CANIS (DUSICYON) AVUS BURMEISTER, 1864 (CARNIVORA, CANIDAE) EN EL PLEISTOCENO TARDIO y HOLOCENO DE LA PROVINCIA DE BUENOS AIRES. ASPECTOS SISTEMÁTICOS Y BIOESTRATIGRAFICOS RELACIONADOS

Abstract

Canis (Dusicyon) avus Burmeister, 1864, inhabited in Buenos Aires province since the Late Pleistocene (Lujanian Mammal-Age) until the Late Holocene, probably nearly to the european arrivaL Remains of this species from the Late Pleistocene have been registered exclusively in the Pampean Region and several probable records are known also from the Early Holocene of the Patagonian and south-chilean regions. The following hypoThesis are formulated: HI: the morphotype of Canis (Dusicyon} avus from the Late Pleistocene is well defined, with clear diagnostic characters which contrast with another species of Canis. H2: the record of Canis (Dusicyon} avus from the Holocene includes morphotypes with imprecise specific characters, most of them shared with Canis (Canis) familiaris. H3: Canis (Dysicyon} avus extinguished during the Late Holocene because of its hibridization with Canis (Canis} familiaris. H4: Canis (Dusicyon) avus extinguished during the Late Holocene because of environmental climatic oscillations. Some considerations are performed through the craneodental analysis of the remains from the Late Pleistocene. They are referred to: (1) carnivorous specialization degree, and (2) systematic relations with another species of Canis registered in Buenos Aires province during the Middle and Late Pleistocene (i. e. Canis gezi L. Kraglievich and Canis nehringi Ameghino, respectively).