Mesozoic era

Mesozoic EraEarth Science By, Elizabeth Bell

July 22, 2012 Footer text here2

The Mesozoic Era

• Began approximately 245 million years ago after a major mass extinction. Is subdivided into 3 periods

• Triassic

• Jurassic

• Cretaceous

• Ends about 66 million years ago with a major mass extinction



Triassic Period



The Triassic Period 245 - 206 million years ago Immediately after the Permian Mass Extinction Lots of new area is open for animals to live Three general types of animals holdovers from before the extinction new groups that lasted only a short time new groups that lasted a long time

Two Groups of Dinosaurs

•Ornithischian•Hips were similar to modern bird hips

• Carnivorous short-necked• Herbivorous, long-necked

•Saurischian

•Hips were similar to reptile hips

• Herbivorous with grinding-teeth

• Herbivorous without grinding-teeth


Earliest Dinosaurs Triassic


Eoraptor:Length:3 feet Height:1 feet Weight:20 pounds

Lesothsaurus: Length:3 feet Height:1 foot Weight:15 pounds

Pisanosaurus Length:3 feet Height:1 foot Weight:15 pound


The Jurassic Period

• 206 - 144 Million Years Ago

• Giant plant-eating dinosaurs

• Vicious carnivore dinosaurs

• Oceans full of fish, squid, sharks, etc.

• Ichthyosaurs and Plesiosaurs

• Pterosaurs

• Birds


Jurassic Plant Eating Dinosaurs

• Many different forms

• Many had ‘armor’ to protect themselves

• Triceratops

• Ankylosaurus

• Many very large (larger than a Rhino/Hippo)

• Some were extremely large (as long as a city block): Diplodocus


Jurassic Carnivorous Dinosaurs• Many different forms

• Some were very large: Tyrannosaurus Rex

• Allasaurus

• Some were smaller:

• Raptors, and many more All had sharp teeth, claws, and speed



The Cretaceous Mass Extinction

• Approximately 60% of all species went extinct.

• Affected many land animals/plants

• Affected fewer marine animals


What organisms were extinct?

•All dinosaurs

•All pterosaurs

•All ichthyosaurs

•Many terrestrial plants

•Many marine animal



Mesozoic era

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