The enlarged thumb claw seen in most spinosaurids has traditionally been interpreted in many ways, the most common current interpretation seemingly being that of a fishing instrument. The author of this text doubts this is a feasible use given the claw's size and shape. Instead, he proposes the idea of the claw being a locomotive organ in shallow water, its bearers using it by anchoring the claws in the ground and then pulling themselves forward with their unusually developed arms.
