GMO- ch. 9

Terms	Definitions
geologic time scale	a scale that describes the sequence and length of the changes on Earth; this scale outlines the development of Earth and life on Earth
geologic column	an ordered arrangement of rock layers that is based on the relative ages of the rocks and in which the oldest rocks are at the bottom; represents a timeline of Earth's history
what the rock layers in geologic columns are distinguished by	types of rock the layers are made of and by the kinds of fossils the layers contain
using a geologic column	to estimate the ages of rock layers (that cannot be dated radiometrically) --> compare the rock layers with similar rock layers that contain the same fossils or that has the same relative position.
surface, climate, and types of organisms	geologic time is divided into different divisions by Earth's --
mega-annum; "million years"	Ma stands for --; means --
eon	the largest unit of geologic time is an --
the Hadean Eon, the Archean Eon, the Proterozoic Eon, and the Phanerozoic Eon	the four eons that geologic time is divided into
precambrian time	a time interval that the first three eons of Earth's history are part of
Paleozoic era, Mesozoic era, and Cenozoic era	3 eras of the Phanerozoic Eon
era	a unit of geologic time that includes two or more periods
period	a unit of geologic time that is longer than an epoch but shorter than an era
epoch	a subdivision of geologic time that is longer than an age but shorter than a period
ages	epochs may be divided into smaller units called --
evolution	the process of change by which new species develop from preexisting species over time
geologic and climate changes	2 causes for evolution
nebula	an immense cloud of gas (mainly hydrogen) and dust in interstellar space
Precambrian time, Palezoic Era, Mesozoic Era, Cenozoic Era	4 time periods in order
fern leaf	bilateral carbon film
ammonite	radial petrification
brachiopod	bilateral petrification
shark tooth	bilateral petrification
gastropod	radial petrification
crinoid stem	bilateral petrification
dinosaur bone	bilateral petrification
horn coral	radial petrification
trilobite	bilateral carbon film
horn coral	bilateral petrification
precambrian time	time period where the first crustal rocks form
precambrian time	time period where the earth's surface is first cool enough for liquid water
precambrian time	time period where the first known unicellular life appears
precambrian time	time period where the Earth's atmosphere starts to become oxygen rich
precambrian time	time period where the first known multicellular life appears
precambrian time	time period where the first fungi appears
precambrian time	time period where the first shelled organisms, such as arthropods and mollusks, appear.
cambrian period	period where the first possible vertebrates appear
ordovician period	period where the modern, oxygen-rich atmosphere has formed
silurian period	period where the first land plants appear
silurian period	period where the first arthropods appear on land
devonian period	period where the first amphibians appear
carboniferous period	period where the first reptiles appear
permian period	period where the formation of pangaea is complete
permian period	period where it ends with a great mass extinction from a huge climate change
triassic period	period where Pangaea begins to break apart
triassic period	period where the first mammals appear
jurassic period	period where the first primitive birds appear
cretaceous period	period where the first flowering plant (angiosperms) appear
cretaceous period	period where the first modern birds appear
cretaceous period	period where the last dinosaurs become extinct (asteroid impact).
eocene epoch	epoch where the most modern mammal families have appeared
eocene epoch	epoch where the first grasses appeared
obligocene epoch	epoch where india collides with asia, and antartica drifts over south pole
miocene epoch	epoch where the first hominids (early human ancestors) appear.
pliocene epoch	epoch where the modern ice age begins
pleistocene epoch	epoch where modern humans appear
holocene epoch	epoch we presently live in
invertebrates	animals that do not have backbones
brachiopods	shelled animals
stromatolites	layered, reef-like deposits
graptolites	colonies of tiny invertebrates
vertebrates	animals that have backbones
eurypterids	scorpion-like creatures
"age of fishes"	the devonian period was known as the ---
lungfish	a type of fish that had the ability to breath air (found in the devonian period)
mass extinction	an episode during which large numbers of species become extinct
"age of reptiles"	mesozoic era is also known as the ---
impact hypothesis	the accepted hypothesis for the mass extinction of the dinosaurs. hypothesis states that an asteroid crashed on earth creating dust that blocked to sun's rays for many years which caused the climate to become a lot cooler.
"age of mammals'	cenozoic era is known as the ---
tertiary period	this period is made up of the paleocene eocene, oligocene, miocene, and pliocene epochs.
quaternary period	this period is made up of the pleitocene and holocene epochs.