A new species of giant clam, Tridacna costata, has been discovered in the Red Sea. These giant two feet long clams might have helped feed prehistoric humans as they first migrated out of Africa. Tridacna costata once accounted for more than 80 percent of giant clams in the Red Sea. Today, these mollusks, the first new living species of giant clam found in two decades, represent less than 1 percent of giant clams living there. This novel clam, whose shell has a distinctive scalloped edge, was discovered while scientists were attempting to develop a breeding program for another giant clam [...]