Lecture 13 - 2.0

Question 1

Sauropsids: Archosaurs (4):

Answer 1

1. Crocodilians
2. Pterosaurs
3. Dinosaurs
   - Ornithischinas
   - Saurischians
4. Birds

Question 2

Archosaurs: Crocodilians (3):

Answer 2

1. Aquatic and predatory lifestyle
2. Ability to regulate body temp by lying with its mouth open
3. Four chambered heart
4. Temp of nest determines offspring sex (seen in other vertebrates)

Question 3

Archosaurs: Crocodilians (Aquatic and Predatory Lifestyle) (3):

Answer 3

1. Nostrils, eyes and ears on top of head
2. Eyelid is transparent
3. Bony flaps in throat

Question 4

Archosaurs: Pterosaurs (4):

Answer 4

1. First vertebrate group to evolve powered flight
2. Used membranous wings supported by elongated forelimb
3. Early forms had long tails and elongated forelimb
4. Later forms lost tail and teeth; had projection at back of head

Question 5

Archosaurs: Dinosaurs (2 Groups):

Answer 5

• Distinguished by the structue of the pelvic girdle
  1. Saurischia = girdle bones radiate outward from the centre (Omnivours)
  2. Ornithischia = ischium and part of the pubis are parallel and project backwards (herbivores)

Question 6

Archosaurs: Birds (Aves) (4):

Answer 6

1. Likely evolved from theropod dinosurs
2. Basic avian design is highly adaptable and their distinguished characteristic is feathers
3. Flyers gain access to flying prey, escape from non-flying predators and have unrivaled migratory abilities
4. Locomotion is Varied - wings exclusively to swim or not used

Question 7

Origin of Flight (Classical Idea: Arboreal Hypothesis)

Answer 7

Gliding from tree to tree

Question 8

Origin of Flight (Classical Idea: Cursorial Hypothesis)

Answer 8

Running start and lifted off the ground for insect foraging

Question 9

Origin of Flight (Modern Flight: Pouncing Proavis Model)

Answer 9

Specialized in ambush from elevated sites, used hindlimb in leaping attacks

Question 10

Origin of Flight (Modern Flight: Wing-Assisted Incline Running):

Answer 10

Use wings to scale inclined objects and trees

Question 11

Can the Modern Species be Synthesized for the Modern Hypothesis? (Y/N)

Answer 11

Yes

Question 12

Skeletal Adaptations in Birds (4):

Answer 12

1. Skull
2. Neck
3. Backbone
4. Pelvic girdle fused with synsacrum

Question 13

Skeletal Adaptations in Birds (Skull):

Answer 13

Reduced number of bones, thinner bones; no teeth (beak) to reduce weight

Question 14

Skeletal Adaptations in Birds (Neck (2)):

Answer 14

1. Exceptionally flexible, compensate for the ‘loss’ of forelimbs
2. Heterocoelous cervical vertebrae

Question 15

Skeletal Adaptations in Birds (Backbone)

Answer 15

Very rigid to minimize the number of muscles needed to maintain streamlined body during flight; thereby reducing energy consumption

Question 16

Skeletal Adaptations in Birds (Pelvic Girdle Fused with Synsacrum):

Answer 16

Bipedal; no symphysis (pelvic bones not fused) so large outlet for massive eggs

Question 17

Synsacrum Modifications:

Answer 17

Fusion of sacral vertebrae to pelvic girdle allows for rigidity and support of hindlimbs

Question 18

Sternum Modifications:

Answer 18

Ossified and well pronounced keel (carina) to provide attachment for flight muscles

Question 19

Integument of Sauropsids
(Reptiles) (3):

Answer 19

1. Relatively few glands - dry integument
2. Gland produce poisons, pheromones as signals for sex, identity, navigation
3. Well developed epidermal keratinized (horny) scales (scutes)

Question 20

Well developed epidermal keratinized (horny) scales (scutes) Aspects (reptiles) (4):

Answer 20

1. Continuous folds of epidermis
2. SHed regularly in lizards and snakes
3. Protection and desiccation
4. Locomotion (snakes)

Question 21

Integument of Sauropsids (Birds) (2):

Answer 21

1. Single large gland (uropygial gland) produces oily secretion for transfer of feathers (waterproofing)
2. Have numerous epidermal derivatives

Question 22

Have numerous epidermal derivatives (In Birds) (4):

Answer 22

1. Scales in places without feathers (legs)
2. Claws at the ends of digits
3. Beaks often include tooth-like protuberances (not ‘true’ dermal teeth)
4. Feathers for thermoregulation, locomotion, and attraction of mates