Paleoecology of the mammalian carnivores (Metatheria, Sparassodonta) of the Santa Cruz Formation (late Early Miocene

PREVOSTI, F.J.; FORASIEPI, A.M.; ERCOLI, M.; TURAZZINI, G.

Early Miocene Paleobiology in Patagonia: high-latitude paleocommunities of the Santa Cruz Formation

Cambridge University Press

Lugar: Cambridge; Año: 2011; p. 999 - 9999

South America had an endemic mammalian fauna during most part of the Cenozoic, when it was isolated from other continents. The predator guild was mainly occupied by metatherians (Sparassodonta) and shared with large terrestrial birds (Phorusrhacidae), agile terrestrial crocodiles (Sebecidae), and giant snakes (Madtsoiidae). The Sparassodonta was a diverse clade, recorded from the Paleocene to the middle Pliocene, with its acme in the late early Miocene (Santacrucian age). In this chapter, we review the paleoecology of the sparassodonts known from the Santa Cruz Formation and include new results obtained by geometric morphometric analyses. The Santa Cruz Formation contains eleven sparassodont species: six Hathliacynidae (Acyon tricuspidatus, Cladosictis patagonica, Sipalocyon gracilis, Sipalocyon obusta, Pseudonotictis pusillus, Perathereutes pungens) and five Borhyaenoidea (Prothylacynus patagonicus, Lycopsis torresi; and three Borhyaenidae Borhyaena tuberata, Acrocyon sectorius, and Arctodictis munizi). These sparassodonts were mainly hypercarnivores exhibiting different locomotor abilities (from scansorial to terrestrial), and a wide range of body masse (between 1 kg and more than 50 kg). The reconstruction of the Santacrucian predator guild suggests that there was a good ecological separation within the sparassodonts, given by the combination of body size, locomotion, and diet differences. The diversity of sparassodonts recorded in the Santa Cruz Formation (eleven species) and in the Estancia La Costa Member (seven species), is similar to that observed in present and past placental hypercarnivore communities.