Many fossils of Apatosaurus have been found in Colorado, Oklahoma, Utah, and Wyoming, in the USA. Apatosaurus was named in 1877 by US paleontologist Othniel C. Marsh. It was called Apatosaurus, which means "deceptive lizard". The first complete Apatosaurus fossil was found by Earl Douglas in Colorado, USA.
APATOSAURUS and BRONTOSAURUS
The American paleontologist Othniel C. Marsh described and named Apatosaurus in 1877. A few years later, in 1879, he described and named another dinosaur fossil, Brontosaurus (which means "thunder lizard"). It turned out that the two dinosaurs were actually two species of the same species. The earlier scientific name, Apatosaurus, was retained, and the name Brontosaurus was no longer used. Some people call Apatosaurus "Long-neck."