Supersaurus

Taxobox
name = "Supersaurus"

---

image_width = 250px
fossil_range = Late Jurassic
regnum = Animalia
phylum = Chordata
classis = Sauropsida
superordo = Dinosauria
ordo = Saurischia
subordo = Sauropodomorpha
infraordo = Sauropoda
familia = Diplodocidae
genus = "Supersaurus"
genus_authority = Jensen, 1985
subdivision_ranks = Species
subdivision =
*"S. vivianae" Jensen, 1985 (type)
synonyms =
* "Dystylosaurus" Jensen, 1985

* "Ultrasauros" Olshevsky, 1991

"Supersaurus" (meaning "super lizard") is a genus of diplodocid sauropod dinosaur discovered in the Upper Jurassic Morrison Formation of Colorado in 1972. It is among the largest dinosaurs known from good remains, possibly reaching 33 to 34 meters (108 to 112 ft) in length, and a weight of 35 to 40 tons .cite journal |last=Lovelace |first=David M. |coauthors=Hartman, Scott A.; and Wahl, William R. |year=2007 |title=Morphology of a specimen of "Supersaurus" (Dinosauria, Sauropoda) from the Morrison Formation of Wyoming, and a re-evaluation of diplodocid phylogeny |journal=Arquivos do Museu Nacional |volume=65 |issue=4 |pages=527–544 ]

History

The original fossil remains of "Supersaurus" yielded only a few bones: the shoulder girdle (type specimen BYU 5500) and a few neck vertebrae. This shoulder girdle (or "scapulocoracoid") stood some 2.4 meters (8 ft) tall, if placed on end.

A new and much more complete specimen of "Supersaurus", nicknamed 'Jimbo', has been found in Converse County, Wyoming. It is currently being excavated and its bones are being held at the Wyoming Dinosaur Center. Originally, it was thought that "Supersaurus" was related to the long-necked diplodocid "Barosaurus" (a member of the subfamily Diplodocinae), but the new specimen makes it clear that "Supersaurus" is actually more closely related to "Apatosaurus" (a member of the subfamily Apatosaurinae).

"Ultrasauros"

Paleontologist James A. Jensen, who described the original "Supersaurus" specimen, simultaneously reported the discovery of another gigantic sauropod, which would later be named "Ultrasaurus" "macintoshi"Jensen, J.A. (1985). "Three new sauropod dinosaurs from the Upper Jurassic of Colorado." "Great Basin Naturalist", 45: 697-709.] (later re-named "Ultrasauros macintoshi"). The type specimen (the specimen used to define a new species) of "Ultrasauros", being a backbone (dorsal vertebra, labeled BYU 9044), was later found to have come from "Supersaurus". In fact, it probably belonged to the original "Supersaurus" specimen, which was discovered in the same quarry in 1972. Therefore, "Ultrasauros" became a junior objective synonym of "Supersaurus", which had been named first and thus retains priority, and the name "Ultrasauros" was abandoned.Curtice, B., Stadtman, K., and Curtice, L. (1996) "A re-assessment of "Ultrasauros macintoshi" (Jensen, 1985)." Pp. 87-95 in M. Morales (ed.), "The Continental Jurassic: Transactions of the Continental Jurassic Symposium", Museum of Northern Arizona Bulletin number 60.]

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". The "Brachiosaurus" bones indicate a large, but not record-breaking individual, a little larger than the "Brachiosaurus brancai" in the Humboldt Museum of Berlin. Larger specimens of "Brachiosaurus" are known from the Tendaguru Beds of Tanzania, in east Africa.

Originally, these "Supersaurus" and "Brachiosaurus" bones were believed to represent a single dinosaur that was estimated to reach about 25 to 30 meters (80 to 100 ft) long, 8 meters (25 ft) high at the shoulder, 15 meters (50 ft) in total height, and weighing maybe 70 metric tonnes (75 short tons). At the time, mass estimates ranged up to 180 tons, which placed it in the same category as the blue whale and the equally problematic "Bruhathkayosaurus".

Naming of "Ultrasauros"

The naming of the chimeric "Ultrasauros" has a similarly complicated history. "Ultrasaur"u"s" 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 in a scientific journal to become official.

Before Jim Jensen published his discovery in 1985, another paleontologist, Haang Mook Kim, 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 femur (leg bone) for a humerus (arm bone). While the logic of naming was incorrect, the "Ultrasaur"u"s" from Kim's find fulfilled the requirements for naming and became regarded as a legitimate, if dubious genus. 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 "Ultrasaur"o"s".

When it was later discovered that the new name referred to bones from two separate, and already known species, the name "Ultrasauros" 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". Since "Supersaurus" was named slightly earlier, the name "Ultrasauros" has been discarded in favor of "Supersaurus".

Additional synonyms

Another diplodocid dinosaur found near the original "Supersaurus" quarry, known from a backbone (dorsal vertebra type specimen BYU 5750), was named "Dystylosaurus edwini" and is now also considered to be a specimen of "Supersaurus vivianae". Hence, "Dystylosaurus" has also become a junior synonym of "Supersaurus".cite book |last=Curtice |first=B. |coauthors=and Stadtman, K. |year=2001 |chapter=The demise of "Dystylosaurus edwini" and a revision of "Supersaurus vivianae" |title=Western Association of Vertebrate Paleontologists and Southwest Paleontological Symposium - Proceedings 2001 |editor=McCord, R.D.; and Boaz, D. (eds.) |series=Mesa Southwest Museum Bulletin |volume=8 |pages=33-40]

References

External links

* " [http://www.dinosauria.com/jdp/misc/ultra.htm Whatever happened to 'Ultrasauros"?] , by Brian Curtice.
* " [http://www.miketaylor.org.uk/dino/faq/s-size/diff/index.html Why do mass estimates vary so much?] ", by Mike Taylor, 27 August 2002. (see footnote)