A newly identified man-eating crocodile might have spawned more than its share of prehistoric nightmares.
Discovered in 1.8-million-year-old rocks from Olduvai gorge in Tanzania, the 7.5-metre Crocodylus anthropophagus would have been the largest predator ancient humans in the region encountered.
鈥淚 can鈥檛 guarantee these crocodiles were killing our ancestors, but they were certainly biting them,鈥� says , a vertebrate palaeontologist at the University of Iowa in Iowa City. Brochu gave the beast its name, which means 鈥渕an-eating crocodile鈥� in Greek: 鈥淚 hope people get the joke.鈥�
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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 at Rutgers University in New Brunswick, New Jersey, and Jackson Njau of the National Natural History Museum in Arusha, Tanzania.
Lots of crocs
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 颁.听补苍迟丑谤辞辫辞辫丑补驳耻蝉 points to far more diversity in African crocodiles in the past 2.5聽million years than thought, Brochu says. 鈥淧eople have always perceived crocodiles as these slowly evolving, living fossils. That鈥檚 just nonsense.鈥�
His team haven鈥檛 found many fossils belonging to 颁.听补苍迟丑谤辞辫辞辫丑补驳耻蝉, and none that is complete, so it鈥檚 impossible to determine its precise relationship to modern Nile crocodiles or when the man-eaters went extinct, Brochu says.
But he has little doubt that 颁.听补苍迟丑谤辞辫辞辫丑补驳耻蝉 threatened the ancient hominids who called Olduvai gorge home and would have been drawn to a nearby source of fresh water. Adults of one species, Homo habilis, were particularly vulnerable, being only around a metre tall and weighing about 40聽kilograms.
Their fossil cut marks, then, were probably delivered by smaller specimens of 颁.听补苍迟丑谤辞辫辞辫丑补驳耻蝉. Brochu鈥檚 team writes: 鈥淟arger crocodiles would be capable of consuming hominids completely, leaving no trace.鈥�
Journal reference: , DOI: 10.1371/journal.pone.0009333
