No one knows her real name, or even if she had a name. Everything we know about Lucy, an early human who lived millions of years ago, has been learned from studying her bones. Her bones were discovered by Donald Johanson in 1974 in Ethiopia.

Lucy lived between 3.8 and 3.2 million years ago. She was about 25 to 30 years old when she died. By comparing Lucy's bones to bones of modern people, archaeologists determined that Lucy walked upright. Lucy was smaller than a modern adult--about 3 feet, 8 inches tall, weighing about 60 pounds.

No one knows exactly what Lucy looked like. We can use clues from her bones to make a good guess. Learning about the life of someone who lived millions of years ago is a kind of science puzzle.