The scientists discovered the croc dietary evidence during an investigation of the evolutionary history of Africa's crocodiles.
"Hominid bones from Olduvai-area rocks of the same age as C. anthropophagus show bite marks interpreted as coming from a crocodile," Brochu said.
In the study, he and his colleagues write: "Curiously, the tooth mark patterning on both (human) specimens indicates that each hominid individual lost its left foot to crocodiles during or shortly after capture, or when being scavenged."
Homo habilis is mentioned as being the possible hominid victim. This early human was relatively small, at least compared to the croc, so the researchers suggest that the predator was somewhat small for its species, perhaps a juvenile, since larger adult crocodiles "would be capable of consuming hominids completely, leaving no trace."
They add, "Crocodiles may have been common hominid predators, and as such should be considered in discussions of the ecological context of human origins."
At first Brochu thought the fossilized crocodile remains belonged to the well-known Nile crocodile, but he and his team noticed horned brows over each eye and other differences, so they knew they were dealing with a new species.