Too Much Terror: A Gigantic Terror Bird (Cariamiformes: Phorusrhacidae) from the Middle Miocene of La Venta, Colombia

Abstract

Phorusrhacids correspond to a group of birds considered to be apex predators, whichare a common element of the American fossil Cenozoic avifauna, especially in Argentina,where it is not unusual to find at least two species of terror birds. Nevertheless, thepresence of more than one species of terror bird outside Argentina is null. Here we report asecond terror bird from the middle Miocene of La Venta locality. The new specimen couldreach approximately 180 kg, being about 15% larger than the previous report of a terrorbird for the locality. Although it is not possible to completely discard the possibility ofthese two specimens belonging to a dimorphic species, morphological differences mayindicate so. Certainly, the presence of two gigantic terror birds coexisting in the La Ventalocality represents an interesting scenario for further studies on their ecology and nichepartitioning; this could be an argument for the presence of large open areas within theforests and wetlands of La Venta, further supporting the complex and diverse ecosystemsin this region during the Middle Miocene period.