The Fossil Record of Mammalian Carnivores in South America: Bias and Limitations

Abstract

South America has a rich fossil record that allows the reconstruction of the continental communities during the Cenozoic. Florentino Ameghino was one of the earliest advocates of a temporal sequence of faunas and biogeographic events, later refined by several authors (e.g., George G. Simpson, Rosendo Pascual, Bryan Patterson). This scheme is continually revised and improved by new faunal, systematic, and chronological studies. The fossil record is always incomplete, and many biases are recognized, some of them—the megabiases affect the interpretation of the global fossil record. For example, in South America, a megabias exists with respect to tropical areas, particularly before the Late Pleistocene. The SA fossil record contains large hiatuses between ages, with some ages being unconstrained by geochronological dates, while others are poorly sampled in terms of fossil recovery, faunal diversity, and identified localities. This form of bias which together with the differential duration of the South American Ages affects interpretation of the evolution of the continental fauna. In this chapter, we examine the spatial distribution of South American fossil localities, their frequency per age in the Cenozoic, and discuss the effect biases in the fossil record by means of a statistical approach.