Fossil Preservation

1
Fossil Preservation

• How to be preserved
• for a long, long time

2
FOSSIL PRESERVATIONTypes of Fossils1. Hard
parts-shells, bones, teeth, skulls,
wood-usually preserved with some
alteration2. Soft parts-skin, hair, feathers,
wings, cartilage and muscles, tendons, rare
internal organs (dino heart)

3
FOSSIL PRESERVATION

• 3. Molds and traces
• -molds are impressions of body fossils,
• are sedimentary replicas of fossils
• -traces indicate presence or activity of
• organisms burrows, tracks, trails
• 4. Chemical fossils
• -carbon compounds and organic materials
• provide indirect evidence of life (important in
  the Precambrian)

4
FOSSIL PRESERVATION
II. Composition of Fossil Material 1. Hard
parts a. inorganic components -CaCO3 (calcium
carbonate), common makeup of shells, limestone
rock -SiO2 (silica), less common in shells
common makeup of quartz, chert rock -CaPO4
(calcium phosphate), common in teeth and bones,
phosphorite rock
5
FOSSIL PRESERVATIONb. organic
components-Chitin (complex carbohydrate
molecule), common in trilobites and other
arthropod shells-Lignin (woody tissue),
contributes to coal (lignite is immature coal)

6
FOSSIL PRESERVATION

• 2. Soft parts
• a. organic components
• -Usually carbon-phosphate compounds
• -Plants Cellulose
• -Animals Skin, hair, and tissue keratin,
  elastin, protein

7
Fossils and Fossilization

• Death
• Taphonomy
• Burial
• Diagenesis
• Fossilization

8
Taphonomy

• Everything that happens after death, and before
  fossilization
• Scavengers, wear, transportation
• Time Averaged Animals may not have lived
  together, or died together, they were just buried
  together

9
Types of Fossilization

• Preservation with little alteration (original
  preservation)
• What are other examples of original preservation?

10
Unaltered Preservation

• Amber Deposits

11
Types of Fossilization

• Preservation with little alteration (original
  preservation)
• How do natural mummies form?

12
Original Preservation

• Natural mummification by drying
• How Old can a Mummy Be?

13
Dinosaur Mummy

• Oldest Mummy found
• Has skin, tendons, muscle
• From an ashfall in Cretaceous Wyoming

14
Dinosaur Mummy

• 77 million years old
• Even has stomach contents!!!
• Duckbill Dinosaur
• Hadrosaur

15
Duckbill Mummy
16
Unaltered Preservation

• Bison and Woolly Mammoth Skin and Hair

17
Mammoth Ivory from Russia

• Thousands of pounds found

18
Freezing

• Otzi the Iceman
• 5300 Years old
• From Italian Alps

19
Otzi the Iceman

• Well preserved
• Incredible detail

20
Reconstruction

• Allows for a visual image of life in the past

21
Types of Fossilization

• Casts
• Molds

22
Molds and Casts

• What kind of animal is shown by this fossil?

23
Molds/Impressions

• What animals are shown by the impressions?

Trilobites
Archaeopteryx
24
Replacement

• Silica replacement of carbonate shell
• What kind of animal is this?

Brachiopod
25
Replacement

• Note new mineral that has replaced carbonate
  shell
• What kind of fossil animal is shown?

Ammonite
26
Petrification

• Petrified wood from the Petrified Forest National
  Park in Arizona

27
Permineralization/Petrification

• Common preservation in wood and bone
• Which image is the altered/permineralized bone?

This one
28
Trace Fossils

• Coprolites

Fossil Poop
29
Gastrolith/ Entrolith/ Stomach Stones

• Birds, reptiles, herbivores use stones in their
  stomachs to grind coarse plant matter
• found either with skeletons or by themselves

30
Gastroliths
31
Trace Fossils

• Footprints, trackways
• Note molds and casts

32
Trace Fossils

• Burrows
• Indicate movement, activity of organism

33
Types of Fossilization

• What types of preservation are shown in this
  image?
• What kind of animal is this fossil?

Horseshoe Crab
34
Carbonization

• Common in plants and animal soft parts

35
Recap of Preservation Types

• Unaltered Preservation
• Encased
• Dried
• Frozen

36
Recap of Preservation Types

• Fossil Conditions
• Casts
• Molds
• Impressions
• Carbonization

37
Recap of Preservation Types

• Replacement
• Permineralization
• Petrification
• Petrified wood, bone
• Very Common
• Usually Dense

38
Recap of Preservation Types

• Trace Fossils
• Ichnofossils
• Tracks
• Burrows
• Coproliths
• Entroliths/ Gastroliths
• Chemical Signatures