The genus Camarasaurus is known from several species
These display differences in the shapes of their skulls and post-crania (Fig. 1). Distinct from the bipedal or tripodal Diplodocus we looked at yesterday, the general build of this genus suggests it did not rise from all fours. Rather elevation of the great neck enabled high browsing, though not as high as its sister in the LRT, Brachiosaurus.
Once considered a Camarasaurus,
the short-limbed, big pelvis Cathetosaurus (Fig. 2) is certainly related, but distinct from the other camarasaurs.
Not only are the bodies distinct,
so are the skulls (Fig. 3) assigned to this genus.
As in many genera
for which several specimens are known, it is always a good idea to start with just one rather complete specimen in phylogenetic analysis. Add others as your interest grows.
Gilmore CW 1925. A nearly complete articulated skeleton of Camarasaurus, a saurischian dinosaur from the Dinosaur National Monument, Utah. Memoirs of the Carnegie Museum 10:347-384.
Madsen JH Jr, McIntosh JS, and Berman DS 1995. Skull and atlas-axis complex of the Upper Jurassic sauropod Camarasaurus Cope (Reptilia: Saurischia). Bulletin of Carnegie Museum of Natural History 31:1-115.
McIntosh JS, Miles CA, Cloward KC and Parker JR 1996. A new nearly complete skeleton of Camarasaurus. Bulletin of the Gunma Museum of Natural History 1:1-87.
McIntosh JS, Miller WE, Stadtman KL and Gillette DD 1996. The osteology of Camarasaurus lewisi (Jensen, 1988). Brigham Young University Geology Studies 41:73-115.
Tschopp E, Wings O, Frauenfelder T, and Brinkmann W 2015. Articulated bone sets of manus and pedes of Camarasaurus (Sauropoda, Dinosauria). Palaeontologia Electronica 18.2.44A: 1-65.