Bactrosaurus

Source: Wikipedia, the free encyclopedia.

Bactrosaurus
Temporal range:
Ma
Skeleton on display at the Central Museum of Mongolian Dinosaurs, Ulaanbaatar
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: †Ornithischia
Clade: †Ornithopoda
Clade: †Hadrosauromorpha
Genus: †Bactrosaurus
Gilmore, 1933
Type species
†Bactrosaurus johnsoni
Gilmore, 1933
Other species
Synonyms

Bactrosaurus (

hadrosauroids
, and although it is not known from a full skeleton, Bactrosaurus is one of the best known of these early hadrosauroids, making its discovery a significant finding.

Discovery

Restored skeleton displayed at the Hong Kong Science Museum

The first Bactrosaurus remains recovered from the Iren Dabasu Formation in the Gobi Desert of China were composed of partial skeletons of six individual B. johnsoni. The specimens collected appear to come from a variety of age groups, from individuals that may be hatchlings to full-sized adults. The fossils were described in 1933 by Charles W. Gilmore, who named the new animal Bactrosaurus, or "club lizard", in reference to the large club-shaped neural spines projecting from some of the vertebrae.[1] The Iren Dabasu Formation has been dated to the Cenomanian stage, around 95.8 ± 6.2 million years ago.[2]

No complete remains have yet to be uncovered, but Bactrosaurus is still better known than most of the early hadrosaurs. Known parts of the anatomy of Bactrosaurus include the limbs, pelvis, and most of the skull (although the crest is notably absent).[3]

"Bakesaurus" is an informal name based on a maxilla from the Majiacun Formation of China assigned to Bactrosaurus in 2001.[4] The nomen nudum was created and pictured in a Chinese-language book by Zhou (2005)[5] and first surfaced on the Internet during February 2006 when it was mentioned on the Dinosaur Mailing List by Jerry D. Harris.[6]

Description

Partial B. johnsoni skull at the Museum of Ancient Life

A typical Bactrosaurus would have been 6–6.5 m (20–21 ft) long and weighed 1.2 metric tons (1.3 short tons).

iguanodont-like features, including three stacked teeth for each visible tooth, small maxillary teeth, and an unusually powerful build for a hadrosaur. It shows features intermediate between those of the two main hadrosaurid groups.[3][9] Its femur measured 80 centimetres (2.6 ft) long.[1]

Bactrosaurus was originally thought to be a

hadrosauromorph.[10]
Basal members do not preserve hollow crests, so Bactrosaurus itself is likely to be crestless.

Paleobiology

In 2003, evidence of

fluoroscope screening. Several other hadrosaurids, including Brachylophosaurus, Gilmoreosaurus, and Edmontosaurus, also tested positive. Although more than 10,000 fossils were examined in this manner, the tumors were limited to Bactrosaurus and closely related genera. The tumors may have been caused by environmental factors or genetic propensity.[11]

See also

References

  1. ^
    hdl:2246/355
    .
  2. doi:10.1016/j.jseaes.2017.12.007. Archived from the original
    (PDF) on 2020-09-19. Retrieved 2020-05-02.
  3. ^
    ISBN 0-7853-0443-6
    .
  4. ^ Li, Z. (2001). "Distribution, burying and classification of dinosaur fossils in Upper Cretaceous strata at Meipu Town, Yunxian County of Hubei Province". Hubei Geology & Mineral Resources. 15 (4): 25–31.
  5. ISBN 978-7-562-52033-7
    .
  6. ^ Harris, Jerry D., 2006. "New Dinosaurs?" Archived 2016-02-22 at the Wayback Machine
  7. ISBN 9780691167664
    .
  8. doi:10.1111/j.1475-4983.2011.01053.x
    .
  9. ISBN 1-84028-152-9
    .
  10. doi:10.4202/app.00821.2020
    .
  11. S2CID 13247222
    .
Retrieved from "https://en.wikipedia.org/w/index.php?title=Bactrosaurus&oldid=1180305844"