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Chapter 8: The History of Life on Earth

Terms in this set (13)

fossil
the trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock
relative dating
any method of determining whether an event or object is older or younger than other events or objects
absolute dating
any method of measuring the age of an object or event in years
geologic time scale
the standard method used to divide the Earth's long natural history into manageable parts
extinct
describes a species that has died out completely
plate tectonics
the theory that explains how large pieces of the Earth's outermost layer, called tectonic plates, move and change shape
Precambrian time
the period in the geologic time scale from the formation of the Earth to the beginning of the Paleozoic era, from about 4.6 billion to 542 million years ago
Paleozoic era
the geologic era that followed Precambrian time and that lasted from 542 million to 251 million years ago
Mesozoic era
the geologic era that lasted from 251 million to 65.5 million years ago; also called the "Age of Reptiles"
Cenozoic era
the most recent geologic era, beginning 65 million years ago; also called the "Age of Mammals"
primate
a type of mammal characterized by opposable thumbs and binocular vision
hominid
a type of primate characterized by bipedalism, relatively long lower limbs, and lack of a tail
Homo sapiens
the species of hominids that includes modern humans and their closest ancestors and that first appeared about 100,000 to 160,000 years ago
THIS SET IS OFTEN IN FOLDERS WITH...