Supersaurus
Supersaurus | |
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A cast of BYU 9025, a scapulocoracoid, the holotype of Supersaurus, Dinosaur Journey Museum | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | Saurischia |
Clade: | †Sauropodomorpha |
Clade: | †Sauropoda |
Superfamily: | †Diplodocoidea |
Family: | †Diplodocidae |
Subfamily: | †Diplodocinae |
Genus: | †Supersaurus Jensen, 1985[1] |
Type species | |
†Supersaurus vivianae | |
Other Species | |
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Synonyms | |
Genus synonymy
Species synonymy (S. vivianae)
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Supersaurus (meaning "super lizard") is a
Discovery
Supersaurus is present in stratigraphic zone 5 of the Morrison, dating from the
A much more complete specimen WDC DMJ-021, was found in
Ultrasauros
Jensen, who described the original Supersaurus specimen, simultaneously reported the discovery of another gigantic sauropod, which would later be named "Ultrasaurus" macintoshi
Other bones that were found at the same location and originally thought to belong to Ultrasauros, like a shoulder girdle (scapulocoracoid, BYU 9462), actually belonged to Brachiosaurus, possibly a large specimen of Brachiosaurus altithorax.[10] The Brachiosaurus bones indicate a large, but not record-breaking individual, a little larger than the "Brachiosaurus" brancai (Giraffatitan brancai) mount in the Berlin's Natural History Museum.[11]
Originally, these Supersaurus and Brachiosaurus bones were believed to represent a single dinosaur that was estimated to reach about 25 to 30 meters (82 to 98 ft) long, 8 meters (26 ft) high at the shoulder, 15 meters (49 ft) in total height, and weighing maybe 70 t (77 short tons). At the time, mass estimates ranged up to 180 tons,[12] which placed it in the same category as the blue whale and the equally problematic Bruhathkayosaurus.
The naming of the chimeric Ultrasauros has a similarly complicated history. Ultrasaurus (with the final "u") was the original choice, and was widely used by the media after the discovery in 1979. However, the name of a new species must be published with a description to become official.[13]
Before Jim Jensen published his discovery in 1985, another paleontologist, Kim Haang Mook, used the name Ultrasaurus in a 1983 publication to describe what he believed was a giant dinosaur in South Korea. This was a different, much smaller dinosaur than Jensen's find, but Kim thought it represented a similarly gigantic animal because he confused a humerus for an ulna. While the logic of naming was incorrect, the Ultrasaurus from Kim's find fulfilled the requirements for naming and became regarded as a legitimate, if dubious genus.[11][13] Thus, because Jensen did not publish his own "Ultrasaurus" find until 1985, Kim's use retained its official priority of name, and Jensen was forced to choose a new name (in technical terms, his original choice was "preoccupied" by Kim's sauropod). In 1991, at his suggestion, George Olshevsky changed one letter, and renamed Jensen's sauropod Ultrasauros, with the final "o".[13]
When it was later discovered that the new name referred to bones from two separate, and already known species, the name Ultrasauros was considered invalid and became a junior synonym for Supersaurus. Since the bones from the Brachiosaurus were only used as a secondary reference for the new species, Ultrasauros is not a junior synonym for Brachiosaurus. The name Supersaurus was kept instead of Ultrasaurus as the animal is a diplodocid and Ultrasaurus had always referred to a brachiosaurid.[10]
Additional synonyms
Another
Description
Supersaurus is among the largest dinosaurs known from good remains, with the WDC and BYU specimens reaching 33–35 meters (108–115 ft) in length and approximately 35–40 metric tons (39–44 short tons) in body mass.[9][15] A larger specimen indicating a body length over 39 metres (128 ft) has been described in a 2021 abstract.[16]
