Rachitrema is a poorly known genus of ichthyosaur from the Triassic of France. Its remains were found in France by two independent collectors, towards the end of the nineteenth century. They were only isolated bone fragments.[1]

Rachitrema
Temporal range: Late Triassic, Rhaetian
Rachitrema pellati type neural arch in posterior (4b), right lateral (4) and anterior (4a) views. After Sauvage (1883)
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Ichthyosauria
Genus: Rachitrema
Sauvage, 1883
Type species
Rachitrema pellati
Sauvage, 1883

Classification edit

The type species is R. pellati, described by Sauvage in 1883. When first described, Sauvage classified it as a dinosaur.[1] Later, Franz Nopcsa referred the genus to Anchisauridae, while Karl Alfred von Zittel referred it to either Zanclodontidae or Megalosauridae.[2][3][4]

The ichthyosaur nature of Rachitrema was recognized by Friedrich von Huene, who synonymized it with Shastasaurus. Sauvage conceded that Rachitrema was non-dinosaurian,[5] and the ichthyosaur classification of the genus became universally accepted by several authors.[6][7][8][9][10] McGowan and Motani (2003) considered Rachitrema dinosaurian without comment.[11] However, recent re-examination of the type material of Rachitrema reaffirms the ichthyosaurian classification of the genus, with most of the original remains referable to Ichthyosauria, and the rest being indeterminate beyond Reptilia.[12]

References edit

  1. ^ a b H.-E. Sauvage. 1883. Recherches sur les reptiles trouvés dans l'étage rhétien des environs d'Autun [Research on the reptiles found in the Rhaetian stage of the environs of Autun]. Annales des Sciences Géologiques 14(3):1-44
  2. ^ Zittel, 1890. Handbuch der Palaeontologie. Volume III. Vertebrata (Pisces, Amphibia, Reptilia, Aves). 900 pp.
  3. ^ Zittel, 1895. Grundzüge der Palaeontologie (Palaeozoologie). 971 pp.
  4. ^ Nopcsa, 1901. Synopsis und Abstammung der Dinosaurier. Földtani Közlöny. 31, 247-288.
  5. ^ Sauvage, 1903. Note sur les reptiles de letage Rhetien des environs d'Autun. Bulletin Societe d'Histoire Naturelle d'Autun (France). 16, 309-318.
  6. ^ Merriam, 1908. Triassic Ichthyosauria: With special reference to the American forms. 196 pp.
  7. ^ Huene, 1922. Die Ichthyosaurier des Lias und ihre Zusammenhänge. Jahresversammlung der palaeontologischen Gesellschaft. Verlag Bornträger, Berlin. 114 pp.
  8. ^ Huene, 1951. Eine neue Ichthyosaurier-Gattung der mitteleren Trias. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 94, 80-92.
  9. ^ Romer, 1976. Osteology of the Reptiles. University of Chicago Press. 772 pp.
  10. ^ Bardet and Cuny, 1993. Triassic reptile faunas from France. Paleontologia Lombarda. 2, 9-17.
  11. ^ McGowan and Motani, 2003. Handbook of Paleoherpetology: Ichthyopterygia, Part 8. 175 pp.
  12. ^ "Fischer V & Goolaerts S. 2013. Shastasaurid ichthyosaurs and other lost critters from the French Rhaetian | Valentin Fischer - Academia.edu". www.academia.edu. Archived from the original on 12 August 2014. Retrieved 22 May 2022.

External links edit