Test #3 Key Definitions.pdf

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18 Mar 2012
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ANT203 Test 3: Definitions
Archonta: a group of mammals consisting of the orders Primates, Plesiadapiformes,
Scadentia, Dermoptera, and Chiroptera
Bilophodont: molars that half four cusps oriented in two parallel rows, a trait characteristic
of Old World monkeys
Catarrhine: member of Catarrhini, a parvorder of Primates, one of the three major divisions
of the suborder Haplorhini; contains the Old World monkeys, apes, and humans
Crown group: all of the taxa that come after a major speciation event; easier to identify than
stem groups because the members possess the clade's shared derived traits
Dental ape:
Euarchonta: the superorder designated for the sister (closely related) orders of tree shrews,
flying lemurs, and primates
Euprimate: "True primates," a term coined by Elwyn Simons in 1972.
Haplorhines: members of the primate suborder Haplorhini, which includes tarsiers,
monkeys, apes, and humans
Island hopping: traveling from one island to the next
Last Common Ancestor (LCA): the final evolutionary link between two related groups
Orthograde: referring to an upright body position - relates to the position of the head and
torso during sitting, climbing, etc., and doesn't necessarily mean that an animal is bipedal
Paleoprimatologist: anthropologists specializing in the study of the nonhuman primate
fossil record
Platyrrhines: members of Platyrrhini, a parvorder of Primates, one of the three major
divisions of the suborder Haplorhini; contains only New World monkeys
Postcranial: referring to all or part of the skeleton not including the skull
Semiorder: the taxonomic category above suborder and below order
Sister groups: two clades that result from the splitting of a single common lineage
Stem group: all of the taxa in a clade beforea major speciation event; often difficult to
recognize in the fossil record, since they don't often have the shared derived traits found in
the crown group
Strepsirhines: members of the primate suborder Strepsirhini, which includes lemurs and
Subfossil: bone not old enough to have become completely mineralized as a fossil
Superorder: a taxonomic group ranking above an order and below a class or subclass
Terrestrial: living and locomoting primarily on the ground
Y-5 molars: have five cusps with grooves running between them, forming a Y shape; a
characteristic of homonoids
Zygomatics: cheekbones
Biostratigraphy: a relative dating technique based on the regular changes seen in evolving
groups of animals as well as the presence or absence of particular species
Blanks: stones suitably sized and shaped to be further worked into tools
Chronometric dating: a dating technique that gives an estimate in actual numbers of years,
also known as absolute dating
Culture: behavioral aspects of human adaptation, including technology, traditions, language,
religion, marriage patterns, and social roles; it is a set of learned behaviours transmitted to
the next by nonbiological (i.e. nongenetic) means
Direct percussion: striking a core or flake with a hammerstone
Environmental determinism: an interpretation that links simple environmental changes
directly to a major evolutionary shift in an organism (oversimplification of evol. processes)
Half-life: the time period in which one-half the amount of a radioactive isotope is converted
chemically to a daughter product
Knappers: people (often archaeologists) who make stone tools
Microliths: small stone tools usually produced from narrow blades punched from a core;
found especially in Africa during the latter part of the Pleistocene
Microwear: polishes, striations, and other diagnostic microscopic changes on the edges of
stone tools
Mosaic evolution: when the rate of evolution in one functional system varies from that in
other systems (ex. in hominin evolution, the dental, locomotor, and neurological systems all
evolved at markedly different rates)
Paleomagnetism: dating method based on the earth's shifting magnetic pole
Phytoliths ("hidden stone"): microscopic silica structures formed in the cells of many
plants, particularly grasses
Pressure flaking: method of removing flakes from a core by pressing a pointed implement
(e.g., bone or antler) against the stone
Principle of superposition: in a stratigraphic sequence, the lower layers were deposited
before the upper layers
Stable carbon isotopes: isotopes of carbon that are produced in plants in differing
proportions, depending on environmental conditions; by analyzing the proportions of the
isotopes contained in the fossil remains of animals (who ate the plants), it's possible to
reconstruct aspects of ancient environments (particularly temperature and aridity)
Stratigraphy: study of the sequential layering of deposits
Taphonomy: the study of how bones and other materials came to be buried in the earth and
preserved as fossils; taphonomists study the processes of sedimentation, the action of
streams, preservation properties of bone, and carnivore disturbance factors
Thermoluminescence (TL): technique for dating certain archaeological materials (such as
stone tools) that were heated in the past and that release stored energy of radioactive decay
as light upon reheating
Aramis: a site in the Middle Awash region where a large assemblage of fossil hominins
was discovered, dating back to about 4.4 mya
Australopiths: a diverse group of Plio-Pleistecene African hominins, the most abundant and
widely distributed of all early hominins and also the most completely studied
Habitual bipedalism: bipedal locomotion as the form of locomotion shown by hominins
most of the time
Obligate bipedalism: bipedalism as the only form of hominin terrestrial locomotion (when
other forms of locomotion, esp. on the ground, become impossible)
Morphological: pertaining to the form and structure of organisms
Plio-Pleistocene: pertaining to the Pliocene and first half of the Pleistocene, a time range of
5 - 1 mya; numerous fossil hominins from this period have been found in Africa
Sagittal crest: ridge of bone that runs down the middle of the cranium and serves as the
attachment for the large temporal muscles, indicating strong chewing
Sectorial: adapted for cutting or shearing; among primates, refers to the compressed (side to
side) first lower premolar, which functions as a shearing surface with the upper canine)
• Sterkfontein:
Acheulian: stone tool industry from Early-Middle Pleistocene; characterized by a large
proportion of bifacial tools; common in Africa, Southwest Asia, and Western Europe
Dmanisi: a site in Georgia where Homo erectus specimens have been found, suggesting
that erectus was the first hominin to leave Africa
Grade: a grouping of organisms sharing a similar adaptive pattern; not necessarily based on
closeness of evolutionary relationship, but does contrast organisms in a useful way (e.g.
Homo erectus with Homo sapiens)
• Nariokotome:
Nuchal torus: a projection of bone in the back of the cranium where neck muscles attach, to
hold up the head
Pleistocene: the epoch of the Cenozoic from 1.8 mya untill 10,000 ya, frequently referred to
as the Ice Age and associated with continental glaciations in northern latitudes