New Speciment of Elphidotarsius russelli (Mammalia, ?Primates, Carpolestidae) and a Revision of Plesiadapoid Relationships

Significant new material of the plesiadapiform Elphidotarsius russelli is described from Montana and Alberta. Previously the most poorly documented carpolestid, this species is now known from numerous isolated teeth and many jaw fragments. New material from the Crazy Mountains Basin, Montana substan...

Full description

Saved in:
Bibliographic Details
Published inJournal of vertebrate paleontology Vol. 21; no. 1; pp. 132 - 152
Main Authors Silcox, Mary T., Krause, David W., Maas, Mary C., Fox, Richard C.
Format Journal Article
LanguageEnglish
Published Society of Vertebrate Paleontology 26.03.2001
Subjects
Cladistics
Evolution
Mathematical cusps
Parsimony
Phylogenetics
Primates
Taxa
Teeth
Vertebrate paleontology
We they distinction
Online AccessGet full text

Cover

More Information
Summary:Significant new material of the plesiadapiform Elphidotarsius russelli is described from Montana and Alberta. Previously the most poorly documented carpolestid, this species is now known from numerous isolated teeth and many jaw fragments. New material from the Crazy Mountains Basin, Montana substantially extends its known geographic range and shows that E. russelli is the most derived species of Elphidotarsius, with many features that foreshadow characteristics of Carpodaptes; consequently, emending the diagnosis of Elphidotarsius has been necessary. A phylogenetic analysis based on 73 characters scored for all species of Elphidotarsius, Pronothodectes, and Saxonella, as well as Purgatorius unio, Purgatorius janisae, Pandemonium dis, Chronolestes simul, and Carpodaptes hazelae, indicates that Elphidotarsius is a paraphyletic stem taxon at the base of Carpolestidae. Numerous crossing synapomorphies among these taxa show that a single anagenetic lineage can no longer represent the evolution of early carpolestids. This analysis also clarifies basal plesiadapoid relationships. Carpolestidae is the sister taxon to Plesiadapidae, and Saxonellidae is sister group to the carpolestid/plesiadapid clade. Contrary to previous hypotheses, Chronolestes and Pandemonium are found to lie outside of a clade including the other members of Carpolestidae, Saxonellidae, and Plesiadapidae, implying that they are basal plesiadapoids that diverged before the evolution of the common ancestor to the three main plesiadapoid families.
ISSN:0272-4634
1937-2809