A Crocodile Too Huge to Fit on the Family Tree

Giant crocodiles, far larger than any known to date, lived in Kenya two million to four million years ago among our human ancestors, according to a new report.
A fossil of one specimen, 27 feet in length, shows that it is not closely related to the Nile crocodile, as some scientists had thought, said Christopher A. Brochu, a vertebrate paleontologist at the University of Iowa and the new study’s first author.Although the two crocodiles look similar, the ancient species has a different skull and jaw formation from the Nile crocodile.“There’s this misconception that crocodiles are these living fossils that haven’t changed,” he said. “This is something different, a species of a true crocodile, but different from anything known.”Dr. Brochu and his colleagues published their report in a recent issue of The Journal of Vertebrate Paleontology. Their findings mean that the origins of the Nile crocodile remain a bit of a mystery.Although crocodiles are ancient, they have evolved considerably over time. Today there are about three to five species of crocodiles in Africa, but in ancient times there may been twice as many, Dr. Brochu said.“This would have been a major part of the life our ancestors,” he said. “If there is something in the water that can swallow you whole, then you’re going to think about to how to approach the water.”