Revision for “Brachiosaurus” created on March 10, 2015 @ 09:59:08

[two_third]Brachiosaurus is a genus of sauropod dinosaur from the Jurassic Morrison Formation of North America. It was first described by Elmer S. Riggs in 1903 from fossils found in the Grand River Canyon (now Colorado River) of western Colorado, in the United States. Riggs named the dinosaur Brachiosaurus altithorax, declaring it "the largest known dinosaur". Brachiosaurus had a disproportionately long neck, small skull, and large overall size, all of which are typical for sauropods. However, the proportions of Brachiosaurus are unlike most sauropods – the forelimbs were longer than the hindlimbs, which resulted in a steeply inclined trunk, and its tail was shorter in proportion to its neck than other sauropods of the Jurassic. Brachiosaurus is the namesake genus of the family Brachiosauridae, which includes a handful of other similar sauropods. Much of what is known by laypeople about Brachiosaurus is in fact based on Giraffatitan brancai, a species of brachiosaurid dinosaur from the Tendaguru Formation of Tanzania that was originally described by German paleontologist Werner Janensch as a species of Brachiosaurus. Recent research shows that the differences between the type species of Brachiosaurus and the Tendaguru material are significant enough that the African material should be placed in a separate genus. Several other potential species of Brachiosaurus have been described from Africa and Europe, but none of them are thought to belong to Brachiosaurus at this time. Brachiosaurus is one of the rarer sauropods of the Morrison Formation. The type specimen of B. altithorax is still the most complete specimen, and only a relative handful of other specimens are thought to belong to the genus. It is regarded as a high browser, probably cropping or nipping vegetation as high as possibly 9 metres (30 ft) off of the ground. Unlike other sauropods, and its depiction in the film Jurassic Park, it was unsuited for rearing on its hindlimbs. It has been used as an example of a dinosaur that was most likely ectothermic due to its large size and the corresponding need for forage, but more recent research finds it to have been warm-blooded. Like all sauropod dinosaurs, Brachiosaurus was a quadrupedal animal with a small skull, a long neck, a large trunk with a high-ellipsoid cross section, a long, muscular tail and slender, columnar limbs. The skull had a robust, wide muzzle and thick jaw bones, with spoon–shaped teeth. As in Giraffatitan, there was an arch of bone over the snout and in front of the eyes that encircled the nasal opening, although this arch was not as large as in its relative. Large air sacs connected to the lung system were present in the neck and trunk, invading the vertebrae and ribs, greatly reducing the overall density.[/two_third][one_third_last]<div class="yesborder"> <div align="center"><em><strong>Brachiosaurus</strong></em></div> <p style="text-align: center;"><a href=""><img class="aligncenter wp-image-1250 size-medium" src="" alt="" width="300" height="281" /></a></p> <p style="text-align: center;">Clade: <strong><a href="">Dinosauria</a></strong> Suborder: <strong><a href="">Sauropoda</a></strong> Family: <strong>Brachiosauridae</strong></p> <a href=""><img class="aligncenter wp-image-1249 size-medium" src="" alt="" width="300" height="155" /></a> <p style="text-align: center;"><strong>Size:</strong> 26m (85 feet) long 12 m (40 ft) tall at head</p> <p style="text-align: center;"><strong>Weight:</strong> 35 metric tons</p> <p style="text-align: center;"><a href=""><img class="aligncenter wp-image-1218 size-medium" src="" alt="" width="300" height="120" /></a></p> <p style="text-align: center;">When: <strong><a href="">Jurassic Period</a></strong> 152 to 145 million years ago</p> <p style="text-align: center;"><a href=""><img class="aligncenter wp-image-327 size-medium" src="" alt="" width="300" height="132" /></a>Where: <strong><a href="">North America</a></strong></p> <p style="text-align: center;">Diet: <strong><a href="">Herbivore</a></strong></p> </div> [/one_third_last]Unusually for a sauropod, the forelimbs were longer than the hind limbs. The humerus (upper arm bone) of Brachiosaurus was relatively lightly built for its size, measuring 2.04 metres (6.7 ft) in length in the type specimen. The femur (thigh bone) of the type specimen was only 2.03 metres (6.7 ft) long. Unlike other sauropods, Brachiosaurus appears to have been slightly sprawled at the shoulder joint, and the ribcage was unusually deep. This led to the trunk being inclined, with the front much higher than the hips, and the neck exiting the trunk at a steep angle. Overall, this shape resembles a giraffe more than any other living animal. Brachiosaurus is thought to have been a high browser, feeding on foliage well above the ground. Even if it did not hold its neck near vertical, and instead had a straighter neck, its head height may still have been over 9 metres (30 ft) above the ground. It probably fed mostly on foliage above 5 metres (16 ft). This does not preclude the possibility that it also fed lower at times, between 3 to 5 metres (9.8 to 16.4 ft) up. Its diet likely consisted of ginkgos, conifers, tree ferns, and large cycads, with intake estimated at 200 to 400 kilograms (440 to 880 lb) of plant matter daily. However, more recent studies estimate that ~240 kilograms (530 lb) of plant matter would have been sufficient to feed a 70 metric tons (77 short tons) sauropod, so Brachiosaurus may have required only about 120 kilograms (260 lb) of fodder a day. Brachiosaur feeding involved simple up–and–down jaw motion. The teeth were arranged to shear material as they closed, and were probably used to crop and/or nip vegetation. <a href=""><img class="aligncenter wp-image-1251 size-large" src="" alt="" width="1024" height="767" /></a>

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