant Aldabra tortoises, which were once common on the island of Mauritius, the same island where the dodo once lived. A species of ebony tree had nearly been driven extinct by logging, but even after logging was stopped in the 1980s, the trees hadn’t rebounded. Researchers determined that giant tortoises had once eaten the ebony tree fruit and pooped out the seeds, much like the dodo and the rare dodo tree palm. When giant tortoises were reintroduced to Mauritius, new ebony trees started to sprout.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 097: Unusual Reptiles

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Thanks to listeners Finn and Leo, who suggested this week’s topics of strange lizards, and the thorny devil and mata mata turtle, respectively! Join us this week to learn about those reptiles and a bunch more!

Thorny devil. Definitely do not eat.

The mata mata turtle. Big leafhead boi

A frilled lizard BWAAAAAMP

A Pinocchio lizard. Wonder where that name comes from.

Poke poke poke does this bother you? poke poke

om nom nom

A shingleback, or as I like to call it, an ambulatory poop:

Show transcript:

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

We have more listener suggestions this week! Ages ago, listener Finn suggested strange lizards, and more recently, listener Leo suggested a particular type of strange lizard and a strange turtle.

We’ll start with Leo’s suggestion, the thorny devil. He describes it as “a cool animal with spikes all around it,” which is definitely a good way to put it. The thorny devil is a lizard from Australia, and it does indeed have spikes all over its head, back, and tail, and smaller spikes on its legs. The spikes are modified scales and are sharp.

The thorny devil grows to around 8 inches long, or 20 cm, with females being larger than males on average. In warm weather its blotchy brown and yellow coloring is paler than in colder weather, when it turns darker. It can also turn orangey, reddish, or gray to blend in to the background soil. Its color changes slowly over the course of the day as the temperature changes. It also tends to turn darker if something threatens it.

It has a thick spiny tail that it usually holds curved upward, which makes it look kind of like a stick. It moves slowly and jerkily, rocking back and forth on its legs, then surging forward a couple of steps. Researchers think this may confuse predators. It certainly looks confusing.

As if that wasn’t enough, the thorny devil has a false head on the back of its neck. It’s basically a big bump with two spikes sticking out of the sides. When something threatens the lizard, it ducks its head between its forelegs, which makes the bump on its neck look like a little head. But all its spines make it a painful mouthful for a predator. If something does try to swallow it, the thorny devil can puff itself up to make itself even harder to swallow, like many toads do. It does this by inflating its chest with air.

The thorny devil eats ants and only ants, specifically various species of tiny black ants found only in Australia. It has a sticky tongue to lick them up. Because it has such a specific diet, it’s hard to keep in captivity. Only a few zoos in Australia have thorny devils on display. If you listened to episode 93, where we talked about invasive ant species having an effect on entire ecosystems, the thorny devil is an example of this. Fortunately the ants it eats are doing just fine, but if an invasive ant species were introduced to the areas where it lives, the thorny devil would probably be in trouble. So no moving ants around, everyone, I mean it.

The thorny devil lives in desert and scrubland regions, and in hot weather it digs a burrow to shelter in. Females lay their eggs in burrows. To get enough water in its desert environment, the thorny devil has microscopic grooves between its scales that suck up water by capillary action. At night dew condenses on the lizard’s body, and it also collects dew by brushing against dewy vegetation or just by standing or lying on damp sand. If it does happen across water in a puddle, it will put a leg in the water and the tiny grooves in its skin suck up water and funnel it to the mouth. It’s like a living straw.

While I was researching this, I found some information on how rattlesnakes drink. When it starts to rain, a rattlesnake will coil up tightly so that rainwater collects in its coils. Then it drinks the water. This sounds like something someone just made up, but it’s real.

Let’s skip right from a snake fact to a weird turtle, because Leo also suggested the mata mata turtle as a topic. This is where I got distracted while researching, and ended up with an entire episode about giant tortoises. If you were wondering, the main difference between a turtle and a tortoise is that turtles spend most or all of their time in water, while tortoises live only on land.

