Lesson 9

Question 1

crown tetropods

Answer 1

• classified as the nearest living ancestor of all living tetropods
• have fewer than or equal to 5 digits
• have the presence of an occipital condyle
• originally – all tetrapods were thought to be carniverous
  if you look at exant lissamphibia –> no adults eat plants

Question 2

what is the purpose of an occipital condyle

Answer 2

like the ball and socket – it enables up and down motion
- aquatic fish do not have this and can’t move their heads up and down

Question 3

amniotes

Answer 3

• we share a more recent common ancestor with a lizard than has to a salamander
  (amniotic eggs sac)
• having this amniotic egg stopped the dependance of water for reproduction
• have waterproof skin
• find at least 2 sacral divisions for fossil amniotes
• lateral phalanges of pterigoids
• an astralagus

Question 4

key derivations of amniotes

Answer 4

• having an astralagus (ankle joint)
• having an amniotic sac

Question 5

roamers gap

Answer 5

• gap in the carboniferous period (gap in tetrapod fossil record)
• very few terrestial rock outcrops
• as a result - early tetrapods are not really known

Question 6

temnospondyli

Answer 6

• range broadly in size from cm to the size of aligators
• have aquatic larvae
  ^^^ and most were semiaquartic

Question 7

early stereosponduli

Answer 7

• presence of sturdy zygapopheses
• interpterygoid vacuity
• lived in lowland swamps – compared to crocodiles

Question 8

importance of sturdy zygapopheses

Answer 8

greatly resist torsion and other forms of vending

Question 9

interpteryoid vacuity

Answer 9

• big opening in skull
• 2 occipital condyles

Question 10

disaurophoydia

Answer 10

• includes batracia (frogs and salamanders)

Question 11

basal amniote skull

Answer 11

paired dermal bones in skull
- gonna really form the basics for formation of phenestrae
^^^^ which is the hole inside the skull through which muscles pass

Question 12

hylonomus

Answer 12

• extinct
• early amniote
• reveals the 4 regions of vertebral column quite well

Question 13

basic amniote character

Answer 13

• lateral flange of pterygoid
• the second vertebra forms a unique vertebra (axis) first one is the atlas
• ankle mesotarsal joint
• separation of axial musculator and appendicular musculature
• at least 2 sacral vertebrae

Question 14

• lateral flange of pterygoid

Answer 14

• important origin for muscle
• for a greater body size – it helps to have a good jaw action for catching prey

Question 15

• the second vertebra forms a unique vertebra (axis) first one is the atlas

Answer 15

process that articulates (dens) enables site of side to side movement

Question 16

ankle mesotarsal joint

Answer 16

thought to be associated with the new skill of feet and to be used for locomotion
– ^^^ prior — feet and hands were more like holdfass

Question 17

albumen (amniotic egg)

Answer 17

• water in the sac
• provides shock absorption

Question 18

yolk sac (amniotic egg)

Answer 18

provides a lot of nutrients and energy and fats
- non amniotic eggs have a sac
- but amniotic eggs have 3 additinal extra-embryonic membranes that funtamentally make it an amniote

Question 19

what did these thick extra embryonic membranes do

Answer 19

they elevated the speed with which metabolic respiration could occur – which allowed for a larger egg – larger hatchling – and ultimately a larger adult

Question 20

coastal ventilation of the lungs (amniotic egg)

Answer 20

• amniotes have evolved this mechanism for bentilatio of lungs
• makes use of muscles between ribs to change the volume of the inside and pump air in and out
• much more efficient than buccal pumps of nonamniotes
  ^^ musculature of buccal pumps is not needed – can run while breathing

Question 21

efficiency of ventilation lungs enabled the evolution of longer necks – PROBLEM

Answer 21

• dead air space
• necks do not have a hgas exchane area and thus it is viewed as ineffecient
• but because of this coastal ventilation – the inefficiency of long necks is countered
  — neck allows for animals to reach lofty heights, but also provides sapce for the elaboration and branching and nerves extending to the limbs
  ———– dexterity and fine motor movement for limbs
  ———— the capactiy to write —— requires great deal of elabortation of nerve fibers

Question 22

patterns of amniote temporal fenestra

Answer 22

• holes on the side of the skull through which muscles pass — ex — important jaw muscles
• form foundation
• hole gets greatly modified, even lost

Question 23

evolution of fenestra

Answer 23

• evolved twice
• synapses and diapsids are not from an original one whole organism ???

