Rebbachisaurids belong to the same broad diplodocoid branch of the sauropod family tree as the North American diplodocids, but they persisted later, into the Cretaceous, and concentrated in what is now South America and Africa. Some genera developed tall neural spines along the back that may have supported a sail-like ridge of skin or a fatty hump, a feature convergent with -- but unrelated to -- the more famous sail of Spinosaurus.
The family's best-known member is Nigersaurus, from Niger, whose skull carried hundreds of slender, constantly replaced teeth packed into a wide, straight-edged jaw -- an adaptation for cropping low ground vegetation like a Mesozoic lawnmower, unusual among sauropods generally associated with high browsing. Rebbachisaurus, the genus that names the family, is known from North Africa.