www.BioInteractive.org Published July 2015; Revised October 2016
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Short Film
Great Transitions: The Origin of Birds
Educator Materials
LIVING DINOSAURS: FACT OR FICTION?
OVERVIEW
The
Living Dinosaurs: Fact or Fiction?
activity is designed to supplement the viewing of the short film
Great Transitions: The Origin of Birds
(http://www.hhmi.org/biointeractive/great-transitions-origin-
birds). Students evaluate and discuss statements about the evolutionary relationship between birds
and dinosaurs and other facts about these groups before and after watching the film. This activity can
be used as an anticipation guide to focus students on several of the key concepts presented in the
film. It also can serve as a pre- and post-assessment.
KEY CONCEPTS AND LEARNING OBJECTIVES
• The fossil record provides a history of life on Earth. It includes some organisms with features
that are intermediate, or transitional, between major groups.
• Evidence that birds are descended from theropod dinosaurs includes shared anatomical
features, as well as inferred physiological and behavioral similarities.
• One way scientists infer evolutionary relationships is by exploring patterns in the presence or
absence of certain morphological characters in different species.
• Feathers evolved before flight and therefore must have originally served other functions, such
as insulation or communication.
• Today, dinosaurs are classified into two groups: avian and non-avian. The non-avian dinosaurs
are extinct, whereas the avian dinosaurs are still with us and are called birds.
Students will be able to
• evaluate claims based on information and evidence provided in a film and
• participate in a collaborative discussion of their interpretations of the evidence with their
classmates.
CURRICULUM AND TEXTBOOK CONNECTIONS
Curriculum
Standards
NGSS (2013)
MS-LS4-1, MS-LS4-2, HS-LS4-1, HS-LS4-4
AP Biology (2012–2013)
1.A.1, 1.A.4, 1.C.1, 4.B.4
IB Biology (2016)
5.1, 11.2
!
Textbook
Chapter Sections
Miller and Levine,
Biology
(2010 ed.)
16.3, 16.4, 18.2, 19.1, 19.2, 26.2
Reece et al.,
Campbell Biology
(AP ed.,
9th ed.)
22.1, 22.2, 22.3, 25.2, 25.4, 25.6, 26.3, 34.6
www.BioInteractive.org Published July 2015; Revised October 2016
Page 2 of 5
Short Film
Great Transitions: The Origin of Birds
Educator Materials
KEY TERMS
Archaeopteryx
, avian dinosaur, bird,
Deinonychus
, fossil record, non-avian dinosaur, reptile, theropod,
transitional fossil
TIME REQUIREMENTS
This activity is designed to be completed during one 50-minute class period, including watching the
film. Depending on the amount of class discussion, the activity may take longer.
SUGGESTED AUDIENCE
This activity is appropriate for middle school life science and all levels of high school biology.
PRIOR KNOWLEDGE
It would be helpful for students to understand that all species evolve from preexisting species and to
be familiar with the concepts of speciation and extinction. An understanding that groups within the
tree of life form nested sets would also be helpful (for example, humans are primates, which are in
turn mammals, which are one group of tetrapods, which are one group of animals, etc.). Students
should be able to describe some characteristics of dinosaurs, reptiles, and birds.
PROCEDURE
Before Viewing the Film
1. Have students work in pairs to complete the “before” column of Table 1 on the student handout.
Let your students know that they are not expected to know all the answers; they should just
record their ideas at this point.
2. Have students watch the film with the objective of finding evidence that supports or refutes their
responses in the handout.
After Viewing the Film
3. Have students first work in pairs to discuss the accuracy of the statements based on information
presented in the film, and then complete the “after” column in Table 1. Students should explain in
one or two sentences why they now think each statement is true or false.
4. Conduct a class discussion to reach a consensus on the accuracy of each statement. As necessary,
prompt students to cite evidence from the film that supports their claims.
