Bifurcated and incipiently bifurcated cervical ribs of sauropods. A , Moabosaurus utahensis holotype individual, left cervical rib BYU 14063 (not right as stated by Britt et al. 2017), probably associated with C5, in medial view. B , Dicraeosaurus hansemanni holotype MB.R.2379, right cervical rib 8 in lateral view. Modified from Janensch (1929, fig.