Wildlife of Gondwana

Transcription

Wildlife of Gondwana
Unit of Work: Level 3
PrimeSCI!
Credits
This teacher resource booklet was devised and produced by the following
members of the staff at the Monash Science Centre (1990 - 2012):
Professor Pat Vickers-Rich
Priscilla Gaff
Dr. Corrie Williams
Special thanks to: Kathy Smith, Dr. Sanja Van Huet
and Cindy Hann - for the education framework and content
Special thanks to: Peter Trusler - for the artwork
The cliparts used in this kit are from CorelDraw 7.
No part of this document may be copied or distributed without the written permission of PrimeSCI!
This excludes the use of handouts for classroom activities in conjunction with this kit.
Contact Us
PrimeSCI!
9 Rainforest Walk
Monash University
Clayton, 3800
Victoria
Australia
The Education Team at the
Monash Science Centre
was proudly supported:
The research on the fossils from
the Precambrian included in the
exhibition has
been generously
supported by:
Phone: 613 9905 1370
Fax:
613 9905 1312
primesci.monash.edu
IGCP493
Special Thanks
The Monash Science Centre would like to
thank Visions of Australia - an Australian
Government Initiative, for their generous
support for the 'Wildlife of Gondwana
Exhibition'.
The Monash Science Centre would also
like to thank the School of Geosciences,
Faculty of Science, Monash University, for
their support of the scientific research and
research materials that are on display in
the 'Wildlife of Gondwana Exhibition'.
Education Level of this Kit
This education kit is suitable for the following year levels:
Prep
1
2
3
4
5
7
6
2
8
9
10
11
12
WILDLIFE OF GONDWANA EXHIBITION
Level 3 Education Booklet
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Index
Item
Page
Credits
How to Contact Us
Index
Key Understandings
National Statement in Science
Part 1: What do we know?
Part 2: What do we want to find out?
Part 3: How can we find out more information?
Part 4: Processing the experience
Activities 1 - 7
Part 5: Linking activities
Background Information
Glossary
Resources
2
2
3
3
3
4
7
10
10
11-18
19
20-21
22-23
24
Grades 3 & 4: Key Understandings
Key Understandings:
4A fossil is the preserved remains of once-living organisms
4Fossils can be formed in a variety of ways.
4Fossils may provide information about the changes that have occurred on Earth over
time.
4Scientists use geological time periods to distinguish specific periods of time in Earth's
history.
4Scientists use fossils to reconstruct living organisms.
4By studying these fossils, palaeontologists can begin to suggest what kind of food they
ate, their behaviour, the conditions they lived in at the time, etc.
4Living things have changed over time.
4Fossils can be formed in a variety of ways.
National Statement in Science:
LEVEL 3: Life & Living - Biodiversity Change & Continuity
3.9 Explains why some living things have become extinct and identifies current endangered
species.
Earth and Beyond
3.2 Relates changes in the physical environment to physical processes.
3
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PART 1: What do we know?
1. Locating the Boundaries of Experience.
The experiences outlined in this document invite
students to think about ideas and information related
to the topic area. In many cases simple stimuli, both
visual and auditory such as picture charts, multi media
images from internet sites, pictures from books, texts,
story telling, etc., have been selected to provide a way
to promote discussion and prompt children to recall
any existing relevant knowledge they may have to
contribute to the exploration of the topic in the
classroom.
Creating a Thinking Board
TEACHER BACKGROUND:
4Act as scribe for your class and create a “Thinking
Board”.
4To find out what the students prior knowledge is on
the topic of fossils, ask the students "What do you
know about fossils?"
4Use the board to record the students ideas and
information.
4This is also the place to record any questions that
have been raised during, or as a result of sharing
ideas.
4Alternatively, students ideas can be written in
outlines of dinosaur shapes on the board.
4In this activity, all student ideas and contributions
are valued and important.
4This board represents the students' areas of interest
in relation to this topic and is therefore useful as a
'working display' in the classroom.
4The board can be returned to on a regular basis. It
may be used many times; as a starting point for
research work, to inform the selection of activities
used in the classroom, to revise topic language, to
display new pieces of information as appropriate
and relevant, to contribute information when
constructing a glossary of terms, etc.
4This input forms the basis for future direction and
topic exploration within the unit.
