A vertebral centrum belonging to a dyrosaurid, a marine crocodilian recovered from the late Paleocene of Niger, bears a large ovoid and deep puncture on its lateral flank. This mark is identified as a wound inflicted by the bite of another crocodilian. Although the wound shows evidence of healing, the vertebral centrum has been severely damaged and deformed. It provides a rare direct evidence of the aggressive interactions taking place between these now extinct marine reptiles, the largest known marine predators of their time before the rise of the archeocetes.