History of life on Earth Flashcards
A record of life forms and geological events in Earth’s history.
Geological Time Scale
It is a set of principles that describe how rock layers are deposited and change over time. These laws are used to identify strata and understand Earth’s history.
Stratigraphic Laws
Remnant, impression, or trace of an animal or plant of a past geologic age that has been preserved in Earth’s crust.
Fossils
The largest division of geologic time scale; half billion to nearly billions of years.
Precambrian & Phanerozoic
EONS
88% of the Earth’s History
Hadean
Archean
Proterozoic
Precambrian
Dericed From the Hadess (god of the underworld in greek mythology)
Hadean eon
Silent
Archean eon
Presence of oxygen due to the emergence of cyanobacteria.
Proterozoic eon
Present eon which subdivided into 3 Era; Paleozoic, Mesozoic, Cenozoic.
Phanerozoic
Periods of tens to hundreds of million years.
ERA
Ancient or old life”; started more than 540 million years ago.
Paleozoic Era
no MORE THAN million of years
Periods
Explosion of new kinds of organisms.
Many types of primitive animals called sponges evolved.
Small ocean invertebrates (Animals without backbones) called trilobites.
Cambrian Period
The ocean were filled with invertebrates of many types.
The first fish evolved.
Plants colonized the land for the first time, but animals still remained in water.
Ordovician Period
In the oceans, corals appeared and fish continued to evolve.
On the land, vascular plants appeared. With special tissues to circulate water and other materials, they could grow larger than earlier. Non vascular plants.
Silurian Period
The first seed plant evolved. Seeds had a protective coat and stored food to help them survive. Seed plants eventually the most common type of land plants.
Fish with lobe fins evolved. They could breathe air when they raise their heads above water.
Devonian Peroid
Widespread forests of huge plants left massive deposits of carbon that eventually turned to coal.
The first amphibians evolved to colonize land, but they had to return to the water to reproduce.
The first reptiles evolved. They were the first animals that could reproduce on dry land.
Carboniferous period
All the major land masses collided to form the supercontinent.
Temperatures were extreme, and the climate was dry.
Plants and animals evolved adaptations to dryness, such as waxy leaves or leathery skin to prevent water loss.
Permian period
The first dinosaurs branched off from the reptiles and colonized and colonized the land, air, and water.
Huge seed ferns and conifers dominated the forests, and modern corals, fish, and insects evolved.
The Supercontinent started to separate.
Triassic period
Dinosaurs reached their peak in size and distribution.
Earth’s overall climate was warm; even the poles lacked of ice.
This period ended with the dramatic extinction of the dinosaurs.
The continents were close to their current location today.
Cretaceous period
Recent Life”; started 65 million years ago and continues up to the present.
“Age of Mammals”
Cenozoic Era
Earth’s climate was generally warm and humid.
Mammals evolved
Tertiary period
Ice age
-first human exist
Quarternary Period
