IUCN / SSC Cat Specialist Group - Digital Cat Library |
|
||||||||||
|
||||||||||
|
|
| Palmqvist, P.; Torregrosa, V.; P‚rez-Claros, J.A.; Mart¡nez-Navarro, B.; Turner, A. | |
| A re-evaluation of the diversity of _Megantereon_ (Mammalia, Carnivora, Machairodontinae) and the problem of species identification in extinct carnivores | |
| 2007 Journal of Vertebrate Paleontology (27): 160-175 | |
In this article, hypotheses about the origin, evolution and dispersal of _Megantereon_ are reviewed using the fossil specimens included in previous comparative studies as well as the remains identified in the late Pliocene site of Fonelas (Spain) and the early Pleistocene localities of Lantian, Lingyi, Longdan, Renzidong (China), and Untermassfeld (Germany). The validity of the two species proposed by Mart¡nez-Navarro and Palmqvist (1995), Megantereon cultridens and _M. whitei_, is evaluated using tooth measurements and multivariate statistical methods. The hypothesis of sexual dimorphism as an explanation for the morphological variability of _Megantereon _is tested with a large sample of sexed individuals of _Panthera pardus_ and _Panthera leo_. Results obtained indicate similar or even smaller differences in tooth dimensions between _M. cultridens _and _M. whitei_ than between sexes in both leopards and lions, except in the case of the lower fourth premolar. However, in spite of a substantial overlap between both Megantereon species in the size of the upper canine, this tooth reverses the differences found for other tooth measurements, because _M. cultridens_ shows larger cheek teeth on average than _M. whitei_ but smaller sabers. This is confirmed by principal components and discriminant analyses, which reveal that sexual dimorphism in leopards and lions is a matter of tooth size and not of relative proportions and argues against the interpretation of M. cultridens and M. whitei as the sexes (males and females, respectively) of a single species. These results indicate that _M. cultridens_ and _M. whitei_ are valid species, because the differences in tooth measurements exceed those expected from sexual dimorphism and do not reveal the effects of biased sampling. Finally, an analysis of jaw anatomy reveals biomechanical differences between both _Megantereon_ species, related to the relative efficiency of the biting muscles at the level of the lower carnassial. |
|
 |
PDF files are only accessible to Friends of the Cat Group. Joining Friends of the Cat Group gives you unlimited access and downloads in the Cat SG Library for one year, and allows you to receive our newsletter Cat News (2 regular issues per year plus special issues). More information how to join here |
(c) IUCN/SSC Cat Specialist Group ( IUCN - The World Conservation Union) |