Earth History and Fossils

Which best describes a fossil that helps determine the relative age of a rock layer?

• trace fossil
• index fossil
• radioactive fossil
• unconformity fossil

Modern mammals was during this era:

• Cenozoic
• Mesozoic
• Paleozoic

Age of reptiles was during this era:

• Cenozoic
• Mesozoic
• Paleozoic

Age of fish was during this era:

• Cenozoic
• Mesozoic
• Paleozoic

______ lived through most of the Mesozoic era:

• Dinosaurs 
• Fish 
• Mammals

The earliest part of Earth's history is called the:

• Cenozoic
• Cambrian
• Holocene
• Precambrian

_________ is a cavity or impression left behind in rock when an organism's buried remains are dissolved. The shape of the organism's exterior can be seen in the walls and floor of the cavity.

• Mold
• Cast
• Trace
• Index

________ is a mold that has been filled in with sediments which hardened and took the shape of the cavity.

• Cast
• Mold
• Trace
• Carbon film

When permineralization and replacement both occur in a fossil, the fossil is said to be

• Petrified
• Cast
• Mold
• Preserved

After Precambrian time, Earth's history is divided into three eras, beginning with the

• Paleozic Era
• Mesozoic Era
• Cenozoic Era