PaleontologyPaleontologyor ‘Study of Fossils’or ‘Study of Fossils’

Historical perspectives Historical perspectives on Fossilson Fossils

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How to become a fossil How to become a fossil without really tryingwithout really trying

Leonardo da VinciLeonardo da Vinci(1452-1519)(1452-1519)

Leonardo sketched fossils and recognizedthem as the remains of ancient life.

FossilsFossils

Remains or traces of ancient lifeRemains or traces of ancient life

Bones, Teeth, Shells, Tracks, TrailsBones, Teeth, Shells, Tracks, Trails

Soft tissues – rareSoft tissues – rare

?-How does an organism ?-How does an organism become a fossil?become a fossil?

Rapid burial is Rapid burial is essentialessential

Protection from Protection from scavengers, scavengers, decomposers, decomposers, physical deteriorationphysical deterioration

What helps? How do we re-What helps? How do we re-build human form?build human form?

Hard or durable Hard or durable tissues, such as:tissues, such as:

ShellsShells

BonesBones

TeethTeeth

ExoskeletonExoskeleton

Woody tissueWoody tissue

bonesbones

woody stemswoody stemsshellsshells

Most fossils Most fossils are formed are formed from the hard from the hard parts of parts of organisms. organisms.

?-What conditions favor ?-What conditions favor preservation?preservation?

Rapid burial is most likely in oceanRapid burial is most likely in ocean

Sea creatures with shells are fairly easy to Sea creatures with shells are fairly easy to preservepreserve

Conclusion: Marine organisms with hard Conclusion: Marine organisms with hard parts are most likely to become fossilsparts are most likely to become fossils

Types of PreservationTypes of Preservation

Original shell, bone or teethOriginal shell, bone or teethMolds and CastsMolds and CastsTrace fossils: burrows, tracks, trailsTrace fossils: burrows, tracks, trailsSoft TissuesSoft Tissues– Carbon filmCarbon film– AmberAmber– Mummified ?-Mummified ?-What does mummification have What does mummification have

to do with fossils?to do with fossils?– FrozenFrozen

Fossils can also form when Fossils can also form when organisms are preserved in organisms are preserved in resins.resins.

Tracks of organisms can be Tracks of organisms can be preserved.preserved.

Where Fossils OccurWhere Fossils OccurAlmost Exclusively in Sedimentary RocksAlmost Exclusively in Sedimentary Rocks

Heat of Melting or Metamorphism Would Heat of Melting or Metamorphism Would Destroy Almost Every Type of Fossil Destroy Almost Every Type of Fossil

Rare Exceptions: Rare Exceptions: – Some Fossils in Low-grade Metamorphic RocksSome Fossils in Low-grade Metamorphic Rocks– Trees Buried by Lava Flow Trees Buried by Lava Flow

To Be Preserved, Organisms Have to Be:To Be Preserved, Organisms Have to Be:

Buried Rapidly After Death Buried Rapidly After Death

Preserved From Decay Preserved From Decay

Ripple Marks, Bay BeachRipple Marks, Bay Beach

Fossil Ripple Marks, Baraboo Fossil Ripple Marks, Baraboo RangeRange

?-What would this observation ?-What would this observation tell a scientist?tell a scientist?

Fossil

Current

Modern Mud CracksModern Mud Cracks

Fossil Mud Cracks, VirginiaFossil Mud Cracks, Virginia

?-What would this observation ?-What would this observation tell a scientist?tell a scientist?

CurrentFossil

Original Hard MaterialOriginal Hard Material

Altered Hard TissueAltered Hard Tissue

Molds and CastsMolds and Casts?-Explain how this happened.?-Explain how this happened.

Carbon FilmCarbon Film

AmberAmber?-Explain how this happened.?-Explain how this happened.

Impression and Carbon filmImpression and Carbon film

?-Explain how this happened.?-Explain how this happened.

Carbon Film - PlantsCarbon Film - Plants?-Explain what this is. ?-Explain what this is.

?-Is it soft tissue or hard tissue and why??-Is it soft tissue or hard tissue and why?

Define: Define: SuperpositionSuperposition::

Mindoro Cut, Mindoro Cut, WisconsinWisconsin

Dating TechniqueDating Technique

?-Why/how do ?-Why/how do we usewe useFossils?Fossils??-What do they ?-What do they tell us?tell us?

History of Life on EarthHistory of Life on Earth

Evolution – appearances of new speciesEvolution – appearances of new species

Extinction – disappearances of speciesExtinction – disappearances of species

Guide in exploring for fossil fuelsGuide in exploring for fossil fuels

Commonly Preserved:Commonly Preserved:

Hard Parts of Organisms:Hard Parts of Organisms:

Bones Bones

Shells Shells

Hard Parts of Insects Hard Parts of Insects

Woody Material Woody Material

Rarely PreservedRarely Preserved

Soft or Easily Decayed Parts of Soft or Easily Decayed Parts of Organisms:Organisms:

Internal Organs Internal Organs

Skin Skin

Hair Hair

FeathersFeathers

Dinosaur Dinosaur Tracks, Tracks, TexasTexas

?-This is ?-This is called called what?what?

Fossil Tree in Lava Flow, Fossil Tree in Lava Flow, HawaiiHawaii