Apatosaurus which Marsh had described "Brontosaurus". Most of the skeleton was found, and after comparison with both "Brontosaurus" and "Apatosaurus ajax", Riggs realized that the holotype of "A.ajax" was immature, and thus the features distinguishing the genera were not valid. Since "Apatosaurus" was the earlier name, "Brontosaurus" should be considered a junior synonym of "Apatosaurus". Because of this, Riggs recombined "Brontosaurus excelsus" as "Apatosaurus excelsus". Based on comparisons with other species proposed to belong to "Apatosaurus", Riggs also determined that the Field Columbian Museum specimen was likely most similar to "A.excelsus". Despite Riggs' publication, Henry Fairfield Osborn, who was a strong
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