The first described specimens of Supersaurus were individual bones that suggested a large diplodocid. A large cervical vertebra BYU 9024 from the same quarry was later assigned to Supersaurus.[17]. This vertebra measures 1.38 m (4.5 ft) in length and is the longest cervical known.[18] This enormous vertebra was reclassified as a Barosaurus vertebra, by Mike Taylor and Matt Wedel.[19] However Brian Curtice has reassigned it to Supersaurus on the basis of additional specimens.[16]
The assignment of the more complete specimen, WDC DMJ-021, to Supersaurus suggests that in most respects it was very similar in anatomy to Apatosaurus but less robustly built with especially elongated cervical vertebrae, resulting in one of the longest-known sauropod necks.[9]
Classification
Most studies of diplodocid relationships have found it to contain two primary subgroups: Diplodocinae (containing those diplodocids more closely related to Diplodocus than to Apatosaurus) and Apatosaurinae (diplodocids more closely related to Apatosaurus than to Diplodocus). Originally, it was thought that Supersaurus was related to the long-necked diplodocid Barosaurus, and therefore a member of the subfamily Diplodocinae, however, with the assignment of the more complete WDC DMJ-021 most later studies found Supersaurus to be a close relative of the familiar Apatosaurus in the group Apatosaurinae.[9] However, some later studies cast doubt on this paradigm. One comprehensive study of diplodocoid relationships published by Whitlock in 2011 found Apatosaurus itself to lie at the base of the diplodocid family tree, and other "apatosaurines", including Supersaurus, to be progressively more closely related to Diplodocus (making them diplodocines).[20]
In 2015, a specimen-level
Diplodocidae |
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References
- ^ .
- ISSN 0524-9511. Archived from the original(PDF) on September 28, 2007.
- .
- ^ PMID 25870766.
- ^ Foster, J. (2007). "Appendix". Jurassic West: The Dinosaurs of the Morrison Formation and Their World. Indiana University Press. pp. 327–329.
- ^ George, J. (May 13, 1973). "Supersaurus, giant of the giants". Denver Post, Empire Magazine. pp. 14ff.
- ^ George, J. (June 1973). "Supersaurus, the biggest brute ever". Reader's Digest. pp. 51–56.
- ISBN 0-253-34542-1.
- ^ ISSN 0365-4508.
- ^ a b c Curtice, Brian D.; Stadtman, Kenneth L.; Curtice, Linda J. (1996). "A re-assessment of Ultrasauros macintoshi (Jensen, 1985)". In Morales, M. (ed.). The Continental Jurassic: Transactions of the Continental Jurassic Symposium (PDF). Vol. 60. Museum of Northern Arizona Bulletin. pp. 87–95.
- ^ a b Paul, G.S. (1988). "The brachiosaur giants of the Morrison and Tendaguru with a description of a new subgenus, Giraffatitan, and a comparison of the world's largest dinosaurs" (PDF). Hunteria. 2 (3): 1–14.
- ISBN 978-0674207707.
- ^ a b c "Supersaurus, Ultrasaurus and Dystylosaurus in 2019, part 1: what we know now". Sauropod Vertebra Picture of the Week. June 13, 2019.
- ^ Curtice, B.; Stadtman, K. (2001). "The demise of Dystylosaurus edwini and a revision of Supersaurus vivianae". In McCord, R.D.; Boaz, D. (eds.). Western Association of Vertebrate Paleontologists and Southwest Paleontological Symposium - Proceedings 2001. Mesa Southwest Museum Bulletin. Vol. 8. pp. 33–40.
- OCLC 985402380.
- ^ a b Curtice, Brian (2021). "New Dry Mesa Dinosaur Quarry Supersaurus vivianae (Jensen 1985) axial elements provide additional insight into its phylogenetic relationships and size, suggesting an animal that exceeded 39 meters in length" (PDF). p. 92. Archived (PDF) from the original on October 8, 2022.
- JSTOR 41712373.
- S2CID 55987496. Archived from the original(PDF) on October 31, 2007. Retrieved October 17, 2016.
- ^ Taylor, Mike (2019). "Supersaurus, Ultrasaurus and Dystylosaurus in 2019, part 2: what we found in Utah". Archived from the original on September 21, 2022.
- .
External links
- "Why do mass estimates vary so much?", by Mike Taylor, August 27, 2002. (see footnote)