Test 2 Flashcards
Osteichthyes timeline
earliest fossils - 420 mya(silurian) - already had distinct lineages, diversified a lot in cenozoic
Osteichthyes synapomorphies
endochondral bone, dermatocranium, teeth with roots on premaxilla maxilla and dentary, dermal bone on roof of mouth, dermal bone operculum (lost in tetrapods), branchiostegal rays (dermal bone on floor of gill cavity, lost in tetrapods), lepidotrichia, scales with enamel or ganoine, lungs
actinopterygii synapomorphy
everted brain. wtf
tribasic fin structure
fan-like. has girdle > 3 basal elements > radial pterygiophores> lepidotrichia
paleoniscoids
mid-devonian - jurassic paraphyletic extinct group, had heterocercal tail but were fish-like.
polypteriformes
bichirs, reedfish. freshwater, central african. ganoid scales, dorsal finlets, ventral paired lungs. my sweet beautiful outgroup of actinopterygians
acipenseriformes
aka chondrostei. sturgeons and paddlefish. lost most bone (some dermal left), evolved gas bladder
sturgeon facts
1-6 m, bony scutes, northern hemisphere freshwater, anadromous, bottom feeders
paddlefish
rostrum 1/3 of their body length, lots of electroreceptors. only 2 spp. planktivores in rivers, modified gill rakers
neopterygii
“new fin” a lot less basals, more lepidotrichia. includes gars, bowfins (holostei) and teleosts. also can swing out maxilla to inc buccal cavity size and improve suction
fish jaw suspension evolution
early = autodiastylic or amphistylic, now modern is methyostylic
methyostyly
hyostyly but with bone (usually can project jaw but the back joint isnt quite as flexible)
holostei
group that includes lepisosteiformes and amiiformes
lepisosteformes
gars. 7 spp, warm, temperate fresh/brackish waters. ganoid scales. physostomous swim bladder
amiiformes
bowfins. 2 spp. suction feeders. asymmetric caudal fin, physostomy
teleost synapomorphies
emerge mid-triassic. ANOTHER hox duplication (most lost 1 and have 7 copies), swim bladder is dorsal and gas exchange is lost, homocercal tail (helps with buoyancy with less use of other fins), leptoid scales (overlapping, saves weight), skull reduction, mobile maxilla and premaxilla, pelagic eggs (lost in some lineages)
pharyngeal jaws
help in place of a tongue, evolved several times in teleosts
imbricated scales
overlapping
how many teleosts
35000 spp.
elopomorpha
includes true eels, tarpon, bonefish. have leptocephalic leaf-like pelagic larvae.
leptocephalus
having a small head
catadromy
some eels - live in streams and have pelagic mating/larvae
osteoglossomorpha
250 spp. freshwater fish. most are obligate or facultative air breathers
clupeomorpha
small, silver, schooling planktivores. like 450 spp inc.herring, anchovies
ostariophysi
includes 80% of freshwater fish. have schrekstoff, some are electric, most have Weberian app. its own group on phylogeny, includes a bunch of things like siluriformes
schreckstoff
scary stuff - alarm pheromone from broken skin
Weberian apparatus
evolved in cretaceous. allows high freq sounds to be heard by fish. gas bladder connected to inner ear via ossicle.
euteleosts
22000 spp. starting with salmoniformes (molecular grouping)
salmoniformes
euteleost group w salmon, trout pike.stealth hunters
acanthopterygii
spiky fishhh. rapidly diversified in Cenozoic. most have ctenoid scales, toothless maxilla, long toothed premaxilla for protrusion, physoclistic swim bladder.
acanthopterygii synapomorphies
spines on fins, higher pectoral fins and anterior pelvic fins.
pelagic
open sea
benthic
bottom dwelling
coral reef habitat
temporal niche partitioning (night/day), fish are specialized for manuevering, big diversity of spp
epipelagic fish
high sun and O2, very productive, but not a lot of room for niches so small diversity but large biomass
mesopelagic fish
live 200-1000m down, vertically migrate to productive zone at dusk to feed but stay low during day to avoid predation
bathypelagic fish.
