Anterior dentition and relationships of the early Eocene omomyids Arapahovius advena and Teilhardina demissa, sp. nov.

Abstract

Two dentaries from the Wasatchian Willwood Formation of the Bighorn Basin, Wyoming, constitute the first evidence of the anterior teeth of the omomyid Arapahovius advena . Another specimen, preserving intact crowns of nearly all the lower teeth, represents a derived new species of Teilhardina. The two species appear to be closely related and provide evidence on the interrelationships of diminutive omomyids. Arapahovius and Anemorhysis are sister taxa that probably evolved from a derived species of Teilhardina.