First comprehensive morphological analysis on the metapodials of Giraffidae

Giraffids are a group of relict pecoran ruminants with only two living taxa. During the Miocene, however, this group was much more diverse, with more than 20 different species showing a wide range of variability. In addition to many other parts of the skeleton this variability is also represented in their metapodials. We find inter-specific anatomical differences in the giraffid metapodials; each taxon evaluated possesses a unique combination of limb morphologies. The proximo-palmar/plantar metapodial surface provides useful characteristics and allows for genus identifications and comparisons.
We describe the central trough of the metapodial shaft; when combined with the absolute length of the limb, the depth of this trough allows for better separation between taxa. We find that the metacarpal robustness index exceeds that of the metatarsals in all except one giraffid evaluated, supporting a front-loaded body weight distribution, consistent with the elongated cervicals or large ossicones seen in many taxa. The morphological features of the giraffid metapodials, as well as the limb lengths and proportions can be a useful tool for phylogenetic analysis.

Last Updated
January 26, 2021
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