Possible evidence for intraspecific aggression in a Pliocene crocodile from north Queensland

A large, fossilised crocodilian metatarsal has been recovered from the Pliocene Bluff Downs Local Fauna exhibiting proliferative bone growth consistent with an episode of osteoperiostitis, possibly resulting from trauma. The nature and location of this trauma suggests that it may have occurred as a result of intraspecific aggression between rival animals. Three crocodilian genera have been recovered from the Bluff Downs Fauna, Crocodylus, Quinkana and Pallimnarchus. The metatarsal does not conform to Crocodylus porosus and therefore most probably represents one of the other two known crocodilian taxa. The nature of the injury suggests that it occurred in water and it may belong to the now extinct Plio-Pleistocene Pallimnarchus rather than Quinkana babarra which is interpreted as being predominantly terrestrial.