Extinct clade of archosauromorph reptiles
Tanysauria (meaning "long lizards") is anextinctclade of long-neckedarchosauromorph reptiles from theTriassic period of Europe, Asia, North America, and South America. It comprises the familiesTanystropheidae andTrachelosauridae (found by the authors to be coextensive withDinocephalosauridae, and a senior synonym of the latter). Within the Archosauromorpha, Tanysauria represents thesister group to theCrocopoda. It contains many of the species formerly placed in "Protorosauria", which is now thought to be aparaphyletic group.[1]
The clade Tanysauria was described by Stephan Spiekman and co-authors in 2024. Its name comes from theGreek τᾰνυ [tany] meaning "long" and σαῦρος [sauros] meaning "lizard," which refers to the long necks and, in some cases, bodies of tanysaurians.[1]
According to thephylogenetic definition given by Spiekman et al., the clade Tanysauria includes all taxa that are more closely related toTanystropheus longobardicus,Dinocephalosaurus orientalis, andTrachelosaurus fischeri than toProtorosaurus speneri,Prolacerta broomi,Mesosuchus browni,Azendohsaurus madagaskarensis, orProterosuchus fergusi.[1]
In their 2024 redescription ofTrachelosaurus, Spiekman and colleagues named Tanysauria as a new clade containing the Tanystropheidae and Trachelosauridae (asenior synonym of Dinocephalosauridae). This clade is the sister taxon to theCrocopoda. The results of their phylogenetic analyses are shown in thecladogram below:[1]