4
some
dinosaurs
were very large
birds
can be
fossils
fish
can
be
fos
sils
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Follow Up: Student Journals
Throughout the topic students write entries on a regular basis
in their journals. The focus of these entries is to enable the
student to record a new piece of information or an
observation they made that was of particular interest to them.
These entries may be shared. At the completion of the first
session related to the Thinking Board students are
encouraged to record such an entry in their journal.
Encourage the use of drawings and key words. Journals may
be an effective strategy for encouraging students to reflect on
new information and consider how this may link with their
existing ideas. These entries are also a useful tool when
assessing student involvement and interest in the unit topic
and may determine the future direction of unit planning.
Post Box Activity
Equipment:
"
"
"
4 boxes to be used as postboxes.
Each box is labelled with a number between 1-4.
Student activity sheets Post Box Activity (see blackline masters).
This activity is designed to provide students with the opportunity to express their understanding of
several questions related to the topic. The activity is completed anonymously, however, all answers
must be a sensible response. This activity also exposes students to a range of views held within the
class and provides an opportunity for students to consider views that are perhaps alternative
explanations to their own. It is also very informative for the teacher to identify the range of views that
exist within the class and the prevalence of these views. These findings can then be used to inform
further teaching in this topic.
i KEY REFERENCE: For further information on this teaching strategy refer to:
Baird, J. Northfield, J. (Eds).(1995). Learning from the PEEL Experience. Monash University Printing Services.
Procedure:
«Distribute to students the blackline master sheet headed POSTBOX ACTIVITY.
«Read through the questions that are listed on the sheet.
«Explain the sequence of procedure to be followed.
«Students work individually and complete their responses to the questions.
«Students post their responses into corresponding boxes.
«Students are placed into four groups. Each group receives one postbox, then the students read
through the responses and categorize these to represent the range of views held.
«Each group presents a report to the class group outlining the types of responses present in their
box and the prevalence of these views.
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Post Box Activity
1
What are fossils?
2
What can fossils tell us?
3
How do fossils form?
4
What kinds of things can be fossilised?
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PART 2: What do we want to find out?
There is research evidence (Biddulph 1990, p.68) that when children have
that opportunity in science they prefer learning from their own questions
and value learning about other children's questions as this often
challenges them to think about aspects of a topic they had not considered.
Fleer, M. Hardy, T. 1996
Pinning Questions on the Wall
4Return to the Thinking Board constructed in the last session.
Review the information.
4Working with students, discuss the information on the board.
4Encourage students to write one or two questions they hope will
be answered during the unit.
4These questions are written in large print and pinned on the walls
of the classroom.
4They are removed only when the author of the question feels it
has been answered, such as after their visit to the exhibition. In
fact, students could bring their question along to the exhibition,
and write the answer on the back.
This activity has the possibility to set an agenda for the unit, to
involve the students in the structure and focus of the unit, to identify
any gaps in information to be taught, to focus on a particular task
each lesson and to reflect on what has been achieved and learned
throughout the unit of work.
How d
o scie
ntists
what
know
dinosa
urs at
e?
What is a fossil?
did life
where
d
n
a
n
e
Wh
?
h begin
on Eart
(Reference: Learning from the PEEL experience Page 242)
Follow Up: Student Journals
At the completion of the 'Post Box Activity' and the
'Pinning Questions on the Wall,' students are encouraged
to record an entry in their journal describing any knew
information they now know about fossils. Encourage the
use of drawings and key words. Journals can be an
effective strategy to encourage students to reflect on new
information and consider how this may link with their
existing ideas. This entry will be a useful strategy when
discussing the coming exhibition with students.
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Preparing for the Visit - Topic Vocabulary
Across:
4. A kind of crustacean, often found as a
fossil, that lived in the ocean before the time of
the dinosaurs.
Clues...
Down:
1.The remains or any evidence,
usually found in rocks, of life from the
past.
2. A person who studies fossils.
3. An animal that has no backbone.
5. A massive supercontinent of the past, that
included South America, Africa, Australia,
Antarctica, New Zealand, India and China all
being joined together.
Across:
1. A type of rock most fossils are
found in.
2. The name for the group of animals
that have a backbone.
3. A skeleton on the outside of an
animals body.
6. A type of reptile, that is now extinct, and
walks with their limbs held directly held under
their body.
8. When a type of animal or plant is no longer
living on Earth.
2
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Topic Vocabulary - ANSWERS
Clues...
Across:
5. The remains or any evidence, usually
found in rocks, of life from the past.
