1 Olduvai Gorge Holds Clues about Early Humans Olduvai Gorge is part of the Great Rift Valley in Tanzania Africa Millions of years ago volcanoes spread layers of ash and rocks across the area About 30,000 years ago draining water began carving through the ash and rock Erosion slowly formed the gorge Layers up to two million years old were exposed Olduvai Gorge holds many clues about our early human ancestors Scientists have uncovered hundreds of fossils In the 1930s archaeologists Louis and Mary Leakey began large excavations at Olduvai Gorge They made several important discoveries They uncovered stone tools The gorge is also called the Cradle of Mankind 4
30 Number of miles 48 2 km that Olduvai Gorge stretches in length Olduvai Gorge was formed nearly 30,000 years ago Scientists have uncovered hundreds of fossils of early humans and stone tools Louis and Mary Leakey found fossilized bones of Homo habilis an early human that lived about two million years ago and fossilized bones of early human species One morning Mary Leakey made one of their most famous discoveries She found pieces of a skull They belonged to a new species of early human called Paranthropus boisei The discovery became known as Nutcracker Man Scientists estimated Nutcracker Man was about 1 75 million years old Later the Leakeys found fossil evidence of another early human species called Homo habilis It was dated to be about two million years old The Leakeys work sparked interest in the study of human evolution Today archaeologists still work at Olduvai Gorge Visitors can tour the excavation sites and visit a museum The museum holds a collection of early human fossils and stone tools Mary and Louis Leakey at a dig site 5
50 ft 10 m Superman's Crawl Dinaledi Chamber Dragon's Back Cave entrance 2 Discovering Homo naledi at Rising Star Cave locked into a curve This suggests that Homo naledi climbed and used tools It stood about five feet tall with long legs and feet almost identical to human feet today This suggests that Homo naledi could walk long distances Many scientists believe it could be one of our earliest human relatives There are still many questions about Homo naledi How old are the bones How did they get into the cave How does Homo naledi fit into the human family tree Scientists are working to answer these questions They hope to learn more about how Homo naledi fits into the history of humans In 2013 two cavers found some ancient bones in Rising Star Cave The cave is near Johannesburg South Africa When scientists came to excavate the bones they discovered nearly 1,500 fossil remains There were bones from at least 15 individuals In 2015 scientists announced these bones were from a new species of early human It was called Homo naledi It had a mix of ancient and modern human features Its brain was about the size of an orange Its hands were human-like but the fingers were The Dinaledi Chamber is the innermost room of the cave where the bones were discovered 6
Width in inches 17 8 cm of the gap skinny scientists squeezed through to reach the fossils in Rising Star Cave In Rising Star Cave 7 scientists have uncovered hundreds of fossils belonging to a new species of early human Homo naledi’s fossils show a mix of ancient and modern human features Scientists believe that Homo naledi might be one of our earliest human relatives Scientists believe Homo naledi is between 236,000 and 335,000 thousand years old 7
