Name one feature that allows you to tell the quail is an ornithodire – Who is the sister group to the ornithodires?
Lab 5: Theropods
Question 1: Bird anatomy
a) Name one feature that allows you to tell the quail is an ornithodire – Who is the sister group to the ornithodires?
b) Name one feature that allows you to tell that the quail is a dinosaur. Who is the sister group to the dinosaurs?
c) Name one feature that allows you to tell that the quail is a maniraptor. Who is the sister group to the maniraptors?
d) What is a pygostyle?
e) What is unusual about the hand and wrist bones (carpals and metacarpals) of modern birds?
Question 2: Allosaurus
a)Name a feature you can see that allows you to identify Allosaurus as a theropod.
b)Name a feature you can see that allow you to identify Allosaurus as a tetanuran.
c)Name a feature that you can see that allows you to tell that Allosaurus is NOT a maniraptor.
Question 3: T. rex
a)Looking at this skull, how could you determine that Tyrannosaurus was not a mammal?
b)Identify a feature that demonstrates this is an archosaur.
c)What’s different about the teeth of Tyrannosaurus compared to knife-like teeth that define early theropods?
Question 4: Velociraptor
a)Identify 2 evolutionary novelties demonstrating that this is a maniraptor.
b)Notice that much of the body length is made up by the extremely stiff tail. What is the benefit of having such a stiff tail?
c)Close relatives of Velociraptor had complex feathers, and there’s evidence of feathers on Velociraptor, as well. Was Velociraptor capable of powered flight? If so, how do you know? If not, what might the feathers have been used for?
Question 5: Basal maniraptorans
a)What feature can you see in the Oviraptor skull that has evolved convergently with birds?
b)Is Oviraptor or Velociraptor (a dromaeosaurid) more closely related to living birds?
c)Unlike most other theropods, what do we think Therizinosaurus ate?
d)What other amniote group(s) have convergently evolved a combination of large size and large claws?
Question 6: Archaeopteryx
a)Identify one feature each that indicates Archaeopteryx is a theropod, a tetanuran, and a maniraptor.
b)List three features that indicate Archaeopteryx is NOT part of Aves.
c)Scientists continue to hypothesize about how well Archaeopteryx could have flown. Do you think Archaeopteryx had powered flight, or was merely “falling in style”? Provide evidence to back up your answer.
Question 7: Feathers
a)These are fossil feathers. Is that information alone sufficient to identify it as coming from a bird? Why or why not?
b)Is a feather fossil a trace fossil or a body fossil?
c)Describe how modern bird feathers are more morphologically complex than early theropod feathers.
d)Feathers serve a variety of functions. What is unique about the shape of flight feathers?