New Research Suggests Lucy Died After Falling From Tree Autopsy sheds light on how an ancient forerunner of modern human died.

 -- Lucy, the famous upright-walking human ancestor who is estimated to be more than 3 million years old, may have died after from falling from a tree, according to a study published Monday in the journal Nature by researchers from the University of Texas at Austin.

What caused Lucy’s death has been the source of much debate in the scientific community since the discovery of her partial skeleton in 1974.

At 3.18 million years old, Lucy’s skeleton is one of the oldest and most complete fossils of an erect-walking hominin ever discovered, according to a statement from UT Austin announcing the research. Lucy’s remains have sparked a major debate over whether her species, Australopithecus afarensis, was arboreal, or spent time in trees, according to the UT researchers.

An autopsy performed on her remains suggests that she spent some time in trees, according to John Kappelman, the lead author of the study and a UT-Austin professor of anthropology and geological sciences, who calls the cause of her death "ironic."

“It is ironic that the fossil at the center of a debate about the role of arborealism in human evolution likely died from injuries suffered from a fall out of a tree,” Kappelman said in a statement.

He studied thousands of high-resolution CT scans of Lucy’s remains and noticed unusual fractures in her bones, which led him to theorize that Lucy fell to her death. He believes that Lucy most likely sought refuge in trees at night, according to the statement.

“When the extent of Lucy’s multiple injuries first came into focus, her image popped into my mind’s eye, and I felt a jump of empathy across time and space,” Kappelman said. “Lucy was no longer simply a box of bones but in death became a real individual: a small, broken body lying helpless at the bottom of a tree.”