Exam 4 Flashcards
chordate ancestral invertebrate features
deuterostomes
triploblasts
chordate derived characteristics
notochord
pharyngeal arches or pouches
dorsal hollow nerve cord
endostyle (becomes thyroid)
post-anal tail
chordates vs vertebrates
chordates don’t have vertebra, verts do
urochordate larva
swimmers, have all 5 traits of chordates
urochordate adults
pharyngeal slits (used for filter feeding)
vertebrate derived characteristics
head and brain above notochord
internal bones
many hormone producing organs
embryonic epidermal placodes (scales, feathers, hair, sensory)
Agnathans
lack jaws, had a myelin sheath
gill pouches
made of muscle
gill arches
skeletal, supported by bone or cartilage
chondrichthyes
sharks and rays
paired appendages
replaceable teeth
bony scales
non-bone vertebral column
osteichthyes
bony fish
bony endoskeleton
had 1st lungs and limbs
swim bladder
operculum (covers gills)
amphibians
frogs and salamanders
cutaneous respiration
complete vertebrate metamorphosis
1st terrestrial
reptiles
amniote egg
feathers
air sacs
pneumatic bone (hollow)
first vertebrate flight
first complete terrestrial vert
aves
birds
endothermy (stable body temp)
keeled breastbone
respiratory cycle
mammals
mammary glands
placenta
hair
diaphragm
sweat glands
chondrichthyes jaws
jaws evolved in placoderms, NOT sharks
don’t attach to skull
have ventral (bottom side) mouth
serrated teeth (have ridges to shred)
1st to replace teeth
chondrichthyes- squalene
oil made by liver, makes sharks less dense, reduces energy needed to swim
chondrichthyes- lateral line
sensory system, can sense water currents and pressure waves
chondrichthyes- ampullary organ of lorenzini
sensory system, detects electrical fields from other orgs
osteichthyes bone type
non-living internal bone, has no living cells
homocercal tail
symmetrical tail (osteichthyes)
heterocercal tail
asymmetrical tail (chondrichthyes)
osteichthyes- sarcopterygii
lobe finned fish, lung fish, what terrestrial orgs evolved from
osteichthyes- actinopterygii
ray finned fish, no muscle in fin
swim bladder- how to increase depth
remove gas
swim bladder- how to decrease depth
add gas
swim bladder use
enables fish to float in water without swimming
physostomous swim bladder
connected to esophagus, breathe in air from mouth
physoclistic swim bladder
not connected to esophagus, gets oxygen from bloodstream
scales- placoid
sharks and rays
have pulp, dentin, enamel
do not grow
scales- ganoid
made of bone, dentin, ganoine
earliest scale
diamond shaped, can grow
scales- cycloid
made of collagen, calcium
flexible
has growth rings
present in modern fish
scales- ctenoid
similar to cycloid, but has no bone
spiny fin of modern fish
scales- cosmoid
lobe finned fish only
2 layers- lamellar and spongy bone covered by cosmine
pectoral fins
pitch, up or down
pelvic fins
brakes only
dorsal fins
vanes, maintain direction
ventral/anal fins
keels, prevent rolling
homocercal tail fin
propulsion and steering
swimming forms- undulatory
body moves in wave like motion
swimming forms- anguilliform
undulation of back 3/4 of body
swimming forms- carangiform
only posterior half of body
swimming forms- ballistiform
wave movement of median fins only
swimming forms- rajiform
rays, up/down motion of fins extending off body
swimming forms- oscillatory
only fins move
swimming forms- ostraciform
only tail fin flexes
swimming forms- labriform
rowing motion of pectoral fins
migration patterns- catadromous
freshwater to marine to spawn
migration patterns- anadromous
marine to freshwater to spawn
migration patterns- oceandromous
marine only
migration patterns- potamodromous
freshwater only
tetrapod evolution- eusthenoptera
cross of lobe finned and lung fish
freshwater
tetrapod evolution- tiktaalik
have a neck, flat head, limbs pointed backwards (bad for walking)
lived in water, where transition to land begins
tetrapod evolution- acanthostega
webbed digits, wrist bones, backward limbs
tetrapod evolution- ichthyostega
webbed digits, thicker skeleton, backward limbs
tetrapod evolution- pederpes
1st terrestrial tetrapod (lifted body), forward pointed limbs
amphibian ancestral characteristics (tadpoles)
back to water to reproduce, tail fin, gills to lungs, scales
amphibian derived characteristics (adults)
flat skull with neck, limbs w/ wrists/ankles, hands/feet, eye position
amphibian muscles
body muscles thin, arm/leg muscles thicken