Camptosaurus

Source: Wikipedia, the free encyclopedia.
Not to be confused with Camposaurus.

Camptosaurus
Temporal range:
Ma
Reconstructed skeleton in Japan
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: †Ornithischia
Clade: †Ornithopoda
Clade: †
Dryomorpha
Clade: †Ankylopollexia
Superfamily: †Camptosauroidea
Marsh, 1885
Family: †Camptosauridae
Marsh, 1885
Genus: †Camptosaurus
Marsh, 1885
Type species
Camptonotus dispar
Marsh, 1879
Other species
Synonyms

Camptosaurus (

period of western North America and possibly also Europe.[1] The name means 'flexible lizard' (Greek
καμπτος (kamptos) meaning 'bent' and σαυρος (sauros) meaning 'lizard').

History of discovery

Historical skeletal restoration by O.C. Marsh, with skull based on remains now referred to Theiophytalia

On September 4, 1879

sacral vertebrae. The holotype was YPM 1877, a partial skeleton.[2] The genus was renamed Camptosaurus by him in 1885 because the original name was already in use for a cricket.[3] In 1879, Marsh named C. dispar (type species of the genus) for material he received from his collectors at Quarry 13 near Como Bluff, Wyoming in the Morrison Formation and C. amplus based on the holotype YPM 1879, a foot found by Arthur Lakes at Quarry 1A. The foot was later shown to have belonged to Allosaurus.[4][5] Throughout the 1880 and 1890s, he continued to receive specimens from Quarry 13 and in 1894 named two additional species: C. medius and C. nanus, based in part on size.[6] Charles W. Gilmore named two additional species, C. browni and C. depressus in his 1909[7] redescription of the Marsh specimens. In the Morrison Formation, Camptosaurus fossils are present in stratigraphic zones 2–6.[8]

Outdated mount of a C. nanus skeleton at the AMNH, now thought to be a growth stage of C. dispar

Then in 1980,

Theiophytalia kerri.[9]

Natural History Museum of Milan

Camptosaurus depressus was recovered from the

Styracosterna).[11] It has been moved to the new genus Uteodon.[12]

Cast of a skull from Bone Cabin Quarry West, Wyoming

While Marsh was describing Camptosaurus species in North America, numerous species from Europe were also referred to the genus in the late 19th and early 20th centuries: C. inkeyi, C. hoggii, C. leedsi, C. prestwichi, and C. valdensis. C. inkeyi (Nopcsa, 1900) consists of fragmentary material, a dentary and articular from Upper Cretaceous rocks of the

Haţeg Basin in Romania. It is almost certainly a rhabdodontid and is no longer considered valid (nomen dubium).[13] C. valdensis is a dubious dryosaurid,[14] based on the holotype and only known specimen NHMUK R167, a poorly preserved left femur lacking the distal end. It is thus difficult to compare it to other dryosaurids, including the contemporary Valdosaurus canaliculatus.[12] C. leedsi is probably a valid dryosaurid that has been moved to the new genus Callovosaurus.[15] C. hoggii was originally named Iguanodon hoggii by Richard Owen in 1874 and was moved to Camptosaurus by Norman and Barrett in 2002.[16] It has since been transferred to the genus Owenodon.[14]

The remaining European species Camptosaurus prestwichii was recovered from Chawley Brick Pits,

styracosternan, more closely related to advanced iguanodonts than to Camptosaurus dispar, similar to the case of Uteodon.[11][12]

In 2022, the first confirmed European remains belonging to aff. Camptosaurus .sp were described by Sánchez-Fenollosa et al..[1] A single specimen was found in the Fuentecillas member of the Villar del Arzobispo Formation in Spain, consisting of an anterior cervical centrum; an anterior dorsal centrum; a dorsosacral centrum; four sacral centra; a caudosacral centrum; two anterior caudal centra; three medial caudal centra; and a distal fragment from the left humerus. The Fuentecillas specimen is seen to be closer to Camptosaurus than to Draconyx from the Jurassic of Portugal,[18] hence its tentative placement within the Camptosaurus genus.[1]

Description

Restoration

Camptosaurus is a relatively heavily built form, with robust hindlimbs and broad feet, still having four toes.[4] Due to the separate status of Uteodon it has become problematic which material from the Morrison Formation belongs to Camptosaurus. The specimens with certainty belonging to Camptosaurus dispar, from Quarry 13, have been recovered from very deep layers, probably dating to the Callovian-Oxfordian.[10] The largest fragments from later strata indicate adult individuals around 6.79 metres (22.3 ft) long.[19] The Quarry 13 individuals are smaller though. They have been described as reaching 6 meters (19.7 feet) in length and 785 – 874 kg in weight.[20] In 2010 Gregory S. Paul gave an even lower estimate: a length of five metres and a weight of half a tonne.[21]

