Placochelys

Placochelys
Temporal range: Late Triassic (Norian to Rhaetian),
221.5–205.6 Ma
Restored Placochelys placodonta skull at the Museum für Naturkunde, Berlin
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Superorder: †Sauropterygia
Order: †Placodontia
Family: †Placochelyidae
Genus: †Placochelys
Jaekel, 1902

Placochelys (from Greek: plax, plakos, "plate" and Greek: chelys, "tortoise")[1] is an extinct genus of placodont reptiles erected by Otto Jaekel in 1902.

Fossil records

Fossils of Placochelys dates back to the Triassic period (age range: 221.5 to 205.6 million years ago). They have been found in Germany, Austria, Hungary and Italy.[2]

Species

This genus includes only one species:

  • Placochelys placodonta Jaekel, 1902 (from Upper Ladinian of Hungary)

Description

Placochelys looked remarkably similar to a sea turtle, and grew to about 90 centimetres (3.0 ft) in length. It had a flat turtle-like carapace covered with knobbly plates, and a compact triangular skull. Its beaked skull had powerful muscles. It had only two pairs of palatal teeth, a large posterior pair, and a small rostral pair. The specialized broad teeth on the palate, were most likely used for crushing shellfish and hard-shelled prey. Its limbs were paddle-shaped for swimming, although, unlike modern sea turtles, they still had discernable toes, and it also had a short tail.[3]

  • Life restoration of Placochelys
    Life restoration of Placochelys
  • Placochelys placodonta fossil skull, lateral view
    Placochelys placodonta fossil skull, lateral view
  • Placochelys placodonta skull seen from below
    Placochelys placodonta skull seen from below
  • Placochelys tooth from Adnet, Austria
    Placochelys tooth from Adnet, Austria

Bibliography

  • Jaekel O. 1902. Über Placochelys n. g. und ihre Beeutung fur die Stammesgeschichte der Schildkroten: Neues Jahrbuch für Mineralogie, Geologie und Palaontologie, Abhandlungen, 1902: 127–144.
  • Mazin, J.-M. and Pinna, G. 1993. Palaeoecology of the armoured placodonts. Paleontologia Lombarda, N. S. 2: 83–91.
  • Rieppel O. and Zanon R.T. 1997. The interrelationships of Placodontia. Historical Biology: Vol. 12, pp. 211–227
  • Yin G., in Yin, G., Zhou, X., Cao, Z., Yu, Y, and Luo, Y., 2000, A preliminary study on the Early Late Triassic marine reptiles from Guanling Guizhou, China.
  • Rieppel O. 2001. The Cranial Anatomy of Placochelys placodonta Jaekel, 1902, And a Review of the Cyamodontoidea (reptilia, Placodonta) Fieldiana: Geology, New Series, No. 45:1-101.
  • Rieppel, O., 2002, The dermal armor of the cyamodontoid placodonts (Reptilia, Sauropterygia): morphology and systematic value: Fieldiana; Geology, new series, n. 46, p. 1-41pp.

References

  1. ^ Colbert, Edwin H. (Edwin Harris); Knight, Charles Robert (1951). The dinosaur book: the ruling reptiles and their relatives. New York: McGraw-Hill. p. 153.
  2. ^ Paleobiology Database
  3. ^ Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 71. ISBN 1-84028-152-9.


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