Few researchers have attempted rigorous cladistic analyses of fossil ochotonids (pikas), largely due to the paucity and morphological conservativism of the fossils. However, pikas were diverse and widespread during the Cenozoic, and we therefore explore the applicability of cladistic analysis utilizing dental characters, which comprise most of their fossil record. We used abundant Barstovian ochotonid specimens from Hepburn's Mesa, Montana, and previously described Miocene material to construct a phylogeny and explore congruencies among the phylogenetic, stratigraphic, and geographic occurrence of Oreolagus from the western United States. Maximum parsimony analysis was conducted using 13 morphological characters. Stratigraphic and geographic occurrences of Oreolagus are generally congruent with the proposed hypothesis of phylogeny and seem to involve an early Hemingfordian first occurrence in the Great Plains, followed by later Hemingfordian and Barstovian radiations into and within the northern Rocky Mountain region, Oregon, and Nevada. Although this study is limited in scope, it illustrates that with further understanding of ontogenetic changes in occlusal morphologies of ochotonids, cladistic analysis is a viable method for reconstructing ochotonid phylogenies and exploring their biogeography.
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. 2004 • No. 36