Geologic Time- Time Scale, Geologic Time Scale – Flashcards
Unlock all answers in this set
Unlock answersquestion
Why are there divisions in the Geologic Time Chart? (Why do we draw lines between time periods and between eras?)
answer
Changes in the fossils preserved
question
What is the order of time divisions from large to small?
answer
Eons, Eras, Periods, Epochs
question
Which "chunk" of time lasted the longest?
answer
Precambrian
question
What is the oldest known fossil?
answer
Blue-green algae
question
What types of fossils, other than blue-green algae, were found at the very end of the Precambrian?
answer
Trilobites and brachiopods
question
What does the word "Paleozoic" mean?
answer
Old life
question
The name for the large number of preserved fossils found immediately after the Precambrian.
answer
Cambrian Explosion
question
What is the name of the formation that contains Cambrian Explosion fossils? It is in Canada
answer
Burgess Shale formation
question
The age (time period) of the oldest known fish
answer
Ordovician
question
The age (time period) of the oldest known land plants and animals (scorpions)
answer
Silurian
question
The time period known as "The age of the fishes". Also has the oldest known amphibian fossils.
answer
Devonian
question
The time period known for the widespread forests that created vast coal deposits. Also contains the first gymnosperm fossils and the first reptile fossils.
answer
Mississippian & Pennsylvanian
question
The time period known for the first mammal-like reptiles (Dimetredon)
answer
Permian
question
The age of the largest mass extinction *95% of all life on Earth goes extinct *Cause of the extinction is unknown
answer
The end of the Paleozoic Era
question
"Middle life"
answer
Mesozoic era
question
"Old life"
answer
Paleozoic
question
The time period when: *the first fossils of dinosaurs appear (small) *the first mammal fossils appear (nocturnal) *gymnosperms (nonflowering plants) common
answer
Triassic
question
"The age of dinosaurs"
answer
Term for the Jurassic
question
The time period when: *the dinosaur fossils are larger *the first fossilized bird is found (archaeopteryx)
answer
Jurassic
question
The time period when: *there are many bird fossils found *the dinosaur fossils are very large *the first angiosperm (flowering plants) fossils are found
answer
Cretaceous
question
The age of a very large mass extinction occurred. *75% of the Earth's species go extinct *The cause of the extinction is well documented
answer
The end of the Mesozoic era
question
"Age of the mammals"
answer
Term for the Cenozoic era
question
The time period when: *mammal, bird and fish fossils are abundant *angiosperms (flowering plants) are abundant *first hominid fossil found ("Lucy")
answer
Tertiary
question
The time period when: *first homo sapien fossils found (human beings) *ice ages occurred (Pleistocene Epoch)
answer
Quaternary
question
How would you describe right now?
answer
Holocene Epoch of the Quaternary Period of the Cenozoic Era
question
A record of the geologic events and life forms in Earth's history.
answer
Geologic Time Scale
question
name for the time in earths early history that accounts for ninety percent of earth's time, but only cellular organisms lived
answer
Precambrian Era
question
it started with the cambrian explosion this is a time when a great number of organisms arose. During this time invertebrates developed along with vertebrates like fishes. Later animals began to reach land. Then the carboniferous period began and reptiles developed. Pangea formed and it ended with a mass extinction. This era lasted from 540 million years ago to 245 million years ago.
answer
Paleozoic Era
question
The period of geologic time, from 250 million to 65 million years ago, during dinosaurs the dominant vertebrates. Ended with extinction of the dinosaurs. Also called Age of Reptiles.
answer
Mesozoic Era
question
The most recent period of geologic time, beginning 65 million years ago, during which mammals became the dominant vertebrates. Also called Age of Mammals.
answer
Cenozoic Era
question
Event in which many types of living things become extinct at the same time. They divide the Geologic Eras
answer
Mass extinction
question
The most massive extinction that has ever occurred, caused by volcanism in Siberia
answer
Permian extinction
question
Lowering of greenhouse gases, cooling, glacial ice and snow reflect heat.
answer
Snowball Earth
question
birds, crocodilians
answer
Dinosaur descendants
question
layered structures produced by the trapping of sediment by blue-green algae
answer
stromatolites
question
blue-green algae that contain chlorophyll and liberate oxygen during photosynthesis
answer
cyanobacteria
question
the interval of time since the formaiton of Earth
answer
geologic time
question
the division of geologic time into units based on evolutionary events of geologic history
answer
geologic time scale
question
the longest division of geologic time that contains two or more eras
answer
eon
question
a major division of geologic time that contains two or more periods
answer
era
question
a division of geologic time that contains two or more epochs
answer
periods
question
a short division of geologic history that contains a notable event
answer
epoch
question
a mineral which contains small traces of uranium, and has been dated back to 4 billion years.
answer
zircon
question
the process in evolution where the traits of more successful organisms get passed on in favor of those in less successful organisms
answer
natural selection
question
the end of a species
answer
extinction
question
a catastrophic, widespread perturbation in which major groups of species become extinct in a relatively short time compared to normal background extinction
answer
mass extinction
