Geologic Time 7th

The period of the Paleozoic era named for large coal deposits that formed is the

During what period did mammals first appear in the Mesozoic Era?

The preserved remains or traces of living things are called

The geologic age of a fossil, or a geologic event or structure expressed in units of time, usually years. Also known as actual age.

The process whereby organisms better adapted to their environment tend to survive and produce more offspring. The theory of its action was first fully expounded by Charles Darwin and is now believed to be the main process that brings about evolution.

Which are the periods of the Mesozoic era in order from the beginning?

A place where organisms live, grow, and interact with each other and with their environment

The middle era: Age of the Dinosaurs is the

Scientists who study the earth are called

Scientists who study fossils are called

All of the following show examples of relative ages EXCEPT:

When many types of living things become extinct at the same time it is called

Fossils provide evidence for all of the following EXCEPT for

How many periods is the Paleozoic Era broken into?

All of the following things scientists learn by studying fossils EXCEPT:

A type of organism that no longer exists and will never again live on Earth is said to be

Based on fossil record, organisms appear to have followed and ordered series of changes. This change in life-forms through time is known as ________

The longest geological time unit in Earth's history

Which time did oxygen appear?

The gradual change in living things over long periods of time is called

Decay: the spontaneous disintegration of a radioactive substance along with the emission of ionizing radiation

Fish dominate this era

A species becomes __________________ when only a small number of its members are living.

Subdivisions of time in the periods of the Cenozoic era are called

Which era did Pangaea break up?

Measurement of the amount of radioactive material (usually carbon 14) that an object contains; can be used to estimate the age of the object

Warm shallow seas covered much of Earth's surface during the _________ era. Because of this, most of the life-forms were marine, meaning they lived in the ocean.

Fossils are usually found in what type of rock?

On the geologic time scale, eras are subdivided into

In the Cambrian Explosion

A _________ has often been defined as a group of organisms that normally reproduce only among themselves

A gap in the geologic record formed when sedimentary rocks cover an erosion surface is called a(n)

__________ also known as the building blocks of life.

__________ are based on the types of life existing at the time and on geologic events, such as mountain building and plate movements.

How old is the earth?

Which era did the climate become cooler and the ice ages occur?

Earths most recent era is the

Hard parts of organisms usually leave fossils because

Homo sapiens first appeared during what era?

The Geologic Time Scale is