Fossils

The end of the Paleozoic era is marked by a mass extinction. What is a mass extinction?

• one species evolves into another similar species

• all members of the same species die out unexpectedly

• large numbers of certain species become extinct overnight

• many species become extinct over a short period of geologic time

Similar fossils of organisms that can't swim have been found on both sides of the Atlantic Ocean. How did this happen?

• carbon film dating

• plate tectonics

• index fossils

• relative age

What have scientists determined about woolly mammoths?

• They were able to live in the very cold climate of the ice age.

• Their fur helped block spears from hunters.

• The more fur on their bodies, the older they were.

• The fur made their bodies too warm and caused them to become extinct.

Kyle found a rock and used a hammer to split it open. One half of the rock had a raised shape of a shell. The other had an impression of a shell. What type of fossil did Kyle find?

• a shell preserved in amber

• a mold and a cast of a shell

• a shell frozen in rock

• a trace fossil of a seashell

The Green River Formation in Wyoming is made of layers of rock that contain fabulous fish fossils. The figure above shows the type of fossils that are found in these rocks. What most likely occurred to allow the fish to be preserved so well?

• Animals ate the fish so the bones were clean and ready to turn to fossils.

• The fish got buried in sediment.

• The fish moved along until it landed in a safe quiet place.

• The temperature increased until conditions were right to form fossils.

Index fossils help determine the age of a rock layer that has been moved out of its normal position by an earthquake. Why?

• They are the oldest fossils ever found.

• They show the relative age of rock formations.

• They are evidence of animal activities in an area.

• They formed at only one particular time.

Which of the following fossils would make a good index fossil?

• a snail that lived in Ohio, in a small population during the Cenozoic

• a trilobite that lived in all areas east of the Mississippi River, in large populations during the end of the Paleozoic

• a tree fern that lived in northeastern Pennsylvania, in a small population during the Mesozoic

• a magnolia flower that lived in the eastern United States, in large populations during the Cenozoic

What have scientists determined about woolly mammoths?

• They were able to live in the very cold climate of the ice age.

• The more fur on their bodies, the older they were.

• Their fur helped block spears from hunters.

• The fur made their bodies too warm and caused them to become extinct.

Plants and animals become fossilized in several different ways. Which object fossilized most recently?

• A

• B

• C

• D

How could you demonstrate relative dating using a stack of newspapers?

• by identifying the age of each paper by the date listed at the top of each one

• by noting the dates of the top and bottom papers

• by describing the placement of the papers within the entire stack

• by comparing the stack of papers to a stack from a different newspaper