Basicranial evidence suggests picrodontid mammals are not stem primates

• DOI: 10.1098/rsbl.2023.0335
• Publication Date: 2024-01-10T00:05:12Z
• Authors: Jordan W. Crowell; John R. Wible; Stephen G. B. Che...
• Keywords: Synapomorphy; Autapomorphy; Morphology

The Picrodontidae from the middle Palaeocene of North America are enigmatic placental mammals that were allied with various mammalian groups but generally now considered to have close affinities paromomyid and palaechthonid plesiadapiforms based on proposed dental synapomorphies. picrodontid fossil record consists entirely gnathic remains except for one partial cranium Zanycteris paleocenus (AMNH 17180). Here, we use µCT technology unveil previously undocumented morphology in AMNH 17180, describe compare basicranial a first time, incorporate these new data into cladistic analyses. Z. is distinct shares similarities Palaeogene Apatemyidae Nyctitheriidae. Results analyses incorporating novel suggest picrodontids not stem primates nor euarchontan synapomorphies uniting and, by extension, evolved independently. highlight need scrutinize highly autapomorphic taxa limited records.