Wyoming Fossils Reveal 1 New Primate Species, Challenging 1987 Evolution Model

1 articles · Updated · Sci.News · Aug 5

Dozens of jaw and tooth fragments from southern Wyoming led paleontologists to identify Tetonius varleyorum, a new 50-million-year-old omomyid primate about the size of a modern mouse lemur.
The fossils came from a single Smiley Draw site in the Great Divide Basin, where researchers also found Arapahovius gazini and Anemorhysis savage—only the second and third known records of those species.
Three omomyid species living together at one early Eocene site had not been documented before, and a fourth, still undescribed omomyid was also recovered there.
That broader Wyoming sample complicates a 1987 Bighorn Basin model that portrayed Tetonius evolution as a straight, non-branching anagenetic sequence, with the new fossils interrupting that lineage.
The findings, published in the Journal of Human Evolution, suggest early North American primate evolution and biogeography were more diverse than the classic fossil record implied.