Mammal overview Flashcards Preview

Mammalian Diversity > Mammal overview > Flashcards

Flashcards in Mammal overview Deck (49)
Loading flashcards...
1

Give the 2 subclasses of the mammal class.

Prototheria (Monotremata)

Theria (Metatheria)

2

Give the 2 infraclasses of the subclass Theria.

Marsupialia
Placentalia

3

What is the difference between organisms in the subclass Prototheria and Theria

Prototheria- Lay eggs

Theria- Have live young

4

What has caused drastic changes in the mammalian phylogeny ?

Fossil findings
Molecular analysis

5

How many mammalian orders are there ?

27
1 Prototherian
7 Marsupial
19 Placental

6

How many species exist in the mammalian order ?

5,488

7

Give a broad description of a mammal.

Group of animals with;
Backbones
Bodies with fur (?)
Nurse infants with milk
Unique jaw articulation

8

What is the mammae ?

Mammary gland, where milk production takes place

9

What is a mammillae ?

A nipple/teat, delivers milk to the infant

10

How many mammaries will an organism have ?

Generally twice as many mammaries as the average litter size.

11

What are the benefits of feeding via the mammary system ?

Guarantees constant supply of food
Female can redistribute energy into milk production

Little energy required for offspring to feed.

12

What one species has paternal lactation ?

Dayak fruit bat

13

What bone has articulated to form the mammalian jaw ?

Dentary bone
Has met with the squamosal bone in the skull to form jaw.

14

Which ancestral bones are responsible for an increase in the acuteness of mammalian in hearing ?

The quadrate and Articular bone.

15

The quadrate bone has become the....

Incus of the inner ear
(decreased in size)

16

The articular bone has become the....

Malleus of the inner ear
(decreased in size)

17

How many jaw joints do mammals have in the present day ?

One jaw joint, giving more efficient chewing.

18

How do mammalian teeth differ from shark teeth ?

They do not continuously grow.
Will replace them once or never.

19

Give cycle of placental mammal teeth.

2 sets
Milk teeth
Adult teeth

20

Which teeth remain constant throughout a placental mammals life ?

Molars, only one set.

21

Give the cycle of marsupial teeth.

1 set
Only last premolar will be replaced

22

What enamel is found on mammalian teeth ?

Prismatic enamel

23

What is an occipital condyle ?

Where the skull meets the top of the neck vertebrate.

24

How many occipital condyles do mammals have ?

2

25

What is the advantage to mammals of having 2 occipital condyles ?

Decreases tension on skull
Allows greater control of head movement

26

How many occipital condyle do birds have ?

1

27

What is the disadvantage of 2 occipital condyles ?

Decreased lateral head movement

28

Give the earliest fossil evidence of mammals.

160 million years ago

29

Who do mammals share there AMNIOTE common ancestor with ?

Reptiles, Dinosaurs, Birds,

30

Give the groups which this amniote ancestor diverged into.

Anapsids
Diapsids
Synapsids