Nautilus shell fossil isolated on black. Sliced fossil in vertical orientation with copyspace. This ammonite is from the Cretaceous Period. Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids i.e., octopuses, squid, and cuttlefish than they are to shelled nautiloids such as the living Nautilus species.

圖片編號： 168327215
拍攝者： Mickem