Skull on display at the American Museum of Natural History, NYC
Reconstruction by Anne Musser
When: Late Oligocene to Miocene (~25 to 12 Million years ago)
Where: Australia
What: Obdurodon is a fossil platypus, as is fairly obvious from a look at its skull. Though upon closer inspection there are some very important differences; Obdurodon had a larger bill than the living platypus and retained teeth as an adult. Modern adult platypus are toothless, shedding all their teeth as juveniles. These teeth are important as they help us place monotremes (platypus and the echidna are the modern representatives) into the mammal family tree. It is now the consensus that marsupials and placentals are more closely related to one another than either is to the monotremes, but there are a great deal of extinct groups of mammals that may fall between therians and the monotremes - such as the multituberculates. Fossils such as Obdurodon which are most assuredly related to modern monotremes, but preserve more primitive features, are critically important for this phylogenetic issue. So then why is it still an issue? All we have of Obdurodon is a skull, despite the full body reconstruction above, and while there are fossils of even older monotremes they are even more scrappy - just isolated teeth or jaw fragments (that still enjoy full body reconstructions…).
How did Obdurodon live compared to the modern platypus? Well, the living form uses its bill in the water to help it sense prey, and as Obdurodon had an even larger bill, it seem likely it also was aquatic, though without a postcranial skeleton it is unknown if it had the same swimming and digging adaptions seen in its extant relatives.
Mounted specimen on display at the Harvard Museum of Natural History
Reconstruction by Roman Uchytel
When: Miocene and Pliocene (~17.5 - 4.5 million years ago, and maybe a couple million years more!)
Where: North America
What:Teleoceras was an aquatic rhinoceros. It was a very common beast in the North American Miocene. Yes, rhinos in North America! I have been eager to share with you all the amazing diversity of North American rhinos. The discovery of a tremendous amount of rhinos, not just in terms of numbers of species but their diversity, is one of the great surprises of North American paleontological expeditions in the 19th and early 20th centuries. This continent was home to rhinos the size of modern pigs, rhinos that could run quickly, and even aquatic rhinos! Teleoceras is one of these aquatic rhinos.
Teleoceras had very short legs for a rhino and a nubby horn. This horn is actually pretty large in the scheme of things. As much as the modern rhinos are famous for their horns the vast majority of fossil rhinos show no evidence of having a horn. We can tell this via the presence or lack of a rough surface on the nasal bones. In life Teleoceras would have probably occupied a niche very simular to the modern hippopotamus.
The carcass is a bloated, blubbery boon, enough meat to last for more days than a borophagine can hold in its head. The dogs patrol the sea cow’s perimeter, climb its hulk, reassuring themselves that the carcass is indeed real. Seabirds are less dubious of the thing and have to be chased away, but the dogs are suspect. Even after filling their bellies on the fatty flesh, the find just feels too good to be true.
As I said last time we went to Mammal Junction, a lot of mammals from the prehistoric Cenozoic are similar to mammals we have now, or look kind of like a generic mammal. Some of them, though, weren’t. Some were absolutely positively bizarre. Let’s talk about one.
This ugly motherfucker is named Daeodon, and lived in North America during the Paleogene-Neogene divide. Daeodon—and other entelodonts, by extension—is essentially what it looks like. It’s a carnivorous ungulate, or, hoofed mammal. No surprises here, other than the fact it existed. Today, the only ungulates who eat meat are whales1. Ungulates make up most of the large land mammals today, and they’re all big grazers. Daeodon and its cousins, however, were apex predators.
If you’ve seen Walking with Beasts, Daeodon might look familiar to you. A similar animal appears in the third episode, “Land of Giants,” called an “entelodont.” That one lived in central Asia and probably belonged the genus Entelodon. If you’ve seen the documentary, you certainly remember maybe the most gruesome scene in the entire franchise, where a territorial fight between two of them leads to one’s face being fucked right up. Even as a violence-loving kid that one kind of made me shudder.
But even though Walking with tends to sensationalize its animals, that wasn’t really the case this time. They were probably a lot like that. Aggressive, terrifying, and ugly as hell. I wanted to give them a little more fur, though, since I personally don’t believe they were naked like a domestic pig. They’ve been nicknamed “Hell pigs” or “Terminator pigs” and I find it hard to disagree.
