The Stories Fossils TellThe Stories Fossils Tell

Can you name the 4 Can you name the 4 types of Fossils ?types of Fossils ?

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Name the 4 types of FossilsName the 4 types of Fossils

MoldMoldTraceTraceCastsCastsTrue formTrue form

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Describe how Mold Describe how Mold Fossils are formedFossils are formed..

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Mold FossilsMold Fossils

--are usually formed in sedimentare usually formed in sediment-organisms like shells, leaves or bones, -organisms like shells, leaves or bones,

are covered with mudare covered with mud-over time mud hardens-over time mud hardens

-water enters mold and dissolves dead -water enters mold and dissolves dead organismorganism

-mold fossils are HOLLOW on the inside-mold fossils are HOLLOW on the inside

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Describe how Casts Describe how Casts Fossils are formed.Fossils are formed.

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Casts fossilsCasts fossils

--need a mold fossilneed a mold fossil first first-after organism dissolves and -after organism dissolves and

leaves an empty spaceleaves an empty space-the empty space fills with -the empty space fills with

minerals –-as time passes it minerals –-as time passes it hardens to form a cast fossilhardens to form a cast fossil

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Describe how Trace Describe how Trace Fossils are formedFossils are formed..

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Trace FossilsTrace Fossils

-are markings left by animals-are markings left by animals-examples include leaf prints, -examples include leaf prints,

footprints, eggs and nestsfootprints, eggs and nests-Trace fossils are good for scientists to -Trace fossils are good for scientists to

use to understand animals’ use to understand animals’ BEHAVIORSBEHAVIORS

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Fossil footprints have yielded information about: Fossil footprints have yielded information about: Speed and length of stride and length of stride

whether they walked on two or four legs whether they walked on two or four legs the bone structure of the foot the bone structure of the foot

stalking behavior (a carnivore hunting a herd of stalking behavior (a carnivore hunting a herd of herbivores) herbivores)

the existence of dinosaur herds and stampedes the existence of dinosaur herds and stampedes how the tail is carried (few tail tracks have been how the tail is carried (few tail tracks have been

found, so tails were probably held above the found, so tails were probably held above the groundground) )

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Describe how True Describe how True Form Fossils are Form Fossils are

formed.formed.

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True Form FossilsTrue Form Fossils

True Form fossils are formed when the animals soft tissues or hard parts did not

decay over the years because they are trapped in sap that hardens to become

amber.

This evidence gives scientists This evidence gives scientists the BEST observation of past the BEST observation of past

plants and animals.plants and animals. 1212

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Fossils start out as living things.Fossils start out as living things.

The organism can be either a plant or an animal.

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When the organism dies . . .When the organism dies . . .

The soft parts that are The soft parts that are exposed to air exposed to air decompose quickly.decompose quickly.

Hard parts like bones, Hard parts like bones, shells, or wood, don’t shells, or wood, don’t decompose as decompose as quickly. They have quickly. They have the greatest chance the greatest chance of becoming a fossil.of becoming a fossil.

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The organism may be buried in layers The organism may be buried in layers deep in the earth. These layers might deep in the earth. These layers might be composed of mud, lava or water.be composed of mud, lava or water.

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Sediments

Basalt

Fossil layer

Sandstone

Basalt

CoalSedimentary Rock

Basalt

Scientists sometimes dig in the Scientists sometimes dig in the Earth looking for fossils.Earth looking for fossils.

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How do fossils help us learn about How do fossils help us learn about the past?the past?

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Thinking like a paleontologistThinking like a paleontologist

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Look at these pictures of things that come from a tree. Make a prediction about the environment where you would find this tree.

Would the tree live in this environment?

… or, would the tree live in this environment?

Let’s practice making inferences Let’s practice making inferences about living things.about living things.

This is more difficult isn’t it? Why? What would help you decide on the correct environment?

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Can you be a paleontologist?Can you be a paleontologist?

Here in an example of the kinds of fossil your team has found. What do you think the environment might have been like in the past?

This is the environment where you are looking for fossils.

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Let’s try another example!Let’s try another example!

You just found the plant fossils, on the left, in an area where it is now hot and dry like the picture on the right. What predictions can you make about what the environment might have been like in the past?

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““Once Upon a Time” is not just Once Upon a Time” is not just for fairy tales.for fairy tales.

Wooly MammothAsian Elephant

How are these two animals the same? How are they different?

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The wooly mammoth is the The wooly mammoth is the ancestor of the modern Asian ancestor of the modern Asian

elephant.elephant.

Wooly MammothAsian Elephant

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Once Upon a Time – A Look at the Once Upon a Time – A Look at the HorseHorse

Horse A

Horse B

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Change Over Time – A Horse’s Change Over Time – A Horse’s FootFoot

Note how the distance of the wrist bones from Note how the distance of the wrist bones from the ground changes. What else has the ground changes. What else has changed?changed?

wrist

Adapted from Florida Museum of Natural History. For more information visit their website at Adapted from Florida Museum of Natural History. For more information visit their website at http://www.flmnh.ufl.edu/natsci/vertpaleo/fhc/relatives1.htmhttp://www.flmnh.ufl.edu/natsci/vertpaleo/fhc/relatives1.htm

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How have the bones in horse feet changed over time? How have the bones in horse feet changed over time? Why might this have happened?Why might this have happened?

Let’s Look More CloselyLet’s Look More Closely

Adapted from Florida Museum of Natural History. For more information visit their website at Adapted from Florida Museum of Natural History. For more information visit their website at http://www.flmnh.ufl.edu/natsci/vertpaleo/fhc/relatives1.htmhttp://www.flmnh.ufl.edu/natsci/vertpaleo/fhc/relatives1.htm

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Fossils are formed under Fossils are formed under very special conditions.very special conditions.

They give us clues about They give us clues about what life was like long what life was like long ago.ago.

Fossils also give us clues Fossils also give us clues about the environment about the environment from a long time ago.from a long time ago.

They help us understand They help us understand that plant and animal that plant and animal species change over species change over time.time.

Wrap-Up

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Group 1, group 3, group 4, Group 1, group 3, group 4, group 2group 2

Group 2 is the youngest.Group 2 is the youngest.

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a.Rivers deposited the shellsb.The region was once under an ocean environmentc.Early Native American left them there.

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b.The region was once under an ocean environment

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