Down:
1. A person who studies fossils.
2. An animal that has no backbone.
6. A massive supercontinent of the past,
that included South America, Africa,
Australia, Antarctica, New Zealand, India
and China all being joined together.
Across:
1. A type of rock most fossils are found in.
2. The name for the group of animals that
have a backbone.
3. A skeleton on the outside of an animals
body.
4. A kind of crustacean, often found as a
fossil, that lived in the ocean before the
time of the dinosaurs.
7. A type of reptile, that is now extinct,
and walks with their limbs held directly
held under their body.
8. When a type of animal or plant is no
longer living on Earth.
1
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PART 3: How Can We Find Out More Information?
Visiting the Exhibition and the students complete Scavenger Hunt Sheet.
PART 4: Processing the Experience.
TEACHER BACKGROUND:
Exploring individual children's understanding of and opinions about science is an important
component of science teaching as these ideas have direct implications for their learning and
the teaching of science. Providing a range of ways for students to express their
understandings is also crucial. Exposing students to a variety of alternative ideas and
interpretations encourages them to consider alternative viewpoints to their own. This can
enhance learning. It can also expose the students to how science really works: hypothesis,
testing, and refinement or even rejection of ideas.
The activities below are designed to encourage students to process and make sense of
information they have covered in classroom research and through their visit to the exhibition.
The following activities focus on visual representation of information, providing students with
a vehicle for expressing their understandings and conveying these to others.
A Period of Time
Create a class mural depicting the periods of geological
time. Use one colour as a background coding for each
period of time. Students contribute to the mural by
constructing representations of plant and/or animal life
from each time period. Include bubbles of background
information composed by students. Display the mural
somewhere in the classroom or in a prominent display
area.
Fossil Diorama
Have students select a fossil of their choice. Students share with
the class their choice and their knowledge of this animal or plant.
Working independently, in pairs or small groups, students now
construct a diorama in a shoe-box depicting an interesting scene
of this fossil's existence. Students may need to undertake further
reading and research to find out more about the fossil they have
selected to determine what other animals and plants are suitable
for inclusion in their diorama.
Dinosaur Vote
Create a class room graph where each student votes for their
favourite dinosaur. Each student must write their name on a
piece of paper (all pieces of paper need to be the same size)
with the name of their dinosaur, these pieces of paper can be
used to create a bar graph in the classroom.
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Activity 1: Fossil Sequence
Cut & paste the following pictures into a logical sequence next
to the sentences to tell the story of how the dinosaur became a
fossil.
The body of the dead
dinosaur falls to the bottom
of the river.
Pressure from the sediments
above makes the buried
layers of mud and sand
become rock.
The muscles and flesh of the
dead dinosaur rot away,
leaving only the skeleton.
Rock is eroded away by the
weather e.g. wind and rain.
Skeleton is covered by layers
of mud and sand.
Fossil is discovered by a
palaeontologist.
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Activity 2: Make your own Fossil
Fossils are evidence of things that were living. Usually fossils are formed in rocks called
sedimentary rocks. In the previous activity, the students should have sequenced the order
of how a fossil can be formed in a sedimentary rock.
Fossils can be skeletons (bone, shell, etc), imprints of left behind (such as leaves), or
traces of activity (footprints). Sometimes when a shell or skeleton is fossilised, the original
part of the animal dissolves and only a hole remains. This hole left by the fossil is called a
mould. Sometimes a cast of the fossil is made when the hole is later filled in by other
minerals, which then takes on the shape of the original fossil.
In this activity students can make our own casts of fossil and modern skeletons and shells
using plasticine and plaster.
Equipment:
4Lots of plasticine
4Stirring sticks
4Shells - lots!
4Small paper or plastic plates
4Plaster (with cup)
4Foam or plastic cups
Procedure:
ðChoose a shell you would like to make a cast from.
ðFlatten a piece of plasticine into a round disc, and ensure the disc is about 3cm thick.
ðPress the plasticine disc onto a paper plate.
ðPress a shell into the plasticine, so as you leave an impression of the shell.
ðRoll some plasticine "sausages". Use these to build a wall around the edge of your
plasticine pad.
ðPlace two tablespoons of water in a cup.
ðAdd three tablespoons of plaster and stir with a stick until the water is mixed through.
ðMake sure your plaster isn't too dry or wet - you may need to experiment with this.
