A description of Colbertia lumbrerense Bond (Mammalia, Notoungulata) is presented. This species is recorded in levels of the Lumbrera Formation (Eocene) in northwestern Argentina. Several specimens were collected; yet its cranial osteology has not been studied in detail. The new description provided herein is based on five specimens, including the type specimen. The external surface of the posterior zone of the skull in this species shows a generalized notoungulate morphology. The development of certain elements (external auditory meatus, meatal crest, epitympanic sinus) is similar to that observed in other Paleogene notoungulates such as Simpsonotus Pascual, Vucetich, and Fernández; Brachystephanus Simpson, Minoprio, and Patterson; and Xenostephanus Simpson, Minoprio, and Patterson. In spite of this generalized arrangement, the skull shows some distinctive features, particularly in the petrosal. Some traits of this bone are shared with Dolichostylodon saltensis García López and Powell, a notoungulate recorded in upper levels of the same formation. The morphology described in this study is consistent with recent phylogenetic analyses of Paleogene notoungulate taxa that place C. lumbrerense in a basal position.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 48 • No. 1