Brontosaurus

*Brontosaurus excelsus*

* Jurassic Park Institute Artwork
* Joe Tucciarone Artwork

***Brontosaurus*** ("thunder lizard") is a genus of sauropod dinosaurs. Originally named by its discoverer Othniel Charles Marsh in 1879, Brontosaurus had long been considered a junior synonym of Apatosaurus; its original species Brontosaurus excelsus was reclassified as A. excelsus in 1903. However, an extensive study published in 2015 by a joint British-Portuguese research team concluded that Brontosaurus was a valid genus of sauropod distinct from Apatosaurus. Nevertheless, not all paleontologists agree with this division.

The same study classified two additional species that had once been considered Apatosaurus and Eobrontosaurus as Brontosaurus parvus and Brontosaurus yahnahpin respectively. Species of Brontosaurus range in age from 155 to 152 million years ago, during the Kimmeridgian age of the lower to middle Morrison Formation in Wyoming and Utah, United States.

As the archetypal sauropod, Brontosaurus is one of the best-known dinosaurs, and has been featured in film, advertising, and postal stamps, as well as many other types of media.

## Description

Brontosaurus was a large, long-necked quadrupedal animal with a long, whip-like tail, and forelimbs that were slightly shorter than their hindlimbs. The largest species, B. excelsus, weighed up to 15 tonnes (15 long tons; 17 short tons) and measured up to 22 m (72 ft) long from head to tail.

The skull of Brontosaurus has not been found, but was probably similar to the skull of the closely related Apatosaurus. Like those of other sauropods, the vertebrae of the neck were deeply bifurcated; that is, they carried paired spines, resulting in a wide and deep neck.[10] The vertebral formula was: 15 cervicals, 10 dorsals, five sacrals, and 82 caudals. The caudal vertebra number was noted to vary, even within a species. The cervical vertebrae were stouter than other diplodocids, though not as stout as in mature specimens of Apatosaurus. The dorsal ribs are not fused or tightly attached to their vertebrae, instead being loosely articulated.[11] Ten dorsal ribs are on either side of the body.[12] The large neck was filled with an extensive system of weight-saving air sacs. Brontosaurus, like its close relative Apatosaurus, had tall spines on its vertebrae, which make up more than half the height of the individual bones. The shape of the tail was unusual for diplodocids, being comparatively slender, due to the vertebral spines rapidly decreasing in height the farther they are from the hips. Brontosaurus also had very long ribs compared to most other diplodocids, giving them unusually deep chests.[13] As in other diplodocids, the last portion of the tail of Brontosaurus possessed a whip-like structure.

## JPInstitute.com Description

Brontosaurus is one of the most well known dinosaurs, but did it really exist? At this point, scientists can't agree on whether Brontosaurus actually existed, as the original type specimen was actually a combination of two different dinosaurs - an Apatosaurus body and a Camarasaurus head. Currently, Brontosaurus is not a valid species, but that may change.

When it was discovered that the head of Camarasaurus was placed on the body of Apatosaurus and called Brontosaurus, most people thought that was the end of this dinosaur that had become an icon for dinosaur fans from the late 19th century through the 1970s. That may not be the case, however, as Dr. Robert Bakker is developing evidence that supports his claim that Brontosaurus should still be recognized as a real dinosaur. He asserts that it was a huge, long-necked plant eater that deserved its name, which means Thunder Lizard.

## Appearance in other media

### *The Land Before Time*

*Read more at the The Land Before Time Wiki*

### *We're Back! A Dinosaur's Story*

*Read more at the*
We're Back! A Dinosaur's Story Wiki

## Links

http://web.archive.org/web/20030216013640fw\_/http://www.jpinstitute.com/dinopedia/dinocards/dc\_bronto.html#