Crocodile attacks on humans are dramatic but relatively uncommon these days. Three million years ago, however, this might not have been the case in Kenya, where Crocodylus thorbjarnarsoni, the largest species of crocodile known to date, lived alongside ancient humans. Christopher Brochu from the University of Iowa recently re-analyzed crocodile fossils in the Nairobi Museum found in eastern Africa that date back to 2-4 million years ago (Plio-Pleistocene) and discovered that they belonged to a new species. C. thorbjarnarsoni is named after John Thorbjarnarson, famed crocodile expert and Brochu’s colleague who died of malaria several years ago. The species grew to more than 27 feet long, making it the longest true crocodile that has been discovered thus far. Modern crocodiles don’t often grow much longer than 16 feet; the largest recorded Nile crocodile was 21 feet long. Very old ancestors of crocodiles did grow to larger lengths—such as the recently discovered so-called “Sheildcroc,” which reached up to 35 feet long some 99 million years ago. However, ancestors such as Sheildcroc were “crocodyliforms” (crocodile relatives), whereas C. thorbjarnarsoni is a true crocodile. Furthermore, the Crocodylus remains were found at the same site as prehistoric human fossils. Although there is no fossil evidence to support it, Brochu surmises that the giant crocodile fed on humans, who would have visited crocodile-infested rivers to get water. Modern crocodiles are known to feed on just about any animal they encounter. Humans during this period of time were smaller (< 4 feet tall), and therefore easier for the enormous crocodiles to swallow, maybe even whole. Read more at ScienceDaily.
The original article was published in the Journal of Vertebrate Paleontology.
Read about Shieldcroc at National Geographic Daily News.