Chapter 9

Question 1

paleontology

Answer 1

The study of extinct organisms, based on their fossilized remains.

Question 2

fossils

Answer 2

The preserved remnants of once-living things, often buried in the ground.

Question 3

geology

Answer 3

The study of the earth.

Question 4

taphonomy

Answer 4

The study of what happens to the remains of an animal from the time of death to the time of discovery.

Question 5

strata

Answer 5

Layers of rock.

Question 6

stratigraphy

Answer 6

the study of the order of rock layers and the sequence of events they reflect.

Question 7

geologic time scale (GTS)

Answer 7

The categories of time into which Earth’s history is usually divided by geologists and paleontologists: eons, eras, periods, epochs

Question 8

provenience

Answer 8

The origin or original source (as of a fossil).

Question 9

relative dating techniques

Answer 9

Dating techniques that establish the age of a fossil only in compari-son to other materials found above and below it.

Question 10

lithostratigraphy

Answer 10

The study of geologic deposits and their formation, stratigraphic rela-tionships, and relative time rela-tionships based on their lithologic (rock) properties.

Question 11

tephrostratigraphy

Answer 11

A form of lithostratigraphy in which the chemical fingerprint of a volcanic ash is used to correlate across regions

Question 12

biostratigraphy

Answer 12

Relative dating technique using comparison of fossils from dif-ferent stratigraphic sequences to estimate which layers are older and which are younger.

Question 13

calibrated relative dating techniques

Answer 13

Techniques that can be correlated to an absolute chronology.

Question 14

chronometric dating techniques

Answer 14

Techniques that estimate the age of an object in absolute terms through the use of a natural clock, such as radioactive decay or tree ring growth.

Question 15

radiometric dating

Answer 15

Chronometric techniques that use radioactive decay of isotopes to estimate age.

Question 16

isotopes

Answer 16

Variant forms of an element that differ based on their atomic weights and numbers of neutrons in the nucleus. Both stable and un-stable (radioactive) isotopes exist in nature.

Question 17

half-life

Answer 17

The time it takes for half of the original amount of an unstable isotope of an element to decay into more stable forms.

Question 18

parent isotope

Answer 18

The original radioactive isotope in a sample.

Question 19

daughter isotope (product)

Answer 19

The isotope that is produced as the result of radioactive decay of the parent isotope.

Question 20

potassium–argon (K–Ar)

Answer 20

dating Radiometric technique using the decay of 40K to 40Ar in potassi-um-bearing rocks; estimates the age of sediments in which fossils are found.

Question 21

argon–argon (40Ar/39Ar)

Answer 21

dating Radiometric technique modified
from K–Ar dating that measures 40K by proxy using 39Ar. Allows measurement of smaller samples with less error.

Question 22

fission track dating

Answer 22

Radiometric technique for dating noncrystalline materials using the decay of 238Ur and counting the tracks that are produced by this fission. Estimates the age of sedi-ments in which fossils are found.

Question 23

cosmogenic radionuclide dating

Answer 23

Radiometric dating technique that uses ratios of rare isotopes such as 26Al, 10Be, and 3He to estimate the time that sediments and the fos-sils in them have been buried.

Question 24

paleosol

Answer 24

Ancient soil.

Question 25

plesiadapiform

Answer 25

Mammalian order or suborder of mammals that may be ancestral to later Primates, characterized by some but not all of the primate trends.

Question 26

prognathic face

Answer 26

Projection of the face well in front of the braincase.

Question 27

postorbital bar

Answer 27

A bony ring encircling the lateral side of the eye but not forming a complete cup around the eye globe.

Question 28

diastema

Answer 28

Gap between anterior teeth.

Question 29

adapoids

Answer 29

Superfamily of mostly Eocene primates, probably ancestral to all strepsirhines.

Question 30

omomyoids

Answer 30

Superfamily of mostly Eocene primates, probably ancestral to all haplorhines

Question 31

dental apes

Answer 31

Early apes exhibiting Y-5 molar patterns but monkey-like postcra-nial skeletons.

Question 32

r-selected

Answer 32

Reproductive strategy in which females have many offspring, interbirth intervals are short, and maternal investment per offspring is low.

Question 33

k-selected

Answer 33

Reproductive strategy in which fewer offspring are produced per female, interbirth intervals are long, and maternal investment is high.

Question 34

molecular clock

Answer 34

A systematic accumulation of genetic change that can be used to estimate the time of divergence between two groups if relative rates are constant and a calibra-tion point from the fossil record is available

Question 35

relative rate test

Answer 35

A means of determining whether molecular evolution has been occurring at a constant rate in two lineages by comparing whether these lineages are equidistant from an outgroup.