1000m or lower, aphotic zone. cold, low O2, less food less activity. weak, small fish. huge jaws and teeth, can distend stomach so they take whatever they can find. some bioluminesce but visibility is poor so rely on olfaction
light produced by..
vibrio or photobacterium
bioluminescence
spp and sex specific, photophores where bacteria is stored can light up
fish gonads
large, LOTS of gametes
gonochores
one sex makes eggs, one makes sperm (88% of fish spp)
simultaneous hermaphroditism
both gonads, make gametes at different times (no self-fertilization), useful in low pop density bc any 2 individuals that meet can mate
sequential hermaphroditism
protandry or protogyny
monogamous examples
convict cichlids, seahorses
polyandrous
multiple males fertilize eggs, inc. pikes
polygynous
mating system where male fertilize and carry eggs of many females (mouthbrooding cichlid)
multiple male forms mating system
one male defends territory, females come in to lay eggs. satellite males intercept females btwn territories, and sneakers pretend to be females to enter and fertilize eggs there. streakers have huge gonads and run through dropping sperm lol
iteroparous
spawn multiple times during life (most fish)
semelparous
spawn once and die (salmon, some eels)
demersal
attached to substrate
spp with demersal eggs
engage in parental care (guarding) impossible w/ pelagic eggs
discus fish
produce nutritive mucus for young
fish sex and parental care
either can do it, usually paternal
viviparous fish
guppies/killifish etc. have matrotropic and lecithotropic. 4-6week development
gonopodium
modified fin used as intromittent organ (in live bearing fish)
seahorse/pipefish eggs
given to dad who fertilizes and then broods in brood pouch for like 4 weeks (in pipefish they are just on him lol)
sarcopterygii groups
actinistia and rhipidistia
spp diveristy for all or actinopterygii vs all of sarcopterygii
about the same
fossil sarcopterygian synapomorphies
monobasic fin, cosmine on scales, intracranial joint in braincase for lifting front of head
actinistia
coelacanths, distinct by 420 mya, thought extinct 66 mya, rediscovered 1938. live 260-300 m deep, lipids in “lung” for buoyancy, hollow spines on fins, viviparous, fins alternate sides (like gait). eat fish and squid
dipnoi
“breathe 2 ways”. lungfish, 6 spp. bottom dwellers in fresh water. autostyly. South American/African and Australian have been distinct since late Cretaceous.
australian dipnoi
1.5m long, 45 kg. use gills mostly. complex courtship and territory, no parental care. lobelike fins
SA/African dipnoi
very thin appendages, usually breathe air and use gills to expel CO2, male parental care of eggs. African estivate
estivation
African lungfish can dig (pushing mud thru gills) and cover itself in mucus for an underground waterproof cocoon to live up to 4 years dormant
rhipidistia
includes lungfish (dipnoi) and tetrapods
tetrapodamorpha synapomorphies
choanae, labyrinthodont enamel, one-bone-two-bone limbs
when and why move to land
mid-late Devonian. less predation, food resources available, we already had adaptations from basking and seasonal drying
eusthenopteron
tetrapodamorph. large, pelagic fish that loses cosmine, has limblike fins (385 mya)
panderichthys and elpistostege
380 mya. wider heads, lost dorsal fin. start of wrist and digit bones, could prop selves up (shallow water)
tiktaalik
transitional (before tetrapods but first with mobile neck). 382 mya
tetrapoda synapomorphies
digits, loss of fin rays on limbs, zygapophysis, more supportive ribs, more lung SA, more layers of muscles, pelvic girdle attaches backbone
acanthostega
tetrapod, 360 mya. lungs and gills, 8 digits, non weight bearing limbs
ichthyostega
tetrapod, reduced gills, 7 digits, forelimbs supported their weight
carboniferous tetrapods
already secondarily aquatic, reduced limbs, lost intracranial joint
earliest tetrapod mystery
395 mya tracks (10 my before the earliest tetrapod fossil)
neotetrapoda synapomorphies
occipital condyles, 5 or fewer digits, muscular tongue
zygapophyses
help hold up body by connecting vertebrae
rectus abdominus
holds torso up
occipital condyles
joints (at skull base) to articulate with atlas
tetrapod feeding
lingual or jaw prehension (must contact food before putting it in mouth once we leave water). muscular tongue, salivary glands needed
hyoid apparatus in tetrapods
(from bottom of hyoid arch) supports tongue muscles
limiting water permeability
stay wet or bony scales»_space; feathers, fur, scales (keratin in amniotes)
new organs for waste management
kidney (does what gills used to do) and bladder (urine cannot be constantly excreted)
ammonotelic
releasing waste as ammonia (via gills)
ureotelic
makes urea (mammals,amphibians)
uricotelic
makes uric acid (reptiles) - conserves water
blood path in double circuit
(oxy) L atrium, body, R atrium, lungs, L atrium etc etc
vein valves
keep blood from back flowing, use normal movement to keep valves working
electroreceptors in tetrapods
lost but reevolved in monotremes
eye changes on land
rounded cornea, flat lens (cornea does the main focusing). lacrimal glands
middle ear
important for tetrapods. stapes/columnella connects tympanum to inner ear (which still has hair cells)
vomeronasal organ
sense pheromones, unique to tetrapods
why endothermy on land
high air temp spatial variation AND easier to retain heat than in water
which can be smaller
ectotherms, surface area limits endotherm minimum size
batrachomorpha** add year
aka temnospondyli. stem amphibians, branch off from reptilomorpha (stem amniotes)
lepospondyli
whole vertebrae, carboniferous to mid permian, lizard size, varied lifestyles. uncertain placement.
