Fossils: When dinosaurs took to the skies

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Fossils: When dinosaurs took to the skies
Earth and Space Sciences
Fossils: When dinosaurs
took to the skies
Earth scientists use rocks and fossils to obtain clues about the environment
that existed many millions of years ago. Just recently, some scientists made
a discovery about a four-winged feathered dino-bird!
In this lesson you will investigate the following:
• What are the different classes of rocks?
• Why do earth scientists use the geological time scale?
• How are fossils made?
• What was it like to live with dinosaurs?
It’s time to spread your wings and soar back into the distant past!
This is a print version of an interactive online lesson.
To sign up for the real thing or for curriculum details
about the lesson go to www.cosmosforschools.com
Introduction: Fossils
The closest living relation to the dinosaurs could be your budgerigar!
We’ve long known that birds evolved from dinosaurs, but a new discovery – the fossil of a feathered flying dinosaur in rocks in a
remote part of China – tells us more than we have ever known about how dinosaurs and early birds took to the skies.
The newly discovered dinosaur is called Changyuraptor yangi. It was the size of a large eagle, weighing roughly 4 kilograms and
measuring about 1.3 metres from snout to tail. And it had not two, but four wings and a long plumed tail.
So well preserved were the feathers of the flying dinosaur's tail that scientists could work out how it was used in flight. They believe
that it allowed the dinosaurs to adjust their pitch – that is, whether they were flying nose up or nose down – as well as to slow their
speed and help them land safely.
The discovery adds to the growing body of evidence that the late Jurassic and early Cretaceous periods were important for the
evolution of feathered flight. As one scientist says, “There were lots of different lineages experimenting with modes of flight at this
time. The lineage that became modern birds was just one of them.”
Read or listen to the full Cosmos magazine article here.
Left: Archaeologists use delicate tools to uncover long-buried fossils. Here, archaeologist Eric Buffetaut can be seen
excavating the neck of a Sauropoda dinosaur. Right: The skeleton of an Argentinosaurus huinculensis, the world's largest
herbivore, is displayed at the Lokschuppen exhibition centre in Rosenheim, Germany. Credits: Patrick Aventurier /
Gamma-Rapho via Getty Images and Luka Barth / epa / Corbis.
Question 1
Imagine: You are a palaeontologist working at a university and have been contacted by a farmer who has stumbled across a
strange looking fossil. Describe how you might feel if you visited the farmer and then spent one month digging up one of the largest
dinosaurs ever found (Argentinosaurus, 36 m from tail tip to nose).
Gather: Fossils
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Credit: Untamed Science / YouTube.
Question 1
Remember: What are the three classes of rocks?
Question 2
Define: Igneous rocks are composed of different minerals that form as magma (molten rock) cools and solidifies. The slower the
magma cools, the larger the crystals formed.
Which of the two igneous rocks below is a granite (that cools deep in the Earth very slowly) and which is a basalt (that cools very
quickly when the magma reaches the surface of the Earth)? Give a reason for your answer.
Two types of igneous rock. Credits: James Driscoll and Thomas Weiland
Question 3
Identify: Sedimentary rocks are formed:
by weathering and eroding other rocks
Question 4
Recall: Sedimentary rocks can be formed by eroded sediments
of other sedimentary rocks, igneous rocks and/or metamorphic
rocks.
under the oceans
True
in rivers and streams
False
any of the above
Question 5
Identify: Which class of rock is represented by the photograph
on the right and how do you know this?
Hint: what has caused the layers in the rock to be deformed?
Credit: iStock.
The rock cycle is a similar concept to the water cycle you studied in Year 7. As we saw from the video there are three main classes of
rock: sedimentary, metamorphic, and igneous, and the differences between them have to do with how they are formed.
Rocks are not always as static and solid as they appear. They are constantly changing over timescales from a few minutes (in the
case of lava flowing out of a volcano in Hawaii) to many millions of years (in the case of the Himalaya mountains in southern Asia
being uplifted and folded).
To start the rock cycle, hot molten rock from the Earth's mantle, also called magma, reaches the surface of the Earth and erupts
from volcanoes as lava. The lava cools and forms igneous rocks.
