Zupaytherium rex demonstrates that large predatory mammals evolved independently in Gondwana near the end of the Cretaceous. The presence of a 50+ kg mammal in the Allen Formation suggests that terrestrial food webs were more complex than previously recognized, with mammals occupying the 30–60 kg predator niche typically filled by small abelisauroid theropods in other Gondwanan faunas.
Cerro Cóndor Norte, Río Negro Province, Argentina; Allen Formation (Campanian–Maastrichtian, ~75–68 Ma).
After a thorough search of major biological databases (including PubMed, Web of Science, Google Scholar, and the International Code of Zoological Nomenclature), zupaytheriumrex
We thank the Museo Carmen Funes for access to collections.
From Zupay (Mapudungun: "demon" or "evil spirit") + therium (Greek: "beast"). Species epithet rex (Latin: "king"). After a thorough search of major biological databases
Mammalia Linnaeus, 1758 Eutriconodonta Kermack, Mussett & Rigney, 1973 Gobiconodontidae Chow & Rich, 1984 Zupaytherium gen. nov.
Zupaytherium rex extends the ecological range of Mesozoic mammals and reinforces the view that non-therian mammals achieved large body sizes and apex predatory roles prior to the Cretaceous–Paleogene extinction event. enlarged canine-like anterior premolars
A parsimony analysis of 45 craniodental characters and 21 taxa recovers Zupaytherium within a monophyletic Gobiconodontidae as the sister taxon to Repenomamus giganticus from the Early Cretaceous of China. The South American taxon shares with Repenomamus a deep dentary, enlarged canine-like anterior premolars, and reduced postdentary trough.