London, Feb 25 (ANI): Scientists have identified the remains of a 7.5-metre man-eating crocodile in 1.8-million-year-old sediments in Olduvai gorge in Tanzania, an animal that would have been the largest predator ancient humans in the region encountered.
"I can't guarantee these crocodiles were killing our ancestors, but they were certainly biting them," Chris Brochu, a vertebrate palaeontologist at the University of Iowa in Iowa City, told New Scientist.
Ancient hominid bones discovered by Mary and Louis Leakey in the same sediments bear distinct bite marks likely to have been inflicted by large crocs.
Yet, most researchers have assumed the gashes were delivered by the same species of crocodile that prowls the banks of the Nile today.
Not so, claims Brochu, who re-analysed numerous incomplete fossils, the most recent of which was unearthed in 2007 by his co-authors Robert Blumenschine at Rutgers University in New Brunswick, New Jersey, and Jackson Njau of the National Natural History Museum in Arusha, Tanzania.
Though roughly the same size as the reptilian denizens of the Nile, the Olduvai crocodiles had thinner, more flared snouts and large horns that are more characteristic of a Madagascan crocodile that went extinct in the past few thousand years.
"The discovery of C. anthropophagus points to far more diversity in African crocodiles in the past 2.5 million years than thought," Brochu said.
"People have always perceived crocodiles as these slowly evolving, living fossils. That's just nonsense," he added.
His team hasn't found many fossils belonging to C. anthropophagus, and none that is complete, so it's impossible to determine its precise relationship to modern Nile crocodiles or when the man-eaters went extinct.
But, he has little doubt that C. anthropophagus threatened the ancient hominids who called Olduvai gorge home and would have been drawn to a nearby source of fresh water.
According to Brochu's team, "Larger crocodiles would be capable of consuming hominids completely, leaving no trace." (ANI)