Premise: The Pari Aike Formation is a Late Cretaceous geologic formation of Cenomanian (formerly believed to be Maastrichtian) age in southern Patagonia, Argentina. The giant titanosaur "Puertasaurus", the megaraptoran "Orkoraptor", and the ornithopod "Talenkauen" have been recovered from the formation alongside turtles and crocodiles.
Hypothesis: Pari Aike Formation was home to horned dinosaurs.