Biodiversity 7: Reptiles and birds

Question 1

Describe the amniotic egg

Answer 1

A self contained waterproof chamber for development
Eliminates larval stage = freed ancestors from need to return to water to breed

Question 2

What is the amniotic egg shell like in reptiles?

Answer 2

Leathery

Question 3

What is the amniotic egg shell like in birds?

Answer 3

calcium carbonate (protected from drying out)

Question 4

What are the 5 membranes present in the amniotic egg?

Answer 4

• Shell
• Amnion
• Chorion
• Yolk sac
• Allantois

Question 5

Describe the shell of an amniotic egg

Answer 5

Shell is waterproof but allows gas exchange so embryo can get O2

Question 6

Describe the amnion of an amniotic egg

Answer 6

fluid cushions and protects embryo

Question 7

Describe the chorion of an amniotic egg

Answer 7

surrounds embryo and regulates gas exchange

Question 8

Describe the yolk sac of an amniotic egg

Answer 8

surround egg yolk mass

yolk mass = accumulation of nutrients from mother

Question 9

Describe the allantois of an amiotic egg

Answer 9

Stores nitrogenous waste (toxic to embryo)

Question 10

What is a fenestra?

Answer 10

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

Question 11

Define anapsid

Answer 11

No fenestra
Extinct forms

Question 12

Define synapsid

Answer 12

1 fenestra
Mammals

Question 13

Define diapsid

Answer 13

2 fenestra
Birds and reptiles

Question 14

Why did anapids go extinct?

Answer 14

probably due to poor bite power

Question 15

‘reptiles are paraphyletic’

What does this statement mean?

Answer 15

multiple lineages, don’t have a single ancestor that distinguishes them from non-reptiles

Question 16

Describe reptiles + examples

Answer 16

Lack a single defining characteristic:
Have amniotic eggs but no feathers (not birds)
Don’t have mammary glands/hair (not mammals)
E.g Turtles, lizards, snakes, crocodile, tuatara

Question 17

Describe the features of reptiles

Answer 17

Heavier ossified skeleton, strong joints, clawed toes
Skin covered in keratinised scales or scutes
Ectotherm (cold blooded) → eat less: only need 10% of calories of an endotherm
Internal fertilisation, eggs laid on land
Efficient predators

Question 18

What covers a reptiles skin and how are these adapted to life on land?

Answer 18

Skin covered in keratinised scales or scutes → prevent dessication

Question 19

What type of fertilsation do reptiles use?

Answer 19

Internal, lay eggs on land

Question 20

In which age were early reptiles dominant?

Answer 20

Mesozoic ‘Age of the Reptiles’

Question 21

When and why did Ichthyosaurs go extinct?

Answer 21

~95 mil yrs ago
couldn’t evolve fast enough to deal with global warming

Question 22

What did early forms of reptiles probaby feed on?

Answer 22

Invertebrates = little competition

Question 23

When and why did the plesiosaurs, pterosaurs and dinosaurs go extinct?

Answer 23

~65 mil yrs ago

Potentially:
Mammals outcompeted
Massive volcanic eruption
Massive asteroid impact
= Most likely due to climate change, triggered by asteroid ash blocking sunlight
→ only 4 orders survived this

Question 24

Which order do turtles, terrapins and tortoises belong to?

Answer 24

Chelonia

Question 25

Describe the Chelonia

Answer 25

Includes marine (turtle), freshwater (terrapin) and terrestrial (tortoise) forms Teeth replaced by sharp horny plates No fenestra = weaker jaws Bony dermal plates fuse to form carapace (top shell) and plastron(bottom shell) Tortoises have retractable neck and limbs to protect against predators

Question 26

Which order do lizards and snakes belong to?

Answer 26

Squamata

Question 27

Describe snakes

Answer 27

Loss of limbs, elongate body form Probably evolved from a burrowing lizard-like ancestor (convergent evolution with earthworms) Eyelid lost, spectacle clear Jaws extremely flexible, moveable joints for large prey

Question 28

Which order do alligators and crocodiles belong to?

Answer 28

Crocodillia

Question 29

Describe Crocodilia

Answer 29

Adapted for life in water Broad flattened tail = powerful propulsion Eye, ear, nose openings on the top of the flat head Most closely related group to the dinosaurs

Question 30

How are crocodilia adapted for life on water?

Answer 30

Broad flattened tail = powerful propulsion Eye, ear, nose openings on the top of the flat head

Question 31

Describe the differences between ailligators and crocs

Answer 31

Difference between alligators and crocs: Alligators lower teeth not visible when mouth is shut Crocs lower teeth stick up (always 4th one) Alligators: prefer freshwater Crocs: prefer saltwater Crocs: more aggressive

Question 32

What order does the Tuatara belong to?

Answer 32

Sphenodontia

Question 33

Describe the Tutara

Answer 33

2 species, both in NZ Very slow growing, 35 yrs to reach full size Mean lifespan 60yrs, one male reproduced successfully at 111 yrs Some biologists predict that in captivity they could live up to 200 yrs

Question 34

What are birds defined by?

Answer 34

Defined by presence of feathers

Question 35

Describe birds modifications to flight

Answer 35

Hollow bones with cross struts Reduced organs (e.g females have 1 ovary) No teeth, food ground in gizzard Lightweight keratin bill Large pectoral muscle anchored to keel (enlarged sternum)= gives power for flight

Question 36

Describe a birds wing

Answer 36

Aerofoil shaped wing Pentadactyl limb

Question 37

What are a birds feathers held together by?

Answer 37

held together with barbs and hooked barbules = link together to give continuous flat mat of feathers

Question 38

what are a birds feathers made from?

Answer 38

Keratin = not living

Question 39

What are the 5 types of feathers on a bird?

Answer 39

Filoplumes Down Flight Contour

Question 40

Describe filoplume feathers

Answer 40

hair-like structures, accompany contour feathers, suggested sensory function

Question 41

Describe down feathers

Answer 41

lie under contour feathers, lack barbules, long fluffy barbs. Trap air for insulation

Question 42

Where are flight feathers on the wing?

Answer 42

posterior

Question 43

Describe contour feathers

Answer 43

overlay body and give bird outershape, cover anterior edges of wings

Question 44

Flight carries a high energetic requirement, what does this necessitate?

Answer 44

Necessitates endothermy, fat and feather circulation Efficient circulation, 4 chambered heart

Question 45

Birds have larger brains than reptiles, give some examples of what this facilitates

Answer 45

Complex behaviours: courtship, flight, navigation Some capable of learning and solving problems Colour vision

Question 46

Describe the kind of dinosaur birds evolved from

Answer 46

Bipedal theropod dinosaur

Question 47

What are 3 hypothesis for possible origins of flight?

Answer 47

1: Ancestors chased insect prey Feathers aided running, jumping then gliding 2: Wings and feathers aided running up inclines, then gliding 3: Ancestors were climbers, feathers evolved as an adaptation for gliding to the ground

Question 48

What does ratite mean?

Answer 48

Any bird with a flat breastbone → Cassowary & emu, kiwi, ostrich, rhea

Question 49

Describe the ratites

Answer 49

Lack keel but wide sternum, suggests lost flight Vestigial wings, large powerful legs Has evolved at least 4 times → not monophyletic

Question 50

Give some examples of carinates

Answer 50

Penguins, waders, raptors