Motivation:
Show students pictures of the following fossils. 1 and 2 were taken
from
http://thinkquest.org/library/site_sum.html?tname=J002507&url=J002507
The other pictures were found in a
Google image search on fossils.
Ask leading questions
such as:
1. What are
these pictures of?
2. Are these
all the same type of fossils?
3. Which fossil
is in amber?
4. Which fossil
shows a plant?
5. Which
fossils show marine life?
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Procedure:
1. Students are to go to the
following sites to research facts for the database below.
http://enchantedlearning.com/subjects/dinosaur/dinofossils and
http://web.ukonline.co.uk/conker/fossils/
Click here for a blank student
question database.
Question |
Answer |
1. What is a fossil? |
Fossils are the remains of ancient animals and
plants, the traces or impressions of living things from past
geologic ages, or the traces of their activities |
2. How are fossils of hard mineral parts (like
teeth and bone) formed? |
- Some animals
were
quickly buried after their death (by sinking in mud, being buried
in a sand storm, etc.).
- Over time, more and more
sediment covered the remains.
- The parts of the animals that didn't rot (usually the harder
parts likes bones and teeth) were encased in the newly-formed
sediment.
- In the
right circumstances (no scavengers, quick burial, not much
weathering), parts of the animal turned into fossils over time.
- After a long time, the chemicals in the buried animals' bodies
underwent a series of changes. As the bone slowly decayed, water
infused with minerals seeped into the bone and replaced the
chemicals in the bone with rock-like minerals. The process of
fossilization involves the dissolving and replacement of the
original minerals in the object with other minerals (and/or
permineralization, the filling up of spaces in fossils with
minerals, and/or recrystallization in which a mineral crystal
changes its form).
- This process results in a heavy, rock-like copy of the
original object - a fossil. The fossil has the same shape as the
original object, but is chemically more like a rock! Some of the
original hydroxy-apatite (a major bone constituent) remains,
although it is saturated with silica (rock).
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3. Where are most fossils found? |
Most fossils are found in sedimentary rocks - rocks
which were created when shells or small loose bits of rock were laid
down in layers. Examples of sedimentary rocks are limestone,
sandstone, clay and chalk.
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2. Have students log onto
http://discoveringfossils.co.uk/fossildictionary.htm and fill in
the following database with the definitions.
Click here for a blank student database.
Word |
Definition |
amber |
A resin
produced by certain trees since the Jurassic period. When secreted
from the bark, resin forms a sticky orange fluid which insects and
small creatures can become trapped in. Over time the resin hardens
to form Amber, thus preserving itself and any insect or creature
within. |
ammonite |
Probably
the most commonly associated fossil in the world. Ammonites are an
extinct group of marine 'cephalopod molluscs' that thrived during
the Jurassic and Cretaceous period (170 - 65 million years ago).
Ammonites consisted of a coiled shell within which the creature
lived. |
cambrian |
The period following the
Pre-Cambrian, where most marine invertebrates evolved 545 million
years ago. Most organisms before this period were not preserved in
the fossil record.
|
cretaceous |
A period
of time stretching from 142 - 65 million years ago. The end of this
period (the KT boundary) was marked by the mass extinction of the
dinosaurs. |
dinosaurs |
The
general name given to describe the land-dwelling reptiles which
lived between during the Triassic, Jurassic and Cretaceous period
(248 - 65 million years ago). |
extinction |
The
resulting term given to mark the end of a species or group of
creatures. Extinction usually results from a long-term change in
the environment, which subsequently triggers a period of decline and
eventual end. |
fossil |
The name given to the
remains of trace of creatures or plants which once existed. A
fossil is a rock-like copy of the original object, resulting from
the replacement of minerals with those of the surrounding rock.
|
Jurassic |
The period of time
extending from 206 to 142 million years ago. During this time, the
Dinosaurs evolved to become the most powerful and diverse group of
creatures to have lived on Earth to that time. |
Mesozoic |
The period of time, marked
with the great expansion of life in the sea and on the land. The
era stretched from 248 to 65 million years ago, and included the
evolution and demise of the dinosaurs. |
paleontology |
The
scientific study of fossils, their formation and preservation; the
formulation of theories and the history and evolution of ancient
life that fossils represent. |
psterosaurs |
The name given to a group
of giant flying reptiles which lived between the Late Triassic and
Cretaceous periods. |
trace fossil |
Evidence of former life
preserved as a mark on a rock. A good example would be dinosaur
footprints. |
triassic |
A period of time
stretching from 248 to 206 million years ago. During this time the
first dinosaurs began to evolve, which later dominated the earth
during the Jurassic and Cretaceous periods. |
trilobites |
A former
group of marine arthropods which were characterized by a hard
exoskeleton and threefold division of the body |
Activities:
1. Fossil Hunt-
Children can go on a fossil hunt in the classroom. Fill a shoebox
with sand, dirt, and gravel. Hide some "fossils" in the box.
As each one is found, children should list the date, the place, and what
the fossil is on an index card. This gives children experience in
fossil hunting and describing a fossil.
2. Fossil Jigsaw
Puzzle- Students can go to
http://www2.trafford.com/clientimages/Dinomike_StudyGuide.pdf and
print a jigsaw puzzle of a fossil. Then they can cut out the pieces
and put the fossil back together! 3.
Fossil Description- Children can log onto
http://usoe.k12.ut.us/curr/science/core/4th/4thSciber/fossils/html/intro.htm
and do the field study of the fossil in the picture as shown below".
Look
closely at the photograph on the left. This "rock" was found by
a student in Utah. Do you see fossils inside the rock?
Write a paragraph describing what the fossils in this rock look
like. |
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4. Have students log onto
http://usoe.k12.ut.us/curr/science/core/4th/4thSciber/fossils/html/whatKind.htm
and learn in which kind of rock a fossil can be found. This is an
interactive question and answer site.
Follow Up: This lesson will lead to
lesson 2- What are the different kinds of fossils?
Use the following links to navigate through
FOSSILS!
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