Glossary
occipital
refers to the posterior (i.e., back) of the head; the bone located at the back and base of the cranium.
occlusal
a relative term referring to the part of the mouth or tooth that is closer to the crown of the tooth.
occlusion
relationship between the upper and lower portions of the teeth.
Old World monkey
primates that are in the superfamily Cercopithecoidea whose natural habitats are in all regions of the world, except Central and South America.
olfaction
smelling.
omnivore
a dietary category that describes animals with no specialized diet and will eat any edible and/or nutritional foodstuffs (i.e., plants and animals).
open environment
an geographic area with little to no canopy of foliage allowing a substantial amount of light to reach the ground.
opposable thumb
a thumb that is able to rotate along its long axis and can grip objects.
orbit
a cavity in the face that protects the eyes and its associated muscles and nerves.
orbital convergence
in primate evolution, the realignment of the orbits from the lateral sides of the face to orbits on the anterior portion of the face.
Order
in taxonomic classification, all members of the same Family but only certain members of the the same Class.
organism
a functional unit of animal or plant life. An organism can consist of one living cell, such as algae, or many living cells, such as a single human being.
origin
[muscle origin] the point from which a muscle arises and is not involved in the movement or action of the muscle.
os
bone
os coxae
[syn. pelvis, hip bone, or innominate] [sing. os coxa] formed of two halves, each consisting of three fused bones: ilium, ischium, and pubis.
ossicle
a small, extra bone
osteoarthritis
disease process that affects both bone and cartilage with inflamation and destruction.
osteoblast
a cell that produces or deposits bone tissue by depositing protein.
osteoclast
a cell that erodes bone tissue.
osteophyte
a small, abnormal bone growth that occurs on the surface of the bone.
outgroup comparison
the assessment of one group's features to another in order to establish evolutionary relationships.