Weathering by wind, ice and rain results in the rocks being eroded, broken up and transported along rivers and streams into the
ocean. The particles of sand, shells and pebbles, which are collectively called sediment, slowly build up over hundreds of thousands
to millions of years. They are compressed, and sedimentary rocks form. Sedimentary rock is the most common type of rock on
Earth. As more and more sediment accumulates increased pressure and temperature leads to deep sedimentary rocks slowly
transforming into metamorphic rocks. Over millions of years the temperature of the Earth may melt some metamorphic rocks back
into magma.
And so the process continues.
Question 6
Identify: Use Google Earth to locate an area that is local to your school where sediment being deposited may form sedimentary
rock in the future.
Upload a snapshot of the area
Annotate where the sediment is being eroded from (Hint: The sketchpad can be used to annotate images)
Describe how the sediment is being transported to the depositional area
Process: Fossils
Left: Dinosaur in the Jurassic Museum of Asturias. Right: Fossil crinoids (Uintacrinus socialis) from the Cretaceous Period
(145.5 – 65.5 million years ago). Credit: Javier Prieto Gallego / Cover / Getty Images and iStock.
Simple cells represent the earliest life forms on Earth. They first appeared approximately 3.6 billion years ago. More complex life
forms evolved only approximately 600 million years ago. When these ancient plants and animals died their remains were
sometimes preserved as fossils in sedimentary rock.
Fossils are much more common than you may think since so many animals and plants live and die and because sedimentary rocks
are so common. Dinosaurs are arguably the most fascinating and well-known fossils. Flying dinosaurs such as Changyuraptor and
Archaeopteryx represent transition animals that existed between dinosaurs and birds.
Earth scientists and geologists who study fossils and ancient life are known as palaeontologists.
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Credit: SheppardSoftwareCom / YouTube.
Question 1
Classify: Which type of animal might have left the trace fossil tracks depicted below right? On paper, draw a sketch of what the
animal may have looked like and upload a photograph or scan of your sketch.
Hint: The animal that left these tracks may have been being swooped by an Archaeopteryx, depicted soaring overhead (below left).
Drag and drop file here to begin upload or
Credit: Corey Ford / Stocktrek Images / Getty Images and Tom Bean / Corbis.
Question 2
Think: How are resin fossils formed? List three animals that may become resin fossils.
Question 3
Paraphrase: On very rare occasions exceptionally well-preserved body fossils have been discovered. Use the information in the
video clip above to explain how dinosaur body fossils can be preserved in rock.
Earth scientists and geologists use the geological timescale, also known as a stratigraphic chart, to measure Earth's history over
millions of years. Geological time is divided into eras, periods, epochs and stages with each division based on a specific set of
geological or palaeontological conditions that make it different from the other divisions, such as varying rock type or fossils. Time is
measured in millions of years (sometimes written as "Ma").
Today we are living during the Holocene Epoch of the Quaternary Period. Using the chart, we could assign a sedimentary rock that
has fossils dating to 105 Ma (105 million years old) as belonging to the Albian Stage of the Lower Cretaceous Epoch of the Mesozoic
Era.
Explore this stratigraphic chart before continuing.
Question 4
Apply: A sedimentary rock contains this flying insect fossil that
has been dated to 309 Ma. Using the geological time scale,
classify the age of the rock into Stage, Period and Era.
Credit: iStock.
Question 5
Infer: The Cosmos article suggests that flying dinosaurs first appeared at the beginning of the Upper Jurassic, and were extinct by
the end of the Lower Cretaceous.
1. Calculate how many millions of years the flying dinosaurs dotted the skies of the Earth.
2. Calculate the percentage of time in Earth's history this represents based on the Earth being 4.6 billion years old.
Question 6
Imagine: You're an old flying dinosaur from the Upper Jurrasic and feel that your death is imminent! But you are a smart dinosaur
that knows about fossilisation and want to make sure that your body is preserved for future discovery by humans.
In the first person, write a narrative of about 200 words to describe the long journey from your last day on Earth to your fossil being
discovered by humans millions of years later. Be creative in your writing!
Apply: Fossils
Exploring your backyard
Sedimentary rocks can reveal secrets from the past (like the shells above left) and create stunning scenery (like "The
Wave" in northern Arizona, above right). Credit: iStock.
Time to choose! There are two tasks below and you may complete either one (or both!). The first task is a hands-on activity, while
the second you can complete from the comfort of your computer screen. Enjoy exploring the secrets of your backyard!
