Class Diapsida - Archosauria Flashcards
archosaurs - write out their line from class to orders
class reptilia subclass diapsida superorder archosauria order crocodilia dinos
when did archosaurs evolve
late permian, early triassic
are archosaurs still diapsid amniotes
yep
what are the 2 main clades of archosaurs
crocs, relative
pterosaurs, dinos + birds
what are the derived characters / synapomorphies of the archosaurs
teeth in sockets
anti-orbital and mandibular fenestrae aka skull
fourth trochanter (FEMUR)
The anti-orbital and mandibular fenestrae (skull) or archosaurs are designed for what…
help reduce weight of skull in early archosaurs
basically just openings in front of the eyes and jaw
what helped archosaurs develop that bipedal gait…
without this, dinos may have never even evolved
the fourth trochanter / femur
better muscle attachment
synapsids are mammal-like reptiles that were replaced by archosaurs after the permian extinction. Why did archosaurs do better than the synapsids in this time, leading to them being able to radiate in the triassic?
it was dryer and reptile have better water conservation than mammal-like reptiles
erect limbs
Crocodilians… write out the lineage
class reptilian
subclass diapsida
superorder archosauria
order crocodilian
crocodilians are descendants from..
thecodonts
the crocodilians are the only surviving what of the archosauria lineage
non avian reptiles
what gave rise to the mesozoic diversification of dinos and birds
crocodilians
order crocodilians differ littler from primitive croc in the early mesozoic.. what are some key features
teeth in sockets
long, reinforced skull + jaw muscles for strong bite
seocndary palate
crocodilians have a shared feature with mammals.. what is it
secondary palate
are crocs more closely related to birds or lizards
birds
part of superorder archosauria
are croc viviparous, ovivparous or ovoviviparous
oviparous
lay eggs in open nest sites
how is the croc sex determined
temp
opposite to turtles
high temp - males :-(
cold temp - females
what is a secondary palate
divide nasal cavity from mouth
what are the three families under order crocodilia
family crocodyliadae (crocs)
family alligatoridae (alligators + caimans)
family gavialidae (gharials)
what are caimans
family alligatoridae
small alligator-like, from south central america
what habitats do crocs live in
semi-aquatic
freshwater
tropics of Asia, Africa, Americas, Australia
what are the 2 species of alligator
american and Chinese alligators
what are gharials
one species native to india semi-aquatic thinner snout than crocs lack jaw strength to catch larger prey
what’s the difference between cros and gators
different families
croc = long, narrow V shaped snout (fish + mammals) gator = wider, U-shaped snouth (more crunch to eat turtles)
upper and lower jaws differ
how are the upper and lower jaws different in crocs and gators
crocs
- upper + lower same width so teeth exposed in interlocking pattern + enormous 4th tooth on lower
gators
- wider upper jaw so lower teeth concealed (fit into socket in upper jaw), enormous 4th tooth hidden in lower
how is crocs feeding different from gators
crocs - atach humans, cattle, deer, larger mammals
alligators less agressive
eat turtles
what allows the crocodilians to breath while eating or when opening mouths underwater
secondary palate
what does the secondary palate do anatomically
separates breathing tube from throat
extra protection for braincase
separate oral and nasal cavities (same as humans)
is crocodilians have a long snout, slender jaw and sharp teeth is was made to eat…
fish
has a weaker jaw
a wider snout with larger teeth is esigned to eat …
larger prey
how do crocodilians eat
death roll
rip shreds of flesh
crocodilians have complex mothering skills… list some key features / cool stuff
mother guards nest
when she hears the babies call inside the egg, she can puncture a tiny hole in egg to help them hatch + carry egg to the water
when dinosaurs roam the earth
triassic - jurassic - cretaceous (231 - 66 mya)
are dinos bipedal or quadrapedal
both
ancestrally bipedal, but could also be quadrupedal
what are the 3 groups of dinos that descended from the tecodonts
pterosaurs
ornithischians
saurischians
