mesozoic era presentation

7/28/2019 Mesozoic Era Presentation

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Mesozoic Era

Prepared by:

Mhel Angelo C. Policarpio

Erica Bianca D. Bote


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Interval of geological time from

about 250 million years ago to

about 65 million years ago.

Often referred to as the Age ofReptiles because reptiles, namely

non-avian dinosaurs, were the

dominant terrestrial and marine

vertebrates of the time.


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Mesozoic

Means "middle life", deriving from

the Greek prefix meso- for "between"

and zon meaning "animal" or "living

being".

One of three geologic eras of the

Phanerozoic Eon, preceded by thePaleozoic ("ancient life") and succeeded

by the Cenozoic ("new life").


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It extends from about 251 mya

to 65 mya and is separated into

three geologic periods

Triassic

Jurassic

Cretaceous

Often called the "Age of theDinosaurs," after the dominant

fauna of the era.


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The Triassic Period

an interval of about 51 million yearsdefined on the geologic time scale as

spanning roughly from 251 to 200 million

years ago (mya).

Noteworthy for a great increase in the

biodiversity of both marine and

continental life, beginning from the

starkly impoverished biosphere that

followed the Permian-Triassic extinction.


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Lies between the preceding Permian

period, which ended the Paleozoic

era, and the following Jurassic

period.Laid the foundation for subsequent

stages of life, including the

dominance of dinosaurs seen during

the Jurassic and Cretaceous periods.


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Named in 1834, by Friedrich Von

Alberti from the three distinct

layersred beds, capped bychalk, followed by black shales,

called as the "Trias" (Latin trias,

meaning triad).


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Usually separated into Early,

Middle, and Late Triassicepochs, and the

corresponding rocks are

referred to as Lower, Middle,

or Upper Triassic. The faunal

stages (divisions based onfossils) from the youngest to

oldest are:


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Upper/LateTriassic(Tr3)

Rhaetian

Norian

Carnian

Middle Triassic(Tr2) Ladinian

Anisian

Lower/Early Triassic(Scythian)

Olenekian

Induan


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Climate

Generally hot and dry, forming typical redbed sandstones and evaporites

There is no evidence of glaciation at or

near either pole; in fact, the polar

regions were apparently moist and

temperate, a climate suitable for reptile-

like creatures. Pangea's continental

climate was highly seasonal, with very

hot summers and cold winters.


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Life In marine environments, new, modern

types of corals appeared in the EarlyTriassic

The shelled cephalopods called

ammonites recovered, diversifying from

a single line that survived the Permian

extinction

The fish fauna was remarkably uniform,

reflecting the fact that very few families

survived the Permian extinction.


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Marine ReptilesSauropterygia

PlacodontsPlesiosaurs

Thalattosauria

Ichthyosaurs


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On land, the holdover plants included

Lycophytesdominant cycads

ginkgophyta (represented in modern

times by Ginkgo biloba)

glossopterids.

Glossopteris (a seed fern) - thedominant southern hemisphere tree

during the Early Triassic period.


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The Triassic period ended with a mass

extinction, which was particularly

severe in the oceans; the conodonts

disappeared, and seemingly all the

marine reptiles except ichthyosaurs and

plesiosaurs. Invertebrates like

brachiopods, gastropods, and mollusks

were severely affected. In the oceans,

22 percent of marine families and

possibly about half of marine genera

vanished.


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The Jurassic Period

An interval of about 55 million yearsdefined on the GTS as spanning

roughly from 200 to 145 million years

ago (mya), from the end of the Triassicperiod to the beginning of the

Cretaceous period.

Noteworthy as the first of two periods

that together comprise the Age of

Dinosaurs.


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The start of the Jurassic period is marked

by the major Triassic-Jurassic extinction

event, which happened just before the

supercontinent Pangea started to break

apart. It is estimated that over 20

percent of marine families and 40

percent of terrestrial tetrapod (four-

legged vertebrate) families went extinct,

including all large Crurotarsi (a group of

non-dinosaurian reptiles) and many of

the large amphibians.


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An immense wealth of fossils have been

found from the Jurassic period. These

provide valuable information in

understanding the evolution of life on

Earth. The Jurassic period is important

for another reason: The oilfields of the

North Sea, near the United Kingdom and

Norway, have much of their origin in this

period.


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Named by Alexander

Brogniart for the extensive

marine limestone exposuresof the Jura Mountains in the

region where Germany,

France, and Switzerland meet.


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Usually divided into lower, middle,

and upper subdivisions, also known as

Lias,Dogger, and Malm

originally referred to British sediments,

where so many of the early fossils forthis period were found

Faunal stages are also used to further

delineate the period. The faunal stages

for this period, from youngest to

oldest, are:


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Upper/Late Jurassic

Tithonian

Kimmeridgian

Oxfordian

Lower/Early JurassicToarcian

PliensbachianSinemurian

Hettangian

Middle Jurassic

Callovian

Bathonian

Bajocian

Aalenian


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Life

Highest life forms living in the seas

Fish

marine reptiles

Ichthyosaurs

Plesiosaurs

marine crocodilesTeleosauridae

Metriorhynchidae.


