Listado especies


SPECIES: Apatosaurus (also known as Brontosaurus)

TIME PERIOD: Late Jurassic


SIZE: 30-35 Tonnes

LENGTH: 21-25 Meters

FOSSIL SITES: Western United States (Oklahoma, Utah, Wyoming, Colorado) and Baja California, Mexico

Apatosaurus was a large sauropod, or long necked, dinosaur. In 1877 the first fossil remains of this beast were discovered by Arthur Lakes in Morrison, Colorado. Dr. O.C. Marsh, the paleontologist overseeing Lakes' digging, named this dinosaur Apatosaurus, which means 'deceptive reptile.' In 1879 two similar sauropod skeletons were found in Como Bluff, Wyoming. One was an almost complete skeleton, but was only missing a skull. It looked much like a larger version of Apatosaurus, but it had four vertebrae near its hips instead of three. Therefore, he named it Brontosaurus, or 'thunder lizard.'

Little did Marsh know, however, was that an Apatosaurus was born with three of these vertebrae and grew a fourth as it grew older. This mistake was discovered by Elmer Riggs in 1903, who disclosed that this meant that Brontosaurus and Apatosaurus were really the same animal. But, Brontosaurus was such a common and familiar name that it stuck. Since Apatosaurus was the first name used for this species, though, it is the correct scientific name.

In life this 70-75 foot long (21-25 meters) dinosaur would have weighed close to 30 tonnes. It lived in the Late Jurassic period, about 156-145 million years ago, and ate a diet that consisted mostly of tree leaves and ferns. Its distinguishing features include a low, sloping head like that of its cousin, Diplodocus, pencil shaped teeth, and neck vertebrae that are heavier and thicker than most other sauropods (including Diplodocus). Recent fossil dig sites in Colorado and Wyoming have yielded new Apatosaurus material, and today several Apatosaur species are known, possibly up to ten.

Dr. Robert Bakker still believes that Brontosaurus is a valid genus, believing that the species Apatosaurus excelsus should be called Brontosaurus. He is in the minority, though. Nice Apatosaurus remains can be seen at the Field Museum of Natural History in Chicago, the Carnegie Museum of Natural History in Pittsburgh, and the American Museum of Natural History in New York City.