Research Training Program

Aimee Betts
Albertson College of Idaho
Caldwell, Idaho

Richard W. Thorington, Jr., Ph.D.
Project Advisor
Department of Vertebrate Zoology
Division of Mammals

"This was an excellent program for me."

Origins of African Tree Squirrels (Rodentia, Sciuruidae)

This paper primarily examines two competing hypotheses regarding the evolution of the African tree squirrel tribes Protoxerini and Funambulini. Moore's hypothesis (1959) was based on four shared cranial characters between the African tree squirrels and the African ground squirrels, the Xerini. His hypothesis was that the African tree squirrels came into Africa as ground squirrels, giving them a Xerini ancestor. The second hypothesis was devised by Lavocat (1978). On the basis or fossil evidence, Lavocat suggested that the African tree squirrels arrived in Africa in a Miocene invasion from Asia. These squirrels were distinctly Asian, perhaps relating them to the Callosciurini, the Asian tree squirrels. Moore's placement of Heliosciurus in the tribe Protoxerini was examined, along with his placement of Funambulus, an Indian tree squirrel, in the tribe Funambulini. After a comparison of 39 cranial and 23 post-cranial characters, comparisons were made of several sister group hypotheses. It was discovered that neither Moore's nor Lavocat's hypotheses about the origin of the African tree squirrels was supported by and shared derived characters between the related tribes. It was also found that no shared status of Heliosciurus could not be resolved. Funambulini has no shared derived characters to support its grouping.

This research was supported by a grant from the National Science Foundation Research Experiences for Undergraduates (Award: BIR-9300225).