Adiciones al conocimiento de los ?Campanorcidae? (Notounglata, Typotheria) en el noroeste argentino

BABOT, JUDITH; GARCÍA LÓPEZ, DANIEL ALFREDO

San Miguel de Tucumán

Congreso; XX Congreso Geológico Argentino; 2017

The informal taxon Campanorco inaugularis (?Campanorcidae?) was originally reported for the upper levels of the Lumbrera Formation (late middle Eocene) based on a single skull. Several new specimens referable to this morphotype allow restudying its morphology and lead to the reinterpretation of its relationships in the context of previous phylogenies. The new traits observed refer mainly to the mandible and lower dentition (previously unknown). The mandible is robust and shows a well-developed angular process. The i1 is small and chisel-like and the molars show a simple entoconid (not expanded mesially) and a reduced talonid in the m3. Some of the specimens analyzed are sub-adults, showing some of the ontogenetic variation affecting the morphology the upper and lower dentition (eruption sequence, size, number of cristae, etc.). Several characters here observed are potentially useful for the formal definition of the taxon. In turn, the observed traits do not support some previous phylogenetic hypothesis that relate ?campanorcids? with members of the Mesotheriidae-?Archaeohyracidae?-Hegetotheriidae lineage. Instead, the morphologic scheme is consistent with alternative studies that point to a basal position of this informal clade within Typotheria. The record of ?campanorcids? and leontiniids, restricted to the upper levels of the Lumbrera Formation and some other equivalent units, may indicate a paleobiogeographic singularity affecting a large area of the Eastern Cordillera during the late middle Eocene.