Physical evidence of crocodylian predation on ungulates in the Middle Miocene of Colombia

South American fossil mammalian assemblages contain a relatively low ratio of predators to prey. Consequently, large non-mammalian predators occupy a major ecological role. In the Middle Miocene assemblage of La Venta, Colombia, crocodyliforms have been previously proposed as the most significant predators of large mammals. Here we present ichnological evidence for predation by giant crocodylians of three large ungulates from La Venta: Pericotoxodon platignathus, Xenastrapotherium kraglievichi, and Granastrapotherium snorki. A partial cranium of P. platignathus preserves a large, bisected circular puncture mark. Part of a distal femur of P. platignathus includes a series of semicircular puncture marks and smaller pits. Two astrapothere mandibles contain multiple puncture marks associated with significant deformation. In all cases, the most likely predator is interpreted as Purussaurus, based on the size and shape of the puncture marks and the presence of significant deformation to the cortical bone. The recognition of the ichnotaxon Knethichnus parallelum in a Xenastrapotherium mandible probably relates to a separate scavenging event by a ziphodont crocodyliform, likely Langstonia huilensis. The similarities between the trace fossils associated with Purussaurus predation and bite marks produced by modern crocodiles support the use of modern crocodiles as analogues to interpret the ecology of Miocene giant crocodylians.