An Aegialodontid Upper Molar and the Evolution of Mammal Dentition
Alexey V. Lopatin1 and
Alexander O. Averianov2
The most obvious key synapomorphy of the therian mammals is
the tribosphenic pattern of their molars. Tribosphenic teeth
are capable of both shearing and grinding, which substantially
increase effectiveness of food processing and, in turn, permit
evolution of a wide range of dietary specializations. Functional
tribospheny developed repeatedly during mammalian evolution
but was successful only in the Boreosphenida. The earliest stage
in the development of boreosphenidan tribospheny has remained
poorly understood, being documented only by lower molars of
aegialodontids. Here, we report a known upper molar of an aegialodontid
mammal, Kielantherium, from the Early Cretaceous of Mongolia.
2 Zoological Institute, Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg 199034, Russia.
E-mail: alopat{at}paleo.ru.
E-mail: lepus{at}zin.ru