The mata mata turtle lives in shallow, slow-moving water in South America, especially swamps around the Amazon and Orinoco river basins. It isn’t closely related to the snapping turtle of North America, but it does resemble a snapping turtle in some ways. Its shell is brown or black, its skin is grayish, and its plastron, or the belly section of its shell, is yellow or brown. It grows to around two feet long, or 60 cm, with a long, broad neck and wide, triangular head. Its nose comes to a point like the stem of a leaf. In fact, if you look down on a mata mata in the water, the shape of its head looks exactly like a dead leaf. It has notches and ridges on its shell, and its knobbly skin has flaps that helps camouflage the turtle among dead leaves and sticks in the water. It also has claws and webbed toes.

Unlike the snapping turtle, the mata mata is harmless to humans and most animals. It doesn’t have a sharp bill and it won’t bite. It can’t even chew its food, just swallows it whole. It eats fish, water insects, and other small animals that it captures by opening its large mouth suddenly under the water. This creates suction, sucking a lot of water and the prey right into the turtle’s mouth.

The only time the mata mata leaves the water is to lay eggs. Unlike many other turtle eggs, the mata mata eggs have hard shells, more like bird eggs. It takes the eggs about 200 days to hatch.

The mata mata spends almost all of its time motionless in the water, waiting for prey to come near, and occasionally extending its ridiculously long neck so it can take a breath from the surface. Its pointy nose is a proboscis that it breathes through. It can swim, but it usually prefers to walk along the bottom of the pond or marsh. I bet its feet squish in the mud. Squish squish squish.

Speaking of pointy-nosed reptiles, the male Pinocchio lizard has a nose that points forward and slightly upward like a rhinoceros horn. But it’s not a horn, because it’s flexible, made of cartilage. It lives in the Mindo cloud forest in Ecuador, and was only discovered by scientists in 1953, when researchers collected six specimens. And that was the last time anyone saw the Pinocchio lizard—until 2005, when some birdwatchers saw a weird lizard, took pictures and posted them online, and herpetologists started freaking out.

The Pinocchio lizard blends in so well with its environment that it’s hard to spot. It turns white when it’s asleep, which helps it look like part of a tree branch. It always perches on the end of a branch to sleep, too. During the day, it climbs verrry slowly into the treetops. It’s not a big lizard, only about three inches long, or 7.5 cm, not counting its tail, which is as long as its body. We still don’t know much about it because it’s so hard to study.

It’s not the only lizard with a horn on its nose. For instance, the rough-nosed horned lizard lives in Sri Lanka and is an ordinary-looking lizard for the most part, although it’s covered with short bristly scales that make it look like it would work well for scrubbing out dirty pots and pans. But it has a really long nose, also covered in bristly scales. Oh, and yellow or orange markings on its face that make it look like it has a big orange clown mouth. Males have longer horns than females. Male mountain horned agamas, which also live in Sri Lanka, have a single white or cream-colored horn that sticks directly forward from their nose like a tiny unicorn horn, except it’s not spiraled. In fact, it’s not a horn at all, it’s a single big pointy scale. But those lizards aren’t related to the Pinnocchio lizard.

The La Gomera giant lizard doesn’t have any horns and it’s not all that giant, less than two feet long, or around 49 cm long, including the tail. It’s black or brown on its back with a white belly. Males also have a white throat, and during mating season males inflate their throat and bob their head to attract females. It mostly eats plants, although it will eat insects too, and it lives in the Canary Islands. It’s not the most exciting lizard to look at, but it has an interesting history.

The Canary Islands are a group of islands off the coast of Morocco. It was once called the Fortunate Isles, so if you ever see that in an old book you know what islands it’s talking about. Pliny the Elder, a historian from ancient Rome, said the name Canaria came from the number of dogs on the islands. The word for dog in Latin is canis. The people of the islands were supposed to worship dogs, and some modern historians believe the old accounts of dog-headed people may be a garbled account of the Canary Islanders. Oh, and the little yellow songbirds that live on the Canary Islands took their name from the islands, not vice versa.

The islands were probably visited in ancient times by Phoenician and Greek sailors, but reportedly no one lived there when the Romans explored it in the 1st century. But when Europeans returned in the late middle ages, there were inhabitants that may have been settlers from North Africa. The islands were invaded by Europeans, who then spent centuries fighting with each other over who ruled them. It’s Spain, currently. Scientific expeditions started in the late 18th century. One of the animals the expeditions reported seeing was the La Gomera giant lizard, but it disappeared sometime after about 1900. Researchers assumed it had gone extinct.

