Lecture Exam 1, 13 February 1997

I. Fill-in. Some answers may require a short phrase. (2 pts. each, 60 pts. total)



The 2 major requirements for flight in any organism.

3.___________________________ 1 piece of evidence supporting the arboreal hypothesis for the origin of bird flight.

4.___________________________ A characteristic shared by only a small number of bird species is known as a ______ characteristic.

5.___________________________ Avian order with totipalmate feet.

6.___________________________ The percentage of total body mass made up of pectoralis muscle in flying birds.

7.___________________________ Large heavy birds have ____ (lower or higher) wing loading than small birds.

8.___________________________ One example of a large flightless avian predator filling the bipedal carnivore niche in the Tertiary Period.

9.___________________________ Dominant muscle fiber type in the pectoralis of the chicken.

10.__________________________ Muscle powering the upstroke of the wing.

11.__________________________ Tibial extension of knee joint in divers providing oar-like leverage from the leg muscles.

12.__________________________ Type of shivering in birds where opposing muscle groups work against each other.

13.__________________________ One problem with trying to establish phylogenies based solely on morphological evidence.

14.__________________________ The selective factor leading to the evolution of flight according to the cursorial hypothesis. (Hint: I'm looking for the advantage provided by the intermediate stages).


2 primitive features not present in modern birds that Archaeopteryx shared with reptiles.

17.__________________________ Name one adaptation to reduce weight in birds.

18.__________________________ Aerodynamic structure producing lift. (Hint: a bird wing is one).

19.__________________________ The most direct type of biochemical evidence used for establishing bird phylogenies.

20.__________________________ The reason why the musculature is shifted ventrally in birds.

21.__________________________ What skeletal feature allows the musculature to be shifted ventrally?

22.__________________________ Structures acting to fuse the rib cage together in modern birds.


The 2 functions of muscles in birds.

25.__________________________ Normal range of body temperatures in birds.

26.__________________________ Feather attached to 1st digit acting as a wing slot.


2 modifications associated with flightlessness.


The 2 specific groups of reptiles that are potential ancestors to the birds.

II. Multiple Choice. Choose the best answer. (2 pts. each, 20 pts. total).

1. Which of the following bird taxa were not present in the Cretaceous period?

a) Passerines b) Ichthyornithiformes c) Enantiornithes
d) Hesperornithiformes e) all were present in the Cretaceous
2. Which of the following Orders is restricted to the Southern Hemisphere?
a) Gaviiformes b) Procellariiformes c) Charadriiformes
d) Passeriformes e) Sphenisciformes

3. Which bone is not a part of the pectoral girdle in birds?
a) scapula b) coracoid c) furcula
d) synsacrum e) all are parts of the pectoral girdle

4. Which of the following is not a characteristic of FOG muscle fibers in birds?
a) relatively high aerobic enzyme activities b) relatively high glycolytic enzyme activities c) fatigue-resistant
d) high mitochondrial numbers e) all are properties of FOG fibers

5. Which wing type is best-suited for long-distance migration?
a) elliptical b) high load bearing c) high speed
d) high aspect ratio e) high lift

6. The steeper the angle of the bird wing relative to the air column, the more lift that is
provided. But, too steep an angle can cause separation of the air stream from the
upper surface of the wing, and this can lead to _____.
a) thrust b) drag c) stalling
d) loss of aspect ratio e) all of the above

7. The number of living bird species is approximately _____.
a) 2500 b) 5700 c) 8200
d) 9600 e) 12,800

8. The geologic time period where the major adaptive radiation of birds occurred is
the _____.
a) mid-Jurassic b) early to mid Tertiary c) Pleistocene
d) late Cretaceous e) early Pliocene

9. Which of the following Orders makes up about 60% of all living bird species?
a) Passeriformes b) Apodiformes c) Coraciiformes
d) Psittaciformes e) Charadriiformes

10. The mechanism by which flightlessness evolves in birds is thought to involve
a) neoteny b) taxonomy c) convergence
d) adaptive radiation e) cladistics

III. Essay. (10 pts. each, 20 pts. total). Use the back of the page if necessary.
1. The general consensus among avian paleontologists is that Archaeopteryx could fly,
but was probably not capable of powered takeoff. Given this consensus, answer
the following questions.

2. Propose the most logical family tree (phylogeny) for the four species listed below
given an initial common ancestor with none of the derived characters (0,0,0,0 initial
ancestor). Please answer by using a cladogram.
Living Species Derived Characters
Species A = C,Z,0,B C = crest
Species B = 0,0,F,0 Z = zygodactyl feet
Species C = C,Z,F,0 F = forked tail
Species D = C,0,0,0 B = decurved bill