PALEOECOLOGY OF THE MAMMALIAN PREDATOR GUILD OF THE SOUTHERN PATAGONIA DURING THE LATEST PLEISTOCENE: ECOMORPHOLOGY, STABLE ISOTOPES, AND TAPHONOMY.

FRANCISCO J. PREVOSTI; FABIANA MARTIN

QUATERNARY INTERNATIONAL

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2012 p. 1 - 12

1040-6182

During the late Pleistocene, Patagonia had a rich fauna of large mammals including some mega-mammals such as ground sloths (Mylodon darwini), horse (Hippidion saldiasi), and camelids (e.g., Lamaguanicoe). The carnivore guild was represented by several extinct taxa such as the sabretooth cat(Smilodon), the Patagonian Panther (Panthera onca mesembrina), a short-faced bear (Arctotherium tar-ijense) and a large fox (Dusicyon avus), but also by the extant puma (Puma concolor). In order toreconstruct the relationships within the predator guild and between these carnivores and theirpotential prey, body size, prey size and diet habits of each predator were estimated. These results arecomplemented with stable isotopic analyses and taphonomic information. Results indicate that theguild was composed of three felids that were large hypercarnivores, two of which (Smilodon, P. onca)could prey on most large mammals. Morphology suggests that the short-faced bear was mainly anomnivore that may have scavenged and occasionally hunted medium-large mammals like camelids andhorses. D. avus was slightly larger and more carnivorous than the living culpeo fox (Lycalopex culpaeus),and preyed mostly on small mammals (rodents) but occasionally on camelids. Stable isotopes (d13Cand d15N) are congruent with these interpretations, although they indicate that Arctotherium and D.avus were highly carnivorous. This could be explained by scavenging habits. Stable isotopes alsoindicate that P. o. mesembrina ate larger proportions of Hippidion and Lama gracilis. Taphonomic studiesshowed that P. o. mesembrina gnawed bones of Mylodon, Hippidion and camelids, a result that suggeststhat these taxa were common prey, and agrees with the ecomorphological and stable isotope in-terpretations. The diversity of potential prey is lower than that observed in lower latitudes (e.g.,Pampean Region) while the number of predators is similar, a relationship that could be explained by thehigh latitude where these mammals lived.