Rebbachisauridae

Rebbachisauridae is a family of sauropod dinosaurs known from fragmentary fossil remains from the Cretaceous of South America, Africa, North America, and Europe. In 1990 sauropod specialist Jack McIntosh included the first known rebbachisaurid genus, the giant North African sauropod Rebbachisaurus, in the family Diplodocidae, subfamily Dicraeosaurinae, on the basis of skeletal details. With the discovery in subsequent years of a number of additional genera, it was realised that Rebbachisaurus and its relatives constituted a distinct group of dinosaurs. In 1997 the Argentine paleontologist José Bonaparte described the family Rebbachisauridae, and in 2011 Whitlock defined two new subfamilies within the group: Nigersaurinae and Limaysaurinae. Cladogram of the Rebbachisauridae after Fanti et al. (2013) which is based on Carballido et al. (2012): Cladogram after Fanti et al., 2015. Although all authorities agree that the rebbachisaurids are members of the superfamily Diplodocoidea, they lack the bifid (divided) cervical neural spines that characterise the diplodocids and dicraeosaurids, and for this reason are considered more primitive than the latter two groups. It is not yet known whether they share the distinctive whip-tail of the latter two taxa. Rebbachisaurids are distinguished from other sauropods by their distinctive teeth, which have low angle, internal wear facets and asymmetrical enamel. Unique among sauropods, at least some rebbachisaurids (such as Nigersaurus) are characterised by the presence of tooth batteries, similar to those of hadrosaur and ceratopsian dinosaurs. Such a feeding adaptation has thus developed independently three times among the dinosaurs.