Reptiles and Birds

Question 1

What was the main feature of evolution from amphibians to reptiles and birds?

Answer 1

The evolution of the amniotic egg

No longer need to breed or lay eggs in/near water

Eliminates the larvae stage

Question 2

What are fenestra?

Answer 2

Openings in the skull for the attachment of jaw muscles, enables the jaw to open widely

NOT EYE SOCKETS OR NOSTRILS

Question 3

How are skulls categorised by fenestra?

Answer 3

Anapsid = no fenestra (extinct forms)

Synapsid = one fenestra (mammals)

Diapsid = two fenestra (birds and reptiles)

Turtles were diapsid but lost their fenestra

Question 4

Are reptiles monophyletic or paraphyletic?

Answer 4

Paraphyletic

Question 5

What are features of reptiles?

Answer 5

Heavy ossified skeleton

Skin covered in keratinised scales or scutes - prevents desiccation

Ectothermal

Internal fertilisation - eggs laid on land

Efficient predators

Question 6

What period was the age of the reptiles?

Answer 6

Mesozoic

Question 7

What were the early reptiles?

Answer 7

Lizard

Crocodile

Tuatara

Ichthyosaur

Plesiosaur

Pterosaur

Dinosaur

Question 8

What animals come under the order Chelonia? What are their features?

Answer 8

Turtles, terrapins and tortoises

Marine, freshwater and terrestrial

Teeth replaced by sharp horny plates

Bondy dermal plates fuse to form a carapace and plastron

Retractable limbs

Question 9

What animals come under the order Squamata?

Answer 9

Lizards and Snakes

Question 10

What animals come under the order Sphenodontia?

Answer 10

Tuatara

Question 11

Are birds monophyletic or paraphyletic?

Answer 11

Monophyletic

Question 12

What are some features of birds?

Answer 12

Hollow bones

Reduced organs

No teeth - food ground in the gizzard

Lightweight keratin bill

Large pectoral muscle anchored to keel gives power for flight

Question 13

What are the different types of feathers?

Answer 13

Contour = gives the outer shape and protects them from water

Down = underneath contour feathers and have no hooks so can trap air for insulation

Flight = posterior end of the trailing wing

Filoplumes = lie with the contour feathers and are for sensory functions

Question 14

How many chambers does a bird heart have?

Answer 14

4

Question 15

What are the different hypothesis for flight?

Answer 15

Hypothesis 1:

Ancestors chased insect prey and feathers aided in running, jumping and then gliding

Hypothesis 2:

Feathers aided for running up inclines and then eventually helped with gliding

Hypothesis 3:

Ancestors were climbers, feathers evolved as an adaptation for gliding to the ground

Question 16

What are the two groups birds are split into?

Answer 16

Ratites

Carinates