are pterosaurs dinos
NO
they are under superoder archosauria but they are no dinos
since pterosaurs were the first flying reptiles, are they related to birds…
nope, no direct ancestor to modern birds
they evolved from traissic to late cretaceous, about 50 mya before birds emerged
give an example of pterosaur
pteradactyl
what were the wings on pterosaurs like
elongated 4th finger
thin membranous wings
skin anchored along side of body
did pterosaurs have feathers/hair
no feathers
are crocodiles dinosaurs
nope
are dinos really extinct
technically no because birds are descendants of dinos
are dinos monophyletic
nope
what are the general unique characteristics of dinos
strong knee and ankle joint
upright stance
standing tall (carrier’s constraint and sprawling gait)
in bipedal thecodonts + crocs, ankles flex in swiveling motion. How is this different in birds and dinos
knee in simple hinge with peg-and-socket ankles gone
ankle bone firmly attached to shin
how does the stance of dinos differ from that of thecodonts/crocs
thecodonts - V-stance, legs angled out, leg bone/femur inward angle into hip - making hip socket
dinos - upright, legs beneath body, top of femur sharply inward, ball fits into hipbone socket, hipbone has no bone at all
what is the carrier’s constraint that lizards faced
can’t breathe when running because of side to side movement
moving stale air from one lung to the other
sideways movement so lizards can’t expand
how did dinosaurs adapt to the carrier’s constraint problem
sprawling gait
hipsocket faced sideways know at top of femur is at an angle
femur can point down instead of out to the side
all the weight is in line
in general. the dinos body evolved to stand tall by having an …
erect gait w two main hips
what are the two main groups of dinosaurs
ornithischian (bird hipped)
saurishcian (lizard hipped)
what is bird hipped
pubis is forward pointing
what is lizard hipped
pubic bone down and toward head
what group of dinosaur did modern birds evolve from
saurischians
herreasaurus was the oldest known…
dinosaur
triceratops, iguanadons, stegosaurs… these are all examples of what type of dinosaur
ornithischian
ornithischians - are the bipedal or qudrupedal
could be both
the beaked, herbivore dinosaurs, with a predentary bone in front of the lower jaw, usually hunted in large herds… what kind of dinosaur was this
ornithischians
were saurischians only carnivores
no, not all carnivores, but all carnivores were saurishcians
what are the two groups of saurischians
theropods - bipedal carnivores
sauropods - qudrupedal herbivores
what group of dinosaurs did all modern birds descend from
bipedal theropods
who were the first land vertebrates to eat trees
sauropods
sauropods don’t have hooves.. they have…
modified hand on forelimbs for weight support = thumb has CLAWS!!!
what are some body characteristics of sauropods
long neck small head big body long tail forelimbs - like pillars, slender hindlimbs - thick + straight w 5 toes SIZE!!! h=they could be 5-6 ft or 100 ft
what type of dinosaur is sometime called beast feet
theropods
maniraptors, velociraotors,
T Rex… what kind of dinos are these
theropods
what are some shared features of theropods with birds
furcular = wishbone
air filled bones - pneumatized
brooding eggs
feathers
the dinosaur renaissance in the 60s changed the way we thought about dinos, which beforehand we thought they were pretty stupid. what were some of the reason why people started believing they were smart
social strucuture for hunting
braincase seemed to be increasing throughout theropod evolution
- cerebrum to brain ratio increasing
what is the number one defining feature of modern birds
feathers
what did feathers originally evolve for
thermoregulation, not flght
why did dinos/saurischians have feathers
they were endothermic so feathers helped them regulate BT
sinosaurpteryx was an early dinosaur known for having…
coloured feathers, fine feathers, no flight
protoarchaeopteryx means before archaeopteryx… what kind of feathers did they have and why
vaned feathers
flightless, but potential gliders because they were arboreal and runners
how was protoarchaeopteryx bird like
vaned feathers, no lfihgt but maybe glided
hollow, pneumatized bones