Then a 1999 expedition from the University of La Laguna on Tenerife, one of the Canary Islands, heard stories from local residents on the island of La Gomera. They said there was a big lizard living in a few places on the island. The biologists in the expedition checked it out…and sure enough, there were giant lizards. Specifically, six of them. Just six lizards. Later they found another small group of the lizards in another area, but the total population was still no more than fifty.

Fortunately, a captive breeding program has been successful and today there are around 250 of the lizards in the wild, living only on two hard to reach cliffs. They’re vulnerable to introduced predators, especially cats, which eat the eggs and young lizards. Another 300 or so live in a recovery center where they’re protected from predators before being released into the wild. So basically, the La Gomera giant lizard isn’t so much strange as just very, very lucky.

Another lizard that is definitely strange is the frilled lizard from northern Australia and southern New Guinea. It’s bigger than the La Gomera giant lizard, almost three feet long, or 85 cm, and eats insects, spiders, and small animals. It lives in trees and is well camouflaged with blotches and spots on a gray or brown background to help camouflage it among branches and against bark.

The frilled lizard gets its name from the frill on eitherside of its head. Most of the time it keeps the frill folded back against itsneck. When it’s threatened, though, it spreads the frill out and opens itsmouth wide. The inside of its mouth is bright yellow or pink, and the frill hasbright red or yellow scales that don’t show when it’s folded. It’s the lizardequivalent of a jump scare in scary movies. Regular lizard, regular lizard…BWAMP BIG SCARY BRIGHT LIZARD

The frill is made up of spines of cartilage that grow from the lizard’s jaw bones, with skin connecting the spines. It’s not small, either. When expanded, it can be almost a foot across, or 25 cm.

The frilled lizard isn’t dangerous, though, and if its threat display doesn’t scare off a predator, it runs away until it finds a tree to climb. It runs so fast, in fact, that it lifts its body up and just runs on its hind legs, which helps it navigate uneven ground and gives it a better view of what’s around it. It also holds its long tail out as a counterweight to keep its body upright.

That’s supposed to be all the strange details about the frilled lizard…but there are sightings of it doing something unexpected on rare occasions. People occasionally report seeing a frilled lizard fall or jump from a tree, and glide down using its frill as a parachute. There’s no proof that this actually happens, but it sounds plausible.

Another Australian lizard called the shingleback, or bobtail, looks kind of like a pinecone with legs. Or a poop with legs, just going to set that down and walk away. It’s brown with darker and lighter speckles or yellow splotches, large overlapping scales, a stubby thick tail, and a broad head. In fact, its head and tail look a lot alike, which confuses predators. It also stores fat in its tail for winter. It grows about a foot long, or 30 cm, and eats snails, insects, flowers, and other small animals and plants. It lives in arid and desert areas, and their tough skin and overlapping scales help reduce water loss. Its eyes are tiny, like little black beads.

The shingleback looks nothing like the frilled lizard, but it has one thing in common with it. When threatened, the shingleback will open its mouth wide and stick out its large, dark blue tongue. It is an impressively blue, impressively big tongue, and the inside of the shingleback’s mouth is otherwise pale, so it’s startling, to say the least.

The shingleback mates for life. Most of the year the shingleback is solitary, but in spring mated pairs find each other again and go around together while they hunt for food. The female gives birth to two live babies instead of laying eggs.

I could go on and on and on about all the weird reptiles in the world. There are just so many! We’ll definitely come back to this topic in the future, but for now, let’s finish up with a snake called Iwasaki’s snail-eater.

The snail-eater lives on a few small islands southwest of Japan’s main islands. It’s small, only about 7 inches long, or 22 cm, and is orangey in color with darker markings and bright orange eyes. And it only eats one thing: snails.

It’s so perfectly adapted to its diet of snails that its jaw is asymmetrical so it can more easily wedge it into the typical snail’s shell, which coils clockwise. If you remember from the little yard animals episode, some snails very rarely coil the opposite way, and the snail-eater snake is so specialized to eat ordinary snails that it has trouble with counter-clockwise coiled snail shells. It has more teeth on its right mandible. There are other snail-eater snakes closely related to Iwasaki’s snail-eater that have this same adaptation, and in some areas where the snakes are numerous, counter-clockwise snails are much more common than in areas without a lot of snail-eater snakes.

