Spinosaurids ("spine reptiles") are the group of relatively tall-spined theropods. They include such forms as Altispinax and Metriacanthosaurus The family was founded on the remains of Spinosaurus which come from the Late Cretaceous of Niger (Africa) and Egypt. The original material is agian somewhat incomplete, including parts of the jaw, and some neck, back and tail vertebrae, but it indicates a large theropod 33-39.4ft (10-12m) long with spines up to 6ft (1.8m) long!