posteroventrally, and the ischium projects posteriorly (1), lateroventrally projecting spurs in the neural spines of the last dorsals (2); and posterior cervical and anterior dorsal diapophyses bearing an anterior projection lateral to the prezygapophyses (3). The pelvis of C. lewisi is rotated forward relative to the sacrum, such that the preacetabular process of the ilium is oriented to point 20° below the axis of the sacrum. Jensen regarded this as one of the most distinctive characteristics of the taxon, and both McIntosh et al. and Mateus and Tschopp included it in their list of diagnostic characteristics for the taxon. However, the condition in other species of Camarasaurus is not entirely clear. In 1921, Osborn and Mook reconstructed the pelvis of C. supremus without the rotation. The condition is unclear in C. grandis, due to the lack of articulated pelves, but the disarticulated ilium of one specimen appears it would not exhibit such a strongly rotated condition. Specimens of C. lentus exhibit a rotated pelvis, but the precise angle is difficult to confirm due to distortion of the bones and may be less than in C. lewisi. The holotype of C. lewisi lacks a skull, but based on the specimen SMA 0002, which may belong to the species, the skull possesses several diagnostic characteristics: frontals with anterior midline projection into the nasals (1); trapezoidal supraoccipital (more expanded dorsally than ventrally) (2); lateral spur on the dorsal part of the lacrimal (3); fenestrated pterygoid (4); and the large pineal foramen between the frontals (5). The specimen SMA 0002, which may belong to C. lewisi, has unusual proportions. It has an exceptionally large skull, which is roughly 58% the length of the femur, leading to it being described as "bobbleheaded". Nearly all sauropodomorphs have a skull less than 50% of the length of the femur, but several Camarasaurus specimens of varying species possess such "bobbleheaded" proportions, which may be due to individual variation or sexual dimorphism. The limbs are shorter in proportion to the body, particularly due to especially short lower limb elements, such that it has been described as "dachshund reminiscent". The ribs are long, extending below knee level. Due to the length of the ribs and the rotation of the pelvis, the taxon would have had an atypically large gut volume. History of study The holotype specimen of C. lewisi was discovered in 1967 by Vivian and Daniel Jones in Pit