ðSlowly pour the plaster mixture onto your plasticine shell impressions and fill the well.
ðGently pat the mixture with your stick to encourage bubbles to float to the top.
ðLeave for about 20 minutes or until the plaster is hard.
ðPeel off the plasticine to reveal your very own fossils!
ðTo make it look more authentic, the students can paint their fossils, and even add sand
to the paint to make it look more like a rock.
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Activity 3: Creatures of the Slime
Creatures of the Slime - these animals (if they are indeed animals!) - predated the
dinosaurs by millions of years! They lived in the oceans on Earth during a time know as
the Precambrian, from around 600 to 542 million years ago. Some of the best fossils of
these organisms are from Australia, Namibia and Russia. The Flinders Ranges in South
Australia is one of the places where these kinds of fossils have been found in great
numbers. The following activities allow students to become familiar with these early
multicellular organisms - some of which may be our ancestors!
Fossilised creatures of the slime!
Background information
The Ediacaran organisms are all soft bodied (a bit like a worm or soft
coral). This means they had no hard parts such as a skeleton, like you
and I have, or hard shells on the outside, like a crab or insect. It is
much easier for the hard-parts (like bones and shells) to end up as
fossils than the soft-parts - which usually wear away or rot before
they have a chance to be fossilized. This experiment explores how
difficult it is for a soft-bodied animals to end up being preserved as a
fossil.
Equipment:
4soft jelly lollies - like raspberry lollies or jelly beans (to be your 'soft
bodied animal)
4shells (to be your 'hard bodied animal'
4plastic cups
4sand or mud
Procedure:
ª The students work in groups of 4.
ª Each group has a 2 cups, a 'soft animal' and a 'hard animal'.
ª Place sand or mud at the bottom of each cup.
ª Then lay an 'animal' at the bottom of the cup.
ª Next fill each cup with water.
ª This is left for a few days, and checked each day to see what
happens to their 'fossils'.
ª Extra: one group might like to 'cover' their animals in sand and
then pour water over.
Discussion Questions:
What happened in your experiment?
Which animal lasted the longest? Why do you think so?
Can you think of any soft-bodied animals you have met?
Can you think of any animals with hard parts?
What does this experiment tell you about how fossils are formed and
what sorts of organisms are most likely to end up as fossils?
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raspberry lolly
in water
hard shell in
water
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Activity 4: Creatures with No Eyes!
Ediacarans (organisms which lived about 548-575 million years ago) lived in the dark because
they had no eyes! We rely on sight to identify objects, to find out way, to appreciate changes in
our environment and just to get through our life each day. Imagine - what it would be like to live
in a world where you could not see?
Procedure:
4Put students in groups of 4.
4Give each group a picture of one of the Ediacaran animals (pictured below).
4Each group, or student, first needs to make a model of their animal in play-dough or
plasticine.
4Check their animals with the picture - make sure they didn’t add any eyes to the animals.
4Next, each group needs to brainstorm about how they think each animal survived in its
environment if they couldn’t see.
They might like to brainstorm the following questions:
Is it possible, and how would it:
ð find food?
ð tell when it found another one of its own kind if it couldn’t see the other animals?
ð tell if it is night or day? And would it matter?
ð tell if it is winter or summer?
ð tell if other animals are nearby?
Remind the students that these animals couldn’t talk like you and I - they had no voice box!
All of these creatures lived in
oceans that covered Australia,
parts of Namibia, northern Russia,
545-575 million years ago!
Dickinsonia
This animal lived about 550
to 565 million years ago. It
looked like a kind of worm
but it may have been
something completely
different! It moved slowly
along the ocean floor, eating
the slimy microbial (like
algae) mats.
Charniodiscus
This animal lived 540 to
553 million years ago. It
most likely lived like a
modern 'Sea Pen',
attached to the ocean
floor and filter feeding or
absorbing food from the
water.
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Pteridinium
This animal lived in the
oceans about 565 to 545
million years ago. It may have
lived partly buried in the
ocean floor sediments.
Palaeontologists still need to
keep studying this creature to
really understand it!
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Activity 5: Dinosaur Footprints
Some dinosaurs were really big. Others were not so large, but many left footprints in
sands and clay when they walked. Some of these were fossilised and have been found
by palaeontologists, both amateur and professional.
On the back of this page are several drawings of a real Australian dinosaur trackway,
found near Winton in southwestern Queensland, Australia.