They had big-ass heads and powerful jaws with pairs of huge canines and incisors, along with batteries of tough, blunt molars. This mixture of teeth is, weird as it probably sounds, sorta convergent with ours. Sharp front teeth and dull, rounded teeth in the back? These were the teeth of an omnivore. They fed themselves with a mix of scavenging and active hunting, and probably rounded out their diet with roots and tubers, an echo of their relationship with other hooved animals. They’re like a concept for a horror movie character. It’s like Kujo for pigs, I think. I don’t know much about Kujo other than the fact that Stephen King was inebriated when he wrote it and doesn’t even remember doing so.
It’s important to mention that they weren’t actually pigs, although we used to think some of them were. They’re the weird cousin pigs don’t talk about. Paleontologists like to disagree on how closely they were related to pigs and other artiodactyls (even-toed ungulates). I did a lot of digging to see where they might fall, and the general consensus looks like “somewhere around hippos and whales2.”
More about this genus specifically, Daeodon was the largest member of the entelodont family, being a bit taller than the average grown man. I am really glad I don’t live alongside these things. One specimen was originally named Dinohyus, which means “terrible pig.” It’s thought that Daeodon, more than other entelodonts, was mostly a scavenger. It followed other carnivores around and waited for them to kill something, then got in there and screamed at them until they ran away. These were huge animals with mouths full of sharp teeth; it probably wasn’t too hard for them to terrify their fellow meatboys.
Daeodon is also interesting because it’s kind of a tangle in the entelodont family tree. First of all: entelodonts are found pretty evenly in Eurasia and North America. So, there’s a cousin of Daeodon who lived in the same region of North America, a few million years earlier, called Archaeotherium. I actually almost talked about that one today instead. The obvious conclusion there is that Daeodon is descended from Archaeotherium, right? And that was the idea for a long time. But, looking closer, we found that it looks more like its cousins on the other side of the Pacific. It might be descended from an immigrant population of entelodonts who crossed over from Asia. Wack.
This leads to some questions, like, were the entelodonts in America just worse at being entelodonts? Did these guys come over the land bridge and just outcompete them? It’s really hard to say, since most animals aren’t fossilized and it’s totally possible they coexisted with native entelodonts and we just haven’t found them. Of course, they might also just be descended from American entelodonts and happened to develop convergent traits with their cousins across the pond. Listen, this science is a total disaster sometimes. We’re doing the best we can with piles of bones we find in the dirt.
So, yeah, that’s Daeodon, the murder “pig.” The Cenozoic is still full of surprises for us. A lot of the animals that didn’t survive to modern times are absolutely buckwild, and if this one doesn’t prove that, I’ll need to try harder. I mean, even if it does convince you, there’s still some weird shit out there that I’d love to cover. And that’s why I’m here!
P.S. If you haven’t seen Walking with Beasts, I highly recommend it. It’s the passion project of the Walking with team, and probably the most accurate installment of the three.
1Whales evolved from ungulates, and so are considered members of that group even though they have no gotdamn legs
2If any of my readers know more about the relationship between entelodonts and other artiodactyls, please let me know. I’m not certain that I’m right on this and I’d love clarification
Primelephas — Late Miocene- Early Pliocene (7-2 Ma)
I love elephants. I came out of hiatus just to say that. They’ve always been one of my favorite animals, and prehistoric proboscideans were one of the first paleontology topics I was really interested in as a kid. That probably shows, considering this is the third one I’ve drawn for this blog. BUT, this is the first true elephant to be featured here, and fittingly enough, its name means “first elephant.” Let’s pretend I did that on purpose and didn’t realize it as I was typing this just now.
Primelephas is pretty mysterious, even though it only went extinct pretty recently. We know a lot about the Miocene/Pliocene as a whole, but we only have a few remains of Primelephas. Those few remains have been found in Africa, although it was probably more widespread than that. It packed the setup we’ve come to expect of an elephant: A long, grasping trunk that doubled as a bendy straw, big, sturdy legs, and a stocky body. We can pretty reasonably assume it was mostly hairless, too, considering the environment it lived in. It sounds an awful lot like a modern elephant, doesn’t it? The main difference is the pair of tusks on the tip of its jaw. Elephant tusks come in all shapes and sizes, so I tried to draw this one with a pair of upper tusks that properly show off the bottom pair.
Oh, also, Primelephas is the common ancestor of three genera of elephant: Mammuthus,Elephas, and Loxodonta. I mention this because those are, in order, the Woolly Mammoth, the Asian Elephant, and the African Elephant. That’s why it looks so much like a modern elephant, because it’s only one step removed. The best part about the Cenozoic is how well we understand the taxonomy of the animals who live in it. Not to mention, cats evolved during the Cenozoic, and I personally find that very important.
