New species of giant clam discovered

Scientists studying giant clams in the Red Sea have found a rare new species hidden among the common type they were studying. Tridacna costata, the first species of giant clam described in some 20 years, can be 60 cm in length. There is evidence these clams were once abundant, and marine ecologist Claudio Richter suspects the species was overhunted by early humans. The population appears to have crashed about 125,000 years ago. Richter calles it "the first example of marine overexploitation."