batrachomorpha synapomorphies/traits
synapomorphies: interpterygoid vacuities, 2 occipital condyles (convergent with mammals). traits: cut verts (early) flat heads, 4 fingers per hand, loss of cranial kinesis
early batrachomorph traits
centrum and neural arch not connected = temno (to cut), large or small, bony scales, terrestrial and aquatic
lissamphibia
smooth skin, includes Anura, Caudata, gymnophiona. but has 2 origins from within batrachomorpha
batrachia
just frogs and salamanders.
gerobatrachus
sister to frogs and salamanders
lissamphibia synapomorphies
moist permeable skin with mucus and granular glands, cutaneous respiration, operculum-columella complex, pedicellate teeth
operculum-columella complex
in lissamphibians, columella used as middle ear for air sounds (detected by basilar papillae), operculum connects and is used to conduct sounds from the ground (detection: amphibian papillae)
pedicellate teeth
lissamphibia synapomorphy. normal crown and base with uncalcified dentine separating them (thinner area)- not shared by all ancestors.
batrachia synapomorphies
green rods added (ability to see in low light in color)- red is ancestral and give peripheral vision, levator bulbi for eyes bulging and swallowing *both are maybe a lissamphibian thing
gymnophiona etymology
gymno= naked like greeks used to be at the gymnasium
adult amphibian characteristics
flat, broad, carnivorous, immobile tongues (except some spp)
pelvic patch
thin, capillary rich patch for amphibians in dry environments to press onto any moist area to draw up water.
amphibians in dry environments
pelvic patch, reabsorb urine water, uricotelic, burrow, wax on skin
amphibian respiration
still use buccal pump, also cutaneous gas exchange
amphibian circulation
2 atria, 1 ventricle, a tiny bit of mixing but it’s pretty separate. adaptive based on whether lungs, cutaneous, or gills are needed.
granular glands
poison is alkaloids, either made of from diet ie. arthropods. location is variable, example = parotoid, behind eyes
aposematism
signaling that you are poison via bright colors
metamorphosis is regulated by..
thyroid hormones
caecilians general stuff
202 spp or smth, tropical, annuli, eye under skin or bone, fossorial or aquatic
sensory tentacle
caecilian trait, they have fossa for them on skull. probs homologous to vomeronasal organ. muscle is homologous to levator bulbi
gymnophiona young/care
75% viviparous, maternal care. eat uterine tissue or milky secretion. young have gills and lose them in the womb or shortly after birth
caudata general
700 spp. undulatory gait
caudata courtship
pheromones, hedonic and mental glands, transferred by biting, contact, wafting. also tail walking
caudata reproduction
oviparity, spermatophores. eggs usually in damp or water. young have legs as larvae
plethodontids
over half of salamanders. widely distributed, lungless, direct developers, more parental care, no buccal pump -hyoid used to shoot tongue out of mouth for feeding
anura
“no tail”. exploded after Dinos died. 6700+ spp.