So that’s a reminder that whether you’re a little snail-eating snake or a regular human being, the things you do have an effect on the world around you, even if it’s in ways too small for you to notice without looking very closely.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 095: Giant Tortoises

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This week let’s learn about giant tortoises! What’s the difference between a turtle and a tortoise? The most basic difference is that the turtle lives in water and the tortoise lives on land. And there are some really, really big tortoises in the world!

A Galapagos tortoise:

Show transcript:

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

This episode was supposed to be about strange reptiles, with more awesome suggestions from listeners. I was going to include some information about a couple of giant tortoises…but the more I researched, the longer that part of the episode became, until it just took over. So here’s an episode about giant tortoises, and we’ll have the strange reptiles episode in a couple of weeks instead. I’m going to give a shout-out to listeners Leo and Finn, who have been waiting patiently to hear their suggestions. Sorry you’ll have to wait a little bit longer.

The biggest tortoise in the world is the Galapagos Tortoise, which as you probably know, or can guess from the name, lives in the Galapagos Islands off the coast of Ecuador. In fact, the islands were named after the tortoises. Galapago means tortoise in Old Spanish. There are eleven species of Galapagos tortoise alive today, but there used to be 15. The others were mostly eaten to extinction by sailors who would stop by the Galapagos Islands, capture tortoises, and sail away with them to eat later.

The biggest individual Galapagos tortoise ever measured was a male named Goliath. When he died in 2002, Goliath was 4.5 feet long, or 1.36 meters, 2 feet three inches high, or 68.5 cm, and weighed 919 pounds, or 417 kg. He was only 42 years old when he died, but Galapagos tortoises frequently live for more than 150 years. Adult tortoises have no predators except humans. They’re just too big, too heavy, too strong, and have too tough a shell for other predators to bother with.

The Galapagos tortoise eats plants, including grass, leaves, fruit, and even cacti. Its neck is long, which allows it to reach plants that are farther away, since it can’t exactly climb trees. It can survive up to six months without water, getting most of its moisture from the plants it eats, but some tortoises on more arid islands will lick dew from rocks to get moisture. Some of the boulders have been licked by tortoises so much over the centuries that they have deep grooves worn in the surface from turtle tongues.

As I’ve mentioned before in other episodes, sometimes herbivores will eat meat when they can get it. The Galapagos tortoise does this too on occasion. There’s a type of finch on the Galapagos that cleans parasites off the tortoises, and to help the finch reach as much of its skin as possible, the tortoise will stand up straight with its legs extended. The finches hop underneath and clean ticks and other parasites from the tortoise’s legs, neck, and the skin between the carapace, or upper shell, and the plastron, the lower shell. But occasionally a tortoise will suddenly pull its legs into its shell and drop, smashing the finches flat. Then it stands up and eats the squashed birds. This is not cool, tortoise. Those birds are trying to help you.

Galapagos tortoises lay round, hard-shelled eggs. The female digs a hole in the dirt that’s about a foot deep, or 30 cm, and lays about a dozen eggs in it. She covers the eggs with dirt, tamps it down with her plastron, and leaves. When the babies hatch, they have to dig their way out of the hole. This can take weeks, but fortunately the babies still have yolk sacs attached that keep them from starving.

One of the Galapagos tortoise species that went extinct recently was the Pinta Island tortoise. The last known individual was called Lonesome George. He was found in 1971 on Pinta Island and taken to the Charles Darwin Research Station on Santa Cruz Island. Although researchers tried to find more Pinta Island tortoises, even offering $10,000 if someone found a female, George turned out to be the very last one. He lived with two females of another Galapagos giant tortoise species, in hopes that they were closely related enough to produce babies, but none of the eggs the females laid ever hatched. Lonesome George died in 2012.

Since then, in 2015, DNA testing on a population of tortoises living on Santa Cruz Island showed that they are a subspecies of their own, and closely related to the Pinta Island tortoises. This had to be an “if only we’d known” moment for the conservationists, who could have paired George with females from that population to produce offspring that were genetically close to the Pinta Island tortoise.

