The law of superposition states that in undisturbed layers of sedimentary rock...

older layers of rock lie beneath younger layers of rock

younger layers of rock lie beneath older layers of rock

Which principle states that in a sequence of undisturbed sedimentary rocks, the oldest layers are at the bottom?

Principle of Original Horizontality

an organism that existed only briefly

distinctive: easily recognizable and unique

widely distributed: found in many different locations around the world

abundant: many fossils of the organism can be found in rock layers

small changes to the environment

Fossil C is younger than Fossil D

Fossil C and D are the same age.

Fossil 1 is older than fossil 4.

Fossil 1 is younger than fossil 2.

Fossil 3 is older than fossil 2.

Fossil 3 is younger than fossil 4.

rock layer C, rock layer R, and rock layer Y

rock layer C, rock layer R, and rock layer Y rock layer B, rock layer Q, and rock layer X

widespread geographically, short lifespan

widespread geographically, long lifespan

it is not short-lived (in numerous layers)

the fossils and rock layers are the same age

the fossils from Montana are older

the fossils from England are older

all four are good index fossils

The fish fossil is not in Layer W of either location.

The fish fossil is in Layer Z of the Location 1.

The fish fossil is in Layer X and Y of location 2.

The fish fossil is not in Layer Z of Location 2.

between 240 and 400 million years old

between 400 and 550 million years old

younger than 240 million years old

older than 550 million years old

an absence of fossils in the layers of the fossil record

the evolution of a single species in the fossil record

organisms becoming more complex in the fossil record

the emergence of a new species in the fossil record.