Christmas hippo Biology skull close-up about vintage art

l, or cranium, is a bony structure of Craniates which serves as the general framework for a head. The skull supports the structures of the face and protects the brain against injury. See more at Wikipedia.org...

>For other uses, see Skeleton (disambiguation). In biology, the skeleton or skeletal system is the biological system providing support in living organisms. (By extension, non-biological outline structures such as gantries or buildings may also acquire skeletons.)Skeletal systems are commonly divided into three types - external (an exoskeleton), internal (an endoskeleton), and fluid based (a hydrostatic skeleton), though hydrostatic skeletal systems may be classified separately from the other two since they lack hardened support structures. Large external skeletal systems support proportionally less weight than endoskeletons of the same size, and thus many larger animals, such as the vertebrates, have internal skeletal systems. Examples of exoskeletons are found in arthropods, shellfish, and some insects: the skeleton forms a hard shell-like covering protecting the internal organs. See more at Wikipedia.org...