Andrewsarchus mongoliensis
What is this thing?
Andrewsarchus mongoliensis is quite a popular animal of the Eocene epoch and the Cenozoic era as a whole, starring in from children’s textbooks, to animatronic parks and documentaries, but very little is known about it. In fact, it is only known from a huge upper skull, almost a metre long, collected in 1923 by an expedition lead by namesake and Indiana Jones inspiration, the American Museum of Natural History’s Roy Chapman Andrews, to the wilds of Inner Mongolia, China.
A cast of the only Andrewsarchus skull discovered at the Natural History Museum in London, with its ghost.
When this skull’s species was first described, it was originally thought to be a mesonychian, an extinct group of wolf-like, hoofed mammals that were the dominant carnivores of much of the Paleogene period, but this one was even bigger than others of its "kind", estimated to be approximately a tonne in weight, making it a contender for the largest mammalian carnivore ever to walk the Earth. It was so that it has been conventionally portrayed in popular culture, such as the 2001 BBC documentary Walking With Beasts, as a big, bad, superpredatory "sheep in wolf’s clothing," that slogan referring to Andrewsarchus’s convergent evolution, or as was supposed.
Emo wolf noises. From Walking With Beasts.
In 2009, it was found that Andrewsarchus was not actually a mesonychian, but a relative of hippopotamuses, whales, and the famous entelodonts, also popularly known as hell pigs, but too aren’t what they seemed to be. Onto the lifestyle of this mysterious megamammal, Andrewsarchus was probably an opportunistic omnivore akin to a giant pig, eating both plants and animals of its Eocene scrubland home. This scrubland lied on the coast of the ancient Tethy’s Ocean, a great shallow sea that would soon be closed off by the connection of Africa and India to the mainland. Its only remnants today are the Mediterranean, Caspian, Black and Aral seas. It is possible, as speculated in Walking With Beasts, that Andrewsarchus sometimes went onto these Tethyan coasts to scavenge whatever has washed up it could get its mouth around, from molluscs to turtles, with the help of its crushing jaws. My reconstruction of this animal here takes inspiration from the related hippos, their anthracothere ancestors, pigs and rhinoceroses, as well as bearing a coarse mane along its body and "tick birds," which gather on the backs of many megafauna today to feed on their plentiful parasites, comfortably relieving their hosts. Though this reconstruction might get outdated as soon as postcranial remains are found, at least mammals get less unpredictably extravagant than reptiles, such as how dinosaurs might’ve been. The Eocene wasn’t relatively too long ago, but 45 million years is an unfamiliar gap, where whales hadn’t completely lost their legs yet, and the related Andrewsarchus was a strange megamammal to come across.
