Edworthia Lerbekmoi, a New Primitive Paromomyid Primate from the Torrejonian (Early Paleocene) of Alberta, Canada
Abstract
A primitive paromomyid plesiadapiform primate,Edworthia lerbekmoinew genus and species, is described from a recently discovered locality in the Paskapoo Formation, exposed at a road cut in Edworthy Municipal Park, Bow River Valley, Calgary, Alberta, Canada. The new taxon, probably middle Torrejonian (To2) in age, is based on two dentary fragments containing well-preserved dentitions that bracket p2-4, m1-3. With the exception of the basalParomomys, E. lerbekmoidiffers from all other paromomyids in retaining p2, but p2 in the new paromomyid is single-rooted, not two-rooted as inParomomys. E. lerbekmoidiffers further fromParomomysin having an enlarged anterior alveolus for a tooth immediately anterior to p2, hypothesized to be il. Unlike other paromomyids with an enlarged il, however, this tooth inE. lerbekmoiwas obliquely, not horizontally, oriented and its alveolus opens dorsally, in the alveolar row, not anteriorly, as in other paromomyids in which il is greatly enlarged. This suggests thatE. lerbekmoirepresents a previously unknown paromomyid lineage that evolved from an ancestor having obliquely oriented lower incisors as in the basal primatePurgatorius, not from an ancestor in which il was already subhorizontal in orientation, as inParomomys.If this working hypothesis is correct or whether in the future some other evolutionary scenario will better account for the unique anterior dentition inE. lerbekmoi, the new paromomyid nonetheless demonstrates that crucial aspects of the earliest history of the important plesiadapiform family Paromomyidae remain to be discovered.
- Publication:
-
Journal of Paleontology
- Pub Date:
- September 2010
- DOI:
- 10.1666/09-072.1
- Bibcode:
- 2010JPal...84..868F