These species have a greatly increased number of vertebrae (Caldwell, 2003; Gomez et al., 2008; Vonk and Richardson, 2008) and, with the exception of the atlas, all of the pre-cloacal vertebrae are often rib bearing.
In contrast to non-elongated species, the dorsal region of the skeleton (in reptiles and amphibians the rib-bearing region of the trunk skeleton is termed ‘dorsal’ instead of ‘thoracic’) is extremely homogeneous with few or no differences between ribs and vertebrae along the antero-posterior axis (Romer, 1997).