Today, the Great Rift Valley spans from the lower tip of the Middle East all the way down to southern Africa. This dry swath of land is interspersed with grasslands that make up the African savannah. But it has not always been that way.
Some 15 million years ago, this part of the world — which would later become the cradle of humankind — looked entirely different. Much of the area was made up of dense tropical rainforests and humid woodlands that made it easier for predators to hide. One of the most dangerous was the giant dwarf crocodile, a vicious carnivore which likely had a taste for the primates that would one day evolve into hominids.