CHAPTER 2 - Death and Fossilization

Question 1

what is Taphonomy

Answer 1

the study of all natural processes that involve an organism after it dies – this includes how it decays, is scavenged by other organisms, becomes fossilized, and erodes.

Question 2

Shortly after death, decay may cause a body to swell with putrid gasses, and this may cause the carcasses of even large animals to float easily and to be transported by shallow and weakly flowing water. This is Called

Answer 2

bloat-and-float

Question 3

Plastic deformation occurs when

Answer 3

pressure causes the shape of a buried fossil to be changed such that, even when the pressure is later removed, the fossil does not return to its original shape.

Question 4

River and stream deposits are called

Answer 4

fluvial deposits

Question 5

when Animals die and are preserved in lakes it is called

Answer 5

lacustrine deposits

Question 6

With only a few rare exceptions, all fossils are found in what type of rock

Answer 6

sedimentary rocks

Question 7

Sedimentary rocks are rocks that form when

Answer 7

mineral and organic particles accumulate and become either cemented or compacted together

Question 8

igneous rocks form when

Answer 8

magma or lava cools

Question 9

metamorphic rocks form when

Answer 9

form deep underground when sedimentary or igneous rocks are changed by extreme heat and pressure.

Question 10

Sedimentology is the science of how

Answer 10

sedimentary rocks form.

Question 11

Understanding the environmental conditions that led to the formation of the particular sedimentary rocks that contain a fossil can

Answer 11

give important clues about the habitat of the fossil organism.

Question 12

Sedimentary rocks that form from mud and silt are called __ and __

Answer 12

mudstone AND shale

Question 13

Sedimentary rocks that form from sand are called

Answer 13

sandstone

Question 14

Coal is a special kind of sedimentary rock that forms from

Answer 14

the compressed remains of plants, and coal indicates a former swampy environment.

Question 15

Limestone is formed from

Answer 15

from the accumulation of shells and exoskeletons of small marine invertebrates, and limestone always indicates a former shallow marine environment.

Question 16

The different ways that fossils form are called

Answer 16

preservation styles

Question 17

Most dinosaur bone fossils form through either

Answer 17

Permineralization or Replacement

Question 18

Permineralization occurs when

Answer 18

the empty internal spaces of a bone are filled with minerals. These minerals are first dissolved in water and are then deposited in the empty bone spaces as water soaks through the bone.

Question 19

Replacement occurs when

Answer 19

the original bone gradually decays and minerals fill the space that the bone once occupied.

Question 20

Why are the badlands an optimal place for fossil search?

Answer 20

Because to prevent a fossil from eroding away, it must remain buried. However, the burial process must be at least partially reversed in order for the fossil to be near enough to the surface to be found. Dinosaur fossils are, therefore, most commonly found in modern environments where there is considerable recent erosion.

Question 21

Overburden is the

Answer 21

rock and earth that covers a fossil specimen and that must be removed before the full extent of the specimen can be judged. Overburden removal usually involves large indelicate tools like shovels, pickaxes, and occasionally even jackhammers and bulldozers.

Question 22

Disarticulation of a skeleton may occur as

Answer 22

carnivores eat the carcass, or because the specimen was transported by water.

Question 23

long bones (like the femur or humerus) that are aligned in the same direction indicate that

Answer 23

the bones were transported by water, and tell us the direction the water was flowing.

Question 24

The amount of abrasion on the bones can give a relative sense for

Answer 24

how far the bones may have been transported by flowing water.

Question 25

Stages in the final excavation of a large dinosaur bone step 1

Answer 25

First, the top surface and sides of the fossil are fully unearthed.

Question 26

Stages in the final excavation of a large dinosaur bone step 2

Answer 26

a protective and cushioning layer of soft and tight-fitting material is added – in this case, moist paper towels.

Question 27

Stages in the final excavation of a large dinosaur bone step 3

Answer 27

the fossil is covered by strips of burlap saturated with plaster. Once hardened, the protective jacket is complete and the fossil may be safely lifted and carried away.