History Of Earth Flashcards
is a scale used by geologists
to understand and describe
the history of the Earth
Geologic time scale
4 era
Precambrian
Paleozoic
Mesozoic
Cenozoic
primitive life-forms existed
approximately 3.5 billion
years ago
the first multicellular
organisms evolved, and
sexual division developed
Precambrian
Called as ancient life; marine invertebrates and primitive fishes.
Plant and animal life
flourished. Amphibians left
the oceans to live on land,
reptiles evolved as fully
terrestrial life-forms, and
insect life began.
Paleozoic
Called as middle life
this era is
best known as the time of
the dinosaurs.
Mesozoic
is internationally accepted as the
youngest of the three
subdivisions of the fossiliferous
part of Earth history.
the interval of time during
which the continents
assumed their modern
configuration and
geographic positions and
during which Earth’s flora
and fauna evolved toward
those of the present.
Cenozoic
Oldest time in Paleozoic; widespread seas several scattered landmasses; no land plants or animals; age of trilobites
Cambrian
Rapid seafloor spreading; intense diversification of Maribel animal life;rise of fish
Ordovician
Global sea level is higher; rose dramatically; extensive glaciers ice age melted
Silurian
Age of fishes; ammonites appear early; first four legged amphibians
Devonian
Mississippian and Pennsylvania; longest period in Paleozoic; refers coal-bearing strata
Carboniferous
Hot and dry condition caused crisis; terrestrial plants broadly diversified; insects evolved they followed plants
Permian
Major landmasses supercontinent Pangea; terrestrial climate warm; reptiles increased; first dinosaur
Triassic
Pangea split apart; rock strata laid down yield gold, coal, petroleum; animals and plants recovered largest mass extinction
Jurassic
Latin for chalk; warmer more humid; very active volcanism; unusual high rates of ss
Cretaceous