Chapter 5 Overview of Living Primates Key Terms

Prosimians Members of a suborder of Primates, the Prosimii. Traditionally, the suborder includes lemurs, lorises, and tarsiers. Anthropoids Members of a suborder of Primates, the Anthropoidea. Traditionally, the suborder includes monkeys, apes, and humans.

Mammalia The technical term for the formal grouping (class) of mammals. Primitive Referring to a trait or combination of traits present in an ancestral form.

Specialized Evolved for a particular function; usually refers to a specific trait (e.g., incisor teeth), but may also refer to the entire way of life of an organism. Primatologists Scientists who study the evolution, anatomy, and behavior of nonhuman primates. Those who study behavior in noncaptive animals are usually trained as physical anthropologists.

Morphology The form (shape, size) of anatomical structures; can also refer to the entire organism. Prehensility The ability to grasp objects, as by the hands and/or feet of primates.

Omnivorous Having a diet consisting of many food types (i.e., plant materials, meat, and insects). Diurnal Active during the day.

Nocturnal Active during the night. Stereoscopic vision The condition whereby visual images are, to varying degrees, superimposed on one another. This provides for depth perception, or the perception of the external environment in three dimensions. Partly a function of structures in the brain.

Binocular vision Vision characterized by overlapping visual fields provided by forward-facing eyes; essential to depth perception. Arboreal Tree-living; adapted to life in the trees.

Adaptive niche The entire way of life of an organism: where it lives, what it eats, how it gets food, how it avoids predators, etc. Arboreal hypothesis The traditional view that primate characteristics can be explained as a consequence of primate diversification into arboreal habitats.

Midline An anatomical term referring to a hypothetical line that divides the body into right and left halves. Cusps The elevated portions (bumps) on the chewing surfaces of premolar and molar teeth.

Quadrupedal Using all four limbs to support the body during locomotion; the basic mammalian (and primate) form of locomotion. Macaques Group of Old World monkeys comprising several species, including rhesus monkeys.

Brachiation A form of locomotion in which the body is suspended beneath the hands and support is alternated from one forelimb to the other; arm swinging. Rhinarium The moist, hairless pad at the end of the nose seen in most mammalian species. The rhinarium enhances an animal’s ability to smell.

Sexual dimorphism Differences in physical characteristics between males and females of the same species. For example, humans are slightly sexually dimorphic for body size, with males being taller, on average, than females of the same population. Estrus Period of sexual receptivity in female mammals (except humans), correlated with ovulation. When used as an adjective, the word is spelled “estrous.”

Hominoidea The formal designation for the superfamily of anthropoids that includes apes and humans. Frugivorous Having a diet composed primarily of fruit.