Archosauromorpha  Archosauromorpha (Greek for "ruling lizard forms") is a clade of diapsid reptiles containing all reptiles more closely related to archosaurs (such as crocodilians and dinosaurs, including birds) rather than lepidosaurs (such as tuataras, lizards, and snakes). Archosauromorphs first appeared during the middle Permian, though they became much more common and diverse during the Triassic period. Although Archosauromorpha was first named in 1946, its membership did not become well-established until the 1980s. Currently Archosauromorpha encompasses four main groups of reptiles: the stocky, herbivorous allokotosaurs and rhynchosaurs, the hugely diverse Archosauriformes, and a polyphyletic grouping of various long-necked reptiles including "Protorosaurus", tanystropheids, and "Prolacerta". Other groups including pantestudines (turtles and their extinct relatives) and the semiaquatic choristoderes have also been placed in Archosauromorpha by some authors. Archosauromorpha is one of the most diverse groups of reptiles, but its members can be united by several shared skeletal characteristics. These include laminae on the vertebrae, a posterodorsal process of the premaxilla, a lack of notochordal canals, and the loss of the entepicondylar foramen of the humerus. The term Archosauromorpha was first used by Friedrich von Huene in 1946 to refer to reptiles more closely related to archosaurs than to lepidosaurs. However, there was little consensus on ancient reptile relationships prior to the late 20th century, so the term Archosauromorpha was seldom used until many years after its creation. The advent of cladistics helped to sort out at least some of the relationships within Reptilia, and it became clear that there was a split between the archosaur lineage and the lepidosaur lineage somewhere within the Permian, with certain reptiles clearly closer to archosaurs and others allied with lepidosaurs. Jacques Gauthier reused the term Archosauromorpha for the archosaur lineage at the 1982 annual meeting of the American Society of Zoologists, and later used it within his 1984 Ph.D. thesis. Archosauromorpha, as formulated by Gauthier, included four main groups of reptiles: Rhynchosauria, "Prolacertiformes", "Trilophosauria", and Archosauria (now equivalent to the group Archosauriformes).