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 ArgentinepaleontologistJosé 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. which is based on Carballido et al. : Cladogram after Fanti et al., 2015. ImageSize = width:900px height:auto barincrement:15px PlotArea = left:10px bottom:50px top:10px right:10px Period = from:1940 till:2040 TimeAxis = orientation:horizontal ScaleMajor = unit:year increment:50 start:1940 ScaleMinor = unit:year increment:10 start:1940 TimeAxis = orientation:hor AlignBars = justify Colors = #legends id:CAR value:claret id:ANK value:rgb id:HER value:teal id:HAD value:green id:OMN value:blue id:black value:black id:white value:white id:1900s value:rgb id:2000s value:rgb id:2000syears value:rgb id:1900syears value:rgb id:1700s value:rgb id:1700syears value:rgb id:latecretaceous value:rgb id:1800syears value:rgb id:paleogene value:rgb id:paleocene value:rgb id:eocene value:rgb id:oligocene value:rgb id:1800s value:rgb id:miocene value:rgb id:pliocene value:rgb id:quaternary value:rgb id:pleistocene value:rgb id:holocene value:rgb BarData= bar:eratop bar:space bar:periodtop bar:space bar:NAM1 bar:NAM2 bar:NAM3 bar:NAM4 bar:NAM5 bar:NAM6 bar:NAM7 bar:NAM8 bar:NAM9 bar:NAM10 bar:NAM11 bar:space bar:period bar:space bar:era PlotData= align:center textcolor:black fontsize:M mark: width:25 shift:
Although all authorities agree that the rebbachisaurids are members of the superfamily Diplodocoidea, they lack the bifid cervicalneural 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 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. So far, rebbachisaurids are known only from the middle and early part of the Late Cretaceous. They constitute the last known representatives of this clade, and lived alongside the titanosaurs until fairly late in the Cretaceous.
