GLGY 305 - Final Exam notes study set
Let's think about how T. rex is related to the other vertebrates. Where does T.
rex fit on this cladogram?
With crocodiles and birds
Why is T. rex not grouped with the sharks?
T. rex had a mineralized skeleton
Why is T. rex not grouped with the lobe-finned fish?
T. rex had four limbs
Why is T. rex not grouped with humans and hares
T. rex had two pairs of holes in the skull behind its eyes
Notice that the caiman has a distinct, sprawling stance but the parrot holds its
legs directly under its body. Are the legs of T. rex directly under the body or
sprawling out to the side?
Directly under the body
,The caiman walks on four legs (quadrupedal), whereas the parrot walk on two
legs (bipedal). Is T. rex bipedal or quadrupedal?
Bipedal
We have never seen a T. rex walk, but we can guess how they walked based
on features of the skeleton. When you look at the skeleton, what feature of the
skeleton makes you think that T. rex is either bipedal or quadrupedal?
Very short arms. His or her head would drag on the ground if T. rex was
quadrupedal.
Finally, examine the fingers of each animal. The caiman has 5 and the parrot
has 3 (birds have lost the 4th and 5th fingers). How many fingers does T. rex
have? (Note that digit number 3 has largely been lost in T. rex and other
tyrannosaurs, but a small remnant metacarpal 3 still exists.)
2 plus a remnant digit 3
Based on your evidence, which group is T. rex most closely related to:
crocodiles/caiman or birds?
Birds
Select two characters that you can observe in the body of this Tyrannosaurus
rex.
Bipedal
,Sharp claws
Select four characters that you can observe in the body of this
Euoplocephalus tutus. (Hint: compared to other dinosaurs, the toes are quite
blunt)
Tail club
Quadrupedal
Blunt or rounded fingers
Spikes or plates on the body
Select two characters that you can observe in the body of this Triceratops
horridus. (Hint: compared to other dinosaurs, the toes are quite blunt)
Blunt or rounded fingers and toes
Quadrupedal
Select four characters that you can observe in the body of this Brachiosaurus
altithorax. (Hint: be sure to look at the variation we observe in the toes and
fingers!)
Sharp claws
Long neck
Quadrupedal
Blunt or rounded fingers and toes
, Select three characters that you can observe in the body of this Iguanodon
bernissartensis. (Hint: be sure to examine all the fingers and toes before
answering this question!)
Quadrupedal
Blunt or rounded fingers and toes
Sharp claws
Select three characters that you can observe in the body of this Stegosaurus
stenops.
Quadrupedal
Blunt or rounded fingers and toes
Spikes or plates on the body
Select two characters that you can observe in the body of this Dromaeosaurus
albertensis.
Sharp claws
Bipedal
Let's think about how T. rex is related to the other vertebrates. Where does T.
rex fit on this cladogram?
With crocodiles and birds
Why is T. rex not grouped with the sharks?
T. rex had a mineralized skeleton
Why is T. rex not grouped with the lobe-finned fish?
T. rex had four limbs
Why is T. rex not grouped with humans and hares
T. rex had two pairs of holes in the skull behind its eyes
Notice that the caiman has a distinct, sprawling stance but the parrot holds its
legs directly under its body. Are the legs of T. rex directly under the body or
sprawling out to the side?
Directly under the body
,The caiman walks on four legs (quadrupedal), whereas the parrot walk on two
legs (bipedal). Is T. rex bipedal or quadrupedal?
Bipedal
We have never seen a T. rex walk, but we can guess how they walked based
on features of the skeleton. When you look at the skeleton, what feature of the
skeleton makes you think that T. rex is either bipedal or quadrupedal?
Very short arms. His or her head would drag on the ground if T. rex was
quadrupedal.
Finally, examine the fingers of each animal. The caiman has 5 and the parrot
has 3 (birds have lost the 4th and 5th fingers). How many fingers does T. rex
have? (Note that digit number 3 has largely been lost in T. rex and other
tyrannosaurs, but a small remnant metacarpal 3 still exists.)
2 plus a remnant digit 3
Based on your evidence, which group is T. rex most closely related to:
crocodiles/caiman or birds?
Birds
Select two characters that you can observe in the body of this Tyrannosaurus
rex.
Bipedal
,Sharp claws
Select four characters that you can observe in the body of this
Euoplocephalus tutus. (Hint: compared to other dinosaurs, the toes are quite
blunt)
Tail club
Quadrupedal
Blunt or rounded fingers
Spikes or plates on the body
Select two characters that you can observe in the body of this Triceratops
horridus. (Hint: compared to other dinosaurs, the toes are quite blunt)
Blunt or rounded fingers and toes
Quadrupedal
Select four characters that you can observe in the body of this Brachiosaurus
altithorax. (Hint: be sure to look at the variation we observe in the toes and
fingers!)
Sharp claws
Long neck
Quadrupedal
Blunt or rounded fingers and toes
, Select three characters that you can observe in the body of this Iguanodon
bernissartensis. (Hint: be sure to examine all the fingers and toes before
answering this question!)
Quadrupedal
Blunt or rounded fingers and toes
Sharp claws
Select three characters that you can observe in the body of this Stegosaurus
stenops.
Quadrupedal
Blunt or rounded fingers and toes
Spikes or plates on the body
Select two characters that you can observe in the body of this Dromaeosaurus
albertensis.
Sharp claws
Bipedal
