Tuesday, March 6, 2012

[Paleontology • 2007] Pseudotribos robustus • Convergent dental adaptations in pseudo-tribosphenic and tribosphenic mammals

A newly discovered Jurassic mammal is seen here in an artist's depiction foraging among fallen ginkgo leaves and arthropod shells (top). Based on the size and shape of the skeleton (bottom), scientists believe the 4.7-inch-long (12-centimeter-long) creature was a powerful digger that ate plants and insects. 
The animal's teeth could both cut and grind, showing that the key dental adaptation evolved separately at least twice in the history of mammals, the researchers add.
Illustration by Mark A. Klingler, Carnegie Museum of Natural History 

Class Mammalia

Clade Yinotheria Chow and Rich, 1982 (emended by ref. 3)

Family Shuotheriidae Chow and Rich, 1982 (ref. 5)

Pseudotribos robustus gen. et sp. nov.

Etymology. Pseudo, false, for superficial resemblance; tribos, grinding, for the grinding and crushing function of the pseudo-tribosphenic molar; robustus, strong, for the stout limb bones of the new mammal.

Holotype. Chinese Academy of Geological Sciences (CAGS)040811A and CAGS040811B are the part and counterpart, respectively, of a partial skeleton with impression and carbonized residues of furs (Fig. 1).

Zhe-Xi Luo, Qiang Ji, and Chong-Xi Yuan. 2007. Convergent dental adaptations in pseudo-tribosphenic and tribosphenic mammals. Nature 450 (7166): 93–97. doi:. 10.1038/nature06221.

New Mammal Fossil Sheds Light on Teeth Evolution: