Big Bend Fossil
Ancient Big Bend fossil. Seas covered the Big Bend area 130 - 183 million years ago. Various mollusks (ammonites, snails, clams, oysters, etc.) thrived in these warm marine waters. These fossils, found in the Terlingua Creek area, are often layer upon layer. The term fossil comes from Latin and means unearthed.
The dark imprint is concave and the lighter one is convex. Nice example of Big Bend bivalve clam shells.