A cow skull is obviously different than a human's, and most people will not confuse a tiger's fangs with a human's incisors. It's much harder, however, to separate human bone fragments from animal, especially when they have been buried for aeons or warped with fire. The two are distinguished by certain traits unique to animals and humans. For instance, a majority of animals have an elongated face and V-shaped jaws. Their bones are designed to support four-footed locomotion versus our bipedal walking. The size of more complete skeletons is often a telling factor, although human infant skeletons often resemble an animal's.
Determine if the inside surface of a skull fragment is generally smooth or more complex. Human skulls have only a few small grooves from blood vessels, as opposed to the rough interior of animal skulls.
Examine the slope of the skull fragment. Animal skulls are more curved and have more developed crests on their skulls to support their muscular system. Human skulls are large and spherical.
Inspect the circumference of the tooth. Human teeth are rounder than an animal's.
Decide whether the connecting bones of the wrist or ankle are joined. A human's tibia and fibula (foot) and radius and ulna (wrist) are separate bones.
Consider the bone's thickness. Animal bones are denser and less porous than a human's when viewed as a cross section. There is little tissue inside an animal's leg bones when compared to a human's long bones.
Human skulls have a comparatively large cranial vault, whereas even large animals have small brains. Eye sockets in a human skull are above and lateral to the nose hole, while an animal's eyes are aligned on a horizontal axis. Take a look at the arrangement of teeth on your jaw bone. Carnivores have pointy teeth with sharp ridges for tearing. Herbivores and grazing animals will have more molars for grinding. Omnivores like humans will have a mixture of the two in each of the jaw's quadrants. Human jaw bones are U-shaped. A human's pelvis bone is bowl-shaped and large versus an animal's elongated and blade-shaped pelvis. Human foot bones are long and narrow with the weight evenly distributed between the toes and heels. Animal feet bear most of the weight on the toes. An animal's femur is equal length to the rest of its bones, but a human's femur is the longest bone in the body.