Episode 442: Trees and Megafauna

Further reading:

The Trees That Miss the Mammoths

The disappearance of mastodons still threatens the native forests of South America

Study reveals ancient link between mammoth dung and pumpkin pie

A mammoth, probably about to eat something:

The Osage orange fruit looks like a little green brain:

Show transcript:

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

Way back at the end of 2017, I found an article called “The Trees That Miss the Mammoths,” and made a Patreon episode about it. In episode 320, about elephants, which released in March of 2023, I cited a similar article connecting mammoths and other plants. Now there’s even more evidence that extinct megafauna and living plants are connected, so let’s have a full episode all about it.

Let’s start with the Kentucky coffeetree, which currently only survives in cultivation and in wetlands in parts of North America. It grows up to 70 feet high, or 21 meters, and produces leathery seed pods so tough that most animals literally can’t chew through them to get to the seeds. Its seed coating is so thick that water can’t penetrate it unless it’s been abraded considerably. Researchers are pretty sure the seed pods were eaten by mastodons and mammoths. Once the seeds traveled through a mammoth’s digestive system, they were nicely abraded and ready to sprout in a pile of dung.

There are five species of coffeetree, and the Kentucky coffeetree is the only one found in North America. The others are native to Asia, but a close relation grows in parts of Africa. It has similar tough seeds, which are eaten and spread by elephants.

The African forest elephant is incredibly important as a seed disperser. At least 14 species of tree need the elephant to eat their fruit in order for the seeds to sprout at all. If the forest elephant goes extinct, the trees will too.

When the North American mammoths went extinct, something similar happened. Mammoths and other megafauna co-evolved with many plants and trees to disperse their seeds, and in return the animals got to eat some yummy fruit. But when the mammoths went extinct, many plant seeds couldn’t germinate since there were no mammoths to eat the fruit and poop out the seeds. Some of these plants survive but have declined severely, like the Osage orange.

The Osage orange grows about 50 or 60 feet tall, or 15 to 18 meters, and produces big yellowish-green fruits that look like round greenish brains. Although it’s related to the mulberry, you wouldn’t be able to guess that from the fruit. The fruit drops from the tree and usually just sits there and rots. Some animals will eat it, especially cattle, but it’s not highly sought after by anything. Not anymore. In 1804, when the tree was first described by Europeans, it only grew in a few small areas in and near Texas. The tree mostly survives today because the plant can clone itself by sending up fresh sprouts from old roots.

But 10,000 years ago, the tree grew throughout North America, as far north as Ontario, Canada, and there were seven different species instead of just the one we have today. 10,000 years ago is about the time that much of the megafauna of North and South America went extinct, including mammoths, mastodons, giant ground sloths, elephant-like animals called gomphotheres, camels, and many, many others.

The osage orange tree’s thorns are too widely spaced to deter deer, but would have made a mammoth think twice before grabbing at the branches with its trunk. The thorns also grow much higher than deer can browse. Trees that bear thorns generally don’t grow them in the upper branches. There’s no point in wasting energy growing thorns where nothing is going to eat the leaves anyway. If there are thorns beyond reach of existing browsers, the tree must have evolved when something with a taller reach liked to eat its leaves.

The term “evolutionary anachronism” is used to describe aspects of a plant, like the Osage orange’s thorns and fruit, that evolved due to pressures of animals that are now extinct. Scientists have observed evolutionary anachronism plants throughout the world. For instance, the lady apple tree, which grows in northern Australia and parts of New Guinea. It can grow up to 66 feet tall, or 20 meters, and produces an edible red fruit with a single large seed. It’s a common tree these days, probably because the Aboriginal people ate the fruit, but before that, a bird called genyornis was probably the main seed disperser of the lady apple.

In episode 217 we talked about the genyornis, a flightless Australian bird that went extinct around 50,000 years ago but possibly more recently. It grew around 7 feet tall, or over 2 meters, and recent studies suggest it ate a lot of water plants. It would have probably eaten the lady apple fruit whenever it could, most likely swallowing the fruits whole and pooping the big seeds out later.

Way back in episode 19 we talked about a tree on the island of Mauritius that relied on the dodo’s digestive system to abrade its seeds so they could sprout. It turns out that study was flawed and the seeds don’t need to be abraded to sprout. They just need an animal to eat the flesh off the seed, either by just eating the fruit and leaving the seed behind, or by swallowing the entire fruit and pooping the seed out later, and that could have been done by any number of animals. The dodo probably did eat the fruits, but so did a lot of other animals that have also gone extinct on Mauritius.

In June of 2025, a study was published showing that the gomphothere Notiomastodon, which lived in South America until about 10,000 years ago, definitely ate fruit. Notiomastodon was an elephant relation that could probably grow almost ten feet tall, or 3 meters. It probably lived in family groups like modern elephants and probably looked a lot like a modern elephant, at least if you’re not an elephant expert or an elephant yourself. The 2025 study examined a lot of notiomastodon teeth, and it discovered evidence that the animals ate a lot of fruit. This means it would have been an important seed disperser, just like the African forest elephant that we talked about earlier.

Another plant that nearly went extinct after the mammoth did is a surprising one. Wild ancestors of modern North American squash plants relied on mammoths to disperse their seeds and create the type of habitat where the plants thrived. Mammoths probably behaved a lot like modern elephants, pulling down tree limbs to eat and sometimes pushing entire trees over. This disturbed land is what wild squash plants loved, and if you’ve ever prepared a pumpkin or squash you’ll know that it’s full of seeds. The wild ancestors of these modern cultivated plants didn’t have delicious fruits, though, at least not to human taste buds. The fruit contained toxins that made them bitter, which kept small animals from eating them. Small animals would chew up the seeds instead of swallowing them whole, which is not what the plants needed. But mammoths weren’t bothered by the toxins and in fact probably couldn’t even taste the bitterness. They thought these wild squash were delicious and they ate a lot of them.

After the mammoth went extinct, the wild squash lost its main seed disperser. As forests grew thicker after mammoths weren’t around to keep the trees open, the squash also lost a lot of its preferred habitat. The main reason why we have pumpkins and summer squash is because of our ancient ancestors. They bred for squash that weren’t bitter, and they planted them and cared for the plants. So even though the main cause of the mammoth’s extinction was probably overhunting by ancient humans, at least we got pumpkin pies out of the whole situation. However, I personally would prefer to have both pumpkin pie and mammoths.

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

Thanks for listening!

Episode 217: Three (Small) Mystery Animals

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

Further Reading:

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

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

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

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

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

A couple of gibbons at MAX FLUFF:

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

All the geese from the painting:

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

The mystery bird rock art:

An emu (with babies):

Genyornis compared to a human:

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

A couple of megapodes in their egg field:

Show transcript:

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

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

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

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

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

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

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

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

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

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

But maybe not quite so easy after all.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Thanks for listening!