Earlier reconstructions, such as those by Marsh and Gilmore, were based on the skull of Theiophytalia and display an incorrect, more rectangular profile. The skull was in fact triangular with a pointed snout, equipped with a beak. Its teeth were more tightly packed in the jaw compared to other Morrison euornithopods.[20] Museum curator John Foster describes them as having "thick median ridges on their lateral sides and denticles along their edges," these features were similar to, but "more fully developed" than those in Dryosaurus.[20] Camptosaurus teeth frequently exhibit extensive wear, which indicates that individuals in the genus had a diet of relatively tough vegetation.[20]

Classification

Marsh in 1885 assigned Camptosaurus to a family of its own: the Camptosauridae. Alternatively some authors considered it an early member of the Iguanodontidae.

Modern phylogenetics has made Camptosaurus by definition part of the clade Ankylopollexia, of which group it would then be a basal member. This would mean that the genus is closely related to the ancestor of later

Othnielosaurus.[20]

In the 2010 and 2011

cladistic analyses of McDonald and colleagues, Camptosaurus was placed as follows:[12][22]

ornithopod
dinosaurs, including Camptosaurus at the far left
Ankylopollexia

Camptosaurus

Styracosterna

Paleobiology

Camptosaurus dispar (blue) compared in size to a human and other ornithopods

Based on studies of other iguanodonts (clade Iguanodontia), scientists believe they may have been able to achieve running speeds of 25 km per hour (15 mph).[20] A tiny 9 inch fossilized embryo, referred to Camptosaurus, was retrieved from Morrison Formation strata at Dinosaur National Monument in Utah.[20]

See also

References

  1. ^
    S2CID 245804125
    .
  2. S2CID 131001110
    .
  3. ^ Marsh, O.C. (1885). "Names of extinct reptiles". American Journal of Science. 29: 169.
  4. ^ a b c Galton, P.M.; Powell, H.P. (1980). "The ornithischian dinosaur Camptosaurus prestwichii from the Upper Jurassic of England". Palaeontology. 23: 411–443.
  5. ^ Bakker, R.T. (1998). "Dinosaur mid-life crisis: the Jurassic-Cretaceous transition in Wyoming and Colorado". In Lucas, S.G.; Kirkland, J.I.; Estep, J.W. (eds.). Lower and Middle Cretaceous Terrestrial Ecosystems. Vol. 14. New Mexico Museum of Natural History and Science Bulletin. pp. 67–77.
  6. S2CID 130777820
    .
  7. ^
    doi:10.5479/si.00963801.36-1666.197
    .
  8. ^ Foster, J. (2007). "Appendix." Jurassic West: The Dinosaurs of the Morrison Formation and Their World. Indiana University Press. pp. 327-329.
  9. ISBN 978-0-253-34817-3
    .
  10. ^
    S2CID 86197297
    .
  11. ^
    PMID 21124919
    .
  12. ^
    doi:10.11646/zootaxa.2783.1.4
    .
  13. doi:10.1016/j.geobios.2005.01.003
    .
  14. ^ a b Galton, Peter M. (2009). "Notes on Neocomian (Late Cretaceous) ornithopod dinosaurs from England - Hypsilophodon, Valdosaurus, "Camptosaurus", "Iguanodon" – and referred specimens from Romania and elsewhere". Revue de Paléobiologie. 28 (1): 211–273.
  15. ISBN 978-0-253-34817-3
    .
  16. ^ Norman D.B. and Barrett, P.M. 2002. Ornithischian dinosaurs from the Lower Cretaceous (Berriasian) of England. Palaeontology 68:161-189
  17. ISBN 978-0-412-62040-9
    .
  18. doi:10.1016/S0753-3969(01)88003-4
    .
  19. doi:10.1093/zoolinnean/zlad076
    .
  20. ^ a b c d e f g Foster, J. (2007). "Camptosaurus dispar." Jurassic West: The Dinosaurs of the Morrison Formation and Their World. Indiana University Press. p. 219-221.
  21. ^ Paul, G.S., 2010, The Princeton Field Guide to Dinosaurs, Princeton University Press p. 284
  22. PMID 21124919
    .

External links

Media related to Camptosaurus at Wikimedia Commons

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