A gigantic new terror bird (Cariamiformes, Phorusrhacidae) from Middle Miocene tropical environments of La Venta in northern South America

Abstract

Our knowledge of the fossil avifauna from the Middle Miocene La Venta locality in Colombia is limited almost entirely to aquatic birds. Phorusrhacidae, popularly known as ‘terror birds’, are a group of highly diversified cursorial birds that played the role of apex predators during most of the Cenozoic. Here we present the first record of a phorusrhacid from the La Venta locality. This terror bird can be assigned to the ‘Phorusrhacinae’, a subfamily for which the monophyly is under debate. The fragment of left distal tibiotarsus represents the most northern record of this group for South America and may correspond to the largest terror bird that ever existed. This suggests that terror birds might also have inhabited more tropical ecosystems, providing evidence that they were apex predators in tropical palaeocommunities. Additionally, our research contributes to an understanding of the biogeographical patterns of the Phorusrhacidae lineage dispersal into northern South America and subsequent colonization of North America.