Lecture 11

Question 1

Placentals

Answer 1

Give birth to well developed young

Question 2

Marsupials

Answer 2

Give birth to underdeveloped young

Question 3

Monotremes

Answer 3

Egg-laying mammals

Question 4

Synapsid

Answer 4

United by features in the skull also found in mammals (but not reptiles, dinosaurs or birds)
1. temporal fenestra
2. differentiation in tooth morphology
3. jaw consisted of fewer bones compared to reptile group
4. second palate appears

Question 5

Palate

Answer 5

the roof of the mouth, separating the cavities of the nose and the mouth in vertebrates

Question 6

Therapsids

Answer 6

1. feet are directly under the body
2. first evidence of hairs in fossil record
3. more holes/space in the bones (for greater blood flow)
4. baby teeth being replaced by adult teeth

Question 7

Cynodonts

Answer 7

1. Evolution of lactation
2. Cheek teeth : to cut up food
3. Jaw muscles moved outside the brain case
4. Evolution of ear bones

Question 8

Diurnal

Answer 8

Active during the day

Question 9

Nocturnal

Answer 9

Active during the night

Question 10

Crepuscular

Answer 10

Active during twilight

Question 11

Nocturnal bottleneck hypothesis

Answer 11

these species could survive only by avoiding daytime activity during times in which dinosaurs were the dominant predator

Question 12

Miocene cooling

Answer 12

Temperatures dropped globally by 5 degrees celsius around 40 million years ago
- radically changed the dominant plant life

Question 13

Cloaca

Answer 13

Single opening for reproduction and waste disposal

Question 14

Sociality

Answer 14

Taking care of our young for so long