One of the more earlier ancestors to primates, there's even this whole odd couple thing where an animal that would be considered prey cuddled up with a thrinaxodon in a burrow where it would be fossilized together. Apparently no one has done artwork of this extinct animal with close connections to primates.

Oh I just did more research, turns out all mammals were connected to it.

I've seen a lot of art of it, especially of it snuggling broomistega. Granted, all wholesome stuff, but it's very much out there if you know where to look.