Sus Cretaceous Biting Clam Fossils

Rastellum carinatum, an extinct genus of prehistoric oysters. These are known as "Biting clams" and get their name due to their very unique appearance. The ridges on the clam's shell are offset and look like the teeth of a zipper (which was once known as a "bite") hence the name! These are Cretaceous in age and around 110 million years old from Madagascar.