Apatosaurus different dinosaur individuals. Among the many notable differences are the widerand presumably strongerneck of "Apatosaurus" species compared to "B.excelsus". Other species previously assigned to "Apatosaurus", such as "Elosaurus parvus" and "Eobrontosaurus yahnahpin" were also reclassified as "Brontosaurus". Some features proposed to separate "Brontosaurus" from "Apatosaurus" include: posterior dorsal vertebrae with the centrum longer than wide; the scapula rear to the acromial edge and the distal blade being excavated; the acromial edge of the distal scapular blade bearing a rounded expansion; and the ratio of the proximodistal length to transverse breadth of the astragalus 0.55 or greater. Sauropod expert Michael Daniel
Apatosaurus Apatosaurus Apatosaurus (; meaning "deceptive lizard") is a genus of herbivorous sauropod dinosaur that lived in North America during the Late Jurassic period. Othniel Charles Marsh described and named the first-known species, A. ajax, in 1877, and a second species, A. louisae, was discovered and named by William H. Holland in 1916. "Apatosaurus" lived about 152 to 151 million years ago (mya), during the late Kimmeridgian to early Tithonian age, and are now known from fossils in the Morrison Formation of modern-day Colorado, Oklahoma, New Mexico, Wyoming, and Utah in the United States. "Apatosaurus" had an average length of ,