New primitive paromomyid from the clarkforkian of wyoming and dental eruption in plesiadapiformes
Clarkforkian late Paleocene freshwater limestone from the Clarks Fork Basin, Wyoming, has yielded four specimens of the plesiadapiform paromomyid, Acidomomys hebeticus gen. et sp. nov. A. hebeticus has a strong metaconid on p4, a small double-rooted p3, and a very diminutive i2. Presence of p3 and i2 is primitive, and their retention in A. hebeticus suggests that this taxon is part of a previously unknown lineage that diverged from other paromomyids by the early or middle Paleocene. Acidomomys hebeticus is represented by virtually complete upper and lower dentitions, all from less than fully mature individuals, with teeth at one of three stages of development. The dental eruption sequence differs from that of other plesiadapiforms in having p3 erupt before p4 (p3 erupts after p4 in microsyopids, and p3 and p4 erupt simultaneously in plesiadapids). A. hebeticus differs from Plesiadapis and primitive primates, in which the premolars erupt after m3 is in place, in having p3/P3 erupt before or at the same time as that of m3/M3. It is similar to Plesiadapis in having p4 erupt after the molars are in place, a condition considered primitive in primates. While these differences in dental eruption sequence between representatives of Paromomyidae, Microsyopidae, and Plesiadapidae could be phylogenetically significant, they may instead reflect adaptive differences in dental morphology, facial architecture, or life history. © 2002 by the Society of Vertebrate Paleontology.
Duke Scholars
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- Paleontology
- 3705 Geology
- 3104 Evolutionary biology
- 0603 Evolutionary Biology
- 0602 Ecology
- 0403 Geology
Citation
Published In
DOI
EISSN
ISSN
Publication Date
Volume
Issue
Start / End Page
Related Subject Headings
- Paleontology
- 3705 Geology
- 3104 Evolutionary biology
- 0603 Evolutionary Biology
- 0602 Ecology
- 0403 Geology