PRIMER REGISTRO DE VERTEBRADOS PARA EL NEÓGENO AFLORANTE EN LA LOCALIDAD DE LAS LAJAS, ENTRE LAS SIERRAS DE ZAPATA Y FIAMBALÁ, CATAMARCA, ARGENTINA

NASIF,NL., ESTEBAN, G.I., GEORGIEFF, S.M., VIDES, M.E. Y BOSSI, G.

Sab Miguel de Tucumán

Jornada; 2ª Jornadas Geológicas; 2008

Fuindación Miguel Lillo

The sedimentary outcrops between Fiambalá and Zapata Ranges (Catamarca Province, Northwest of Argentina) reach 2,325 m thick. The strata have been assigned to Neogene age and represent the southern part of Santa María – Hualfín Basin. According their lithostratigraphic characteristics, five units were proposed, from base to top: Hualfín, Las Arcas, Chiquimil, Andalhuala and Corral Quemado Formations. The first vertebrate records for this area are showed in this contribution; they belong to Chiquimil and Andalhuala Formations. The best record is provided by the Andalhuala Formation, from a stratum about 100m over the base. Some fragments from the maxilla and tympanic bullas of one individual were collected and identified. The fragments were assigned to notoungulate Hegetotheriidae Hemihegetoterium torresi (Cabrera and Kraglievich) Zetti (=Pseudohegetotherium torresi) from the teeth morphology and the relative smaller size to others species of these genus (H. achataleptum Rovereto, and H. trilobus Croft y Anaya). The specimen-type of H. torresi is recorded in the Las Barrancas Member from the Arroyo Chasicó Formation, Chasiquense Mammal Age and there is only one record in the Los Baños Member from Chiquimil Formation in Catamarca Province. The presence of H. torresi in the Andalhuala Formation allows to assign a Chasiquense Mammal Age to the lower section of this unit in the Las Lajas area.