Ohio State University geologists said they successfully extracted organic molecules directly from the fossilized remains of crinoids, spindly animals with feathery arms known today by the plant-like name "sea lily."
The ancient marine creatures were buried alive in storms during the Carboniferous Period when North America was covered with vast inland seas, the researchers said.
"There are lots of fragmented biological molecules -- we call them biomarkers -- scattered in the rock everywhere. They're the remains of ancient plant and animal life, all broken up and mixed together," Earth sciences Professor William Ausich said. "But this is the oldest example where anyone has found biomarkers inside a particular complete fossil."
Comparing the organic molecules from the fossils with molecules common in living crinoids today, the researchers confirmed these particular molecules occur in both living crinoids and their fossilized ancestors.
"These molecules are not DNA, and they'll never be as good as DNA as a means to define evolutionary relationships, but they could still be useful," Ausich said. "We suspect that there's some kind of biological signal there -- we just need to figure out how specific it is before we can use it as a means to track different species."