 Carpenter (2006) disagreed about the synonymy of "A. altus" and "A. fragillimus", however, citing numerous differences in the construction of the vertebra also noted by Cope, and suggested these differences are enough to warrant a separate species or even a separate genus for "A. fragillimus".However, he went on to caution that the validity of "A. fragillimus" as a separate species is nearly impossible to determine without the original specimen to study.Although "Amphicoelias latus" is clearly not "Amphicoelias", it is probably synonymous with "Camarasaurus grandis" rather than "C. supremus" because it was found lower in the Morrison Formation and the deeply concave articular faces on the caudal vertebrae are more consistent with "C. grandis".