Spinosauridae is a family of specialised theropod dinosaurs. Members of this family were large predators with elongated, crocodile-like skulls, sporting conical teeth with no or only very tiny serrations. The front dentary teeth fanned out, giving the animal a characteristic look. The name of this family alludes to the typically conspicuous sail-like structure protruding from the back of species in the type genus, Spinosaurus.