 The specimen was given the accession number AMNH 5764, then including two dorsals, a pubis, a femur, a tooth, a scapula, coracoid and an ulna.While the forelimb material was not originally assigned to "Amphicoelias", paleontologists Henry Fairfield Osborn and Charles Mook in 1921 added them to the holotype specimen on the basis that they were found in the same strata not far away, and bore differences from the "Camarasaurus" they were found alongside.Because of the uncertainty about the referral of these remains, in 2015 Emanuel Tschopp and colleagues hesitantly rejected the referral of the tooth, scapula and coracoid, but accepted the ulna referral.