wishbone
symmetrical feather on tail
how do we know the protoarchaeopteryx was flightless
it has symmetrical feathers on its tail and modern birds w this feature are flightless
bird like dinosaurs have what common features
feathers - downy or vaned long mobile S shaped neck wishbone / furcular lunate wrist bone - fold wing downward grasping forelimb saurischian like pelvis
what was the first known bird, found 150 mya mid jurassic, discovered in the 1860s
archaeopteryx
how were the archaeopteryx feather designed for flight
asymmetric
central support lift
leading edge to support lift
what is the arboreal theory of the origin of flight
ancestors were tree climbers
jumped from branch to branch
gliding less energy and minimal wing flapping
up –> down
what was the cursorial hypothesis about the origin of flight
flapping from ground bipedal runners
ground –> up
modern birds that do this
the jesus christ lizard… what is it and how does it relate to the origin of flight
all the archaeopteryx fossils came from marine sediment
suggests that flight helped them fly over the water
what are the features of a feather
hollow quill (calamus)
barbs on rachis / shaft
vane
- hundreds of barbs make flat, webbed surface
what are feathers / where do they come from / how are they made
venations of epidermis
quill emerges from skin follicle
birds feathers are homologous to…
reptile scales
rachis / shaft and barbs - they keratinize near end of growth
type of feathers:
remiges are…
rectrices are…
remiges - wing feathers
rectrices - tail feathers
the skeleton of birds was inherited from a basal theropod dinosaurs. what makes the skeleton so light
hollow, pneumatized bones
how has the skeleton of birds been adapted for flight - the wishbone / furcular
stores energy while it flaps during wing beats
how has the skeleton of birds been adapted for flight - the pelvic girdle
more rigid, supports legs
how has the skeleton of birds been adapted for flight - the ribs
fused w vertebrae, pectoral girdle, sternum
how has the skeleton of birds been adapted for flight - the lunate wrist
multiple carpal bones
swivelling motion while flying
rotates wing to hover
how has the skeleton of birds been adapted for flight - keel on sternum
secure attachment of larger pectoral muscles
used to beat wings
briefly describe how a birds skeleton is adapted for flight
rigide vertebrae
wishbone / furcular store E during wing beats
lunate wrist - helps hover and swiveling motion w carpal bones
keel on sternum - muscle attachment of pectoral muscles - wing beats
ribs fused w vertebrae, pectoral girdle, sternum - more rigid
how has the skull and jaw changed in birds
skull fused into one piece
- they are diapsid, but so specialized its hard to eben tell anymore
toothless (archaeopteryx has teeth, modern birds don’t) - they have keratinized beaks
the flying muscles - which muscles depress the wing in flight
pectoralis muscles
the flying muscles - which muscles raisse the wing + where is it attached to
supracoracoideus muscle
attached to keel
what are the important muscles involved in flight
pectoralis
supracoracoideus
leg muscles to connect feet and toes
muscles to control tai;
do the feet of birds have muscles
no
they depend on tightening of tendons to perch + keep weight down
the digestive system of birds involve the crop, gizzard and cloaca … explain each
crop - stores food at lower esophagus
gizzard - grinds food
cloaca - poops it out
what kind of heart do birds have
4 chambers
birds have small lungs which could make respiration hard to keep up with high metabolic demand… what do they use instead
air sacs instead
the tube like passages in the air sacs of birds are called
parabronchii
where do the air sacs of birds extend into
throax, abdomen, long bones
eplain the breathing air sac mechanism of birds
inspiration
- air bypass lungs
- air flows into air sac, bellows ventilated lungs
exiration - oxygenated air flow through the lungs and out
air flow in one coninuour direction
why do birds have the most efficient respiratory system of any land vertebrate
air flow in one direction
greater quantity of oxygen on inhale
how do bird excrete + save water
uric acid
no bladder
the nervous system of birds has well developped..