Other Galapagos tortoise species were luckier. The Española Island tortoise was down to only 14 individuals in the wild in 1963. They were all taken to the research station on Santa Cruz Island, joined a few years later by another Española tortoise that had been living in the San Diego Zoo. The breeding program was successful and these days there are over a thousand Española tortoises on the island. Similarly, rats introduced to Pinzón Island in the late 19th century nearly drove that island’s species of tortoise to extinction by eating their eggs and hatchlings. By 1965 there were fewer than 200 adults left alive, and no babies had survived for the better part of a century. Scientists started collecting eggs to incubate in safety at the research station, and rear in captivity until they were big enough to survive rat attacks. By 2012, all the rats had been removed from the island and tortoise nests started to hatch naturally in the wild again.

But the Galapagos tortoise isn’t the only giant tortoise alive. The Aldabra giant tortoise is from the Aldabra Atoll in the Seychelles [pronounced say-SHELZ], a collection of 115 islands off the coast of East Africa. It’s about the same size as the Galapagos tortoise and looks similar, but it’s not closely related. Females lay leathery-shelled eggs in shallow nests. In hot weather, some Aldabra giant tortoises will dig burrows to shelter from the heat. It eats plants and has a long neck like the Galapagos tortoise to reach branches, but unlike the Galapagos tortoise it will sometimes rear up on its hind legs to reach leaves. This is dangerous for a tortoise, because if it topples over on its back, it might not be able to right itself and can die.

Like the Galapagos tortoise, some species of Aldabra giant tortoise have gone extinct in the recent past, and for the same reasons. This included Arnold’s giant tortoise, which lived on one of the central Seychelles islands.

In 1995, the Nature Protection Trust of Seychelles was told about two unusual tortoises in a hotel garden. A couple of scientists went to investigate. The tortoises were both male, extremely old, and appeared to fit the description of Arnold’s giant tortoise, which had supposedly gone extinct over a hundred years before. Where had they come from?

It turns out that the hotel had recently bought the tortoises from a very old local man. They had been in the man’s family for longer than anyone alive could remember. Originally there had been three tortoises, but one had died only a matter of months before the scientists discovered them. They were able to get the dead tortoise’s skeleton for study, which proved that these weren’t just regular old Aldabra giant tortoises, they were Arnold’s giant tortoises—possibly the last two alive in the world.

But the researchers weren’t going to give up that easily. They started digging into reports of other unusual tortoises on the islands. Not only did they eventually find a handful of other Arnold’s giant tortoises, they found a second subspecies that had supposedly gone extinct in 1840, referred to as hololissa after its scientific name, Aldabrachelys hololissa.

As if that wasn’t awesome enough, after all this excitement in the tortoise studying community, the Blackpool Zoo in England took a closer look at the Aldabra giant tortoise that had been living there for the last 25 years, named Darwin. It turns out that Darwin was a hololissa tortoise all along. After that, other zoos brought in experts to examine their giant tortoises, and more hololissa and Arnold’s individuals turned up. The problem is that these tortoises all look pretty much alike except to experts. The tortoises have been placed in a successful captive breeding program in the Seychelles.

Researchers used to think that giant tortoises grew so big due to island gigantism, where a species isolated on an island evolves to become larger. In addition to the Seychelles and the Galapagos, giant tortoises used to live on the Canary Islands and the Mascarene islands, including on Mauritius. You know, where the dodo used to live.

But giant tortoises used to be common all over the world, not just on islands where they mostly live today. Big as these living tortoises are, there used to be giant tortoises even bigger.

The biggest known giant tortoise lived in what is now India and Pakistan, and probably in other places too. It lived around two million years ago and may have only gone extinct about 100,000 years ago, or maybe even more recently. It was twice the size of the Galapagos tortoise, possibly as much as nine feet long, or 2.7 meters, and six feet high, or 1.8 meters.

The giant land tortoise, Hesperotestudo crassiscutata, lived even more recently in North and Central America. It was a little bit larger than the Galapagos tortoise, maybe six feet long, or 1.8 meters, but it went extinct only 12,000 years ago. Researchers think humans may have played a part in driving that tortoise to extinction too, by eating it and its eggs. Since I’m recording this episode on Thanksgiving day in the United States, I’m feeling a little guilty about eating so much turkey. Fortunately, turkeys, unlike giant tortoises, are not endangered.

I’m thankful that some species of giant tortoises have survived until today. They’re awesome animals.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. 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 whatever platform you listen on. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 092: Marine Reptiles

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This week we return to the sea to learn about some marine reptiles, both living and extinct!

