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
Barosaurus might have favoured those with longer necks. (See video "Neck Impossible" at reference.) Books: Barosaurus Barosaurus ( ) was a giant, long-tailed, long-necked, plant-eating dinosaur closely related to the more familiar "Diplodocus". Remains have been found in the Morrison Formation from the Upper Jurassic Period of Utah and South Dakota (and possibly Africa, as exemplified by the Kadsi Formation). It is present in stratigraphic zones 2-5. The composite term "Barosaurus" comes from the Greek words "barys" (βαρυς) meaning "heavy" and "sauros" (σαυρος) meaning "lizard"; thus "heavy lizard". "Barosaurus" was an enormous animal, with some adults measuring more than 26 meters