Apatosaurus (Apatosaurus ajax) was one of the best-known long-necked dinosaurs of the Jurassic Period. With a huge body, a thick muscular neck, and a long tail, Apatosaurus represents the classic image of a giant sauropod moving through river floodplains.
Time Period
Apatosaurus lived during the Late Jurassic. In your site filter, this is grouped under Jurassic, a time when sauropods were among the dominant herbivores in North America.
Habitat
Most fossils of Apatosaurus come from the Morrison Formation in the western United States. The Morrison is commonly reconstructed as a landscape of rivers, floodplains, forests, and seasonal dry periods—supporting enormous herds of plant-eaters and the predators that hunted them.
Size and Appearance
Apatosaurus reached roughly 21–23 meters in length. Compared with some other diplodocids, it is often depicted as more heavily built, with a strong neck and a deep torso. Like most sauropods, it had a small head relative to its body, and a long tail that helped with balance.
Diet and Lifestyle
Apatosaurus was an herbivore that fed on Jurassic vegetation such as conifers, ferns, and other plants. It likely swallowed plant material in bulk and relied on a large digestive system to break down tough vegetation.
Apatosaurus and “Brontosaurus”
Apatosaurus is famously connected to the name “Brontosaurus.” For many years, Brontosaurus was treated as the same dinosaur as Apatosaurus, and the names were used interchangeably in popular culture. Modern studies debate details and may separate them again, but Apatosaurus remains one of the most iconic Morrison Formation sauropods.
