4 Paleontology I: Morphology, Evolution, and Environment
Sunday, 28 October 2007
8:00 AM - 12:00 PM
EVOLUTION OF CAMELID PODIALS AND CONSEQUENCES FOR ESTIMATION OF MIOCENE MAMMAL DIVERSITY IN THE GREAT BASIN
Paper number: 4-13
Program: Technical Sessions
Time: 11:00 AM – 11:15 AM
Authors
Abstract
Astragali and metapodials have shown great promise for taxonomic identification because of their structural constraints. Both are relatively large podial elements, however, and tend to have a higher incidence of breakage than some of the smaller elements. These smaller elements contain less structural information but provide a larger average sample size. In combination, all of the elements can provide greater confidence in the taxonomic composition of a fauna.
There is some suggestion that lateral elements are more variable, and there is a weak correlation between number of articular surfaces and taxonomic utility. As expected, there is a weak inverse correlation between element size and relative abundance. There is no clear distinction in discriminant ability between carpal and tarsal elements or between left and right sides. As with astragali, the major genus-level taxonomic discriminant is overall size, with some evidence that shape differences can distinguish species within generic size-bands. Careful examination of these differences is beginning to elucidate the nuances of camel locomotor evolution.