If you don’t know elephant taxonomy (and I don’t blame you if you don’t), you might find it weird that 1) African and Asian elephants are different genera, I didn’t know that until recently, and, 2) the Woolly Mammoth shares such a recent common ancestor with them. The other furry proboscideans, the Mastodons, diverged from their modern cousins during the Oligocene, around 30 million years ago, so it would make sense if mammoths did that, too. Except, they didn’t, because there are no rules in biology. Here’s a chart showing the family tree of modern elephants. Like the last time I did one of these, it’s very simplified and only shows the stuff that’s relevant.
So, as you can see, mammoths are descended from Primelephas, just like modern elephants. Not only that, but mammoths are more closely-related to Asian elephants than Asian elephants are to African elephants. Considering mammoths evolved so recently from an ancestor who most likely only had sparse hair like a modern elephant, and considering just how close they are to Asian elephants, it’s very likely that heavier fur is a trait that’s relatively easy for natural selection to “turn on” or “turn off” in proboscideans. Also keep in mind this happened more than once, because Mastodons did it too. This is something we’ve studied pretty closely, and this is actually tapping on the window of a really cool subject that will have to be covered another day. For now, I have to crawl back into my hiatus cave and do some more research. I’ll see you all next week!
I kind of wish I was uploading this on a Tuesday, so I could call it Tallboy Tuesday, but no, it’s Monday. I’ll think of something, but in the meantime, it’s Aepycamelus.Aepycamelus pairs nicely with an elegant white wine, perhaps a chardonnay.
Aepycamelus is a camel who first shows up in the dawn of the Neogene period, and sticks around for most of it. It lived on the prairies of North America and was convergent with giraffes, of all things. Its long legs and neck were perfect for life on a grassland dotted with clusters of tall trees. Its remains are found all over North America, from Florida to California. It was a successful genus, with ten identified species. Older paleo fans might recognize it as Alticamelus, which is just a different name for the same animal. It’s similar to the Apatosaurus/Brontosaurusdichotomy.
Aepycamelusis a bit of a landmark form of fossil camelids. Camelids before it walked flat on their feet, but Aepycamelus has evolved the padded toes found on its modern cousins. It has the same stilt legs and general body plan, but it also has a lot of differences.
Today, we only know one genus of camel, Camelus. There are two species, C. dromedarius and C. bactrianus, the Dromedary and Bactrian camels. I’m a big fan of the Bactrian myself. They’re quite different, but have a lot of features in common. They’re desert dwellers with wide toes for walking on sand. They can go long periods of time without food or water, and store fat in humps on their back, which can see them through serious droughts and allow them to travel long-distance. Their stamina is something else.
Looking at evolution in hindsight, there’s only one genus of camel still around, and there aren’t many steps from there to the belief that camels were “evolving toward” the form of Camelus, that this is what a camel is supposed to be. The thing is, starting from the beginning of the camelid tree and working forward in time, you see that Camelus is a really weird genus of camel. It’s not the end goal or the standard for camels, but actually a highly-specialized form suited for living in deserts. Historically, camels looked much more like their cousins, the alpacas. Extinction is uncaring and unfeeling, and, for one reason or another, only the specialized forms of camel made it to this end of the Neogene-Quaternary boundary. It’s also worth mentioning that camelids evolved in North America before spreading to South America and Eurasia and going extinct on their continent of origin.
The history of camelids—and many modern groups—is replete with stories like this. There’s no shortage of twists and turns in the history of life, and camelids represent the concept pretty nicely. They’re a weird group with a handful of weird representatives in Eurasia and South America today. There are other mammals with similarly rich histories and only a few remaining survivors—hyraxes, sloths, and proboscideans being some of the most famous examples. But we’ll talk about them another day.
Aepycamelus is a nostalgic animal to me. I mentioned at the beginning of this writeup that they’re synonymous with Alticamelus, and that’s exactly how I first knew it. I read about it in a book from my grandparents called Prehistoric Monsters did the Strangest Things. Unfortunately, I couldn’t track down scans of the pages it’s on, but the book is pure, unadulterated classic dinosaur literature for kids. It’s super-outdated now, since it’s around 40 years old, but it’s full of charming art and it was one of my favorite books when I was a young paleo enthusiast.
