Exam #3 Dinosaurs Flashcards
are birds (Aves) a member of Saurischia or Ornithischia?
Saurischia
Traditional classifications group dinosaurs based on the orientation of the pubis - forward in Saurischia (“lizard-hip”) and backwards in Ornithischia (“bird hip”). Birds are Saurischian dinosaurs, yet their pubis points backwards. In what dinosaur clade do we first see a retroverted (backward pointing) pelvis?
-Avialae
- Avetheropoda
- Aves
- Paraves
Paraves
Close examination of the endocranial cavity (where the brain sits) of troodontid theropods reveals an expansion of the regions related to powered flight in living birds. What does this suggest about bird evolution?
- the ancestors of birds possessed the brain power for flight before they had the muscular and feather adaptations needed
- Troodontids were capable of powered flight
- troodontids were capable of powered flight
The ancestors of birds possessed the brain power for flight before they had the muscular and feather adaptations needed
Which of the following species of theropod is a member of Avialae, fully capable of powered flight, and is considered by many to be the “earliest bird”? (Hint: it was first known from a single feather discovered in a German limestone quarry in the mid-19th Century.)
- microraptor gui
- archaeopteryx
- allosaurus fragilis
- yi gi
Archaeopteryx lithographica
Regarding the origin of flight, which major hypothesis is best supported by anatomical data, including the long and powerful hind limbs and body covered with pennaceous (quill-like) feathers in paravian theropods that preceded the evolution of powered flight?
-Cursorial Hypothesis
- Arboreal Hypothesis
curosorial hypothesis
What is the stratigraphic range of Aves?
-Triassic to Recent
- Cretaceous to Recent
-Restricted to the Cenozoic Era (i.e., did not evolve until after the Cretaceous Period)
-Jurassic to Recent
Cretaceous to Recent
Out of all of the features that we think of as characterizing living birds, which was the last to evolve? (I.e., which of the following is a synapomorphy of Aves?)
-Retrograde (backwards-pointing) pubis
- asymmetric flight feathers
- furcula
- loss of teeth c
Loss of teeth
What is the name of the fused bones within the wrist of living birds and some of their extinct relatives that serves as a solid base for the attachment of flight feathers?
- pygostyle
- tarsometatarsus
- carpometacarpus
- alula
carpometacarpus
In what theropod dinosaur clade do we first see the pygostyle, or the fusion of the last few caudal vertebrae to form a solid structure for attachment of tail feathers?
- ornithurae
- aves
- pygostylia
- ornithothoraces
-
pygostylia
True or False: There are living dinosaurs. (Easy peasy!)
True
False
True
Are sauropods (Sauropoda) members of Saurischia (“lizard-hip”) or Ornithischia (“bird-hip”)?
ornithischia
saurischia
saurischia
Given the most recent anatomical evidence, how do paleontologists reconstruct the neck of most sauropods?
- a relatively straight neck oriented horizontally or at a slight incline
- an “S”-shaped neck like a swan
- a “J”-shaped neck like a giraffe
a relatively straight neck oriented horizontally or at a slight incline
What is the stratigraphic range of Sauropodomorpha?
Triassic only
Jurassic and Cretaceous only
Jurassic only
Cretaceous only
Correct!
Triassic, Jurassic, and Cretaceous
Triassic, Jurassic, and Cretaceous
Which of the following features is shared by Sauropoda and Theropoda? (I.e., what is a synapomorophy of Saurischia?)
- enlarged claw on big thumb
- overlapping metatarsals
- carpometacarpus
- fully retracted bony nares posterior to antorbital fenestra
enlarged claw on big thumb
Which clade of dinosaur includes the longest terrestrial animal (but not necessarily the heaviest) to ever walk on Earth?
- theropda
- diplodocodidea
- ornithiscia
- titanosauria
Diplodocodiea
