Cenozoic Primates (final)

Question 1

What are the 2 suborders of primates?

Answer 1

Prosimians : Tarsiers, lemurs, lorises

Anthropoids : Monkeys and apes (includes humans)

Question 2

When did primates evolve?

Answer 2

They evolved by the Late Cretaceous
- began small but were large by Eocene

Question 3

What are the general trends in primate evolution?

Answer 3

• skeletal changes
• change in mode of locomotion
• increase in brain size
• shift towards smaller, fewer, and more specialized teeth
• development of stereoscopic vision (depth perception)
• grasping hand with opposable thumb evolved

*these were not linear changes
*define primates in terms of their arboreal ancestry

Question 4

Explain the Prosimian group and their characteristics

Answer 4

Prosimians (before ape)
Oldest primate lineage > fossil record dated to Paleocene > Eocene - abundant in northern continents > today, found only in tropical areas

• small, arboreal
• five-digit hands
• claws or nails
• typically omnivorous
• large eyes, norturnal

Question 5

What is the Anthropoid group? What are the 3 Superfamilies in this group?

Answer 5

Anthropoids (resembling human beings)

Superfamilies:
1. Ceboidea (NEW WORLD MONKEYS)
- ex. spider monkey
- originated in the Americas
*prehensile tail, flat face, widely separated nostrils

2. Cercopithecoidea (OLD WOLD MONKEYS)
   - ex. baboon
   - originated in Africa and Asia
   *downward nostrils, grasping hands, and non-prehensile tail
   *we are more closely related to these
3. Hominoidea (apes and humans)
   - ex. chiimpanzee
   - diverged from Old World monkeys before Miocene

Question 6

Explain how the climate and environment impacted the Hominoidea evolution?

Answer 6

They evolved in Africa
- climates cooled and became drier after Late Eocene
- rain forests replaced by mixed forests, savannas, and open grasslands
- extinction of forest dwellers, adaptations for plains dwellers and *upright posture

Question 7

What are the 2 families of Hominoidea?

Answer 7

1. Family Hylobatidae: (lesser apes)
   - ex. Gibbons
2. Family Hominidae: (great apes)

> Subfamily Ponginae
- ex. organgutans

> Subfamily Homininae (Hominoids)
- ex. chimps, gorillas, humans and our extinct ancestors

Question 8

What are the specific evolutionary traits of Hominins (chimps and humans)

Answer 8

• fossil record extends to nearly 7 million years
• enlarged brains
• feature reduced canine teeth
• have omnivorous diets
• have upright posture
• are bipedal
• developed increased manual dexterity
• evolved to use sophisticated tools
• details of hominin evolution are debated because of gaps in fossil record