A marine iguana, eatin:

Another marine iguana, swimmin:

Maybe Darwin was right about the marine iguana looking like imps of darkness:

A mosasaurus skeleton:

A plesiosaur skeleton:

Thalattosaurs:

Show transcript:

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

It’s been a while since we had an episode about the ocean, and I thought it would be interesting to learn about reptiles that evolved to live in a marine environment. Some marine reptiles we’ve already covered in previous episodes, including saltwater crocodiles, sea turtles, and sea snakes. But we haven’t talked much about extinct marine reptiles, and I don’t think we’ve ever had an episode about the marine iguana.

The marine iguana is only found on the Galapagos Islands. It eats seaweed and algae that grow in shallow water around the islands, so it swims and dives to find its food. It’s a large, strong iguana that can grow up to five feet long, or 1.5 meters, with short legs, a short snout, and a row of spines along its back. It’s black or gray in color, which absorbs heat from the sun and keeps the iguana warmer. Many have colorful markings, especially males during the breeding season. The markings might be red or pink, blue-green, yellow, or off-white, depending on subspecies. Some researchers think the kinds of algae eaten by the various subspecies of marine iguana also contributes to the colors of their markings. Males are larger than females.

The marine iguana is well adapted to swimming, although it’s not a fast swimmer. It uses its flattened tail and partially webbed toes to propel itself through the water, and the spines on its back keep it stable in the water. It has long claws that it uses to hold onto rocks to keep from being swept away. Newly hatched babies can swim immediately, but they stay out of the water whenever possible until they’re at least a year or two old. The water around the islands is cold, so the marine iguana will forage in the water for a short time, then come back on land to bask in the sun and warm up.

Only the biggest marine iguanas, mostly adult males, will dive for their food. Females and smaller males usually stay in shallow water, especially at low tide when the algae is easier to reach. A marine iguana can dive up to almost 100 feet, or 30 meters, and stay underwater for half an hour. During bad weather, the iguanas stay on shore, often gathered together to conserve body heat.

Researchers used to think the marine iguana evolved from land iguanas that were swept from Central or South America by storms and floated to the Galapagos islands on rafts of vegetation. Then genetic studies showed that the marine iguana started evolving separately from land iguanas around 8 to 10 million years ago. The Galapagos islands are of varying ages, formed by volcanic activity, but the oldest is only about 3.2 million years old. So obviously the two groups of iguana were separated long before the Galapagos formed. Researchers then speculated that there may have been other, older islands in the Galapagos or nearby that are now submerged, which were where the marine iguanas first started to evolve separately from land iguanas. Then new genetic studies indicated that marine and land iguanas actually separated about 4.5 million years ago, which is not that much of a difference from the oldest islands of the Galapagos, so researchers are back to the original hypothesis. As I’ve said before, science isn’t wrong or right, scientists learn new things and adapt their theories to account for the new information.

For instance, at the moment researchers aren’t sure how marine iguanas shrink during years when weather conditions keep them from finding as much food as they need. I don’t mean they lose weight, I mean they actually shrink. Results of a study published in the journal Nature say marine iguanas shrank up to 2.7 inches, or 6.8 cm, during years with El Nino weather patterns, which brings stormy weather. The iguanas’ bones actually shrunk, making them both shorter and smaller. Not only that, after weather patterns returned to normal and the iguanas were able to find more and better food, the shrinking reversed and they grew larger again. Shrinking reduces the iguanas’ dietary requirements, making them able to survive on less food without long-term health issues.

Because the marine iguana eats algae and other plants that grow in the ocean, it ingests a lot of salt. It has a special gland on the nose that filters excess salt from the blood, which the iguana then expels by sneezing. Many times marine iguanas look like they have white markings on the head, but in actuality it’s just dried salt that they’ve sneezed out.

Like most of the animals that live on the Galapagos Islands, the marine iguana is found nowhere else in the world. It would have been easy for early visitors to the islands to have eaten them to extinction the way they did so many other species. But sailors considered marine iguanas so ugly that they refused to eat them. Even Charles Darwin called them disgusting imps of darkness. That’s harsh, especially since I think they’re cute, but it kept them safe until people understood the need for conservation.

Many marine reptiles are extinct, including the ichthyosaurs we talked about in episode 63. These days the top predators in the ocean are sharks and whales, but mosasaurs and plesiosaurs used to fill those ecological niches.

