| Diet | Herbivore |
| Height | 4.5m |
| Length | 22m |
| Weight | 20 tonnes |
| Speed | 15 km/h |
| Environment | Land |
| Era | Jurassic |
| Period | Late Jurassic |
| Type | Sauropod |
| Location | North America |
Apatosaurus was one of the most impressive sauropod dinosaurs that roamed North America during the Late Jurassic period, approximately 152 to 151 million years ago. This massive herbivore lived in what is now Colorado, Oklahoma, New Mexico, Wyoming, and Utah, where its fossils have been discovered in the famous Morrison Formation. Despite its enormous size, Apatosaurus was built for a peaceful existence, spending its days browsing on prehistoric vegetation.
This colossal sauropod measured an average of 21-23 metres in length and weighed between 16-22 tonnes, though some exceptional specimens may have reached up to 30 metres long and weighed as much as 33 tonnes. Apatosaurus possessed the classic sauropod body plan: a incredibly long neck for reaching high vegetation, a relatively small head, a barrel-shaped body, and a lengthy tail that served as a counterbalance. Its four pillar-like legs supported its massive frame as it moved slowly across the Jurassic landscape.
As a herbivore, Apatosaurus fed on conifers, ferns, and other prehistoric plants. Its long neck allowed it to browse vegetation at various heights without moving its massive body frequently. The dinosaur's teeth were simple, peg-like structures designed for stripping leaves rather than chewing, so it likely swallowed stones to help grind plant material in its stomach.
Apatosaurus had an exceptionally long neck comprising 15 vertebrae, a relatively small head compared to its massive body, and a whip-like tail. Its robust build and thick, pillar-like legs distinguished it from more slender sauropods, giving it a particularly imposing appearance.
Apatosaurus likely lived in herds for protection from predators like Allosaurus, as evidenced by trackway fossils showing multiple sauropods travelling together. It spent most of its time feeding, requiring enormous quantities of plant matter daily to fuel its massive body, and may have used its long tail as a defensive weapon when threatened.
Apatosaurus has appeared in numerous films and documentaries, often under its former name Brontosaurus. It features prominently in Disney's Fantasia and more recently in Pixar's The Good Dinosaur.
| Phylum | Chordata |
| Class | Saurischia |
| Family | Diplodocidae |
| Genus | Apatosaurus |
Apatosaurus was first described by Othniel Charles Marsh in 1877. The original fossils were discovered at Morrison Formation, Colorado, USA.
