Oct. 11, 2010 University of Florida researchers presenting new
fossil evidence of an exceptionally well-preserved 55-million-
year-old North American mammal have found it shares a common
ancestor with rodents and primates, including humans. The study,
scheduled to appear in the Oct. 11 online edition of the
Zoological Journal of the Linnean Society, describes the cranial
anatomy of the extinct mammal, Labidolemur kayi. High resolution
CT scans of the specimens allowed researchers to study minute
details in the skull, including bone structures smaller than
one-tenth of a millimeter. Similarities in bone features with
other mammals show L. kayi's living relatives are rodents,
rabbits, flying lemurs, tree shrews and primates. Researchers
said the new information will aide future studies to better
understand the origin of primates. "The specimens are among the
only skulls of apatemyids known that aren't squashed completely
flat," said study co-author Jonathan Bloch, an associate curator
of vertebrate paleontology