Una nueva especie de megaterio del Mio-Plioceno de Catamarca, Argentina

ALFREDO A., CARLINI; DIEGO, BRANDONI; GUSTAVO J., SCILLATO-YANÉ; FRANÇOIS, PUJOS

AMEGHINIANA

Asociación Paleontológica Argentina

Lugar: Buenos Aires; Año: 2002 vol. 39 p. 367 - 377

0002-7014

    A new species of Megatherinae of the genus Pyramiodontherium is described.  This genus was so far represented by a single species, P. bergi, from the Mio-Pliocene of Catamarca and Tucumán. The new material, was found in levels unformally named "Araucanense" from the Bajo de Andalhualá, Catamarca province (Late Miocene-Pliocene).  The rostrum is wider than long, oval in section and downward directed; the oblique longitudinal crest from the maxillar apophysis of the zygomatic arch up to the base of the rostral portion is marked; the maxillar root of the zygomatic apophysis is high; the upper molariform are quadrangular in section, the first molariform is trapezoidal and the last one, the smallest, is subrectangular with rounded angles and the posterior margin of compact dentine forming a concave crest backwards; the prism of the first lower molarifom is more curved than that of P. bergi; the proximal diaphysis of the humerus is trapezoidal in cross section; the diaphysis of the femur has lower degree of torsion. Only two monospecific genera of Megatheriinae were known up to date in the Late Miocene-Pliocene of northwestern Argentina, Plesiomegatherium hansmeyeri and Pyramiodontherium bergi, consequently, the new species here described, enlarges both the diversity of the megatherines from the “Araucanense” and of the genus.