Bactrosaurus (/ˌbæktrəˈsɔːrəs/; meaning "Club lizard," "baktron" = club + sauros = lizard) is a genus of herbivoroushadrosauroiddinosaur that lived in Asia during the Late Cretaceous, about 96-85 million years ago. The position Bactrosaurus occupies in the Cretaceous makes it one of the earliest known 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.
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]
A typical Bactrosaurus would have been 6–6.5 m (20–21 ft) long and weighed 1.2 metric tons (1.3 short tons).[7][8] It was an early relative of Lambeosaurus and shows a number of 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 lambeosaurine hadrosaurid, supposedly the oldest and most primitive known, and its crestless head was seen as an anomaly. A 1990 popular book suggested that it had an incompletely preserved crest,[3] but recent studies place Bactrosaurus as a more basal hadrosauromorph.[10] Basal members do not preserve hollow crests, so Bactrosaurus itself is likely to be crestless.
Paleobiologyedit
In 2003, evidence of tumors, including hemangiomas, desmoplastic fibroma, metastatic cancer, and osteoblastoma was discovered in fossilized Bactrosaurus skeletons. Rothschild et al. tested dinosaur vertebrae for tumors using computerized tomography and 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]
^ abGilmore, C. W. (1933). "On the dinosaurian fauna of the Iren Dabasu Formation". Bulletin of the American Museum of Natural History. 67 (2): 23–78. hdl:2246/355.
^Guo, Z. X.; Shi, Y. P.; Yang, Y. T.; Jiang, S. Q.; Li, L. B.; Zhao, Z. G. (2018). (PDF). Journal of Asian Earth Sciences. 154: 49–66. Bibcode:2018JAESc.154...49G. doi:10.1016/j.jseaes.2017.12.007. Archived from the original (PDF) on 2020-09-19. Retrieved 2020-05-02.
^ abc"Bactrosaurus." In: Dodson, Peter & Britt, Brooks & Carpenter, Kenneth & Forster, Catherine A. & Gillette, David D. & Norell, Mark A. & Olshevsky, George & Parrish, J. Michael & Weishampel, David B. The Age of Dinosaurs. Publications International, LTD. p. 131. ISBN0-7853-0443-6.
^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.
^Zhou, S.Q.D. (2005). The Dinosaur Egg Fossils in Nanyang, China. China University of Geosciences Press. pp. 1–145. ISBN978-7-562-52033-7.
^Harris, Jerry D., 2006. "New Dinosaurs?" 2016-02-22 at the Wayback Machine
^Paul, G. S. (2016). The Princeton Field Guide to Dinosaurs (2nd ed.). Princeton, New Jersey: Princeton University Press. pp. 151−152. ISBN9780691167664.
^Prieto-Marquez, A. (2011). "Cranial and appendicular ontogeny of Bactrosaurus johnsoni, a hadrosauroid dinosaur from the Late Cretaceous of northern China". Palaeontology. 54 (4): 773−792. doi:10.1111/j.1475-4983.2011.01053.x.
^Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 146. ISBN1-84028-152-9.
^Prieto-Márquez, Albert; Carrera Farias, Miguel (2021). "A new late-surviving early diverging Ibero-Armorican duck-billed dinosaur and the role of the Late Cretaceous European Archipelago in hadrosauroid biogeography". Acta Palaeontologica Polonica. 66. doi:10.4202/app.00821.2020.
^Rothschild, B. M.; Tanke, D. H.; Helbling II, M.; Martin, L. D. (2003). "Epidemiologic study of tumors in dinosaurs" (PDF). Naturwissenschaften. 90 (11): 495–500. Bibcode:2003NW.....90..495R. doi:10.1007/s00114-003-0473-9. PMID 14610645. S2CID 13247222.