Interpreting the Fossil Footprints
Photocopy the track-way for each student.
Let the students know that they are now 'palaeontologists', as they will be studying fossil
footprints, much like a palaeontologist would who studies 'trace fossils' - otherwise know as
'ichnofossils'.
Discuss the following questions with the class:
1. How many animals made the trackway?
2. What kinds of animals do you think they were? Why do
you think this? Give evidence.
3. How many toes did each animal have? How can you
tell?
4. In what direction did the animals move?
5. Did they change speed or direction? How can you tell?
6. What do you think might have happened to produce
this trackway?
Students could either:
$ write their own story
$ work together and roll play their story
$ draw a cartoon of the story
Remind students that they can interpret the track-way
however they like, so long as they can justify their story
using the evidence. Alternative stories might be: the
animal leaving behind the small footprints was a bird and
it flew away, or a baby dinosaur and it got on its mother's
back, or maybe one of the dinosaurs was eaten!
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Activity 5: Dinosaur Footprints
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Activity 6: Body Bits
Aim:
To become familiar with the names of bones in the vertebrate body of a dinosaur.
Equipment:
ð coloured pencils or textas
ð photocopy of this sheet
Procedure:
1. To get to know the names of dinosaur bones, colour the different bones of the
dinosaur using the colour chart below.
2. After you have finished colouring in the dinosaur, create your own jig-saw puzzle by
cutting up the picture. Then try to put all of the pieces back together.
Orbit (eye socket)
Nostril
Sacral vertebra
Ilium
Mandible
Scapula
Humerus
Ischium
Phalanx
Ulna
Radius
Femur
Pubis
Rib
Fibula
Tibia
Metatarsal
Phalanyx
Colour chart:
Humerus and femur
Ulna, radius, tibia and fibula
Skull and jaws
Neck and tail
Ribs
red
yellow
blue
pink
black
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Activity 7: Megafauna Mural
After the time of the dinosaurs, some amazing large animals - known as Megafauna lived in Australia. Many of these animals lived in Australia about 50,000 years ago, and
have become extinct. Animals like giant pythons, huge kangaroos, enormous wombatlike creatures, and VERY BIG birds!
As a class, research these animals and create a classroom mural.
Students could work in pairs to create their contribution to the mural.
Each pair should provide information about their animal, just like a museum provides
information about the fossils or animals on display.
Students could then practise their communication skills by giving the class an oral
presentation about their chosen animal.
Use the following website to find out information about the kinds of animal you might like to
chose:
8 http://www.abc.net.au/science/ozfossil/megafauna/fauna/fauna.htm
8 http://abc.net.au/beasts/
8 http://abc.net.au/science/ausbeasts/factfiles/
8 http://www.parks.sa.gov.au/naracoorte/wonambi/animals/extinct/index.htm
Here are animals you might like to chose that lived in Australia about
50,000 years ago!
Diprotodon:
a giant
wombat that
was about 2
meters tall.
Procoptodon: a
giant short-faced
kangaroo that was
2 to 3 meters tall.
Thylacoleo:
a marsupial lion that was
the largest meat eating
marsupial to have ever
lived in
Australia.
Megalibgwilia
ramsayi: a very
large long-beaked
echidna.
Megalania: a 6
meter long giant
lizard.
Genyornis: a 2
meter tall flightless
bird.
Wonambi: a 5 to 6
meter long snake.
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Part 5: Linking activities
Planning for learning requires the inclusion of explicit activities that 'focus on
building a richer meaning for the knowledge presented by the teacher by linking it to
elements of memory.” (p.187 Baird.J & Mitchell, I. 1995).
In this unit, concept mapping is used as a strategy to provide valuable feedback about the
effectiveness of the processing activities outlined earlier in the unit. The activity outlined
below allows the students to work in groups and explore all the possible links they can think
of between key concepts covered to date. How well students understand the content
covered to date may be reflected in the types responses each group composes.
Activity: Completing Statements from the Stem
Students complete responses to sentence stems. Some examples include:
$ We know about animals that lived in the past because……………..
$ Some fossils tell us that……………….
$ My favourite fossil was _________ because …………………
Students complete sentences and these are shared with rest of the class by displaying them
in a special area of the room. Students can be encouraged to go on a print walk and read
other students responses. For the younger students, the sentence stem can be written on
the board, and the teacher can list for the students all the ideas they have for sentence
endings.
