Chiromyoides

The type species of Chiromyoides, Chiromyoides campanicus, was originally described in 1916 from fragmentary craniodental material discovered in Cernay, France, with additional material also later found at Berru. Gingerich (1973) described the first North American species, Chiromyoides caesor, from two upper incisors found in northern Wyoming. Several years later, he described three additional North American species, Chiromyoides major, Chiromyoides minor, and Chiromyoides potior, from isolated upper incisors found in northern Wyoming, southern Wyoming, and southern Colorado, respectively. Secord (2008) named Chiromyoides gingerichi from material found in northern Wyoming and southern Montana, Burger and Honey (2008) named Chiromyoides gigas from several incisors found in northern Colorado, and Beard et al. (2020) named Chiromyoides kesiwah from material found at several localities in southwestern Wyoming. == Evolutionary relationships ==

Chiromyoides is known only from isolated teeth, mandibular fragments, and maxillary fragments, and its relationships to other plesiadapiforms are not well understood. Chiromyoides is generally acknowledged to be a member of the family Plesiadapidae, along with Plesiadapis, Platychoerops, Nannodectes, and Pronothodectes. Recent phylogenetic analyses suggest that Chiromyoides is descended from Plesiadapis, perhaps most closely related to Plesiadapis walbeckensis or Plesiadapis tricuspidens. Beard et al. (2020) found that species of Chiromyoides separated into two distinct clades: a more southern clade consisting of Chiromyoides gigas, C. minor, and Chiromyoides kesiwah from southern Wyoming and Colorado, and a northern clade including Chiromyoides major, Chiromyoides gingerichi, Chiromyoides campanicus, and Chiromyoides mauberti. Chiromyoides caesor formed a polytomy with the two main clades. Chiromyoides potior was not included in their analysis. The nesting of the European species C. campanicus and C. mauberti in the northern clade suggests that Chiromyoides dispersed into Europe from North America. == Age and biogeography ==

The oldest specimens of Chiromyoides are C. minor from the Chappo Type Locality in Lincoln County, Wyoming, and an edentulous mandible from the Black Peaks region of southwest Texas that has been referred to either C. minor or an indeterminate species of Chiromyoides. Chiromyoides caesor and C. kesiwah come from slightly younger Tiffanian (Ti4) beds in the Bighorn Basin and Washakie Basin, respectively, == References ==