Diversity, affinities and adaptations of the South American basal sparassodont Patene Simpson, 1935 (Mammalia, Metatheria)

RANGEL CS; CARNEIRO LM; BERGQVIST LP; OLIVEIRA EV; GOIN FJ; BABOT MJ

AMEGHINIANA

ASOCIACION PALEONTOLOGICA ARGENTINA

Lugar: Buenos Aires; Año: 2019 vol. 56 p. 263 - 289

0002-7014

The Sparassodonta were the main mammalian predators during mostof South America?s Cenozoic.The early EoceneItaboraí Basin/Formation in southeastern Brazil includes the second oldest fossil records of sparassodontans in South America: Patene and Nemolestes. Patene is by far the most abundant sparassodont from this formation, with more than 30 preserved specimens referable to a single taxon, Patene simpsoni. Some specimens recovered from the Quebrada de Los Colorados (former Lumbrera Formation) in Northwestern Argentina have been also referred to P. simpsoni. In order to test the affinities of Patene and the taxonomy of the Argentinean specimens, we performed a review of the genus. We conclude that the specimens from Northwestern Argentina show significant differences from the Brazilian specimens: smaller size, paraconid more developed, and metaconid, entoconid and hypoconid more reduced. As a result, the specimens from Quebrada de Los Colorados Formation are assigned to a new species, Patene coloradensis. Our study supports previous studies that exclude Patene from the Hathliacynidae, as the former is recovered as a more basally divergent lineage. The results also indicate that Patene evolved to increase faunivorous adaptations through the Eocene, as the younger species are more specialized than P. simpsoni, the oldest and most generalized species of the genus. The early Paleocene Allqokirus australisfrom Tiupampa, Bolivia, is the oldest known South American sparassodont. In turn, the late Cretaceous, North American species of Varalphadonwere recovered in our phylogenetic analysis as the oldest and more generalized sparassodonts so far known.