Lecture 1 - Characteristics and evolution

Question 1

What is the definition of DENTARY?

Answer 1

Single bone in jaw

Question 2

What is the definition of HETERODONTIC?

Answer 2

Different types of teeth

Question 3

An example of mammals which have a near absence of hair?

Answer 3

Naked mole rat, cetaceans (dolphins)

Question 4

An example of a mammal that is not diphyodontic?

Answer 4

Elephant

Question 5

An example of a mammal that is secondarily homodontic?

Answer 5

Toothed whales e.g. orcas

Question 6

Example of mammals that have lost teeth?

Answer 6

Platypus, anteater

Question 7

Definition of a monotreme mammal?

Answer 7

A mammal which lacks a placenta

Question 8

Definition of a choriovitelline placenta?

Answer 8

Embryo develops from yolk sack, seen in marsupials

Question 9

Definition of a chorioaallantoic placenta?

Answer 9

A placenta which develops later in pregnancy from embryotic membranes

Question 10

Definition of endothermy?

Answer 10

Reliance on internal body heat to raise temperature - seen in mammals and birds

Question 11

Definition of homeothermy?

Answer 11

Maintenance of temperature at a relatively constant level

Question 12

What does a four-chambered heart do?

Answer 12

Improve circulation, more efficient

Question 13

What does a more complex lung allow for?

Answer 13

More efficient oxygen exchange

Question 14

What does the elongation of limbs facilitate?

Answer 14

Increased acceleration, speed and maneuverability

Question 15

Why did shorter tails develop?

Answer 15

No longer required as counterbalance for rest of the body

Question 16

How many external openings do monotremes have?

Answer 16

One: cloaca: anus, bladder, vagina

Question 17

How many external openings do marsupials have?

Answer 17

Two: anus and cloaca

Question 18

How many external openings do placentals have?

Answer 18

Three: Anus, urethra, vagina

Question 19

What are specialised skin glands used for?

Answer 19

Temperature regulation
Communication
Rearing of offspring

Question 20

When did amniota arise?

Answer 20

Carboniferous period (360 mya)

Question 21

What is amniota characterized by?

Answer 21

Shelled egg

Question 22

What are the three main lineages by the end of the carboniferous period?

Answer 22

Anapsids
Synapsids
Diapsids

Question 23

How many temporal openings do anapsids have and what did they give rise to?

Answer 23

0 temporal openings

Turtles

Question 24

How many temporal openings do synapsids have and what did they give rise to?

Answer 24

1 temporal opening

Mammals

Question 25

How many temporal openings do diapsids have and what did they give rise to?

Answer 25

2 temporal openings | Lizards and snakes

Question 26

In late Carboniferous, what did synapsids diversify into?

Answer 26

Pelcosaurs and Therapsids

Question 27

Were pelcosaurs or therapsids dominant in late Carboniferous?

Answer 27

Therapsids

Question 28

What four major advances did therapsids show?

Answer 28

Increased jaw musculature, erect gait, expansion of cerebellum, start of secondary palate

Question 29

When did therapsid dominance end?

Answer 29

The end of Permian/Triassic (245 mya)

Question 30

What were the next group of dominant terrestrial vertebrates after therapsids?

Answer 30

Archosaurs

Question 31

When were archosaurs dominant and how long for?

Answer 31

Dominant throughout Mesozoic Era for 180 million years

Question 32

Which group of therapsids survived?

Answer 32

Cynadonts

Question 33

What 2 major advances did cynadonts, the group of therapsids that survived extinction, show?

Answer 33

Enlarged dentary bone, completion of secondary palate

Question 34

In late Triassic what did cynadonts give rise to?

Answer 34

Early mammals

Question 35

What four new traits did early mammals show?

Answer 35

Hair, mammary glands, specialised skin glands, molars and jaw that allow shearing action

Question 36

What arose in early Jurassic?

Answer 36

Ancestor of modern Prototherians

Question 37

What two traits did early prototherians exhibit?

Answer 37

Three ear ossicles, modified vertebrae and long bones

Question 38

When did the ancestor of modern Therian mammals arise?

Answer 38

Late Jurassic

Question 39

What two traits did early Therians exhibit?

Answer 39

Modification of braincase and vertical tympanic membrane

Question 40

What three traits did late Therians exhibit?

Answer 40

Chorioallantoic placenta, long gestation and brown adipose tissue

Question 41

When did rise of mammals begin?

Answer 41

Cenozoic Era

Question 42

What were the major groups in the Carboniferous era?

Answer 42

Amniotes and Synapsids

Question 43

What was the major group in the Carboniferous/Permian era?

Answer 43

Therapsids

Question 44

What was the major group in the Permian/Triassic era?

Answer 44

Cynodonts

Question 45

What was the major group in the Triassic era?

Answer 45

Early mammals

Question 46

What was the major group in the Early Jurassic era?

Answer 46

Ancestor of Prototherians, today represented by monotremes

Question 47

What was the major group in the Late Jurassic era?

Answer 47

Ancestor of Therians, today represented by marsupials and placentals

Question 48

What occurred in the Cenozoic era, tertiary period?

Answer 48

Age of mammals

Question 49

What occurred in the Cenozoic era, quartenary period, Pleistocene epoch?

Answer 49

Ice age, homo erectus

Question 50

What occurred in the Cenozoic era, quartenary period, Holocene epoch?

Answer 50

Rise of homosapiens