Biomedical Engineering Reference
In-Depth Information
INTRODUCTION
Morphologically, nonhuman primates are more similar to
humans (Homo sapiens) than to typical laboratory or
domestic mammalian species. As with other orders, inter-
specific variations from the generalized norm can be
characterized as adaptations to a specific environmental
niche and/or evolutionary divergence which resulted in
considerable diversity in habitats, diets, and morphologies.
The order Primata consists of two suborders.
1
Prosim-
ians (suborder Prosimii) are rarely used as laboratory
animals and are not included in this chapter.
Martin (1990)
includes morphological details of how prosimians differ
from other primates and are similar to other mammals. In
the USA, the Duke University Lemur Center has had the
most extensive experience with the animal husbandry of
a variety of prosimian species.
The suborder Anthropoidea (higher primates) includes
the rest of the order and is divided into three groups based
on evolutionary divergence. One of these major groups is
the New World monkeys, infraorder Platyrrhini, that
includes two families: Callitrichidae (marmosets and
tamarins) and Cebidae (e.g. spider, howler, cebus, and
squirrel monkeys). The majority of New World monkeys in
captivity are Cebidae, but some facilities (e.g. the
Wisconsin National Primate Research Center) have had
extensive experience with Callitrichidae.
The second and third groups of Anthropoidea together
comprise the infraorder Catarrhini. Although sometimes
discussed as an infraorder, these two groups are more
frequently referred to as the superfamilies Cercopithecoi-
dea and Hominoidea. The Cercopithecoidea include all the
Old World monkeys within the family Cercopithecidae and
are divided into two subfamilies, Cercopithecinae (cheek-
pouch monkeys) and Colobinae (leaf-eating monkeys).
The last major group, the Hominoidea, includes two
families: Hylobatidae (lesser apes) and Hominidae (great
apes and humans).
2
Each of these anthropoid groups has
distinct morphological characteristics, yet many features
are shared by all, including humans. Because of the
morphological similarities between humans and nonhuman
primates, books on human anatomy and/or surgery are
usually excellent basic guides for nonhuman primates.
However, numerous aspects of anatomy and morphology
obviously vary from species to species as well as from
humans.
For example, the locomotor morphology of nonhuman
primates can be divided into two general patterns based on
habitat use and are of importance in designing artificial
housing. Species that live primarily on the ground have
a terrestrial-type morphology, whereas species that live
primarily in trees have an arboreal-type morphology.
A subset of arboreal-type morphology reflects extensive
use of suspensory locomotion, e.g. brachiation, with
concomitant adaptations for limb use in tension as well as
compression. This type of adaptation is most prevalent
among the apes and New World monkeys with prehensile
tails. Thus, morphology classified by habitat use does not
necessarily correlate with the groupings that are determined
by evolutionary/genetic proximity.
In addition to morphology that differs from most other
laboratory or domestic mammals, nonhuman primates are
unusual in that they are generally multiple-use animals.
They are used simultaneously and/or consecutively for
a variety of purposes and are rarely euthanized except when
terminally ill. The resultant long-term maintenance of
nonhuman primates, including social housing and in-house
breeding programs, necessitates a depth of knowledge of
their overall morphology beyond that usually necessary for
other laboratory animals. Furthermore, at least in the USA,
housing requirements for nonhuman primates include not
only weight and size but also additional considerations
based on locomotor morphology and psychological well-
being.
Traditionally, rhesus macaques (Macaca mulatta) have
been the nonhuman primates most commonly housed in
research facilities and thus most of the morphological
descriptions in this chapter, unless otherwise indicated,
refer to this species. Major differences between macaques
and other species are noted whenever possible but inter-
specific variations are common and too numerous to be
considered comprehensively in this chapter. By providing
a general description of higher primate anatomy, this
chapter is intended to serve as a basis for the analysis and
interpretation of the functional morphology of any of the
higher nonhuman primates.
Finally, due to the postural differences among the
various species of higher primates, the more universally
applicable anatomical terms ventral, dorsal, cranial, and
caudal are used here for all primary descriptions. In addi-
tion, where morphology within a given species is discussed,
the terms most appropriate to that species are given in
parenthesis.
1
Since the 1970s, in response to the recognition that numerous features of
tarsiers more closely align them with higher primates as opposed to
prosimians, usage of an alternative division of primates into the suborders
Strepsirhini (prosimians not including tarsiers) and Haplorhini (anthro-
poid primates plus tarsiers) has become an increasingly popular taxonomy
among primatologists and anthropologists. For a detailed discussion of
primate taxonomy the reader is referred to Chapter 3 of this volume.
Tarsiers are not examined in this chapter, but a discussion of their biology
may be found with that of other primates placed in the traditional
suborder Prosimii.
2
Currently, the taxonomy of the Hominoidea varies considerably from
one worker to another. In this chapter, we've lumped all of the great apes
together with humans in the Hominidae. We adhere to the taxonomic
placement of humans into the separate tribe Hominini (common term
hominins) and use the term “nonhuman” in this chapter to refer to taxa
outside of the Hominini.
