Discussion on To The Point toady on NPR.
The skeleton was in a layer of earth between two volcanic ash layers, so it was rather easy to date. There were many other fossils with the skeleton, including pollens, tree, other bones... tooth analysis showed a diet mostly of fruit.

Scroll down here to reporter's notebook, and you can listen to the interview with the science writer for the Los Angeles Times.
Click Here OCT 2, To the Point, KCRW