Question 24

basal turtle

Answer 24

• extant turtles have no fenestra
• there ^^ is discussion over where they belong becasue of their lack of fenestra — but the question was answered —- there were early turtles with a diapsid condition
  ^^^ can call extant turtles anapsids (no hole)

Question 25

t/f post orbital bar has been lost in mammels

Answer 25

true

Question 26

diapsid

Answer 26

lizards --> lose lower temporal bar snakes -- losed lower and upper temporal bar (lower and upper phenestra merge) - birds - extinct dino

Question 27

synapsid condition

Answer 27

one hole

Question 28

diapsid condition

Answer 28

2 holes

Question 29

a flat skull acts as a bellose

Answer 29

- flat thing that blows wind - does not enable complex jaw movement

Question 30

range of motion of any muscle is directly proportional to hiw ling that muscle is

Answer 30

- would have been selection between tall skull --- allowing for longer muscles of jaw motion ------- but if it strains the skull too much -- its not really able to support the range of motion BUT --------- a small hole would have relieved some of that stress ---------- providing elasticity

Question 31

THEORY of small hole

Answer 31

originated as a small hole to relieve stress --- larger hole for muscles arouse of out that -- allowing them to buldge outward and wrap around skull

Question 32

ankle evolution

Answer 32

3 tarsals fuse to form astralagus - forming new joint - some groups deviate and fully devolve - food more acting as a lever

Question 33

more amniotic egg

Answer 33

- presence of shell with pores - shell doesn't need to be mineralized - a lot have kind of this soft-leather kind of egg - enables the developing embryo to bypass that larval stae - there are no larval stages in amniotes - no gills -- exchange gases by diffusion through pores of

Question 34

aquatic amniotes

Answer 34

- usually come ashore to lay eggs - or could be viverous

Question 35

earliest mammals

Answer 35

thought to be egg legging

Question 36

all amniotes have

Answer 36

internal fertilization --> due the presence of the sell - many have evolved a penis to make this possible

Question 37

tradeof for gasses passing readuly

Answer 37

- not just CO2 and O2 that are passing through - microbes also pass through - can compromise the life of the embryo

Question 38

bird and egg susceptibility

Answer 38

female lays her eggs then the egg is immediately susceptible to the invasion of microbes through pores of the shell - by incubating --> she raises the temperature to about 39 degress celcius and the microbes die

Question 39

if the bird lays more than 1 egg

Answer 39

- vast majority can only lay 1 per day - if ou have a 4 day spread of egg laying -- 4 day spread o f hatching ----- there will be a runt - runts cannot compete with the older birds - most birds don't start incubation right away so that way you don't have a competing older and younger bird situation

Question 40

TRADEOFF of incubate

Answer 40

you can incubate early to make sure everyone hatches but there will be a separation of births and most likely a runt, or you can wait to incubate so everyone hatches together (first ones to be born may not hatch)

Question 41

how many eggs you lay

Answer 41

- if you lay 1 -- not a problem - 2 eggs - one day apart, not gonna be a big deal ex: 10 eggs ------ tremendous spread of hatching

Question 42

latitudinal variation

Answer 42

more affect in the tropics bc of warm climates (not good when it is too warm for incubation)

Question 43

latitudinal variation of clutch size

Answer 43

birds of higher latitude lay more eggs --> becasue the microbial threat is not as large