WednesdayNovember 28,

2012(The Phanerozoic Eon:

The Mesozoic Era – The Age of Reptiles)

The Launch PadWednesday, 11/28/12

The beginning of the Cambrian Period marks an important event

in animal evolution, the appearance of organisms with

__________________.A. wingsB. cells

C. shells and other hard partsD. vertebrae

E. none of the above

AnnouncementsHappy Make Your Own Head Day!

AnnouncementsIf you would like to keep

your Solar Interior Poster, please remove it from the

hallway before close of school today.

Assignment Currently Open

Summative or

Formative?Date Issued Date Due Date Into

GradeSpeed Final Day

Quiz 11 S1 11/9 11/9 11/30

Lab – The Geologic Time

ScaleF3 11/14 11/16 11/30

Quiz 12 S2 11/16 11/16 12/7

WS - The Precambrian Eon:

Formation of Continents and

Steps Leading to Higher Life Forms

F4 11/26 11/30 11/30

WS - The Phanerozoic Eon: The Paleozoic Era

- Life Explodes

F5 11/27 11/30 11/30

Recent Events in Science'Pac-Man' Moons: Cassini Finds a Video Gamers'

Paradise at Saturn

www.sciencedaily.com/releases/2012/11/121126151127.htm

Read All About It! You could call this "Pac-Man, the

Sequel." Scientists with NASA's Cassini mission have spotted a second feature shaped like the 1980s video game icon in the

Saturn system, this time on the moon Tethys. (The first was

found on Mimas in 2010). The pattern appears in thermal data

obtained by Cassini's composite infrared spectrometer, with

warmer areas making up the Pac-Man shape.

The Phanerozoic Eon The Mesozoic Era

The supercontinent of Pangaea existed during the

late Paleozoic and early Mesozoic eras, forming

about 300 million years ago.

The Phanerozoic Eon The Mesozoic Era

Pangaea began to rift around 200 million years ago, first forming the two continents of

Laurasia and Gondwana.

Laurasia included most of the landmasses which make up today's continents of the

Northern Hemisphere, chiefly North American continent,

Baltica, Siberia, Kazakhstania, and the North China and East China cratons.

Gondwana was the southern-most of two and included most of the landmasses in

today's Southern Hemisphere, including Antarctica, South

America, Africa,Madagascar and the Australian continent, as well as

the Arabian Peninsula and the Indian subcontinent, which have now moved entirely into the Northern Hemisphere.

The Phanerozoic Eon The Mesozoic Era

Early in the Mesozoic Era, much of present-day North America was above sea level, but by the middle Mesozoic, seas invaded the western regions of the continent.

The Phanerozoic Eon The Mesozoic Era

As Pangaea continued its rift, the westward-

moving North American plate began to override

the Pacific plate.

This resulted in crustal deformation along the entire western margin

of North America.

The Sierra Nevada and Rocky Mountains were

formed at this time.

The MesozoicThe Phanerozoic Eon

The Mesozoic Era was known as the “Age of Reptiles.”

Reptiles became the dominant

land animals.

The first reptiles were small, but evolved rapidly, particularly the dinosaurs.

The Phanerozoic Eon

Diversity of reptiles included:

• large herbivorous dinosaurs such as Apatosaurus

•large carnivorous dinosaurs such as Allosaurus

•Pterosaurs or flying reptiles

•Archaeopteryx, the predecessor of modern birds

The Phanerozoic Eon

Archaeopteryx fossilArchaeopteryx

fossil

Ichthyosaur Fossil, a marine reptile

Dinosaur Tracks

The MesozoicThe Phanerozoic Eon

The early Mesozoic Era

consisted of the Triassic Period.

The middle Mesozoic Era

consisted of the Jurassic Period.

The MesozoicThe Phanerozoic Eon

The late Mesozoic Era consisted of

the Cretaceous Period.

The MesozoicThe Phanerozoic Eon

About 65 Mya, at the close of the Mesozoic Era, an impactor with an estimated

diameter of 6.2 miles struck the Earth near the present-day Yucatan Peninsula of

Mexico.The impact delivered an estimated energy

equivalent of 100 teratons (100 trillion tons) of TNT.

By contrast, the most powerful man-made explosive device ever detonated, the Tsar Bomba, had a yield of only 50 megatons

( 50 million tons) of TNT.This makes the Chicxulub impact 2 million

times more powerful.Even the most energetic known volcanic eruption, which released approximately

240 gigatons (240 billions tons) of TNT and created the La Garita Caldera,

was substantially less powerful than the Chicxulub impact.

The Phanerozoic Eon

www.youtube.com/watch?v=5qJPTjMnwNk

A few types survived, including the turtles, snakes,

and lizards.

As a result of the Chicxulub impact,

many reptile groups became

extinct.

The Phanerozoic Eon

The elimination of the dinosaurs and

other reptiles cleared the way for

the rise of the mammals, who, up to this point, had

consisted of small, hole-dwelling

creatures.

The Phanerozoic Eon

Worksheet

The Phanerozoic Eon:The Mesozoic Era – The

Age of Reptiles