Activity: Group Concept Maps
Concept mapping is a procedure that assists students in their understanding of the
connections between the major concepts in a content area. (Baird.J & Mitchell, I. 1995).
«Using key words from the topic list select 5 and paste on large cards.
fossil
«Place these cards on the floor in a random arrangement.
«Place students in teams of at least 4. Each team is given a piece of
streamer.
«The team must select two words from the floor ,and when it is their
turn they must place their strip of streamer between these cards and
dinosaur
explain their understanding of how these words could be linked.
«On a sheet of paper record the main ideas expressed (in key words)
and place this sheet on the piece of streamer.
«Continue until all groups have had a turn. If there are further ideas, continue again for
another round. This can also be completed on a pin board, and the results can be left on
display.
This activity provides informative feedback about how students are making sense of the
information which has been covered through the unit, and also exposes students to other
students' ideas.
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What are fossils?
Fossils are the remains of once living organisms.
How do fossils form?
Fossils are usually found in sedimentary rocks.
Sedimentary rocks are often made up of
particles sand, silt or gravel. When an organism
dies, it may be covered by layers of sediment,
which later consolidate into sedimentary rocks.
Sediments are usually deposited in the bottom
of lakes, rivers or in the sea, or even from windblown sand dunes. These layers can sometimes
enclose the remains of the organism. If
conditions are right, the layers will consolidate
(solidify) into rocks, and the preserved remains
of the dead organism will become fossils.
How old is the Earth?
The Earth began to solidify and divide into its
layers, and have a solid surface, about 4.6
billion years ago, or in other words that's 4600
million years ago long, long ago!
When did life begin?
The oldest records of life on Earth are 3.8 billion
years old that's 3800 million years ago!
What did the first life look like?
Very small! Microscopic. The oldest life forms on
Earth were so small, to see them you would
need a microscope. These organisms were
single celled - made up of only one cell. We are
multicelled animals, made up of many cells.
When did the first vertebrate animals
appear?
The first fossils of backboned (vertebrate)
animals are Cambrian in age, dating back nearly
530 million years. These first vertebrates were
fish but fish that had no jaws.
Can fossils tell you the age of a rock?
Fossils can give a relative date, not a date in
years. Trilobites are found in rocks that lie
below those that contain dinosaurs, and so
trilobites lived before the dinosaurs. Trilobites
became extinct approximately 245 million years
ago, so if you find a rock with a trilobite in it you
know the rock must be older than 245 million
years old.
When did the biggest extinction event
occur?
The extinction of the dinosaurs at the end of
the Cretaceous time period (some 65 million
years ago) was nothing when compared to
what happened on Earth at the end of the
Permian about 245 million years ago. Some
palaeontologists have suggested that up to
97% of life was wiped out at that time. Life
was almost lost at the end of the Permian.
What happened to cause such a massive
wipe out of species at the end of the
Permian?
There are many theories, but for the moment
this is one of the big mysteries that is not so
well explained. In the millions of years before
the end of the Permian, there had been a
lengthy glaciation big ice sheets moved from
the north and the south affecting many
continents. So, times were cold. But during
the Permian, glaciation subsided and at the
end of Permian times there were great
volcanic outpourings and Earth may have
been blasted by a large meteorite!
With all the water tied up in ice, the sea level
was lowered and many of the areas of the
world that form the shallow marine waters
around the continents were laid bare. These
are areas where most marine animals today
thrive and would have in the Late Permian.
So, those shallow marine animals would have
been under great stress.
We know that the was vast volcanic activity
at this time would have thrown ash up in the
air which would have caused climatic change
that affected animals and plants the world
around.
And the recent evidence that a gigantic
meteorite hit Earth and caused rapid and
catastrophic climatic cooling, wildfires, acid
rain may well have also contributed to the
mass extinctions that occurred at this time.
Thankfully life survived - but maybe only just!
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PrimeSCI! © 2015
What killed the dinosaurs?
The debate still rages between palaeontologists
as to what killed the dinosaurs, some 65 million
years ago, it may have been instantaneous or
prolonged over a period of hundreds of
thousands or possibly even a few million years.
At present, there are two main ideas about what
wiped out the dinosaurs.
Asteroids and comets?
One theory suggests that the extinction of the
dinosaurs was brought about by the impact of
an extraterrestrial object, a comet or an asteroid.
