Wyoming Primates: Tetonius varleyorum
Meet Tetonius varleyorum, an omomyid primate, a separate, now extinct lineage of primates that lived around the northern hemisphere ~50 million years ago, closely following the extinction of the non avian dinosaurs.
Trevor Schulz
8/10/20261 min read
Publication Info:
Transcript:
Parker D. Rhinehart et al. 2026. A diverse new omomyid primate fauna from the early Eocene of southern Wyoming with implications for interpreting macroevolutionary patterns among anaptomorphines. Journal of Human Evolution 218, 103867; doi: 10.1016/j.jhevol.2026.103867
Meet Tetonius varleyorum, an omomyid primate, a separate, now extinct lineage that lived around the northern hemisphere ~50 million years ago.
Episode 323
Notes:
One of our early relatives was just discovered in Wyoming, only 16 million years after the dinosaurs went extinct. And no, before you get worried that it's some kind of weird conspiracy about humans evolving in North America, that's not it. Think older. Think much older. We're not talking about the genus Homo, we're not talking about hominids or hominins. We're talking about primates because primates, at least proto-primates, first evolved in North America. With animals like Purgatorius showing up pretty much immediately following the extinction that wiped out the non-avian dinosaurs. There's a good chance they were probably around at least a little bit before that. One of the first groups of true primates were the omomyids, which are small tarsier-like animals that fall on the primate family tree kind of right between the lineage that led to monkeys and apes and obviously us, and the lineage that led to animals like lemurs. The brand new omomyid is Tetonius varleyorum which was just discovered in 50-million-year-old deposits in Wyoming. And usually when these early primates are discovered, they're discovered because of their jaw bones, because it's pretty much the most durable bone, the most likely to preserve. And this is no exception. But that doesn't mean it's only known from one bone, because 12 jaw fragments were found in the same sandstone locality. And Tetonius varleyorum wasn't alone. It was discovered with three other very close relatives: Arapahovius, Anemorhysis, and a yet-to-be-named species. As usual, if you want more information, here's the source.