anuran locomotion
simultaneous movement of hindlimbs. tendons store energy, elongate with tibiofibula, radioulna, urostyle, abbreviated spinal column, strong pelvis and forelimbs for impact
early frogs/ saltation evolution
triadobratrachus, 230mya= no elongation yet. may have started jumping to quickly get into stream when predators approached. OR synced legs for swimming
anuran feeding
tongue attached at front of mouth, flips out to catch prey
anuran breeding types
explosive (usually emphemeral spawning sites) - seasonal, promiscuous, few days to a week. prolonged breeding = chorus, males have territories females can visit
amplexus
positions frogs do to stimulate females into having eggs- could be several days
inguinal amplexus
hands around waist
axillary amplexus
hands under arms
anuran parents
lay eggs in wet places, some make foam nests, many guard. some brood on body - gastric brooding = no stomach acid while brooding eggs, young emerge. some defend tadpoles. poison dart frogs carry tadpoles up trees to bromeliads
reptilomorpha synapomorphy and traits
group that includes extant and stem amniotes. synapomorphy = vertebrae w large pleurocentrum. traits: 5-finger hand, terrestrial, domed skull, skull kinesis
synapsida
lineage leads to mammals
sauropsida
lineage leads to reptiles
stem amniotes
anthracosaurs (some secondarily aquatic), seymouriamorphs (aquatic larvae w gills and lateral line, terrestrial adults), diadectomorphs (up to 3m, terrestrial, unknown reproductive mode)
amniota synapomorphies
first found in carboniferous, diversified in permian, dominated by mesozoic. synapomorphies: amniotic egg, keratinous skin and claws, costal ventilation, metanephron
amniotic egg membranes
amnion (physical protection), yolk sac, allantois (waste and gas xchange, both from mesoderm), chorion around all others for gas exchange
eggshell of amniotic egg
can be soft (lizards, snakes, turtles, monotremes), or calcified (some squamates, archosaurs). physical protection, gas exchange via pores, shell gland in uterus
intromittent organ in amniotes
PROBS synapomorphy, many have lost it
amniotic egg drawback
eggs cannot be laid in water bc gas exchange, sea animals give live birth or lay eggs on land L. this probs evolved btwn seymouriamorphs and amniotes
amniote skin
all have alpha keratin, sauropsids also have beta (harder). all have thicker dermis and lipids. keratin limits abrasion and permeability
alveolar lungs
branching tubes with pouches (alveoli), mammals / synapsids have these.
faveolar lungs
unidirectional system of tubes with faveoli being the walls where the gas exchange takes place. found in sauropsids, very efficient.
costal ventilation
uses negative pressure. lungs drawn down to bring air in (needs energy) and relaxed to expel it. intercostals expand and contract ribcage to do this.
costal ventilation consequences
allows narrower head and longer neck (easier to pump w negative pressure), rings on trachea due to this. longer neck w more space for nerves gives more control of forelimbs. undulatory motion becomes harder bc it compresses one lung, this helps encourage the shift to dorsoventral flexion
dorsoventral flexion
movement when legs are under body rather than sprawling
metanephric kidney
lots more nephrons, allows highly conc urine, and tube becomes distinct from gonads.
for costal ventilation what is active
inhaling is active, exhaling is passive
skull bones around fenestra
postorbital and squamosal are middle bar, jugal and quadratojugal are bottom bar
synapsid skull condition
1 hole below postorbital bar
sauropsid skulls
started with anapsid skulls, then diapsid, and modified inc. losing bars and becoming anapsid (turtles)
diapsid
2 skull fenestra
anapsid
0 skull fenestra
fenestration purpose
insertion of the jaw closing muscles. helps with predation. the muscle can get longer so its contraction is also longer. larger holes means more potential muscles, more purposes, finer control, and saggital crest in some mammals allows even more and higher attachment for more power. this is also why our heads are less flat than amphibians.
teeth occlusion
teeth fit together. first found in amniotes, allows for herbivory
sauropsida and subsequent groups
early and modern sauropsids. includes parareptilia, captorhinidae and protorothyridae (both former are also in reptilia)
diapsida
extant reptiles
lepidosauromorpha
includes stem and extant lepidosaurs. inc. icthyosaurs and sauropterygia
ichthyosaurs
lepidosauromorphs (look like sharks/dolphins. predatory, viviparous, secondarily aquatic, 1-20m)
sauropterygia
includes pliosaurs, plesiosaurs, placodonts and some convergent turtle like animals (also herbivorous), the saurs have long necks, flippers, hyperphalangy - flippers made of wayyyy too many finger segments
lepidosauria + traits
inc. rhyncocephalia and squamates. have overlapping scales, diapsid. shed their scales, have transverse cloaca, tail autotomy, determinate growth, semi divided heart
tail autotomy details
fracture planes within caudal vert, segments of muscles line up and blood vessels have sphincters. cost is calories, balance maybe. basalisks, most snakes, and varanids dont do this.
