Relative Dating
any method of determining whether am event or object is older or younger than other events or objects.
Relative Dating
The trace or remains of an organism that lived a long time ago, most commonly preserved in Sedimentary rock.
Fossil
These Cambrian organisms are related to modern horseshoe crabs.
trilobites
The early earth was like this environment.
Hot and molten , volcanic
The unit of Geologic time that began 65.5 million years ago and continues to the present day _____.
Cenozoic Era
A principle that states that younger rocks lie about older rocks if the layers have not been disturbed.
Law of Superposition
_________ fossil is an example of insects caught in soft, sticky tree sap.
Amber
__________ is a mark or cavity made in a sedimentary surface by a shell or other body.
Mold
Cenozoic, Mesozoic, and Paleozoic are all these time amounts.
Eras
Age of the mammals______.
Cenozoic Era
Rock layers in which the oldest rocks are at the ________.
bottom
Most early life was _________ .
bacteria, algae, single celled
Footprints or worm burrows are evidence of how an animal lived, so they are called this.
Trace fossils
Humans are from this era.
Cenozoic
This was the cause of the dinosaur extinction at 65 mil years,
asteroid falling
Newest rocks are deposited here.
On the top of older rocks.
___________ places where asphalt/ tar wells up at the Earth's surface in thick, sticky pools.
Tar pits
______ fossil is found in the rock layers of only one geologic age and that is used to establish the age of the rock layers.
Index
The death of every member of the species is called____.
Extinction
Monkeys came along during which time period?
Cenozoic
Three examples of hard parts that are often preserved as fossils.
bones, shells, teeth, exoskeletons
_________ fossils are preserved form the last ice age.
Frozen
Fossils are most often preserved in _______ rocks.
Sedimentary Rock
__________ is the age of the reptiles/ dinosaurs.
Mesozoic
Sharks appeared during the ___ time period.
Paleozoic