The Great Paleozoic Extinction

• The formation of Pangea resulted in a much dryer climate.

• By the end Permian 57% of the amphibian families declined and plants decreased in number and variety.

• Many marine organisms did not adapt or survive.

• The estimate is that 80-95% of all marine organisms became extinct because they could not adapt.

What Dies out and Why?

• _________ great extinctions1. 440 m.y.a.~ only a few species survived2. 370 m.y.a. ~70% of marine invertebrates3. 225 m.y.a. ~ 80-96% of marine species4. 200 m.y.a. ~ many sea and land species5. 65 m.y.a. ~ 33% of all species. All marine

reptiles, dinosaurs, etc.

Causes Extinction

• ***** _________• _________• _________• _________• _________

Extinctions are _________ causing evolutionary changes.

• Each of the five extinctions wiped out large masses of families and species and in each case the survivors having little or no competition diversified to fill the vacated niches.

Mesozoic Era: Age of Reptiles

This era is divided into three periods:

• Cretaceous• Jurassic• Triassic

Mesozoic History

• Much of North America is above sea level.

• By the end of the Jurassic period shallow seas (epicontinental seas) invaded western North America, the Atlantic and Gulf coasts.

• These shallow seas eventually formed gigantic swamps and later developed into coal deposits.

• Pangea begins to break up. • The eastern part of the United States

splits from Africa giving birth to the Atlantic Ocean.

• The western part of North America pushes westward over riding the Pacific plate causing tectonic activity to increase resulting in the formation of the Rocky Mountains.

Mesozoic Life

• On land life adapted to a dryer climate flourished.

• _________ or seed bearing plants develop taking advantage of nutrient rich soils.

• They became the dominant plant of the Mesozoic.

• Gymnosperms include:• _________ – resemble a large

pineapple plant • _________ – cone bearing – includes

pine, firs, and junipers• _________ – fan-like leaves

The Shelled Egg vs The Egg Without A Shell

Amphibian Eggs:• _________• _________• _________• _________

• _________• _________• _________• _________

Reptile Eggs

Reptiles Dominate

Lets take a look at the land the dinosaurs lived on and then take a good look at the evolution of reptiles………

Oldest ( reptiles )

• Are _________ million years old• Many were small and squatty looking• A few actually walked upright• At first they were not huge like they

became later.

What was it for?

Some early dinosaurs had a fin on their back.

• _________

• _________

Why did the dinosaurs become so large?

• When the climate becomes _________, reptiles will become larger and dominate.

• As the climate _________, mammals will become large and dominate

Would there have been…….

•more herbivores or more carnivores?

• _________

Sauropods

• Apatosaurus (Brontosaurus)

• Brachiosaurus• Superiosarus

All had long necks, large bodies and were herbivores

Cretaceous

• No grasses yet, but we already have flowering plants

• _________ – herbivores that could chew their food.

• _________ – could not chew their food (gizzard).

• _________ – bird like dinosaurs including veloceraptor.

• Reptiles radiate until they even occupy the poles.

Flying reptiles not dinosaurs:They were pterosaurs – flying reptiles

Jurassic

• Dinosaurs split in to two groups:

_________

_________

What do we know about T. Rex adults?

Most likely a _________ because?

• _________• _________. • Thigh bone to long to be

able to run fast. Compare to birds who are fast. T. Rex was a better _________.

• Great sense of _________ l.

• _________– optic nerve very small.

How did carnivores get their food?

1. _________.

2. _________.

3. _________.

Reptiles at the poles, how is this possible?

1. _________.2. _________.

Is it possible that…..

Some of the smaller dinosaurs were warm blooded.

If that is true, then is it possible that some of them could have evolved into :

_________

Original birds

has feathers, some could fly, had teeth

EX: _________ - could fly _________

Dinosaur Extinction

What was the over all reason for dinosaur extinction ?

_________This was caused by:

1. _________

2. _________3. _________

This directly affect the dinosaurs by?

1. _________2. _________3. _________4. _________

Cenozoic Era

Age of _________ - 65 m.y.a.

The Cenozoic is divided into two periods:

Quaternary – the last 2 million years

Tertiary

Cenozoic Life

• Mammals become the dominant form of life.

• Angiosperms – flowering plants with covered seeds replace gymnosperms as the dominant land plant.

• _________ influence the development of both birds and mammals.

• _________ develop by the Tertiary period making them one of the newest plants.

• This fostered the emergence of herbivorous mammals that later established conditions for carnivore evolution.

Warmblooded means:

1- a constant _________2- a need to _________3- more _________ organisms4- development of _________, more

efficient _________ and lungs, _________ to nourish young

Mammal diversification adaptations include:

1- increase in _________2- increase in _________3- specialization of _________ to better

accommodate a particular diet4- specialization of _________ to better

equip the animal for life in a particular environment

Original Mammals

1. _________ : ex: _________ _________

Original Mammals

2. _________ :

pouched mammals

EX: _________ _________ _________ _________ _________ _________ _________

Original Mammals

3. _________ : ex: all modern mammals

Large Mammals and Extinction

• Many large mammals existed until 11,000 years ago.

• This list includes:• Mammoth• Saber-toothed cats• Horses• Giant ground sloths• Large beaver• Giant bison• Camels

Human’s Affect Other Species

• Humans may have played a part in the extinction of the animals, but there must be a much better reason. What could it be?

• If an animal can reproduce at a rate that is ____% higher than a competing organism, the animal with the higher birth rate will win out and survive while its competitor will become extinct.