Evolution of the carnivorous dinosaurs during the Cretaceous: The evidence from Patagonia

摘要: Abstract Patagonia has yielded the most comprehensive fossil record of Cretaceous theropods from Gondwana, consisting 31 nominal species belonging to singleton taxa and six families: Abelisauridae, Noasauridae, Carcharodontosauridae, Megaraptoridae nov. fam., Alvarezsauridae, Unenlagiidae. They provide anatomical information that allows improved interpretation discovered in other regions Gondwana. Abelisauroids are best represented Patagonia. underwent an evolutionary radiation documented Early through latest Cretaceous, by clades Abelisauridae Noasauridae. Patagonian carcharodontosaurids known three (Tyrannotitan, Giganotosaurus Mapusaurus), as well isolated teeth, collected Aptian Cenomanian beds. These allosauroids constituted top predators during mid-Cretaceous, which gigantic titanosaur sauropods were largest herbivores. Megaraptorans have become better recent years with discovery more complete remains. Megaraptor, Aerosteon Orkoraptor been described beds Argentina, these exhibit close relationships genera Australovenator, Australia, Fukuiraptor, Japan. The Gondwanan megaraptorans gathered into new family Megaraptoridae, Asiatic Fukuiraptor is recovered immediate sister taxon this clade. Although recently interpreted members Allosauroidea, we present evidence they deeply nested within Coelurosauria. Moreover, supports Megaraptora closely related Asiamerican Tyrannosauridae than thought. improve our knowledge about scarcely basal coelurosaurs tyrannosauroids a whole. Information at hand indicates South America was cradle for different coelurosaurian lineages, including some forms (e.g., Bicentenaria, Aniksosaurus), megaraptorans, alvarezsaurids less derived those Laurasia, unenlagiids, revealing played sharply differing ecological roles, taxonomically diverse northern continents. unenlagiids represent endemic American clade found be birds dromaeosaurid theropods. Analysis theropod Gondwana shows highest peak origination index occurred Aptian–Albian intense one Campanian time spans. Additionally, peaks extinction recognized Turonian–Coniacian In comparison, Laurasian pattern differs presence older event time-span high rate time-bin. Both records show rates Campanian.