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 Author Spiekman, Stephan N. F. * Author Ezcurra, Martín D. Author Rytel, Adam Author Wang, Wei Author Mujal, Eudald * Author Buchwitz, Michael Author Schoch, Rainer R. * text Swiss Journal of Palaeontology 2024 10 2024-03-15 143 1 1 33 http://dx.doi.org/10.1186/s13358-024-00309-6 journal article 10.1186/s13358-024-00309-6 1664-2384 12004587 Trachelosauridae Abel, 1919 1 (= Dinocephalosauridae Spiekman, Fraser and Scheyer, 2021 ) Phylocode registration number. Trachelosauridae is identified in the international clade names repository as registration number 1028. Phylogenetic definition. The definition of Trachelosauridae is modified from the definition for Dinocephalosauridae ( Spiekman et al., 2021b ) as follows: the most inclusive clade containing Trachelosaurus fischeri Broili, 1918 and Dinocephalosaurus orientalis Li, 2003 but not Tanystropheus longobardicus ( Bassani, 1886 ) , Macrocnemus bassanii Nopcsa, 1931 , Protorosaurus speneri von Meyer, 1832 , or Prolacerta broomi Parrington, 1935 . This is a maximum clade definition. Reference phylogeny. Phylogenetic hypotheses recovered in this paper. Composition. The composition is based on our reference phylogenies. Trachelosauridae includes the following nominal species: Dinocephalosaurus orientalis , Trachelosaurus fischeri , Austronaga minuta , Pectodens zhenyuensis , and ambiguously Gracilicollum latens , and Fuyuansaurus acutirostris . Diagnosis. Trachelosauridae is a clade that is defined among other archosauromorphs by possessing the following unique combination of character states: external naris positioned far from the anterior end of the premaxilla, resulting in an anteroposteriorly deep base of the prenarial process; jugal without posterior process; cervical column composed of ten or more vertebrae (also present in some deeply nested tanystropheids); axis with postzygapophysis confluent with and not protruding posteriorly from the base of the neural spine in lateral view (also present in Tanystropheus spp. and Amotosaurus rotfeldensis ); mid-dorsal vertebrae with very wide and ‘wing-like’ transverse processes; presence of holocephalous anterior dorsal ribs (also present in some tanystropheids); metatarsal V without a hook-shaped proximal end.