cerebral hemisphere, cerebellum, optic lobes
birds nervous system has what large ratio
large brain to body ratio
the medulla is part of the brainstem that controls…
heart rate, respiration ,blood pressure
do birds have a good sense of smell + taste
nope they got tiny olfacotry lobes so they no smell good
good taste in carnivorous birds, flightless birds,
who has the most advanced eyes in the animal kingdom? Bird!! tell me about bird eyes
mostly immobile
birds of prey - forward facing eyes - better depth perception
rods and cones - rods for night, cones for the day
unique thing called PECTIN - for oxygen and nutrients
fovea
what are fovea
keen vision spots on the retina
found in birds
what are the two things birds need to do to fly
generate enough force to exceed mass
propulsion to keep moving
how are the wings of birds adapted for flight
streamlined
concaved lower surface (cambered)
leading edge has small, flight feathers
designed so air can move smoothly over wing to make lift w little drag
some lift is created by the positive pressure underneath the bird’s wing, but most of the lift is generated from…
negaive pressure above the wing
- airstream travel farther and farther over the convex surface of wing
how do birds glide
vertical and forward force from wings
llift force is at right angle to air flow
explain the motion of flapping for a bird
wings make more lift w flap by rotating forward
adds thrust
counteracts drag
down and up stroke that folds slightly inwards
why do bird fold slightly inwards when flapping
to reduce energetic cost of flapping
how is stalling prevented in flight
wing slot along leading edge - direct rapid moving air across leading surface
what are wing slots
move air across leading surface
what is an alula
group of small feathers on thumb, makes a midwing slot
what are the two forces needed for flapping flight
vertical lift and horizontal thrust
which forces for flapping flight are primary and which secondary
vertical lift - secondaries
horizontal thrust - primaries
what parts of the wing to the primaries and secondaires make up
upper convex and lower concave surface of wing
explain how the primaries and secondaries work together in flapping flight
greatest amount of power in down stroke
primary feather bens up + twists at steep angle
in the upstroke - primary feather bend so upper surface twists and makes thrust
how can you generate thrust from lift?
tip direction of lift forward
thrust comes from the wingtip
are birds monogamous or polygamous
polygamous, lots of mating going on with these lil birdies
what birds are mean and steal things from other birds, and are found on the galapogos, also called pirate birds
frigate birds
what sweeps out the sperm from previous mates in argentina lake ducks when males mate with the corkscrew vagina females
bristle on end of penis sweep out sperm
do birds have a penis
most lack a penis and use their cloacal surface in contact to mate
precocial birds have what type of young
ready to go
covered in downy fethers, eye open, can feed and run or swim as soon as they’re born
altricial birds are..
naked and afraid
helpless, not mobile, naked, must be fed in nest
what kind of young to gulls make
intermediate btw altricial and precocial birds
the modern birds are the… what order…
order neornithes
when did the order neornithes evolve
cenozoic/paleozoic - after the K-T explosion 66mya
what are the 2 superorders of neornithes
paleognathae (ratites, ratite-like birds)
neognathae (divided further)
what superorder is considered to have the old jaws…
superorder paleognathae or the neornithes
what kind of birds were the paleognathae of the neornithes…
ratites
flightless, largest living birds
ostriches, exticnt moa bird, tinamous
what bird has a primitive palate and a flat sternum and is the largest birds that are alive today
paleognathae of the neornithes
what superorder of birds is considered to be new jaw
neognathae
what are the two main groups of the neognathae
galloanserae - fowl birds
neoaves - most other birds
what are the two orders of galloanserae (superorder neognathae of the neornithes)
anseriformes - ducks
galliformes - chickens, quail, goose, phaesants, turkeys, ptarmingans, grouse
galloanserae are the fowl birds, explain the type of birds in the two groups of galloanserae
anseriformes - water fowl birds
galliformes - good runner, not flyer, almost in every environment all around the world
the passeriformes belong to what group of the neognathae
neoaves
classify perching birds
order neornithes, superorder neognathae, neoaves - passeriformes
