Tanysauria, Spiekman, Ezcurra, Rytel, Wang, Mujal, Buchwitz, Schoch, 2024

Spiekman, Stephan N. F., Ezcurra, Martín D., Rytel, Adam, Wang, Wei, Mujal, Eudald, Buchwitz, Michael & Schoch, Rainer R., 2024, A redescription of TraCheloSaUrUS fiSCheri from the Buntsandstein (Middle Triassic) of Bernburg, Germany: the first European DinoCephaloSaUrUS-like marine reptile and its systematic implications for long-necked early, Swiss Journal of Palaeontology (10) 143 (1), pp. 1-33 : 7-8

Tanysauria clade nov.

Etymology. ‘ Tany ’, meaning long (Greek), and ‘ sauros ’, meaning lizard, referring to the elongated necks and in some cases also bodies of the taxa belonging to this clade.

Phylocode registration number. Tanysauria is identified in the international clade names repository as registration number 1027.

Phylogenetic definition. All taxa more closely related to Tanystropheus longobardicus ( Bassani, 1886) , Dinocephalosaurus orientalis Li, 2003 , and Trachelosaurus fischeri Broili, 1918 than to Protorosaurus speneri von Meyer, 1832 , Prolacerta broomi Parrington, 1935 , Mesosuchus browni Watson, 1912 , Azendohsaurus madagaskarensis Flynn et al., 2010 , or Proterosuchus fergusi Broom, 1903 . This is a maximum clade definition.

Reference phylogeny. Phylogenetic hypotheses recovered in this paper.

Composition. The composition is based on our reference phylogenies. Tanysauria includes the following nominal species: Tanystropheus longobardicus , Tanystropheus hydroides , Tanytrachelos ahynis , Ozimek volans , Sclerostropheus fossai , Raibliania calligarisi , Langobardisaurus pandolfii , Amotosaurus rotfeldensis , Macrocnemus bassanii , Macrocnemus fuyuanensis , Macrocnemus obristi, Luxisaurus terrestris, Augustaburiana vatagini , Dinocephalosaurus orientalis, Gracilicollum latens, Trachelosaurus fischeri , Fuyuansaurus acutirostris, Austronaga minuta, Pectodens zhenyuensis , and ambiguously Jesairosaurus lehmani and Elessaurus gondwanoccidens .

Diagnosis. Tanysauria is a clade that is defined among other archosauromorphs by possessing the following unique combination of character states: premaxilla with five or more tooth positions (absent in Langobardisaurus pandolfii ); postfrontal medial margin lateral to parietal; parietal extending over interorbital region (absent in Tanytrachelos ahynis ); interclavicle anterior margin with a median notch (absent in taxa that lack an ossified interclavicle); and humerus with moderate medial development of the entepicondyle, being poorly projected from the level of the shaft (absent in Ozimek volans ). In addition, the following character states are absent in Jesairosaurus lehmani and are synapomorphies of Tanysauria if this species is not recovered at the base of the clade or are apomorphies of a more restricted Trachelosauridae + Tanystropheidae clade if Jesairosaurus lehmani is positioned at the base of Tanysauria: axis with an anterodorsally expanded neural spine; anterior to middle postaxial–cervical vertebrae strongly elongated, with a ratio between centrum length versus height of anterior articular surface greater than 2.92; scapula with a semi-circular outline in lateral view formed by a scapular blade that has a convex anterior margin and a predominantly posterior orientation; and scapula and coracoid that are unfused with each other in non-early juvenile individuals (absent in Ozimek volans ).