determinate growth
growth stops when ossification of bones is finished ie. a max size exists. this is lost in snakes.
lepidosaur hearts
divided ventricle, blood goes lungs, cavum arteriosum(L), L ventricle, body, cavum pulmonale (R), R ventricle, back to lungs
muscular ridge
part of the lizard heart that divides the ventricles
rhyncocephalia
diverged 200 mya. tuatara. were diverse in the mesozoic but no more. hole for pineal eye in youth, lower bar of skull reclosed (synapomorphy), acrodont dentition, double tooth row on top jaw so jaws act like shears, slow growth and life cycle. maturity at 10-20 yrs, lay eggs every 3 or so, die at 60-100. secondarily lost intromittent organ, have temp dependent sex determination, warm=male
sex determination types
genetic (GSD) or environmental (ESD) (usually temp)
squamata synapomorphies
streptostylic jaw suspension (quadratojugal lost, lower jaw articulates with the quadrate), hemipenes (each has a testis, dec. refractory period)
squamate reproduction
some viviparous, no parental care post-natally.
scleroglossa
all lizard groups except iguania. thin, forked tongues, very active VNO, rely on scent cues, less territorial, active hunters, be small and longer
iguania general traits
have fleshy, projectible tongues. heavier-bodied, sit and wait predation, use visual cues, territorial
squamata typical defenses
crypsis, autotomy, fleeing, active defense (ie shooting blood or shedding all scales)
chromatophores
neural crest derived, cells that can localize pigment at a spec part to change outer color. used for social signaling, camoflage, thermoreg
iridophores
neural crest derived, change colors (physical colors - blue, silver) by localizing guanine crystals in spec cell parts.
venom in squamates
evolved via gene duplications. usually hemotoxic or neurotoxic, compressor muscles around glands squeeze to release venom when needed, it runs in fangs or along tooth grooves. snakes, varanids, heloderma
limb reduction in squamates + why?
25+ independent losses. fossorial or on substrate. gene is hox expression changes. in the womb limb buds form but they are reabsorbed.
legless lizard traits
have eyelids, have ear holes, some have longitudinal fold, have long tails compared to body
sepentes diversity
4100 spp. we use scolecophidia, alethinophidia, colubroidea
scolecophidia
snake group with 470 spp, blind snakes. tiny, burrowing, reduced eyes, a little pelvic girdle. usually eat insects/their eggs
alethinophidia
true snakes, basically boas and pythons and similar. retain some pelvic girdle
colubroidea
colubrids, viperids, elapids, lamprophiids. no pelvic girdle at all.
lamphrophiidae
burrowers, blunt heads, small eyes. inc stilleto snakes(can rotate out fangs), asps
colubridae
represents 2/3s snake diversity. 2000 spp
elapidae
usually neurotoxic, mostly slim, active foragers. inc cobras, coral snakes, sea snakes, mambas, etc etc
viperids
usually hemotoxic, heavier bodied ambush predators. triangular head. shares pit organ with boas and pythons
pit organ
pit btwn eye and nostril w membrane full of thermoreceptor cells
skull adaptations serpentes
post orbital and squamosal no longer form middle bar, lose jugal. quadrate is looong and articulates with the jaw and also the squamosal above it > so much kinesis. unattached dentary (just ligament) leads to jaw walking. very strong braincase
serpentes feeding adaptations
jaw walking, trachea at bottom of mouth very close to opening so large prey can be swallowed while still breathing. constriction evolved several times, constrict until preys heart stops, but this flexibility conflicts with a need for speed.
columella becomes what in mammals
stapes
anguimorpha
sister to iguania, includes anguids, varanids, heloderma
percomorpha
most derived fish, in acanthopterygii
tulerpeton
6 fingers, strong limbs. last tetrapod
