FIRST RECORD OF SUPERNUMERARY TEETH IN GLYPTODONTIDAE (MAMMALIA, XENARTHRA, CINGULATA)

GONZÁLEZ-RUIZ, LAUREANO; CIANCIO, MARTÍN R.; MARTIN, G.; ZURITA, A. E.

JOURNAL OF VERTEBRATE PALEONTOLOGY

SOC VERTEBRATE PALEONTOLOGY

Lugar: Lawrence; Año: 2015 vol. 35 p. 1 - 6

0272-4634

The presence of extra teeth, defined as the presence of teeth in excess of the normal expected number in any of the dental arcades, has been reported for nearly all orders of recent mammals but are rarely recorded for fossils. In this contribution we describe the first case of supernumerary teeth for a glyptodont (Glyptodontidae, Xenarthra) and discuss possible explanations for its occurrence. The specimen under study corresponds to a skull of an adult of Boreostemma acostae from La Venta (Huila, Colombia), specifically from the Villavieja Formation, ?Monkey Unit? The ?Monkey Unit? is located at the base of Villavieja Formation (ca. 12.9?11.5 Ma) (middle Miocene) of the Honda Group. Most glyptodonts have eight trilobed and molariform teeth in each hemimaxilla and eight in each dentary (Mf 8/mf 8), none of them located in the premaxillary bone. In some taxa, the first two or three have a simpler morphology (i.e., not evidently lobed or trilobed) and the Mf1 have been called by several authors incisiforms though without implying homologies but function. The specimen described herein present an upper right dental series that is composed of nine well preserved Mf teeth. On the left dental series, the presence of eight Mfs is inferred by the preservation of the first four Mfs and the four alveoli of the last four Mfs. The presence of a supernumerary molariform in Boreostemma acostae might be explained by a mutation producing new tooth germ or by a division of an existing tooth germ.