Most of the distinguishing skeletal features of "Barosaurus" were in the vertebrae, although a complete vertebral column has never been found. "Diplodocus" and "Apatosaurus" both had 15 cervical (neck) and 10 dorsal (trunk) vertebrae, while "Barosaurus" had only 9 dorsals. A dorsal may have been converted into a cervical vertebra, for a total of 16 vertebrae in the neck. "Barosaurus" cervicals were similar to those of "Diplodocus", but some were up to 50% longer. The neural spines protruding from the top of the vertebrae were neither as tall or as complex in "Barosaurus" as they were in "Diplodocus". In contrast to its neck vertebrae, "Barosaurus" had shorter caudal (tail) vertebrae than "Diplodocus", resulting in a shorter tail. The chevron bones lining the underside of the tail were forked and had a prominent forward spike, much like the closely related "Diplodocus". The tail probably ended in a long whiplash, much like "Apatosaurus", "Diplodocus" and other diplodocids, some of which had up to 80 tail vertebrae.