January 01, 1970
bactrosaurus, ɔːr, meaning, club, lizard, baktron, club, sauros, lizard, genus, herbivorous, hadrosauroid, dinosaur, that, lived, asia, during, late, cretaceous, about, million, years, position, occupies, cretaceous, makes, earliest, known, hadrosauroids, alth. Bactrosaurus ˌ b ae k t r e ˈ s ɔːr e s meaning Club lizard baktron club sauros lizard is a genus of herbivorous hadrosauroid dinosaur that lived in Asia during the Late Cretaceous about 96 85 million years ago The position Bactrosaurus occupies in the Cretaceous makes it one of the earliest known 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 BactrosaurusTemporal range Late Cretaceous 96 85 Ma PreꞒ Ꞓ O S D C P T J K Pg N Skeleton on display at the Central Museum of Mongolian Dinosaurs Ulaanbaatar Scientific classification Domain Eukaryota Kingdom Animalia Phylum Chordata Clade Dinosauria Clade Ornithischia Clade Ornithopoda Clade Hadrosauromorpha Genus BactrosaurusGilmore 1933 Type species Bactrosaurus johnsoniGilmore 1933 Other species B kysylkumensis Riabinin 1931 originally Cionodon Synonyms Bakesaurus Zhou 2005 nomen nudum Cionodon kysylkumensis Riabinin 1931 Contents 1 Discovery 2 Description 3 Paleobiology 4 See also 5 ReferencesDiscovery edit nbsp 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 edit nbsp 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 7 8 It was an early relative of Lambeosaurus and shows a number of 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 lambeosaurine hadrosaurid supposedly the oldest and most primitive known and its crestless head was seen as an anomaly A 1990 popular book suggested that it had an incompletely preserved crest 3 but recent studies place Bactrosaurus as a more basal hadrosauromorph 10 Basal members do not preserve hollow crests so Bactrosaurus itself is likely to be crestless Paleobiology editIn 2003 evidence of tumors including hemangiomas desmoplastic fibroma metastatic cancer and osteoblastoma was discovered in fossilized Bactrosaurus skeletons Rothschild et al tested dinosaur vertebrae for tumors using computerized tomography and 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 editTimeline of hadrosaur researchReferences edit a b Gilmore C W 1933 On the dinosaurian fauna of the Iren Dabasu Formation Bulletin of the American Museum of Natural History 67 2 23 78 hdl 2246 355 Guo Z X Shi Y P Yang Y T Jiang S Q Li L B Zhao Z G 2018 Inversion of the Erlian Basin NE China in the early Late Cretaceous Implications for the collision of the Okhotomorsk Block with East Asia PDF Journal of Asian Earth Sciences 154 49 66 Bibcode 2018JAESc 154 49G doi 10 1016 j jseaes 2017 12 007 Archived from the original PDF on 2020 09 19 Retrieved 2020 05 02 a b c Bactrosaurus In Dodson Peter amp Britt Brooks amp Carpenter Kenneth amp Forster Catherine A amp Gillette David D amp Norell Mark A amp Olshevsky George amp Parrish J Michael amp Weishampel David B The Age of Dinosaurs Publications International LTD p 131 ISBN 0 7853 0443 6 Li Z 2001 Distribution burying and classification of dinosaur fossils in Upper Cretaceous strata at Meipu Town Yunxian County of Hubei Province Hubei Geology amp Mineral Resources 15 4 25 31 Zhou S Q D 2005 The Dinosaur Egg Fossils in Nanyang China China University of Geosciences Press pp 1 145 ISBN 978 7 562 52033 7 Harris Jerry D 2006 New Dinosaurs Archived 2016 02 22 at the Wayback Machine Paul G S 2016 The Princeton Field Guide to Dinosaurs 2nd ed Princeton New Jersey Princeton University Press pp 151 152 ISBN 9780691167664 Prieto Marquez A 2011 Cranial and appendicular ontogeny of Bactrosaurus johnsoni a hadrosauroid dinosaur from the Late Cretaceous of northern China Palaeontology 54 4 773 792 doi 10 1111 j 1475 4983 2011 01053 x Palmer D ed 1999 The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals London Marshall Editions p 146 ISBN 1 84028 152 9 Prieto Marquez Albert Carrera Farias Miguel 2021 A new late surviving early diverging Ibero Armorican duck billed dinosaur and the role of the Late Cretaceous European Archipelago in hadrosauroid biogeography Acta Palaeontologica Polonica 66 doi 10 4202 app 00821 2020 Rothschild B M Tanke D H Helbling II M Martin L D 2003 Epidemiologic study of tumors in dinosaurs PDF Naturwissenschaften 90 11 495 500 Bibcode 2003NW 90 495R doi 10 1007 s00114 003 0473 9 PMID 14610645 S2CID 13247222 Retrieved from https en wikipedia org w index php title Bactrosaurus amp oldid 1180305844, wikipedia, wiki, book, books, library,
