History of life on Earth

Question 1

When “eras” are grouped together, this will create the longest geologic subdivision called an “eon.”

Answer 1

Eon

Question 2

When “periods” are compacted together according to their characteristics

Answer 2

Era

Question 3

The concept of geologic time scale, basic unit of geological time during which a specific kind of rock system is produced.

Answer 3

Period

Question 4

Some “periods” have their own subdivision

Answer 4

Epoch

Question 5

Two main eons

Answer 5

1. Phanerozoic eon
2. Precambrian eon

Question 6

This is the most recent among the eras of the Phanerozoic Era; this era marks the age of mammals and the first human evolution.

Answer 6

Cenozoic era

Question 7

This era marks the beginning of dinosaurs, mammals, birds, and plants due to mass extinction.

Answer 7

Mesozoic era

Question 8

The explosion of diverse marine life and the largest mass extinction of marine organisms

Answer 8

Paleozoic era

Question 9

characterized by Earth’s initial formation—from the accretion of dust and gases and the frequent collisions of larger planetesimals

Answer 9

Hadean eon

Question 10

the evolution of earth’s first life forms

Answer 10

Archean eon

Question 11

modern plate tectonics became active, and the ancient cores of the continents moved over wide areas of the globe

Answer 11

Proterozoic eon

Question 12

• No continents
• Vas amount of carbon dioxide in the atmosphere
• began 3.8 billion years ago and ended 2.5 billion years ago

Answer 12

Archean eon

Question 13

• Era of old life
• plants became prevalent
• first vertebrate animals colonized the land
• divided into six periods: Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian
• started with a breakup of one supercontinent into
  the continents of Gondwana and Laurasia

Answer 13

Paleozoic era

Question 14

• famed for its explosion of abundant and diverse life forms
• life had diversified into many ways of living
• some creatures had evolved hard parts such as shells
• geologist find beautiful fossils of soft and squishy creatures like Burgess Shale site
• no life on land and in little or none in freshwater
• began 545 million years ago and ended 495 million years ago

Answer 14

Cambrian period

Question 15

• few animals and plants began to explore the margin of the land but nothing colonized beyond these beachheads
• ended with a mass extinction
• began 495 million years ago and ended 443 million years ago

Answer 15

Ordovician period

Question 16

• reefs got their act together, grew really big and created a completely new type of ecosystem for marine life.
• a period of extensive seas
• bony fish made their first appearance
• On land, plants became more established
• began 443 million years ago and ended 417 million years ago

Answer 16

Silurian period

Question 17

• Age of fishes
• sea levels were high and the global climate was warm
• Growth rings from coral living
• began 417 million years ago and ended 354 million years ago

Answer 17

Devonian period

Question 18

• famed for having the highest atmospheric oxygen levels
• plants grew and died at such a great rate
• called the coal measures after its proliferation of coal- breaking rocks
• In North America, this period is divided into two epochs: Mississippian and the Pennsylvanian

Answer 18

Carboniferous period

Question 19

• started with an ice age and ended with the most devastating mass extinction the Earth has ever experienced
• all the continents of the world finally coalesced into one supercontinent
• The oxygen level plummeted too from 35% to around 15%
• began 290 million years ago, ended 248 million years ago

Answer 19

Permian period

Question 20

• Middle life
• era of dinosaurs that lasted for almost 180 million years ago
• Age of Reptiles
• divided into Triassic period, Jurassic period and
  Cretaceous period

Answer 20

Mesozoic era

Question 21

• was characterized by heat, vast deserts and warm seas
• even the polar regions were warm
• very first mammals and dinosaurs evolved
• giant supercontinent Pangaea began to break apart.
• the period ended as it had begun, with an extinction event
• began 248 million years ago and ended 205 million years ago

Answer 21

TRIASSIC PERIOD

Question 22

• life was quick to recover
• became host to the most diverse range of organisms that Earth had yet seen
• First birds and some of the dinosaurs
• continental break-up during this time gave rise to the sea that would eventually widen to become the Atlantic Ocean.

Answer 22

JURASSIC PERIOD

Question 23

• with the most famous mass extinction in history
• the existing birds, mammals and plants diversifies
• Atlantic Ocean grew much wider as North and South America drew apart from Europe and Africa.
• Indian was formed at this time
• began 142 million years ago, ended 65 million years ago

Answer 23

Cretaceous period

Question 24

• • era of recent life
    age of the mammals
• divided into three periods and seven epochs:
  1. Paleogene period (Paleocene, Eocene, and Oligocene epochs)
  2. Neogene period (Miocene and Pilocene epochs)
  3. Quarternary period (Pleistocene and Holocene epochs)

Answer 24

Cenozoic era

Question 25

• time of dense forests and evolutionary experiments
• island continent of India moved north and collided with Asia
• At the end of the epoch, an abrupt rise in temperature across the planet made the climate much wetter and caused a sea level rise.
• began 65 million years ago and ended 54.8 million years ago

Answer 25

Palaeocene epoch

Question 26

• began as a time of global warming, with temperatures across the planet soaring.
• became cooler and drier
• As the India continued to drift northwards, pushing against the Eurasian continent, the mass of rocks thrust up between them formed the Himalayas
• many species of grass evolved
• began 54.8 million years ago and ended 33.7 million years ago

Answer 26

Eocene epoch

Question 27

• saw the start of the global cooling
• Worldwide, this was the time when grasslands began to expand and forests-especially tropical ones-shrank correspondingly
• Open landscape and many fast-running prey and
  predator species arose as a result.

Answer 27

Oligocene epoch

Question 28

• apes arose and diversified
• by the end of this epoch, the ancestors of humans had split away from the ancestors of the chimpanzees to follow their evolutionary path
• kelp forests made their first appearance
• grasslands continued to expand and forests dwindle in extent
• began 23.8 million years ago and ended 5.3 million years ago

Answer 28

Miocene epoch

Question 29

• very similar to Earth today as North and South America had been drifting
• As the world cooled in the late Pilocene, ice at the North Pole became thrived
• human lineage split away from the chimpanzees’ early on in this epoch
• began 5.3 million years ago and ended 2.6 million years ago

Answer 29

Pliocene epoch

Question 30

• expansion of the deserts and the action of glaciers grinding up rocks meant that dust storms.
• began 2.6 million years ago and ended 11.7 thousand years ago

Answer 30

Pleistocene epoch

Question 31

• current geological epoch which started 11,500 years ago
• Ongoing phase of Earth’s history
• period that humans evolved

Answer 31

Holocene epoch