Loricata

Loricata is a clade of archosaur reptiles that includes crocodilians and some of their Triassic relatives, such as Postosuchus and Prestosuchus. More specifically, Loricata includes Crocodylomorpha (the persistent archosaur subset which crocodilians belong to) and most "rauisuchians", a paraphyletic grade of large terrestrial pseudosuchians which were alive in the Triassic period and ancestral to crocodylomorphs. Loricata is one branch of the group Paracrocodylomorpha; the other branch is the clade Poposauroidea, an unusual collection of strange "rauisuchians" including bipedal, herbivorous, and sail-backed forms. The vast majority of typical "rauisuchians", which were usually quadrupedal predators, occupy basal (early-branching) rungs of Loricata leading up to crocodylomorphs. Loricata was initially named in a completely different context by German naturalist Blasius Merrem in his 1820 Versuch eines Systems der Amphibien. Merrem considered it to be one of three groups of Pholidota (reptiles), the other two being Testudinata (turtles) and Squamata (lizards and snakes). Loricata was an early name for the order that includes crocodiles, alligators, and gharials. That order is now referred to as Crocodilia (or Crocodylia), the crocodilians. The name Loricata gained a new phylogenetic definition in 2011. In his study of early archosaur phylogeny, paleontologist Sterling J. Nesbitt defined it as the most inclusive clade containing Crocodylus niloticus (the Nile crocodile), but not Poposaurus gracilis, Ornithosuchus longidens, or Aetosaurus ferox, all of which were extinct species of Triassic archosaurs closer to crocodilians than to dinosaurs. Nesbitt considered the following features to be synapomorphies (distinguishing features) of Loricata: Four teeth in the premaxilla (the toothed bone at the tip of the snout). A ridge on the surface of the lower branch of the squamosal (the multi-pronged bone forming the upper rear corner of the skull).