Fossil Record

Question 1

uniformitarianism

Answer 1

a principle that states the geologic process that occurred in the past can be explained by current geologic process

Question 2

catastrophism

Answer 2

a principle that states that geologic change occurs suddenly

Question 3

paleontology

Answer 3

the scientific study of fossils

Question 4

relative dating

Answer 4

any method of determining whether an event or object is older or younger than the events or objects

Question 5

absolute dating

Answer 5

any method of measuring the age of an event or object in years

Question 6

superposition

Answer 6

a principle that states that younger rocks lie above older rocks if the layers have not been disturbed

Question 7

isotope

Answer 7

an atom the has the same number of protons (or the same atomic number) as other atoms of the same element do but that has a different number of neutrons ( and thus a different atomic number)

Question 8

radioactive decay

Answer 8

the process in which a radioactive isotope tends to break down into a stable isotope of the same element or a different element

Question 9

half-life

Answer 9

the time needed for half of a sample of radioactive substance to undergo radioactive decay

Question 10

fossil

Answer 10

the remains or physical evidence of an organism preserved by geological process

Question 11

trace fossil

Answer 11

a fossilized mark that is formed in soft sediment by the movement of an animal

Question 12

mold

Answer 12

a mark or cavity made in a sedimentary surface by a shell or other body

Question 13

cast

Answer 13

a type of fossil that forms when sediments fill in the cavity left by a decomposed organism

Question 14

unconformity

Answer 14

a break in the geologic record created when rock layers are eroded or when sediment is no deposited for a long period of time

Question 15

mass extinction

Answer 15

when a big group of organisms go extinct at the same time

Question 16

Jurassic period (for 16-20 list when the time period was and what was the dominant animal group on Earth)

Answer 16

00,000 results (0.62 seconds)
The Jurassic period (199.6 million to 145.5 million years ago) was characterized by a warm, wet climate that gave rise to lush vegetation and abundant life. Many new dinosaurs emerged—in great numbers. Among them were stegosaurs, brachiosaurs, allosaurs, and many others

Question 17

Cretaceous period

Answer 17

The Cretaceous is defined as the period between 145.5 and 65.5 million years ago,* the last period of the Mesozoic Era, following the Jurassic and ending with the extinction of the dinosaurs (except birds).

Question 18

Devonian period

Answer 18

The Devonian is a geologic period and system of the Paleozoic, spanning 60.3 million years from the end of the Silurian, 419.2 million years ago, to the beginning of the Carboniferous, 358.9 Mya. It is named after Devon, England, where rocks from this period were first studied

Question 19

Quaternary period

Answer 19

The Quaternary Period is the third and last of the three periods of the Cenozoic Era. You and I are living in this period, which began only 2.58 million years ago. This is less than 0.1% of all of geologic time! A thin layer of sediments deposited during the Quaternary covers much of the Earth’s land surface.

Question 20

Permian period

Answer 20

The Permian is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period 298.9 million years ago, to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era.