Lower Triassic postcanine teeth with allotherian-like crowns

ABDALA, F.; MOCKE, H.; HANCOX, P. J.

SOUTH AFRICAN JOURNAL OF SCIENCE

ACAD SCIENCE SOUTH AFRICA A S S AF

Lugar: Johannesburg; Año: 2007 vol. 103 p. 245 - 247

0038-2353

The Allotheria are fossil mammals with upper and lower postcanines usually showing two longitudinal rows of cusps separated by a central valley. The group comprises the poorly known haramiyids, mostly represented by isolated teeth, and the notably diverse and long-lived multituberculates; its monophyly is uncertain. The oldest records of this particular group are the Late Triassic (Norian?Rhaetian) haramiyids. We present here postcanines with haramiyid-like crowns that were recovered from the Lower Triassic of South Africa. A distinguishing feature of the new teeth is that they are single-rooted. This is the oldest record of mammal-like teeth with crowns having parallel rows of cusps, representing a temporal extension of some 43 million years from similar crown patterns ofharamiyids and tritylodontids. This finding reinforces evidence of the remarkable faunal turnover of therapsids in the Early/Middle Triassic, at which time an explosive origin followed by a rapid early diversification of herbivorous/omnivorous forms with occludingexpanded postcanines took place.