2022/03/15 by Shawn P. Zack, Ashley W. Poust, Hugh Wagner · 2 citations
Earth and Planetary Sciences · Environmental Science · #Evolution and Paleontology Studies #Paleontology and Evolutionary Biology #Amphibian and Reptile Biology
paper · doi:10.7717/peerj.13032
openalex publication_date 2022/03/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
Machaeroidinae is a taxonomically small clade of early and middle Eocene carnivorous mammals that includes the earliest known saber-toothed mammalian carnivores. Machaeroidine diversity is low, with only a handful of species described from North America and Asia. Here we report a new genus and species of machaeroidine, Diegoaelurus vanvalkenburghae , established on the basis of a nearly complete dentary with most of the dentition from the late Uintan (middle Eocene) portion of the Santiago Formation of southern California. The new taxon is the youngest known machaeroidine and provides the first evidence for the presence of multiple machaeroidine lineages, as it differs substantially from Apataelurus kayi , the only near-contemporaneous member of the group. Phylogenetic analysis indicates that Diegoaelurus is the sister taxon of Apataelurus , while older species are recovered as a monophyletic Machaeroides . Both phylogenetic results are relatively weakly supported. The new taxon extends the record of machaeroidines to the end of the Uintan, potentially tying machaeroidine extinction to the faunal turnover spanning the middle to late Eocene transition in North America.