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In the invertebrate world, several new

groups appeared, such as:

Planktonic foraminifera and

calpionelids

Rudists, a reef-forming variety ofbivalves

Belemnites (an extinct type of marine

cephalopod)

Brachiopods of the terebratulid and

rinchonelid groups


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Ammonites (extinct, shelled

cephalopods) were particularly

common and diverse, forming 62

biozones.

Ichthyosaurs were abundant in theJurassic period

giant marine reptiles that had a

porpoise-like head and a long,

toothed snout, as well as a large tail

fin.


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Plesiosaurs were large aquaticreptiles as well. Despite being large

Mesozoic reptiles, they were not a

type of dinosaur. The typical

plesiosaur had a broad body and a

short tail, as well as limbs in the formof flippers.


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Terrestrial animals

Large archosaurian reptiles remaineddominant

Sauropods - great, plant-eating

dinosaurs that roamed the land,

feeding on prairies of ferns and palm-

like cycads and bennettitales-Were preyed upon by the theropods,

the large carnivorous dinosaurs.


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Plants

The warm, humid climate allowed lushjungles to cover much of the landscape.

Flowering plants had not evolved yet,

and conifers dominated the landscape,as they had during the Triassic period.

Conifers, in fact, were the most diverse

group of trees, and constituted thegreatest majority of large trees during

this period.


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The Cretaceous Period

One of the major divisions of the GTS,reaching from the end of the Jurassic

period, from about 146 to 136 million

years ago (Mya) to the beginning of thePaleocene epoch of the Paleogene

period, or Tertiary sub-era (about 65.5 to

64 Ma).

longest geological period, constitutes

nearly half of the Mesozoic.


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Dinosaurs were dominant during this

period, while mammals remained

small. An interesting development

during the Cretaceous was thegrowing importance and diversity of

flowering plants, an advance aided

by a harmonious interaction with

bees and other insects.


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The Cretaceous (from Latin creta

meaning "chalk") as a separateperiod was first defined by a Belgian

geologist Jean d'Omalius d'Halloy in

1822, using strata in the Paris basin

(GSE 1974) and named for the

extensive beds of chalk, found in theupper Cretaceous of the continental

Europe and Great Britain.


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As with other older geologic periods,

the rock beds that define theCretaceous are well identified but the

exact dates of the period's start and end

are uncertain by a few million years.No great extinction or burst of diversity

separated the Cretaceous from the

Jurassic. However, the end of the periodis most sharply defined, being placed at

an iridium-rich layer found worldwide.


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The Cretaceous is usually separated

into Early and Late Cretaceousepochs. The faunal stages (divisions

based on changes in the observed

fossil assemblages) from youngest to

oldest are listed below. Time is

referred to as early or late, and thecorresponding rocks are referred to

as lower or upper:


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Upper/Late

CretaceousMaastrichtian

CampanianSantonian

Coniacian

Turonian

Cenomanian

Lower/Early

CretaceousAlbian

Aptian

Barremian

Hauterivian

ValanginianBerriasian


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Climate

Considered to have been very warmand without any ice at the poles. Sea

level was much higher than today and

large areas of the continental crust

were covered with shallow seas.

Sediment cores also show thattemperatures in the deep ocean were

15-20C higher than today.


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Flora

Flowering plants (also known as

angiosperms), spread during the

Cretaceous, although they did notbecome predominant until near the

end (Campanian age). Their

evolution was aided by the

appearance of bees.


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FaunaOn land, mammals were a small and

still relatively minor component ofthe fauna. The fauna was dominated

by archosaurian reptiles, especially

dinosaurs, which were at their mostdiverse.


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During the Cretaceous, the insects

began to diversify, and the oldestknown ants, termites, and some

lepidopterans appeared. Aphids,

grasshoppers, and gall wasps

appeared. Another important insect

to evolve was the eusocial bee,which was integral to the ecology

and evolution of flowering plants.


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Marine animals

In the seas, rays, modern sharks, and

teleosts became common. Marine

reptiles included ichthyosaurs in theearly and middle of the Cretaceous,

plesiosaurs throughout the entire

period, and mosasaurs in the Late

Cretaceous.


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Baculites, a straight-shelled form of

ammonite, flourished in the seas.

The Hesperornithiformes were

flightless, marine diving birds thatswam like grebes.

The Cretaceous also saw the first

radiation of the diatoms in the

oceans


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Extinction

In the extinction event that defines

the end of the Cretaceous, a

significant number of species

(around 50 percent) and knownfamilies (around 25 percent)

disappeared. Plants appeared to be

nearly unscathed, while marine

organisms apparently were hit the

hardest.


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Dinosaurs are the most famous

victims of the Cretaceous extinction.Dinosaurs that were unique to the

very end of the period were wiped

out. The last of the pterosaursbecame extinct and the vast majority

of birds.

The intensive, mid-Cretaceous insect

extinction began during the Albian.


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mesozoic era presentation

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