TAXONOMIC IMPLICATIONS OF MAMMOTH MOLAR MORPHOLOGY AS MEASURED VIA COMPUTED TOMOGRAPHY (CT)
A new taxonomic method is needed to help resolve the relationship between M. columbi and M. primigenius. The ideal method will provide precise character measurements while offering internal inspection of the molars to account for the effects of dental wear. This study explores the utility of computed tomography (CT) in providing such a means of delineating species. Using CT, we digitized a sample of unworn teeth from both species. A model of continual wear was created by removing slices from the chewing surface to the base of the crown. At each time slice, we calculated the lamellar frequency, enamel thickness, and occlusal enamel percentage of the exposed surface of the tooth. We then examined the relationship between relative wear percentage and dental characters to determine if there was a separation between the two species of mammoth with wear.
Our results demonstrate a high degree of intraspecific variation, making a consistent separation of species difficult. In the absence of accompanying cranial morphologies or molecular data, delineation of the North American mammoth species based solely on molar morphology remains challenging, if not impossible, even with the use of CT scanning. This study’s small sample size (n = 6) allows for the possibility that our data lie within the natural variation in dental characters for the genus. Future studies should examine a larger sample size of molars from both species and from numerous populations in order to resolve whether a divergence becomes more apparent.