Task 1: Mini practical task
Aim
To simulate the settling of sediments and the beginning of fossil formation.
Materials
2 L clear, plastic bottle with lid
¼ cup of mud
¼ cup of fine sand
¼ cup of coarse sand
10 small pebbles (less than 1 cm diameter)
10 small shells (less than 1 cm diameter)
1.5 L cold water
Hint: You may find a lot of these materials by searching in your own backyard!
Method
1. Add the mud, fine sand, coarse sand and pebbles to the plastic bottle so that the bottle is about one quarter filled. These
components simulate sediment in an environment.
2. Add the shells to the bottle. These shells simulate organisms that may become fossilised.
3. Pour in cold water until the bottle is full.
4. Ensure the lid is tightly closed and then shake the bottle for several seconds.
5. Stop shaking the bottle and place immediately onto a table.
6. Use the project space below to describe what you observe occurring inside the bottle. You may like to include photographs, a
short video clip or a labelled sketch in addition to a written description.
7. Repeat your observations, as in step 6, twice more in 10 minute intervals.
Results
Question 1
Use this project space to record your observations in an organised way.
Discussion
Question 2
Sequence: List the components in the bottle into their settling
order, beginning with the first component to settle.
Question 4
Locate: Identify where in the bottle's layers most of the ‘fossils’
(shells) settled.
Question 3
Explain: Suggest an explanation for the sequence of settling you
noted in Question 2.
Question 5
Generalise: Review the conditions required for preservation of
fossils that you have learned about in this lesson and predict
whether you would expect the shells in the bottle to be
preserved if this were a real world scenario. Give reasons for
your response.
Task 2: Dinosaurs in Australia
Question 6
Research: Using the information you have gathered in this lesson, in addition to an internet search, complete the following tasks in
the project space below.
Plot on a map of Australia where dinosaurs have been found.
Annotate the map locations with the age that the dinosaur was alive (in millions of years and whether this is the Triassic,
Jurassic or Cretaceous Era).
Include a description and image of the dinosaur's appearance
Describe the environment that the dinosaur lived in.
Career: Fossils
Sometimes Erika Canola feels like she works in a fishbowl. Her lab at the Museum of Natural History in Los Angeles is
surrounded by glass walls on all sides, allowing an audience to watch her every move.
The lab is part of the Dinosaur Institute, where the public gets to
watch scientists prepare fossils with pneumatic tools – mini
hammers and chisels that use compressed air to separate the
ancient sediments that have moulded to the fossils.
At first, Erika found it strange to be watched while she worked,
but now it’s just a part of her everyday job as a paleontological
preparator. Sometimes she’ll look up from her work and see
kids making funny faces through the glass. Even celebrities
come through to watch her work – one day she saw an actor
from Jurassic Park staring right back at her!
When not in her “fishbowl”, Erika does fieldwork and has
travelled to places like Mexico and the Petrified Forest in
Arizona. Her favourite place for fieldwork is Utah, with its red
sandstone, pillowy clouds and stunning blue skies. At these digsites, she uses sledgehammers, jackhammers, and pneumatic
tools to cut through the sandstone in the hope of finding new
fossils. It’s hard work, she says, but it truly makes her feel like a
treasure hunter.
Before her time at the Museum of Natural History Erika worked
in professional hair and make-up. She was required to be
creative and detail-oriented in that job, and she thinks the work
has given her a unique perspective on working with fossils. But
Erika soon found herself wanting more out of her career, and
her love for bones, mystery and the outdoors switched her on
to a degree in physical anthropology.
When she isn’t hunting for long-lost fossils, Erika enjoys
tinkering with electronic gadgets, camping outdoors, and
hanging out with her three dogs.
Question 1
Discover: ​There are a number of career opportunities available in the field of palaeontology and archaeology. Perform an internet
search to find a career in one of these fields that interests you and describe what you would enjoy most about the job.
Hint: You may find this website to be a good starting point.
Cosmos Live Learning team
​Lesson authors: James Driscoll & Kathryn Grainger
Profile author: Megan Toomey
Art director: Robyn Adderly
​Education director: Daniel Pikler
Editors: Bill Condie, Hayley Bridgwood, Jim Rountree, Yi-Di Ng & James Whitmore

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