Such an impact could have brought about an
immediate rise in the surface temperature of the
Earth, causing widespread wildfires, dramatic
increase in global ocean temperatures, and a
short period of terrible acid rain. This short-term
event may have then been followed by a longer
term cooling of Earth temperatures because of
the dust particles kicked up in the atmosphere
by the impact, restricting the amount of sunlight
reaching the Earth's surface.
Volcanic activity?
A second theory about dinosaur extinction
suggests that intensive volcanic activity filled the
atmosphere with particles and reduced the
amount of energy reaching the surface of the
Earth from the Sun. Effects of even small
volcanic eruptions such as Krakatoa, Pinatubo or
Mount St Helens have shown a temperature
drop due to volcanism.
Or a double whammy?
Some scientists have suggested that perhaps
the impact of a comet or asteroid triggered
massive volcanic activity on Earth, such as that
in India at about this same time. In any case, the
biological consequence of one or both of these
events brought about a relatively rapid turnover
in the vertebrate and invertebrate fauna of the
Earth.
What happened to life on Earth after
the dinosaurs become extinct?
During the last 65 million years, once most
of the dinosaurs became extinct, the world
changed a great deal. From the warm
Greenhouse conditions of the Cretaceous
some 100 to 65 million years ago, the
Earth's climate began to cool. It was
during this time, without the dinosaurs that
mammals and birds, insects and teleost
fishes exploded into many different kinds of
new species.
The flora changed too. Plants bearing
flowers became dominant and so the
whole smell of the world changed from that
of the green conifer forests of the Mesozoic
to the blossom-bearing shrubs and trees
that are typical of today.
What is megafanua?
Megafauna is defined as reptiles, birds, and
mammals over 40 kilograms in weight.
During the Plesitocene Period (1.8 million
years to 10,000 years ago), Australia
supported a diverse assemblage of
megafaunal mammals such as Diprotodon,
megafaunal birds such as Genyornis, and
megafaunal reptiles such as Megalania.
Why did the megafauna in Australia
become extinct?
A few theories have been suggested as
possible explanations of what caused the
extinction of the megafauna of Australia.
Natural climate change is one theory,
habitat change resulting from human
burning of the bush is another, and hunting
of the megafauna by humans is yet another
theory.
Were mammals living during dinosaur
times?
Yes, mammals lived and developed at the same
time as the dinosaurs. But as long as dinosaurs
were around, mammals were relatively small, and
probably nocturnal. Once the dinosaurs were
gone, mammals took over the world!
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PrimeSCI! © 2015
Glossary
Absolute date:
a method which
determines the time order
in rock sequences,
measured in years by
radiometric techniques
that is, those techniques
which depend on the
regular and statistically
predictable decay of
radioactive elements
(Carbon14 for example).
Amphibian:
animals that live in water
and on land during their
life. However, some
amphibians were
completely aquatic and
some were completely
terrestrial.
Ancient:
old
Aquatic:
living in water.
Bacteria:
microscopic single-celled
organisms, they lack
chlorophyll, and they
reproduce by fission.
Biostratigraphy:
ordering of rock
sequences, to determine
their approximate age,
based on the fossils found
in the rock.
Carnivore:
an animal that eats mostly
meat.
Cell:
the smallest living unit that
makes up most living
things.
Character:
a distinguishing feature.
Conifer:
a plant that reproduces
through the production of
seeds in cones.
Cycad:
an ancient type of seed
plant that was around at
the dinosaurs, and still
lives today.
Deposit:
to lay down in one place,
eg: sediments are
deposited in lakes.
Erosion:
wearing away of the land
surface by the
transportation of debris by
wind or water.
Evolution:
changes over generations
in the characteristics of
plants and animals.
Fossil:
From the Latin word
meaning to "dig up". The
remains or impressions of
life, that lived in the past.
Gondwana:
a massive supercontinent
of the past, that included
South America, Africa,
Antarctica, Australia, New
Zealand, India, and
perhaps parts of China.
Glacier:
a large mass of ice on the
land or over a water body,
which moves in a definite
direction.
Habitat:
a place where an animal or
plant lives.
Herbivores:
an animal that eats mostly
plants.
Extinct:
no longer living on the
Earth.
Hibernate:
to pass the winter in a
torpid state. During this
state, the animal's
metabolism slows down
and there is no need to
eat.
Fauna:
animals living in one area
or at a particular time.
