Deciduous teeth morphology of some tremarctines (Ursidae, Tremarctinae). Descriptions, comparissons and possible evolutive implications

SOIBELZON L. Y CARLINI A.A.

AMEGHINIANA

ASOCIACION PALEONTOLOGICA ARGENTINA

Año: 2004 vol. 41 p. 217 - 224

0002-7014

Deciduous teeth morphology of some tremarctines (Ursidae, Tremarctinae). Descriptions, comparissons and possible evolutive implications Leopoldo SOIBELZON and Alfredo CARLINI Key words. Ursidae, Tremarctinae, Arctotherium, deciduous tooth. Palabras clave. Ursidae, Tremarctinae, Arctotherium, dientes deciduos. Abstract. The morphology of some deciduous teeth of Arctotherium tarijense and A. latidens (Ursidae: Tremarctinae) is here described and compared for the first time. The crown morphology of dP4 and dp4 is similar to that of M1 and m1. The general morphology of dP/dp4 in A. tarijense and Ursinae is similar, but their permanent morphology dentition is different. The dP/dp4 of A. tarijense seems to bear a generalized set of characters (i.e. crown outline, the protocone and parastyle of dP4, the metaconid and hypoconid of dp4); unfortunately these teeth cannot be compared with their homologues in other tremarctines. Consequently, we are unable to include these characters in the phylogenetic analysis of the Tremarctinae subfamily in order to know whether the phylogenetic relationships are affected or not. It is noteworthy, that if these characters were present in M/m1 of A. tarijense, at least, some of them could be undoubtedly regarded as plesiomorphic features. In this respect, is the deciduous teeth morphology more conservative than that of permanent teeth?