Brontosaurus

From Wikipedia, the free encyclopedia

The dinosaur genus originally known as Brontosaurus is now officially designated Apatosaurus. Please see that article for more information.

Brontosaurus
Fossil range: Late Jurassic

Brontosaurus skeleton by O.C. Marsh

Conservation status

Extinct (fossil)

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Class:	Sauropsida
Superorder:	Dinosauria
Order:	Saurischia
Suborder:	Sauropodomorpha
Infraorder:	Sauropoda
Family:	Diplodocidae
Genus:	Apatosaurus

Binomial name

Apatosaurus excelsus
(Marsh, 1879) vide Riggs, 1903

Synonyms

Brontosaurus excelsus Marsh, 1879c

Brontosaurus (pronounced /ˈbɹɒn.təˌsɔː.ɹəs/), meaning "thunder lizard" (from the Greek brontē/βροντη meaning 'thunder' and sauros/σαυρος meaning 'lizard'), is a deprecated genus of sauropod dinosaurs. The species Brontosaurus excelsus was named by its discoverer Othniel Charles Marsh, in 1879 and the designation persisted as an official term in the general public's literature until at least 1974, though it was recognized as a species of a previously-named genus, Apatosaurus, in 1903.

1 History
2 In popular culture
3 See also
4 References
5 External links

[edit] History

Othniel Marsh, a Professor of Paleontology at Yale University who described and named an incomplete (and juvenile) skeleton of Apatosaurus ajax in 1877, two years later announced the discovery of a far larger and more complete specimen at Como Bluff Wyoming — which, because of discrepancies including the size difference, Marsh incorrectly identified as belonging to an entirely new genus and dubbed Brontosaurus excelsus. [Etymology: from Latin excelsus, "to exceed in number", suggesting the greater number of vertebrae in the sacrum than in any other genus of sauropod then known.]

The finds — the largest dinosaur ever discovered at the time and nearly complete, lacking only a head, feet, and portions of the tail — were then prepared for what was to be the first ever mounted display of a sauropod skeleton, at Yale's Peabody Museum of Natural History in 1905. The missing bones were created using known pieces from close relatives of Brontosaurus. Sauropod feet that were discovered at the same quarry were added, as well as a tail fashioned to appear as Marsh believed it should and what he felt was the correct skull for the massive creature. This was not a delicate Diplodocus-style skull (which would later turn out to be more accurate), but instead, a composite composed of "the biggest, thickest, strongest skull bones, lower jaws and tooth crowns from three different quarries", primarily those of Camarasaurus, the only other sauropod for which good skull material was known at the time. This method of reconstructing incomplete skeletons based on the more complete remains of related dinosaurs continues in museum mounts and life restorations to this day. There is, however, some debate on whether Marsh was actually involved in the creation of this skeletal mount, or whether it was other Yale professors, as he has been reported to have died in 1899, six years before the display apparently took shape.

It was not until after the debut of the mounted skeleton, which cemented the name Brontosaurus in the public consciousness, that Elmer Riggs published a paper in the 1903 edition of Geological Series of the Field Columbian Museum which argued that Brontosaurus was not different enough from Apatosaurus to warrant its own genus, and created the combination Apatosaurus excelsus:

...In view of these facts the two genera may be regarded as synonymous. As the term "Apatosaurus" has priority, "Brontosaurus" will be regarded as a synonym.

Despite this, some paleontologists — most notably Robert Bakker — argue that A. ajax and A. excelsus are in fact sufficiently distinct that the latter continues to merit a separate genus.

[edit] In popular culture

Main article: Brontosaurus in popular culture

The length of time taken for Marsh's misclassification to be brought to public notice meant that the name Brontosaurus, associated as it was with one of the largest dinosaurs, became so famous that it persisted long after the name had officially been abandoned in scientific use. The terms brontosaurus, brontosaurs, and brontosaurians (no capital 'B'; no italics) are often used to refer generically to any of the sauropod dinosaurs.

As late as 1989, the U.S. Post Office issued four "dinosaur" stamps, Tyrannosaurus, Stegosaurus, "Pteradon" (misspelling of Pteranodon, which is a pterosaur and not a dinosaur) and Brontosaurus, for which it was accused, amongst other things, of "fostering scientific illiteracy." The Post Office defended itself (in Postal Bulletin 21744) thus:

1989 US Postage stamp featuring the Brontosaurus

Although now recognized by the scientific community as Apatosaurus, the name "Brontosaurus" was used for the stamp because it is more familiar to the general population.

Stephen Jay Gould supports this position in his essay "Bully for Brontosaurus", echoing Riggs' original argument that "Brontosaurus" is a synonym for "Apatosaurus". Nevertheless, the creature has developed and continues to maintain an independent existence in the popular imagination.