group of reptiles with lightweight skulls and serrated teeth set in deep sockets. Dinosaurs are among the most famous subset of archosaurs, as are modern crocodilians and their prehistoric ancestors. Many newly discovered "prolacertiforms", including Tanystropheus-, Protorosaurus-, and Prolacerta-like species, were described in the 1970s, not long after the field of paleontology was reinvigorated by the “dinosaur renaissance” in the 1960s and beyond. Cladistics and Archosauromorpha (1980s-1990s) In the 1980s, the advent of cladistics saw a paradigm shift in the field of taxonomy, emphasizing monophyletic clades (all-encompassing groups defined by shared ancestry) over other categorization styles. Phylogenetic analyses were invented to evaluate reptile evolution in a quantitative manner, by collecting a set of characteristics in sampled species and then using computational models to find the simplest (most parsimonious) path evolution could take to produce that character distribution. Cladistics stabilized and defined a fundamental split in the family tree of reptiles: one side of the family tree, Lepidosauromorpha, leads to lepidosaurs such as squamates (lizards and snakes) and the tuatara. The other side, Archosauromorpha, leads to archosaurs. Cladistics was one of many lines of evidence that helped to demonstrate the dinosaurian origin of birds. This left crocodilians and birds as the two surviving archosaur groups. A series of phylogenetic analyses in the late 1980s and 1990s strongly supported the proposal of Gow (1975). Tanystropheus, Macrocnemus, Protorosaurus, and Prolacerta were always placed as members of Archosauromorpha, closer to archosaurs than to squamates. “Protorosauria” and “Prolacertiformes” were used interchangeably for the archosauromorph subgroup encompassing these superficially lizard-like reptiles. Some authors preferred “Protorosauria” for its priority. Most others used "Prolacertiformes" arguing that "Protorosauria" was a name that carried too much historical baggage, since it had previously encompassed non-archosauromorph “euryapsids” like Araeoscelis. As a "prolacertiform", Tanystropheus is typically considered the sister taxon to Tanytrachelos, a much smaller tanystropheid from Virginia. Another small tanystropheid, Cosesaurus from Spain, is allied with the Tanystropheus + Tanytrachelos clade in many analyses of the 1980s and 1990s. Within Archosauromorpha, “prolacertiforms” are joined by several other groups. The clade Archosauriformes is a diverse archosauromorph subset including crown group archosaurs and their predatory close relatives such as Euparkeria and Proterosuchus. Stocky Triassic herbivores like rhynchosaurs, Trilophosaurus, and azendohsaurids additionally qualify as archosauromorphs. The bizarre chameleon-like drepanosaurs were also included by many analyses, though more recently they have been reinterpreted as a more basal type of reptile unrelated to Archosauromorpha. The following cladogram