Date of Award

Spring 1-1-2014

Document Type


Degree Name

Master of Science (MS)


Museum and Field Studies

First Advisor

Jaelyn J. Eberle

Second Advisor

Christy M. McCain

Third Advisor

William A. Clemens

Fourth Advisor

Patricia A. Holroyd


A new genus and species of earliest Paleocene (Puercan) arctocyonid `condylarth,' Sigynorum magnadivisus, is described from the Great Divide Basin of southern Wyoming. The fossils are from the China Butte Member of the Fort Union Formation, and the fauna suggests an early Puercan (Pu1) age. The new taxon appears most similar in size and molar morphology to the early Puercan arctocyonid Oxyprimus erikseni, but possesses distinctive features that are lacking in O. erikseni. A phylogenetic analysis utilizing 18 taxa and 52 dental characters was performed, and the resulting strict consensus tree shows that S. magnadivisus is closely related to Oxyprimus spp. and Protungulatum donnae. This analysis is the first to focus on a large set of Puercan `condylarth' taxa across geographically-widespread localities, and, with the addition of S. magnadivisus to the known early Puercan arctocyonids, suggests that diversity among early Puercan `condylarths' may be higher than previously thought.