20: Mammals

Question 1

What three features do all mammals share?

Answer 1

Hair (modified for hooves, horns etc); Three bones in inner ear; Milk produced from mammary glands (which are modified from sweat glands)

Question 2

Name the three groups of mammals

Answer 2

Placentals (Eutherians), Monotremes, Marsupials

Question 3

Name where masrupials originated from, and where they spread to

Answer 3

Originated in South America, spread to Australia (via Antarctica), and to North America and Europe

Question 4

What are the two largest groups of mammals?

Answer 4

Rodents (first) then bats

Question 5

How many synapomorphies do rodents have, and what are they?

Answer 5

THREE:
- single pair of continuously growing incisors
- no canines
- trough-like mandibular fossa (where temporal bone articulates with lower jaw)

Question 6

Two species which are NOT included in rodents?

Answer 6

Rabbits and shrews

Question 7

What are bats’ wings homologous to?

Answer 7

Hands

Question 8

Name the three main groups of primates

Answer 8

Strepsirrhini, Haplorhini, Simians (includes Catarrhini - which we are - and Platyrrhini)

Question 9

Where is mammal diversity richest?

Answer 9

South America and Central-East Africa