Choristodera

Choristodera
	Champsosaurus livedin North America from the Late Cretaceous to the early Eocene
Temporal occurrence
	Upper Triassic ( Norium ) to early Miocene
	216.5 to approx. 20 million years
Locations
	Europe; Asia; North America;
Systematics
	Land vertebrates (Tetrapoda)
	Amniotes (Amniota)
	Sauropsida
	Diapsida
	Archosauromorpha
	Choristodera
Scientific name
	Choristodera
	Cope , 1884

The Choristodera are aquatic , crocodile-like , extinct diapside reptiles that lived in Europe, Asia, and North America from the Upper Triassic to the early Miocene .

The animals had the very elongated snout typical of fish-eaters , as it occurs today in the gharial convergent . The characteristics of their skull anatomy include the displacement of the original upper of the two diapsid temples behind the lower and the strong lateral widening of the zygomatic arches . This adaptation in the cranial structure was used to provide space for strong jaw muscles. The ribs of the choristodera were thickened from pachyostosis . Her limbs were only weakly ossified, one sternum was missing. Probably the animals swam like today's crocodiles , by winding movements of body and tail and with legs pressed against the body. The largest Choristodera were three meters long.

Some Choristodera survived the mass extinction on the Cretaceous-Tertiary border and a species of the genus Lazarussuchus recently discovered in the Czech Republic appears to have lived in the early Miocene.

Systematics

The systematic position of the Choristodera is uncertain. If they were previously assigned to the Lepidosauromorpha , today it is believed that they belonged to the Archosauromorpha as a primitive group only distantly related to the Archosaurs .

Monjurosuchus in the Hong Kong Science Museum

Hyphalosaurus

Choristodera
- Irenosaurus Efimov, 1983
- Khurendukhosaurus Sigogneau-Russell & Efimov, 1984
- Lazarussuchus Hecht, 1992; Upper Oligocene - Early Miocene
- Cteniogelys Gilmore, 1928; Middle - Upper Jura
- Pachystropheus Huene, 1935; Upper Triassic
- Monjurosuchidae Endo, 1940
  - Philydrosaurus Gao & Fox, 2005; Lower Cretaceous
  - Monjurosuchus Endo, 1940; Lower Cretaceous
- Hyphalosauridae Gao & Fox, 2005
  - Shokawa Evans & Manabe, 1999
  - Hyphalosaurus Gao, Tang & Wang, 1999 Lower Cretaceous
- Neochoristodera Evans & Hecht, 1993 (Champsosauriformes Hay, 1929)
  - Simoedosauridae Lemoine, 1884
    - Tchoiria Efimov, 1975
    - Ikechosaurus Sigogneau-Russell, 1981
    - Simoedosaurus Gervais, 1877
  - Champsosauridae Cope, 1884
    - Eotomistoma
    - Champsosaurus Cope, 1876

literature

Robert L. Carroll : Paleontology and Evolution of the Vertebrates. Thieme, Stuttgart et al. 1993, ISBN 3-13-774401-6 .
Martin Sander : Reptiles. 220 individual representations (= Haeckel library. Vol. 3). Enke, Stuttgart 1994, ISBN 3-432-26021-0 .

Individual evidence

^ Susan E. Evans, Jozef Klembara: A choristoderan reptile (Reptilia: Diapsida) from the Lower Miocene of Northwest Bohemia (Czech Republic). In: Journal of Vertebrate Paleontology. Vol. 25, No. 1, 2005, ISSN 0272-4634 , pp. 171-184, doi : 10.1671 / 0272-4634 (2005) 025 [0171: ACRRDF] 2.0.CO; 2 .

Web links

Commons : Choristodera - collection of images, videos and audio files

Mikko's Phylogeny Archive Choristodera
Palaeos.com

[1] Susan E. Evans, Jozef Klembara: A choristoderan reptile (Reptilia: Diapsida) from the Lower Miocene of Northwest Bohemia (Czech Republic). In: Journal of Vertebrate Paleontology. Vol. 25, No. 1, 2005, ISSN 0272-4634 , pp. 171-184, doi : 10.1671 / 0272-4634 (2005) 025 [0171: ACRRDF] 2.0.CO; 2 .