Large felid footprints from South America and associated ichnofauna: a new record from the late Pleistocene of Buenos Aires Province, Argentina

Abstract

New large felid footprints from the Monte Hermoso site (Late Pleistocene) located in the Pehuen Co–Monte Hermoso Nature Reserve (Buenos Aires Province, Argentina) are described and compared to Felipeda cf. bottjeri. The discovery consists of a trackway of five footprints associated with sloth footprints. Although the preservation quality of the trackway is moderate, diagnostic features – such as the tetradactyl configuration, subrounded digital pads arranged in an arc, and a subrounded metapodial pad with a flat to slightly concave anterior margin – support its assignment to Felipeda, comparable to Felipeda bottjeri. It would therefore be the only record of this ichnospecies for South America. Comparisons indicate that the Monte Hermoso footprints differ from those of a Late Pleistocene big felid from Argentina recognized as Felipeda miramarensis in the morphology of the metapodial pad and in the marked differences in size between the manus and pes prints observed in the latter. The occurrence of F. biancoi which exhibit distinct morphological characteristics compared to the analysed specimen in stratigraphically equivalent layers at the nearby Pehuen Co site indicates the presence of two distinct morphotypes of Felipeda in deposits of comparable age. The associated large sloth footprints assigned to cf. Mylodontidichnum isp. suggest coexistence of large felids and ground sloths. The footprint-bearing level, located in the middle member of the Agua Blanca Sequence (Late Pleistocene), which is consistent with other megafauna ichnological assemblages from the Pehuen Co site (dated between 28.5 and 12.0ka). Morphometric and ichnological comparisons with modern and fossil felid footprints point to a large pantherine cat-possibly Panthera onca mesembrina as the most probable trackmaker, whereas Smilodon fatalis appears a less likely candidate. These findings expand the ichnological and paleoecological record of Late Pleistocene large felids in the Pampas region and reinforce the significance of the Monte Hermoso-Pehuen Co Natural Reserve sites.