Rebbachisauridae is a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

sauropod Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their b ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

s known from fragmentary

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

remains from the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

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Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

and possibly

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Taxonomy

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. Khebbashia is a clade within Rebbachisauridae. P. D. Mannion, P. Upchurch, D. Schwarz and O. Wings. (2019). Taxonomic affinities of the putative

titanosaur Titanosaurs (or titanosaurians; members of the group Titanosauria) were a diverse group of sauropod dinosaurs, including genera from all seven continents. The titanosaurs were the last surviving group of long-necked sauropods, with taxa still thr ...

s from the

Late Jurassic The Late Jurassic is the third Epoch (geology), epoch of the Jurassic Period, and it spans the geologic time scale, geologic time from 161.5 ± 1.0 to 143.1 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic stratum, strata.Owen ...

Tendaguru Formation The Tendaguru Formation, or Tendaguru Beds are a highly List of fossiliferous stratigraphic units in Tanzania, fossiliferous Lithostratigraphy, formation and Lagerstätte located in the Lindi Region of southeastern Tanzania. The formation represe ...

Tanzania Tanzania, officially the United Republic of Tanzania, is a country in East Africa within the African Great Lakes region. It is bordered by Uganda to the northwest; Kenya to the northeast; the Indian Ocean to the east; Mozambique and Malawi to t ...

: phylogenetic and biogeographic implications for eusauropod dinosaur evolution. ''

Zoological Journal of the Linnean Society The ''Zoological Journal of the Linnean Society'' is a monthly peer-reviewed scientific journal covering zoology published by Oxford University Press on behalf of the Linnean Society. The editor-in-chief is Maarten Christenhusz (Linnean Society) ...

'' 185(3):784-909 Members of Khebbashia were medium-sized sauropods from the early Cretaceous period of South America, Africa and Europe. The name "Khebbashia" is derived from "Khebbash" or "Khebbache", a Moroccan tribe that inhabited the region where the first rebbachisaurid specimen was found in North Africa. Khebbashia is defined as the least inclusive clade including '' Limaysaurus tessonei'', '' Nigersaurus taqueti'', and '' Rebbachisaurus garasbae''. It therefore includes the rebbachisaurid subfamilies Rebbachisaurinae and Limaysaurinae, to the exclusion of more basal forms. Rebbachisaurinae is a

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...

which is within both Rebbachisauridae and Khebbashia, defined to include '' Rebbachisaurus garasbae'' and exclude '' Limaysaurus tessonei'', which belongs to its own subfamily, Limaysaurinae. It was first proposed as a rank by Jose Bonaparte in 1995, to include ''Rebbachisaurus''. Some phylogenies however, include ''Rebbachisaurus'' in a clade with ''Limaysaurus'', and thus the subfamily was not used. In 2015, a phylogenetic analysis was conducted, and it found ''Rebbachisaurus'' instead to be closer to '' Nigersaurus'' and related genera than ''Limaysaurus'', and thus was used to replace Nigersaurinae as Rebbachisaurinae is the older term and is named after the genus used for the formation of the family Rebbachisauridae. The 2015 cladogram of Fanti et al. is shown below.

Evolutionary relationships and characteristics

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 facet Wear is the damaging, gradual removal or deformation of material at Solid, solid surfaces. Causes of wear can be mechanical (e.g., erosion) or Chemistry, chemical (e.g., corrosion). The study of wear and related processes is referred to as trib ...

s 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 Hadrosaurids (), also hadrosaurs or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod fami ...

and

ceratopsia Ceratopsia or Ceratopia ( or ; Ancient Greek, Greek: "horned faces") is a group of herbivore, herbivorous, beaked dinosaurs that thrived in what are now North America, Asia and Europe, during the Cretaceous Period (geology), Period, although ance ...

n 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 the diplodocoids, and lived alongside the

titanosaurs Titanosaurs (or titanosaurians; members of the group Titanosauria) were a diverse group of Sauropoda, sauropod dinosaurs, including genera from all seven continents. The titanosaurs were the last surviving group of long-necked sauropods, with tax ...

until fairly late in the Cretaceous.

References

* * McIntosh, J. S., 1990, "Sauropoda" in ''The Dinosauria'', Edited by

David B. Weishampel Professor David Bruce Weishampel (born November 16, 1952) is an American palaeontologist in the Center for Functional Anatomy and Evolution at Johns Hopkins University School of Medicine. Weishampel received his Ph.D. in Geology from the Univer ...

, Peter Dodson, and Halszka Osmólska.

University of California Press The University of California Press, otherwise known as UC Press, is a publishing house associated with the University of California that engages in academic publishing. It was founded in 1893 to publish scholarly and scientific works by faculty ...

, pp. 345–401. * Upchurch, P., Barrett, P.M. and Dodson, P. 2004. "Sauropoda". In ''The Dinosauria'', 2nd edition. Weishampel, Dodson, and Osmólska (eds.). University of California Press, Berkeley. pp. 259–322. * * ------ (2005) "Overview of Sauropod Phylogeny and Evolution", in ''The Sauropods: Evolution and Paleobiology'' * Wilson, J. A. and Sereno, P.C. (2005) "Structure and Evolution of a Sauropod Tooth Battery" in ''The Sauropods: Evolution and Paleobiology'' in Curry Rogers and Wilson, eds, 2005, ''The Sauropods: Evolution and Paleobiology'',

, Berkeley, {{Taxonbar, from=Q132733 Dinosaur families