WASHINGTON – Local scientists have made a discovery that may lead researchers world-wide to examine fossils in a new way.
A colorful species of mollusk collected at Calvert Cliffs, Maryland, on the Chesapeake Bay contains some of the oldest and best preserved examples of a protein ever found in a fossil shell.
“When things die you think of them decaying, you think of them going away. These things didn’t go away. For some reason, they got preserved. It’s the most amazing thing – 15 million years and you still have that biological material,” says Carnegie Institution senior staff scientist Robert Hazen.
Hazen worked on the project with a team of scientists from the Carnegie Institution of Washington that includes John Nance, John Armstrong, George Cody, and Marilyn Fogel.
The discovery process began with Hazen walking the beach of Calvert Cliffs wondering why ancient Ecphora shells keep their rich orange-brown color when 600 other species of shells, snails and clams along the beach do not.
Hazen surmised the color might come from iron. But it doesn’t. The investigation continued with Ecphora shells being soaked in a light acid, which unleashed the find.
“Brown plastic-like sheets come floating out…and it’s amazing. In some cases almost 2 percent of the weight of the shell is this organic material. That’s shocking. We were just floating when we found this out,” Hazen gushes.
The sheets of organic material unleashed by soaking the shells in the light acid are sometimes half an inch across. “Completely intact, the way they were 15 million years ago. This just doesn’t happen,” says Hazen.
Ecphora mollusks now are extinct, but their fossils at Calvert Cliffs include specimens as small as 1/8 inch and as large as a softball. They also range in age between 18 million and seven million years old.
Analyzing amino acids in the protein of differently-aged shells promises to provide great insight into the evolution of shells and in the ecology the Chesapeake Bay. New information learned about the bay could include temperature changes and the salinity of the water.
Hazen believes the discovery of perfectly preserved protein in ancient shells might lead scientists worldwide to look at fossils differently. “They may say well, we’ve got a colored fossil from Germany or from China or from Australia, maybe we can do the same thing.”
The research is published in the inaugural issue of the journal of the European Association of Geochemistry: “Geochemical Perspectives Letters.”
