Brachiosaurus: Jurassic Sauropod

Brachiosaurus was one of the largest terrestrial animals to ever exist on Earth. It belonged to the sauropod family of dinosaurs and lived during the late Jurassic Period in areas of North America, Africa, and Eurasia. Several species of brachiosaurus have been identified, and the most complete remains come from Tanzania, Africa.

Like other sauropods, brachiosaurus had a very long neck, tiny head, huge body, and a large tail. However, unlike contemporaries like diplodocus, brachiosaurus had a relatively short, thick tail. Part of brachiosaurus' success story lies in its ability to raise its neck nearly forty feet off the ground. This would have allowed it access to choice leaves at the tops of trees which was not able to be reached by any other dinosaur. Other sauropods like diplodocus held their necks horizontally and were thus not able to reach the top canopy of vegetation. This monopoly on a very abundant source of food allowed brachiosaurus to reach its titanic size. Special, peg-like teeth in the skull allowed brachiosaurus to strip enormous amounts of vegetation and swallow it whole. It probably used gastroliths (stomach stones) to grind up the fermenting vegetation as it passed through its digestive tract. Once it reached a certain mass, it was unlikely that any Jurassic predator could possibly hope to challenge brachiosaurus.

Brachiosaurs also presents evidence for the contention that dinosaurs were at least partially warm-blooded. If brachiosaurus was warm-blooded, it would have taken around a decade to reach its full size of up to eighty tons. On the other hand, if it was cold-blooded it would have taken nearly one hundred years. Although brachiosaurus like other sauropods might have reached this advanced age, it seems unlikely that it would have been able to fend off predators for several decades while at smaller sizes.

The biggest area of contention surrounding brachiosaurus is its neck. Commonly, scientists have made the neck curve upward, holding the head high off the ground. The problem with this is that brachiosaurus would have required an enormous heart in order to pump blood under sufficient pressure to reach the head forty feet above the ground. There have been some theories suggesting that brachiosaurus actually had a secondary heart-like organ inside its neck which would intake blood and then pump it the rest of the distance to the head. Unfortunately, scientists may never know the answer to this mystery since the only information we have to go on comes from fossilized bones, not tissues.

As the climate on Earth grew hotter and drier, many of the forests that brachiosaurus depended on were shrinking. Unable to support their massive nutritional requirements, the giant sauropods soon shrank to around half their Jurassic size as they entered the Cretaceous Period.