Ancient Eras And Periods Flashcards
Their nomenclature
Name of eras and with “oic”, except for the pre-cambrian era.
Eras and periods, aren’t both representing time?
Sure, each era have two or more periods that made it up
How many eras there are
There are four eras in the history of earth:
1. Precambrian era
2. Palezoic era
3. Mesozoic era
4. Cenozoic era l.
That’s their orders from oldest to present day
Pre-cambrian era
👉🏾The oldest and longest era known
👉🏾Said to have started with the birth of earth till about 544 mya
👉🏾The era was said to house about 88% of earth history
👉🏾The era we have quite the vague information about
Palezoic era
👉🏾called the ancient life,
👉🏾because it is the earliest era that we have information about
👉🏾begins with the end of pre-cambrian era, 544mya.
👉🏾Ends at about 245mya.
👉🏾Has six periods:
Periods in the palezoic era
*Cambrian period, 505mya
*Ordovician period, 438mya
*Silurian period, 408mya
*Devonian period, 360mya
*Carboniferous period, 285mya
*Permian period, 245mya
What happened during the precambrian era?
•Life arose
•First tectonic plates arose and began to move
•Eukaryotic cells evolved
•Atmosphere became enriched in oxygen
•And, just before the end of the Precambrian, complex multicellular
organisms, including the first animals, evolved.
What happened in the palezoic era
The Cambrian period is the 1stperiod of the Paleozoic Era. “Age of the
Trilobites”
•Explosion of life in the oceans began during this era.
•Most of the continents were covered in warm, shallow seas.
–Invertebrates were dominate -Trilobites
–Fish emerged during this time
–Fish led to the arrival of amphibians
_The early Plants are: pine, mosses and fern
What happened in the Cambrian period
*Appearance of all invertebrates phyla
*Dominated by trilobites and brachiopods
What happened in the Ordovician period
*Appearance of vertebrates (armoured fishes)
*Brachiopods and cephalopods dominate this era
What happened in the Silurian period
*Lands are invaded by plants, brachiopods, and primitive jawless vertebrates
What happened in the Devonian period
*Fishes(mostly freshwater) dominates
*1st trees and 1st amphibians emerge
What happened in the Devonian period
*Fishes(mostly freshwater) dominates
*1st trees and 1st amphibians emerge
What happened during the carboniferous period
*Ferns dominate the land plant
*Sharks and crinoids are abundant in the sea
*Radiation of amphibians
*1st reptiles emerge
What happened in the Permian period
*Radiation of the reptiles;
*Which later displaces amphibian as the dominant group on land
*Widespread radiation also occur
👉🏾MESOZOIC ERA👈🏾
*Spanned from about 208mya till 65mya
*Also called the middle era
•Reptilesbecame the most abundant animals because of their ability to
adapt to the drier climate of the Mesozoic Era.
–Skin maintains body fluids
–Embryos live in shells
•Life diversified rapidly and giant reptiles anddinosaurs roamed the Earth.
•Modern bird appeared.
•Gymnosperms dominated the land.
•Angiosperms (Flowering plants) appeared during the end of this era.
Periods in the mesozoic era
3 periods
1. Trassic period, 208mya
2. Jurassic period, 145mya
3. Cretaceous period, 65mya
What xupped in the triassic period
*1st dinosaurs, turtles, litchyosaurs, plesiosaurs, and cycads develop.
*They also dominate the period
What happened in the Jurassic period
*Reptiles dominate the land, sea and air
*First archaic mammals also developed
What happened during the cretaceous period?
*Flowering plants dominate the land plants
*Large reptiles and ammonites extincted towards the end of this period
👉🏾CENZOIC ERA👈🏾
*Also called the modern life
•Began about 65 million years ago and continues today!!!!!
–Climate was warm and mild.
–Marine animals such as whales and dolphins evolved.
–Mammals began to increase and evolve adaptations that allowed
them to live in many different environments –land, air and the sea.
–Grasses increased and provided a food source for grazing animals.
•This era is sometimes called the “Age of Mammals”
•Marine animal examples:
–Algae, Mollusks, Fish and Mammals
Flowering Plantswere common during the Cenozoic Era
Periods in the Cenozoic era
There are only two;
1. Tertiary period, 54mya
2. Quartenary period, 1mya
What happened in the tertiary period
*Rise of aves
*Rise of placental mammals
What happened in the quartenary period
*Modern existence of mammals
*Extinction of the large forms
*Human dominated all life
What are eras and periods
*Era is a unit of time that is less than 1 billion years but greater than a period
*Period is also a unit of time that usually spans between few tens to hundreds of millions of years
*Period is a subdivision of era
