This document delves about the past events specifically the living planet.

2. I D E N T I F Y T H E F O L L O W I N G I M A G E

3. M ES OZO I C E R A C E N OZO I C E R A

4. C A M B R I A N
P E R I O D
O R D OV I C I A N
P E R I O D

5. H A D E A N E O N A R C H E A N E O N

6. P R OT E R OZO I C
E O N
A R C H E A N E O N

7. H I S T O R Y O F L I F E
O N E A R T H

8. O B J E C T I V E
At the end of the lesson students shall be able to;
• Distinguish between eons, eras, periods, and epochs
• Describe the characteristics of the major groups of organisms present during the
periods of the geologic time scale;
• Illustrate through a diagram the sequence of events of the geologic time scale.

9. W H A T I S
G E O L O G Y ?
Science that deals
with studying Earth
– its materials and
processes

10. P R I N C I P L E S
Uniformitarianism
The principle states that forces and processes that
can be observed shaping the Earth at present, have been
at work for a long time since the Earth’s beginnings.
•Principles of relative dating
•Principle of fossil succession

11. P R I N C I P L E O F R E L AT I V E D AT I N G
- is the process of determining if one rock or geologic event is older or younger
than another without knowing their specific ages

12. P R I N C I P L E O F F O S S I L S U C C E S S I O N
- states that different fossil species always appear and disappear in the same order,
and that once a fossil species goes extinct, it disappears and cannot reappear in
younger rocks.

13. • Radiometric dating- calculates an age in years for geologic
materials by measuring the presence of short-life radioactive
element (carbon-14) or long-life radioactive element
(potassium-14/agron-40)

14. G E O L O G I C T I M E S C A L E
- divides the history of the earth into time
intervals which are; EONS, ERAS, PERIODS, AND
EPOCHS

15. E O N S
-the longest
time interval, which
can be subdivided
into smaller intervals
called eras

16. T H E P R E C A M B R I A N S U P E R E O N
Hadean eon- is characterized by earth’s initial formation. The
stabilization of its core and crust and the development of its atmosphere
and oceans
Archean eon- is said to be the time when first signs of life began. The first
organisms were known as photosynthetic bacteria and archaea
(prokaryotes that able to survive in extreme environment)
Proterozoic eon - the time when the eukaryotes (unicellular organisms
with true nucleus and multicellular organism) begin to evolved.

17. T H E P H A N E R O Z O I C E O N
- is the more recent eon and is subdivided into eras
which include Paleozoic era, Mesozoic era, and Cenozoic era.
These eras are further subdivided into periods and the most
recent periods are subdivided into shorter time intervals
called epochs.

18. T H E PA L E O Z O I C E R A
• Paleozoic Era (“Age of Invertebrates”)
-represents the time of the “ancient life”
which was dominated by ancient marine
invertebrates. Paleozoic era is subdivided into six
periods namely: Cambrian, Ordovician, Silurian,
Devonian, Carboniferous, and Permian

19. PA L E O Z O I C E R A
 Cambrian Period
-period is also known as “Cambrian explosion”. During this time red and green algae, sponges,
jellyfishes, and worms which were found in the Cambrian seas
 Ordovician Period
-first vertebrates, the jawless fishes called the ostracoderms.
period ended with a large-scale mass extinction of marine
invertebrates.
 Silurian Period
-the first plants with water-conducting and mineral conduction tissues known as vascular plants
evolve at this time. The first land animals also left fossil evidence which looked like scorpions
which were predators of smaller animals.

20.  Devonian Period
-This period is known as the “age of fishes” as more fishes diversified as bony and cartilaginous
fishes. By the end of the period, the first amphibian appeared which resembled fishes but with
paddle like legs and toes.
 Carboniferous Period ( COAL BEARING)
-This period is known as the “age of amphibians” as more amphibians dominated both land and
water. This period is subdivided into two epochs, namely (oldest to more recent): Mississippian
(oldest ) and Pennsylvanian (recent). Many land plants like ferns and early seed plants and
many different kinds of insects dominated
 Permian Period
-During this period, gymnosperms (non-flower bearing plants) became dominant while reptiles
were the dominant animals including the ancestors of dinosaurs. The Permian period ended with
the most catastrophic mass extinctions, also known as “the mother of mass extinctions,” as it
affected 90% of species, which were mostly marine invertebrates found in shallow areas of the
seas.
PA L E O Z O I C E R A

21. T H E M E S O Z O I C
E R A
• Mesozoic Era
known to be the age of Reptiles,
it is dominated by small and huge
reptiles called the dinosaurs. This era is
subdivided into three periods, namely:
Triassic, Jurassic, and Cretaceous
periods.

22. M E S O Z O I C E R A
 Triassic Period
-The ancestors of the now-extinct dinosaurs called the archosaurs increased during this period. The
ancestors of mammals called therapsids also appeared.
 Jurassic Period
-This period is known as the “age of dinosaurs”. Both herbivorous and carnivorous reptiles dominated the
land, including large marine crocodiles, the ancestors of birds (Archeopteryx) and dinosaurs. The first
flowering plants (angiosperms) appeared during this period. The first frogs and the first true mammals,
which were the size of rats, appeared at this time.
 Cretaceous Period
-Huge diversification of organisms both plants and animals occurred at this time. The Cretaceous period
ended with the mass extinction of 75% of species including the large reptiles, the dinosaurs, and thus,
ending the Mesozoic era. The mass extinction cleared the way for the dominance of smaller organisms that
survived the asteroid impact (said to be the cause of the mass extinction) which included the birds,
amphibians, and mammals.

23. T H E C E N O Z O I C E R A
• Cenozoic Era
-known as the Age of Mammals, it has
been dominated by the greatly diversified
mammals. This era is subdivided into three
periods, namely: Paleogene, Neogene, and
Quaternary periods

24. C E N O Z O I C E R A
Paleogene Period
• -it is subdivided into three epochs
Paleocene Epoch- early placental mammals appeared including the
first primates, speciation of birds and insects.
Eocene Epoch- angiosperms dominated, origin of the mammalian
orders including the appearance of the primitive whales.
Oligocene Epoch- origins of the different primate groups including the
apes; tropical rainforests appeared in many continents; pigs, cats and
rhinos appeared; marine life was dominated by mollusks.

25. C E N O Z O I C E R A

Neogene Period
•-it subdivided into two epochs

Miocene Epoch—coevolution of angiosperms and insects; continued speciation of mammals.

Pliocene Epoch—origin of the hominids (Homo)

Quaternary Period
•- (most recent) Subdivided into two epochs:

Pleistocene epoch—origin of modern humans; major glaciation events occurred (ice ages)

Holocene epoch—rise of human civilization, impact of human activities are widespread and
continues to the present time
•Anthropocene- scientist think that we are now in a new epoch, which marked by extensive
human impact to the environment.

27. LESSON RECAP

28. THANK Y O U 