TEACHING TIPS
• Before watching the film, discuss and clarify any statements that seem confusing or
ambiguous to students. After watching the film, if students are unsure about a statement, ask
them what additional information they would need to reach a firm conclusion. Explain to
students that the point of this exercise is not to get the “right” answer, but rather to be able to
support a claim with evidence.
www.BioInteractive.org Published July 2015; Revised October 2016
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Short Film
Great Transitions: The Origin of Birds
Educator Materials
• If time permits, have students discuss some additional thought-provoking questions, such as
these:
o What are transitional fossils, and why did Charles Darwin anticipate their discovery?
o The fossil records of some groups of organisms, such as bats and turtles, lack transitional
forms that link them to other groups. Does this mean that these forms never existed? Why
or why not?
o How could you best explain why the following statement is false? “Birds couldn’t have
evolved from dinosaurs because birds and dinosaurs lived at the same time.”
o How can scientists make claims about the behavior of extinct animals?
o Dr. Julia Clarke says in the film that there are too many similarities between theropods and
birds to be explained by anything except common ancestry. What does she mean? How
does common ancestry explain the similarities between the two groups?
• The following is a list of films, videos, articles, and activities that provide additional
information about evolution and transitional fossils:
o
The Day the Mesozoic Died
(http://www.hhmi.org/biointeractive/day-mesozoic-died)
o
How To Find a Dinosaur
(http://www.hhmi.org/biointeractive/how-find-dinosaur)
o
Great Transitions: The Origin of Tetrapods
(http://www.hhmi.org/biointeractive/great-
transitions-origin-tetrapods)
o
Great Transitions: The Origin of Humans
(http://www.hhmi.org/biointeractive/great-
transitions-origin-humans)
o
Great Transitions Interactive
(http://www.hhmi.org/biointeractive/great-transitions-
interactive)
o
“It’s a Fishapod!”
(http://www.hhmi.org/biointeractive/article-fishapod)
o
Young Students Recognize a Transitional Tetrapod
(http://www.hhmi.org/biointeractive/young-students-recognize-transitional-fossil)
EXPLANATIONS
Each statement below is followed by information that may be helpful in guiding a class discussion.
1. The discovery of the fossil of Archaeopteryx provided evidence that birds evolved from
mammals.
This statement is false. When the first complete fossil of
Archaeopteryx
was described in 1861, it
was clear that birds were closely related to some group of reptiles. In 1872, the sixth edition of
On
the Origin of Species
included this paragraph on
Archaeopteryx
, which clearly identifies its
common characteristics with reptiles—not mammals:
Not long ago, palaeontologists maintained that the whole class of birds came suddenly into
existence during the eocene period; but now we know, on the authority of Professor Owen,
that a bird certainly lived during the deposition of the upper greensand; and still more recently,
www.BioInteractive.org Published July 2015; Revised October 2016
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Short Film
Great Transitions: The Origin of Birds
Educator Materials
that strange bird, the
Archeopteryx
[
sic
], with a long
lizard-like tail
, bearing a pair of feathers
on each joint, and with its wings furnished with two free claws, has been discovered in th
e
oolitic slates of Solenhofen. Hardly any recent discovery shows more forcibly than this, how
little we as yet know of the former inhabitants of the world
.
(Charles Darwin,
On the Origin of
Species
, 6th ed., 1872, 444, emphasis added)
2. Flight evolved once in the history of life—in birds.
This statement is false. In the film, Dr. Clarke talks about pterosaurs, a group of reptiles, which
seemed like an obvious candidate to be a close relative of birds because they had light, hollow
bones and were capable of flight. However, the wings of birds and pterosaurs have very different
structures, so scientists concluded that flight evolved independently in both groups. Today, there
are flying mammals (bats) and many thousands of flying insects, which are not closely related to
birds.
3. All dinosaurs were large and slow moving.
This statement is false. As shown in the film, the discovery of
Deinonychus
by Dr. John Ostrom in
1963 set off a revolution in how scientists think about dinosaurs.
Deinonychus
’s large claws were
clearly used for slashing at prey—a hunting strategy not associated with slow-moving animals.
The large claws and
Deinonychus
’s lightly built and agile body led Dr. Ostrom to propose that
some dinosaurs may have had a higher metabolic rate than a typical living reptile.
