Bactrosaurus

from Wikipedia, the free encyclopedia
Bactrosaurus
Bactrosaurus johnsoni in the Hong Kong Science Museum

Bactrosaurus johnsoni in the Hong Kong Science Museum

Temporal occurrence
Upper Cretaceous ( Campanium )
83.6 to 72 million years
Locations
Systematics
Pelvic dinosaur (Ornithischia)
Cerapoda
Ornithopoda
Iguanodontia
Hadrosaurs (Hadrosauridae)
Bactrosaurus
Scientific name
Bactrosaurus
Gilmore , 1933
Art
  • Bactrosaurus johnsoni
  • Bactrosaurus kysylkumensis

Bactrosaurus was a genus of bird basin dinosaurs from the group of Hadrosauridae . Fossil finds of this genus come from the late Upper Cretaceous ( Campanium ). The fossils of the type species B. johnsoni were found in the Gobi desertin Inner Mongolia and described in 1933.

features

Bactrosaurus reached a body length of four to six meters with a weight of two tons.

By B. johnsoni are single bones and full skull during at least six nearly complete skeletons of different ages present from B. kysylkumensis are known only to a few thoracic vertebrae, maxilla and individual teeth.

References

The first B. johnsoni fossils were found in 1933 in the Iren-Dabasu Formation near the city of Eren Hot in Inner Mongolia, People's Republic of China, in the Gobi Desert. As early as 1921, the American paleontologist Roy Chapman Andrews discovered the first dinosaur remains in this rich site .

A number of other dinosaur skeletons were discovered in numerous excavations in the Iren-Dabasu Formation, including the theropods Alectrosaurus olseni and Archaeornithomimus asiaticus and Gilmoreosaurus mongoliensis , another early representative of the hadrosaurs. In the nearby Minhe Formation, which is also assigned to the Upper Cretaceous, other species were found, including the Velociraptor mongoliensis (Theropoda), the Protoceratopsids Microceratops gobiensis and Protoceratops andrewsi, as well as remains of unassigned theropods and sauropods.

Systematics

Bactrosaurus is regarded as a representative of the subfamily Lambeosaurinae and classified there in the closer relationship of the genera Parasaurolophus , Lambeosaurus , Corythosaurus and Hypacrosaurus . This relationship is justified on the basis of various skull and bone features, u. a. through modified nasal cavities, the development of the temporomandibular joint, the formation of the teeth, elongated vertebral processes and the pelvic formation. Together with Prosaurolophus , he is the most original representative of the Lambeosaurinae, as these do not yet have such pronounced nasal cavities as more developed species. Due to another skeleton find in 1998, this assignment was canceled because Bactrosaurus had no forehead crest in front of the eyes.

Alternatively, Bactrosaurus probably represents an early hadrosaur from the family of Gilmoreosaurus , whereby it would also belong to the family circle of the genera Claosaurus , Tanius and Secernosaurus , but a more precise assignment of these is currently not available due to the sparse material.

The type species B. johnsoni was first discovered in 1933 by Charles W. Gilmore and described together with a number of other dinosaurs. In addition to the type species, the genus is also assigned B. kysylkumensis, first described by Anatoly Riabinin in 1937 as Cionodon kysylkumensis and newly described by Lev Alexandrovich Nessov in 1995 as part of a comprehensive revision of the Russian dinosaur finds .

The B. prynadai , also described by Riabinin, is regarded as a noun dubium together with Tanius prynadai .

literature

Individual evidence

  1. ^ Gregory S. Paul : The Princeton Field Guide To Dinosaurs. Princeton University Press, Princeton NJ et al. 2010, ISBN 978-0-691-13720-9 , p. 295, online ( memento of the original of July 13, 2015 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. . @1@ 2Template: Webachiv / IABot / press.princeton.edu
  2. ↑ a b after Weishampel et al. 1992, p. 557
  3. ↑ a b c d e Bactrosaurus ( Memento from October 5, 2007 in the Internet Archive ), data sheet on Dinoruss.org.
  4. ↑ a b after Weishampel et al. 1992, p. 133.
  5. ↑ a b c d according to Weishampel et al. 1992, p. 555.
  6. ↑ Published as: Pascal Godefroit , Dong Zhi-Ming, Pierre Bultynck, Hong Li, Lu Feng: Sino-Belgian Cooperative program, "Cretaceous dinosaurs and mammals from Inner Mongolia". Volume 1: New Bactrosaurus (Dinosauria: Hadrosauroidea) material from Iren Dabasu (Inner Mongolia, PR China) (= supplement to: Institut Royal des Sciences Naturelles de Belgique. Bulletin. Sciences de la Terre. Vol. 68, ISSN  0374-6291 ) . Edition de l'Institut Royal des Sciences Naturelles de Belgique, Brussels 1998.
  7. ↑ Published as: Charles W. Gilmore : On the dinosaurian fauna of the Iren Dabasu Formation. In: Bulletin of the American Museum of Natural History. Vol. 67, Article 2, 1933, ISSN  0003-0090 , pp. 23-78, online .
  8. ↑ Published as: А. Н. Рябинин: О находке шлемоносных форм Dinosauria в верхнемеловых отложениях Южного Казахстана. In: Природа. No. 9, 1937, pp. 91-92.
  9. ↑ Published as: Л. А. Несов: Динозавры Северной Евразии: новые данные о составе комплексов, экологии и палеогеографии. Санкт-Петербург 1995.

Web links

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