What is a pecten fossil?

What is the closet relative of the fossil pecten?

• Answer:

  SCALLOPS Fossil: Giant Pecten Pecten propratulus Scallops (or pectens) have flat shells and distinct flat extensions to the hinge line called "wings" In western Washington, giant fossil scallops are generally more than 85 mm wide and are found in rocks that are 35 million to 5 million years old. The very large family Pectinidae contains thousands of fossil species and hundreds of living species. Scallops first appeared in the Triassic (about 230 million years ago) and have always been more numerous in warm shallow seas. Pecten propatulus can be 100 mm wide and is found in rocks around Clallam Bay that are approximately 20 million years old. This species has shells ornamented with 27 or 28 flat ribs, and the wings on the hinge line have a distinct notch. The ribbing on the right valve (or shell) looks different from that on the left valve and these have often been mistaken for two different species. http://www.washington.edu/burkemuseum/collections/paleontology/marine/scallops.php