It was the morning of July 17, 1959. Mary Leaky and her husband Louis were fossil hunting in East Africa. They had previously found stone tools in the ancient river bed called Olduvai Gorge, near the African Rift Valley, and were looking for more evidence of early humans there. On that particular day, Mary’s husband was unwell, reportedly suffering from a headache and fever. So Mary set out to work by herself (in the company of her two Dalmatians). While walking through the gorge, Mary noticed a fossil protruding from a section of the wall. Upon closer examination, she recognized part of an upper jaw and two intact teeth.
The fossil Mary eventually removed from the wall of the gorge was a 1.8 million year old skull, which she named Zinjanthropus boisei. Zinjanthropus after the Arabic word for that region of East Africa and boisei after the benefactor funding the Leakey’s expedition. The fossil has since been renamed Australopithecus (or Paranthropus) boisei.
Mary’s Zinjanthropus is arguably one of the most famous fossils from the fossil-rich Olduvai Gorge. Zinj is a member of an extinct hominin lineage known for their robust nature and “nutcracker” diet. Read more about Zinjanthropus here. Mary’s discovery of the Zinj fossil sparked many debates in paleoanthropology, especially taxonomic debates, some of which continue to the present day.
Mary has written that Zinj was a turning point in her career. She spent years working in the field and was an inspiring scientist who was responsible for many important discoveries. To read about Mary, check out this interview with her from Scientific American.
Mary Leakey was more interested in finding things than making big claims about the things she found. Marguerite Holloway summed it up well when she said, “in a profession scarred by battles of interpretation and of ego, Leakey’s unwillingness to speculate about theories of human evolution is unique.”
Mary Leakey once said: “For me it was the sheer instinctive joy of collecting, or indeed one could say treasure hunting: it seemed that this whole area abounded in objects of beauty and great intrinsic interest that could be taken from the ground.”
The whole Leakey family has been very influential throughout the history of paleoanthropology, here’s an interesting 2009 interview with Mary’s son reflecting on both the fact that his family is chock full of paleoanthropologists and this particular discovery.
“There is so much we do not know…” -Mary Leaky