oldowan tools are named after olduvai gorge in tanzania, where oldowan tools were first found. the archaeologist louis leakey made this discovery in the 1930s. for a long time after that, archaeologists thought that the oldowan were the earliest tools ever made. now they know that hominids made stone tools much earlier in history - about 3.3 million years ago. this was before the genus "homo" had evolved.