Invertebrate:
animal that has no
backbone.
Flora:
a group of plants living in
on area or at a particular
time.
Labyrinthodont:
crocodile-like amphibians
that lived before and along
side the dinosaurs.
22
PrimeSCI! © 2015
Glossary
Lungfish:
most of these fish breathe
in oxygen from the air
rather than taking it from
the water. They are a
particular group.
Mammal:
a group of vertebrates that
usually give birth to live
young. Mammals usually
have hair, are warmblooded, and feed their
young with milk.
Marsupial:
a mammal that gives birth
to its young at a very early
stage. The baby marsupial
crawls into the pouch and
grabs onto a teat where it
stays, drinking milk, for a
while, until developed
enough to get about on its
own.
Megafauna:
very large animals,
generally animals that
weigh more than 40
kilograms.
Vertebrate:
Animals with a backbone.
Meteorite:
a solid body from outer
space; there are two kinds;
- those that are mostly
stone and those that are
mostly iron.
Multicelled:
many cells, an animal that is
multi-cellular is made up of
more than one cell.
Nocturnal:
active at night.
Organism:
a living bacteria, plant, fungi
or animal; they can
duplicate itself.
Omnivore:
an animal that eats both
plants and meat; thus has a
varied diet.
Plesiosaur:
an extinct group of seadwelling reptiles.
Plesiosaurs had a barrelshaped body, a short tail
and paddle-like limbs
perfect for swimming.
Placental Mammal:
mammals that give birth to
highly developed young,
with a specialised tissue the placenta - which
nourishes the developing
embryo.
Reptile:
a group of vertebrates (have
a backbone), which are
covered by scales, and lay
eggs on land to reproduce.
Sedimentary Rocks:
rocks formed of sediments
deposited by water or air,
e.g.: claystone, sandstone,
siltstone or conglomerates.
23
Sediments:
the grains and organic
debris that are the result
of rocks weathering
(breaking down) and the
'debris' being transported
by wind and water, laid
down in some kind of
sedimentary environment
(e.g.: a lake, ocean or
sand dune).
Skeleton:
the bones that make up
the internal structure of a
vertebrate animal, or the
external covering of an
invertebrate animal (such
as a crab shell).
Solidify:
to become solid or firm.
Species:
a unique kind of animal or
plant, e.g.: Homo sapiens
(the scientific name for
humans).
Weathering:
the break down of rocks
into smaller pieces by
exposure to wind, water,
sun, heat, cold and
chemicals.
Vegetation:
plants growing in a place.
e.g.: all of the plants
growing in Southeast
Australia.
PrimeSCI! © 2015
Resources
Web Sites
http://primesci.monash.edu
This is the website for PrimeSCI! (previously the Monash Science Centre) at
Monash University.
http://www.dinosaurdreaming.net/
This is the official site of the dinosaur dig in Victoria. This site gives excellent information
about the Inverloch dinosaur dig and the dinosaurs found there. It also has links to
other dinosaur sites around the world.
http://www.abc.net.au/dinosaurs/
This site has more information about Australian dinosaurs from around the world.
http://www.nhm.ac.uk
The Natural History Museum, London site has data files on the most well known dinosaurs,
plus it has great suggestions for classroom activities on dinosaurs.
http://www.ucmp.berkeley.edu/fosrec/Learning.html
This sites lists classroom activities on dinosaurs and fossils. It also has excellent interactive
lessons online, including topics such as geological time.
http://www.dinosaurvalley.com/activity_guide/
This site contains free pictures of dinosaurs to colour in. You could print out some of
the pictures and make dinosaur jig-saw puzzles of your own.
http://www.museum.vic.gov.au/dinosaurs/
The Museum Victoria fossil project web site. This site contains lots of information on fossils,
fossilisation, megafauna and dinosaurs.
http://www.oum.ox.ac.uk/thezone/fossils/games.htm
http://www.sdnhm.org/exhibitions/current-exhibitions/fossil-mysteries/
Interactive activities for students about fossils.
http://www.nhm.ac.uk/nature-online/evolution/
Watch a short video on the evidence for evolution
http://www.abc.net.au/science/ausbeasts/
Information and games about Megafauna.
http://www.monash.edu/science/research-groups/earth-atmosphere-environment/precsite
Information about Precambrian life and environments.
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PrimeSCI! © 2015

Wildlife of Gondwana

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