Lesson 2: Death and Fossilization

Question 1

What is taphonomy?

Answer 1

The study of all natural processes that involve an organism after it dies, including decay, scavenging, fossilization, and erosion.

Question 2

What is the phenomenon where a carcass floats due to decay gases?

Answer 2

Bloat-and-float.

Question 3

What are some factors that can contribute to the disarticulation of a skeleton?

Answer 3

• Partial consumption by carnivores
• Water currents carrying different portions
• Prolonged exposure to sunlight
• Trampling by animals
• Leaching by plant roots.

Question 4

What is plastic deformation in the context of fossils?

Answer 4

A process where pressure changes the shape of a buried fossil, which does not return to its original shape after pressure is removed.

Question 5

Which environments are best for preserving fossils?

Answer 5

Wet environments where burial by sand or mud occurs.

Question 6

What type of deposits are associated with lakes and have a better chance of preserving soft tissues?

Answer 6

Lacustrine deposits.

Question 7

What type of sedimentary rock usually indicates a former swampy environment?

Answer 7

Coal.

Question 8

What are the three basic types of rocks?

Answer 8

• Sedimentary rocks
• Igneous rocks
• Metamorphic rocks.

Question 9

What is sedimentology?

Answer 9

The science of how sedimentary rocks form.

Question 10

What are the two main processes by which dinosaur bone fossils form?

Answer 10

• Permineralization
• Replacement.

Question 11

Fill in the blank: Fossils are most commonly found in _______ rocks.

Answer 11

[sedimentary]

Question 12

What is overburden in paleontology?

Answer 12

The rock and earth that covers a fossil specimen.

Question 13

What is the ideal condition for finding dinosaur fossils?

Answer 13

Fossils that are freshly and barely exposed above ground.

Question 14

How are fossils protected during transport from field to laboratory?

Answer 14

Wrapped in protective material and covered with burlap soaked in plaster to form a rigid jacket.

Question 15

What clues can indicate how a dinosaur might have died?

Answer 15

Disarticulation of a skeleton, orientation of fossils, amount of abrasion on bones, and scratches indicating carnivore feeding.

Question 16

True or False: Fossils can be found in igneous rocks.

Answer 16

False.

Question 17

What is the significance of mapping the location of bones in a dinosaur excavation?

Answer 17

Helps in reconstructing the skeleton and provides important taphonomic clues.

Question 18

What type of deposits are formed from the accumulation of shells and exoskeletons?

Answer 18

Limestone.

Question 19

What is the effect of prolonged exposure to sunlight on skeletons?

Answer 19

Weakens and disintegrates bone.

Question 20

List the types of sedimentary rocks formed from mud and silt.

Answer 20

• Mudstone
• Shale.

Question 21

What indicates that bones were transported by water?

Answer 21

Alignment of long bones in the same direction.

Question 22

What does the orientation of long bones in a bonebed indicate?

Answer 22

It indicates that the bones were transported by water and shows the direction of water flow.

Long bones like femur or humerus aligned in the same direction provide insights into taphonomic processes.

Question 23

What can scratches on bones indicate?

Answer 23

They can indicate tooth marks from carnivores that fed on the carcasses.

Scratches do not necessarily mean the dinosaur was killed by that carnivore.

Question 24

What is the first step in the fossilization process?

Answer 24

The conditions necessary for a bone to become fossilized.

This includes rapid burial and anoxic conditions to prevent decay.

Question 25

In what types of environments are fossils most likely to be found?

Answer 25

Fossils are most likely found in sedimentary rock environments. ## Footnote These environments include riverbeds, lakes, and ocean floors.

Question 26

What are the stages in the final excavation of a large dinosaur bone?

Answer 26

1. Unearth the top surface and sides of the fossil 2. Add a protective layer of soft material 3. Cover with burlap strips saturated with plaster. ## Footnote The hardened plaster jacket allows for safe transport of the fossil.

Question 27

Fill in the blank: The amount of _______ on bones can give a relative sense of how far the bones may have been transported.

Answer 27

abrasion

Question 28

What should learners be able to evaluate regarding dinosaur fossils?

Answer 28

They should be able to evaluate the taphonomic history of a dinosaur fossil. ## Footnote This includes interpreting the processes that occurred after the organism's death.

Question 29

True or False: The presence of tooth marks on a bone always indicates that the dinosaur was killed by that carnivore.

Answer 29

False

Question 30

What is one suggestion for interpreting taphonomic processes?

Answer 30

Provide examples of environmental conditions and fossilization stages. ## Footnote This may include factors like sediment type and burial depth.

Question 31

What does the term 'taphonomic history' refer to?

Answer 31

The series of processes that affect an organism from the time of death to its discovery as a fossil. ## Footnote This includes decomposition, transportation, and burial.