DENVER (AP) — Researchers at the University of Colorado have discovered a 10,000-year-old hunting weapon they say had been preserved in ice before being melted out by rising temperatures.

The spearlike dart was discovered in 2007 near Yellowstone National Park and dated in 2008 but CU only announced the find Tuesday. Research associate Craig Lee says he wanted to try to get the findings published in a scientific journal first and avoid attracting amateur archaeologists.

Lee says increased global temperatures are melting ice fields, releasing artifacts as well as plant material and animal carcasses, in Alaska, Canada and Europe.

Later this summer, Lee plans to visit Montana's Glacier National Park to work with Indian tribes there to find and protect artifacts that may have been freed from melting ice.