Mosasaurs looked a lot like sharks in some ways, and like whales in other ways, but they were reptiles. There were a lot of them, from one barely more than three feet long, or 1 meter, up to some species that grew some 50 feet long or more, or up to 17 meters.

All species of mosasaur had four flippers, long powerful tails, and small heads with short necks. Its skull resembled a snake’s in that it was flexible, allowing the mosasaur to swallow prey larger than its head. It also had double-hinged jaws that could open extremely wide. It’s also possible that the mosasaur had a forked tongue. We have skin impressions of mosasaurs, so we know at least some species had finely scaled skins like snakes. Some species had fluked tails shaped like a shark’s tail. The mosasaur used its tail to propel itself through the water, with its flippers only helping it maneuver. Some researchers think the closest living relative of the mosasaur is the Komodo dragon and other monitor lizards, but others think the mosasaur was more closely related to snakes.

The mosasaur came to the surface to breathe every so often like other marine reptiles. It also gave birth to live young. It probably swallowed its prey whole, although some species had specialized teeth that allowed them to crush mollusk shells, such as ammonites. Some studies suggest the mosasaur may even have been warm-blooded. It went extinct at the same time as the dinosaurs.

The plesiosaur looks similar to the mosasaur in many ways, including overall shape and size, but was probably more closely related to turtles than to the mosasaur. Most plesiosaurs had a broad body, a very long neck and small head, and a fairly short tail. It propelled itself with its four long flippers like sea turtles do and was probably relatively slow. Some plesiosaurs, known as pliosaurs, had shorter necks and much larger heads, and swam much faster.

Like the mosasaur, the plesiosaur may have been warm-blooded, and gave birth to live babies instead of laying eggs. The longest plesiosaur was called elasmosaur, which had an extremely long neck. Some elasmosaur species had as many as 76 neck vertebrae. This is your reminder that almost all mammals have seven neck vertebrae. While the elasmosaur could grow up to 50 feet long, or 15 meters, much of its length was neck. Researchers used to think plesiosaur necks were flexible like a goose or swan’s neck, but new findings indicate that it was probably fairly stiff and could mostly just move side to side. Skin impressions show slightly wrinkled skin and some species may have had a tail fluke.

Long-necked plesiosaurs had large eyes and probably hunted by sight. Researchers hypothesize that the long neck might have allowed it to sneak up on fish before they could sense the movement of water from the plesiosaur’s approaching body.

At least one elasmosaur was a filter feeder, with interlocking teeth that it used to filter small prey from either the water or sand, or possibly both. It shows many similarities in skull shape to early baleen whales, too. Researchers think it had a valve at the base of the nostrils that closed them while the animal was feeding, since plesiosaurs and some other marine reptiles have nostrils that open into the mouth.

Like mosasaurs, plesiosaurs died out at the same time as the dinosaurs. They did not live on as the Loch Ness Monster, okay?

While mosasaurs and plesiosaurs lived throughout the world’s oceans, the various species of thalattosaur lived around what is now North America, western Europe, and parts of China. They lived during the mid-Triassic period, up to about 250 million years ago, and we don’t know a whole lot about them because we don’t have all that many fossils. We’re not even really sure where they fit in the reptile family tree.

The thalattosaur hunted in warm, shallow water but otherwise probably lived on land. It resembled a lizard, but with some interesting adaptations to the water. It had four short legs, probably had webbed toes, its body was slender and flexible, and its long tail widened at the end to form a paddle. Some species grew up to 13 feet long, or 4 meters. Some species had nostrils near the eyes, some had snouts that point downward, some had snouts that point upward. Some probably ate jellyfish and other soft foods, others probably ate fish, and a few had teeth that could crush mollusk shells—and had teeth on the roof of its mouth.

This actually isn’t unusual in reptiles and some amphibians. Most snakes have a double row of teeth in the upper jaw, one row growing from the jaw like normal, the other row growing from the roof of the mouth. Some lizards have small teeth that grow from the roof of the mouth, as do many frogs. These help the animal grasp its prey and keep it from escaping while it’s being swallowed whole. This is pretty neat, but it’s not as neat as shrinking iguanas. Nothing beats that.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. 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 whatever platform you listen on. We also have a Patreon if you’d like to support us that way.

Thanks for listening!