Dwarves Are Grody

I love Therapsids. It’s a big group, and it includes not just cool prehistoric creatures like Inostrancevia and Anteosaurus, but also your house cat or dog, any bats or pigs or wolves or dolphins you might see, and human beings — because all mammals are part of the therapsidia. That’s right, despite what this headline says, Anteosaurus wasn’t a reptile at all, but a dinocephalian therapsid, and a relative of ours.

Of course, while I love dinocephalians, the gorgonopsids are my absolute favorite of the ancient, long extinct lineages that were our cousins. Big beasts like Inostrancevia and smaller but still agile predators like Aelurosaurus — these particular predators had a lot of adaptations that we see today in mammals, but also lacked some, like the larger mammalian neocortex. The non-mammalian therapsid brain was apparently, according to their skulls shape and size, more like that of a reptile than ours. But while the synapsids (including therapsids) started out as a cousin group to the sauropsids, their divergence led them down a path that differed in many ways from their counterparts in the reptilia. And for many millions of years, before the Permian-Triassic extinction called The Great Dying, therapsids ruled the Earth.

And while they were mostly pushed out by the archosaurs after the PT extinction, they hung on throughout the entire Mesozoic, with the cynodonts evolving into true mammals by the late Triassic. And today, those very cynodonts are giraffes and lions and hippos and squirrels and yes, humans — not only are all mammals therapids, all mammals are cynodonts as well.

So that’s a long winded explanation of why I put a picture of my dog at the top of today’s Queue, because she’s the cutest little therapsid you’re ever gonna see.