4. Like birds, some dinosaurs laid eggs and cared for their young.
This statement is true. In the film, Dr. Jack Horner talks about his 1978 discovery of a large dinosaur
nesting ground at “Egg Mountain,” Montana. The dinosaurs associated with this nest were given
the name
Maiasaura
, meaning “caring mother lizard.” Vegetation found near the nests suggests
that dinosaurs covered the eggs, a practice employed by some species of modern birds. Baby
Maiasaura
up to 1 meter long were found associated with the nests, suggesting that the young
remained for some time after hatching, likely being fed by their parents—again, a characteristic of
many living birds. Further, nests were found at different layers at the site, suggesting that
Maiasaura
returned to the site year after year to lay their eggs.
5. The skeleton of a T. rex has many similarities to the skeleton of a chicken.
This statement is true. Although a
Tyrannosaurus rex
and a chicken are different in size, they have
many anatomical similarities. In the film, Dr. Julia Clarke compares the foot of a
T. rex
to that of a
chicken, and they both have three forward-facing digits and a smaller digit in the back. Similarities
include the presence of a wishbone, an S-shaped neck, and many others.
6. The fossil record shows that some dinosaur species had feathers nearly identical to those
found on birds today.
This statement is true. Earlier in the fossil record, dinosaurs, such as
Sinosauropteryx
, referred to in
the film as a “fuzzy dinosaur,” had wispy, feather-like structures and could not fly. Later in the fossil
record, scientists found theropods with feathers that looked more like the variety of feathers we
see in birds today, from fluffy down feathers to asymmetrical flight feathers.
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Short Film
Great Transitions: The Origin of Birds
Educator Materials
7. Birds evolved feathers on wings so that they could fly.
This statement is false. Traits do not appear on demand because an organism needs them to do
something. Although it may seem logical to assume that feathers first evolved in connection with
flight, it is now clear that feathers long predate the first flying birds. Dinosaurs with wispy, feather-
like structures, such as
Sinosauropteryx
seen in the film, could not fly. What advantages might a
primitive feather-like structure give an organism? Looking at living birds offered two strong
hypotheses—early feathers may have helped keep the dinosaurs warm and/or they may have
helped the dinosaurs communicate.
8. Archaeopteryx is the direct ancestor to all living birds.
This statement is false.
Archaeopteryx
is sometimes described as “a missing link” between
dinosaurs and birds. This phrasing can give the impression that evolution proceeded in a straight
line. But non-avian dinosaurs did not morph into
Archaeopteryx
, which then morphed into
modern birds. Indeed, as the film emphasizes, all kinds of feathered dinosaurs and birds lived at
the same time.
9. The first birds appear in the fossil record about 66 million years ago after the extinction of
the dinosaurs.
This statement is false. Scientists widely agree that a mass extinction occurred approximately 66
million years ago after a large asteroid smashed into Earth (see the HHMI short film
The Day the
Mesozoic Died
, http://www.hhmi.org/biointeractive/day-mesozoic-died, about the evidence for
the asteroid hypothesis). Before the impact, feathered and nonfeathered dinosaurs coexisted with
birds and all kinds of other animals.
10. Dinosaurs are alive today.
This statement is true. Students may, however, point out that we don’t call them dinosaurs, which
is a valid point. In modern taxonomy, groups form nested sets. Birds are dinosaurs, which are in
turn reptiles, which are in turn tetrapods, which are in turn chordates . . . and so on. Tell your
students that calling birds dinosaurs does not mean there is no such thing as birds. The point of
calling birds dinosaurs is to emphasize their evolutionary origin within the dinosaur clade. Birds
are dinosaurs just as humans are primates.
AUTHORS
Written by Mark Bloom, PhD and Ann Westbrook, PhD, BSCS; Laura Bonetta, PhD, HHMI; Stephanie Keep, consultant
Reviewed by Paul Beardsley, PhD, Cal Poly Ponoma
Field tested by Paul Strode, PhD, Fairview High School; Ann-Marie Hutcheson, Bowie High School, Austin, TX; Jack Saffer, Central Islip High
School, Central Islip, NY; David Knuffke, Deer Park High School, Deer Park, NY; Randi Neff, Tuscola High School, Waynesville, NC; Chris Chou,
Longmont High School, Longmont, CO; Dana Grooms, Thousand Oaks High School, Moorpark, CA; V. Gudi, Robert Morgan Educational
Center, Miami, FL; Angela Lennox, Exeter High School, Exeter, NH; Nancy Bates, Montclair Cooperative School, Montclair, NJ
