Download Names: Date: ______ Period: ______ Fossils The ______ or

Names: ________________________________ Date: ___________ Period: _____________
Fossils
The ___________ or __________ of prehistoric life.
The type of _____________ that is formed is determined by _____________ __________________.
____________ Remains: for example ___________, ___________ and ______________.
____________ Remains

__________ often become _________ or turned to ____________.

_________ or _________ are another types of fossil

Carbonization ____________ leaves and delicate animals by burying them under
fine _________________.
_____________ Evidence

___________ fossils are indirect evidence of prehistoric life. For example, prints
burrow holes and fossilized poop (coprolites).

_________ conditions are important for preservation:
1. ___________________________
2. Possession of ________ ___________.
The Principle of fossil succession states that fossil organisms succeed one another in a definite and
determinable order. Therefore: __________ time period can be recognized by its ____________
____________.
Index fossils are
1. widespread geographically or _____ _________ _____________.
2. limited to short span of geologic time or __________ __________.
3. occur in large numbers.
Fossils can also be used to interpret and describe ____________ environments.
Index Fossil Activity #1:
1. Stack the letters in a sequence. TC represents the oldest layer of rock, with the oldest fossils in this
sequence.
2. Now, look for a card that has either a “T” or “C” written on it. Since this card has a common letter
with the first card, it must go on top of the “TC” card.
The fossils represented by the letters on this card are “younger” than the “T” or “C” fossils on the
“TC” card which represents fossils in the oldest rock layer.
3. Sequence the remaining cards by using the same process.
Write the letters in order from youngest to oldest. Use the letters only once.
____ ____ ____ ____ ____ ____ ____ ____ ____ __C__ __T__
1. How do you know that “X” is older than “M”?
2. Explain why “D” in the rock layer represented by DM is the same age as “M”.
3. Explain why “D” in the rock layer represented by OXD is older than the than “D” in the rock
layer resented by DM.
Index Fossil Activity #2
!. Carefully examine the second wet of cards which have sketches of fossils on them. Each card
represents a particular rock layer with ta collection of fossils that are found in that particular rock
layer. All of the fossils would be found in sedimentary rocks of marine origin.
2. The oldest rock layer is marked with the letter ”M” in the lower left-hand corner.
3. Find a rock layer that has at least one of the fossils you found in the oldest rock layer. This rock
layer would be younger as indicated by the appearance of new fossils in the rock layer. Remember
after an organism disappears from the sequence or becomes extinct it cannot reappear later.
Arrange the cards from oldest to youngest with the oldest layer on the bottom and the youngest on
top.
4. Using the letters printed in the lower left-hand corner of each card, write the sequence of letters
from the youngest layer to the oldest layer. ____ ____ ____ ____ ____ _____ _____ ______
1. Which fossil organisms could possibly be used as index fossils?
Assume that these fossils are in many places and there are many specimens.
Remember that they must be in only one layer to be an index fossil.
2. Name three organisms represented that would not be good index fossils and explain why.
3. What is the Law of Superposition and explain how this activity shows this law.
4. Explain why fossils are only found in Sedimentary Rocks?