Trachelosauridae

Trachelosauridae
Temporal range: Triassic, 245–237 Ma
IVPP V20295, a complete, articulated specimen referred to Dinocephalosaurus orientalis, the type species
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauromorpha
Clade: †Tanysauria
Family: †Trachelosauridae
Abel, 1919
Genera[1]

Trachelosauridae[1] (also known as Dinocephalosauridae)[2] is an extinct clade of archosauromorph reptiles that lived throughout the Triassic period. Like their close relatives the tanystropheids, they were "protorosaur"-grade archosauromorphs characterized by their long necks. Unlike tanystropheids, which lengthen their neck primarily by elongating the individual cervical (neck) vertebrae,[3] trachelosaurids achieved their long necks by the addition of more vertebrae. The most extreme example of this trend was Dinocephalosaurus, which had at least 32 vertebrae in the neck alone, far more than the 13 neck vertebrae of Tanystropheus.[4]

Trachelosaurids are known from Europe (Poland, Germany, Austria, Netherlands)[1][5] and China.[6][7][8] Some members of the family (i.e. Dinocephalosaurus) were solely marine animals with paddle-like limbs, inhabiting the coastlines of the Tethys Ocean.[4] Dinocephalosaurus was so specialized for aquatic life that it evolved to be viviparous (live-bearing), the only undisputed example of an archosauromorph adapted for live birth.[9] Other members (i.e. Pectodens) were better suited for terrestrial life, suggesting wide ecological diversity in just the few known species in this family.[7]

  1. ^ a b c Spiekman, Stephan N. F.; Ezcurra, Martín D.; Rytel, Adam; Wang, Wei; Mujal, Eudald; Buchwitz, Michael; Schoch, Rainer R. (2024-03-15). "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 archosauromorphs". Swiss Journal of Palaeontology. 143 (1): 10. doi:10.1186/s13358-024-00309-6. ISSN 1664-2384.
  2. ^ Cite error: The named reference :0 was invoked but never defined (see the help page).
  3. ^ Rieppel, O. (2001). "A new species of Tanystropheus (Reptilia: Protorosauria) from the Middle Triassic of Makhtesh Ramon, Israel". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 221 (2): 271–287. doi:10.1127/njgpa/221/2001/271.
  4. ^ a b Spiekman, Stephan N. F.; Wang, Wei; Zhao, Lijun; Rieppel, Olivier; Fraser, Nicholas C.; Li, Chun (2024-02-23). "Dinocephalosaurus orientalis Li, 2003: a remarkable marine archosauromorph from the Middle Triassic of southwestern China". Earth and Environmental Science Transactions of the Royal Society of Edinburgh: 1–33. doi:10.1017/S175569102400001X. ISSN 1755-6910.
  5. ^ Sennikov, A. G. (2011). "New tanystropheids (Reptilia: Archosauromorpha) from the Triassic of Europe". Paleontological Journal. 45 (1): 90–104. Bibcode:2011PalJ...45...90S. doi:10.1134/S0031030111010151. S2CID 85193597.
  6. ^ Li, C. (2003). "First record of protorosaurid reptile (Order Protorosauria) from the Middle Triassic of China". Acta Geologica Sinica - English Edition. 77 (4): 419–423. Bibcode:2003AcGlS..77..419L. doi:10.1111/j.1755-6724.2003.tb00122.x. S2CID 128905838.
  7. ^ a b Li, C.; Fraser, N.C.; Rieppel, O.; Zhao, L.-J.; Wang, L.-T. (2017). "A new diapsid from the Middle Triassic of southern China" (PDF). Journal of Paleontology. 91 (6): 1306–1312. Bibcode:2017JPal...91.1306L. doi:10.1017/jpa.2017.12.
  8. ^ Cite error: The named reference Austronaga was invoked but never defined (see the help page).
  9. ^ Liu, J.; Organ, C.L.; Benton, M.J.; Brandley, M.C.; Aitchison, J.C. (2017). "Live birth in an archosauromorph reptile". Nature Communications. 8: 14445. Bibcode:2017NatCo...814445L. doi:10.1038/ncomms14445. ISSN 2041-1723. PMC 5316873. PMID 28195584.