Apatosaurus, also known by the popular but scientifically redundant synonym Brontosaurus, was a sturdy beast. It had a long, whiplash tail, which had about 80 bones in it.
Apatosaurus was a huge, quadrupedal sauropod, as long as a tennis court. It fed on leaves that it snipped from plants and trees with its weak, peg-like teeth. Its very long neck, which had 15 huge bones in it, was held up by strong muscles that ran along the neck bones.
Name: Apatosaurus, meaning ‘deceptive reptile’
Size: 21-25m long and 5.8m high
Food: leaves and shoots of trees and shrubs
Lived: about 150 million years ago in the Late Jurassic Period in North America
Apatosaurus is a heavily built diplodocid. The vertebrae have a groove along the top. This held a strong ligament that supported the weight of the neck and the tail, like the cables on a suspension bridge. The ‘deceptive lizard’ of the name refers to the fact that the chevron bones attached to the vertebrae look confusingly like those of the aquatic reptile Mosasaurus. Although the head is about the size of that of a horse, the brain is only as big as that of a cat. The whole skeleton is similar to that of Diplodocus, but is much more stocky and massive, going for weight rather than length.
Apatosaurus had an extremely long tail, almost half of which was thin and whiplike. It probably used its tail to lash out at the hungry carnivores that preyed on the weakest members of the herd, such as the young and the very old dinosaurs. Recent computer modelling suggested that sauropods such as Apatosaurus were capable of producing a whiplike cracking sound of over 200 decibels with their tails, comparable to the volume of a cannon.
To support its great weight, Apatosaurus’ pillar-like legs ended in broad feet, rather like those of an elephant. Its front feet had a claw on the inside toe, which it used to kick out at attackers.
One of the most popular dinosaurs, Apatosaurus, keeps changing its identity. For almost a century it went by the evocative name Brontosaurus, the ‘thunder lizard’. In 1877 Othniel Charles Marsh discovered A. ajax and named it. Two years later he found a more complete animal which he named Brontosaurus excelsus. It was not until the twentieth century that it was realized that these were actually two species of the same genus. When there is confusion of this kind, with one animal given two names, it is the first name given that is deemed to be the valid one, in this case Apatosaurus. The official change took place in 1903. The length of time taken for Marsh’s misclassification to be brought to public notice meant that the latter name, 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.