chapter 17-23 Flashcards
Rectilinear motion
large-bodied snakes
Slow movement
belly scales are alternately lifted
Lateral undulation
common locomotion
Concertina Locomotion
- involves alternately pulling
crawling through tunnels
Sidewinding
snakes crawling on smooth
or slippery surfaces
Snakes - Chemosensory
pit-like Jacobson’s organs
(vomeronasal organ) in the roof of the
mouth, which are olfactory organs.
Snakes - Thermosensor species
(pit vipers such as
rattlesnakes) have heat-sensitive pit
Predation Snakes
grabbing it and swallowing
kill their prey by constriction
venom
Colubrid snakes
have Duvernoy’s gland = homologous to
venom gland of vipers/elapids
Neurotoxic
nervous system or muscle function
Cytotoxic
breaks down and digests tissue
Hemotoxi
causing blood to congeal, or lowering blood pressure, immobolized
Aglyphous
no fangs
Opisthoglyphus
rear fangs
Solenoglyphus
= large hollow fangs, rotate forward
Proteroglyphus
fixed, hollow fangs on front of maxilla
Shell and Skeleton turtles
Ribs and vertebrae are fused to the shell and the head and
limbs can be
Plastron formed mostly from
dermal ossification
Entoplastron from interclavicle
* Epiplastra from clavicles
prototherians, crocodilians, and birds.
furcula
Birds - retain the clavicle and the
interclavicle joins to the two clavicles
One hinge:
box turtles the anterior and
posterior ends of the plastron can be
raised to close off the front and rear
openings of the shell.
Two hinges:
mud turtles there are two hinges,
plastron is often reduced, so “closing”
isn’t as complete
Cryptodira
Hidden-necked turtle
Suborder PPleurodira –
Side-necked turtles
Tubercle
protuberances of skin
Barbels:
whisker-like protuberances
usually on chin
Keel:
ridge along midline of carapace
Serrations:
jagged edge usu along shell or
beak
Vent
same thing as cloaca
makes normal
breathing impossible
Fusion of ribs to shells
Lungs are attached to carapace
dorsally and
laterally; to viscera ventrally via connective
tissue
Turtles: respiration
Downward movement of viscera pulls lungs
down, expanding space, allows inhalation
Softshell turtle respiration
leathery skin
septum - turtle
that partially divides the ventricle into separate left
and right chambers.
Temperature-Dependent Sex
Determination
Higher incubation temperatures
produce the larger sex, which in
turtles is female
parental care-turtle
Generally no parental care
Sea turtles: eggs
100 or so eggs on
sandy beaches. When the young hatch
they must escape a host of waiting
predators
Box turtles repro
only a handful of eggs are
laid at a time
Navigation by sea turtles: * Evidence suggests baby loggerheads use three cues:
Light – move toward bright light at hatching
2. Wave direction – swim into the waves
3. Magnetism – tells them direction and latitude (orientation)
Tactile cues:
male fanning females
(aquatic spp), biting, ramming
Olfactory:
tortoises can produce
pheromones (
Sympatric
ivsual cues
for turtle; esp when
there are multiple
species in the
same pond
Mobile
Gastral
muscle from
pelvis inserts on
gastralia to help
increase volume
of chest and
allow inhalation
Crocodylians and
birds losely
related to
Archosaurian
Characteristics of Diapsids
Antorbital fenestra
Fourth Trochanter- femur
Types of motion: Crocodilia
crawling
walking
belly sliding
galloping
specialist fish predator
Gharial
quadrate bone fixed allows
skull strength
teeth set in
sockets
Feeding
Broad snout (alligators, b) = crushing hard prey
* Wedge-shaped snout (crocs, c) = varied diet * Slender snout (gavials, d) = fish
secondary pala
allows
breathing during feeding
Foramen of panizza
connects the left and right
aorta.
Ornithischians and Saurischian
Dinosaur
Two branches of Archosaurs
Pseudosuchia = Crocodylomorpha – Avemetatarsalia = Pterosaurs, “dinosaurs” and birds
Ornithischians similar
similar to that of birds,
but did
Therapods
carnivorous lineage
of Saurischian dinosaurs
furcula
Coelurosaur lineage of Therapods
include
Tyrannasuroides – T-Rex –
Maniraptorans = “predators that
grasp with hands”, but were also
feathered
Maniraptorans
Name refers to
highly flexible wrist
* Appearance of
feathers
Evolution of features: birds
Loss of bones in hands –
down to 3 of birds
* Hollow bones
* Furcula * Toothless beak
Pneumatization of non-cranial bones
Air spaces in bones = lighten skeleton
Uncinate processes
extra projection off
rib surface; help strengthen rib cage and
help with inspiration
Avian Characters in Nonavian birds
Notable reduction in body size
cursorial hypothesis
Ground-up
Wing-assisted incline running
fossil of Microraptor gui
arboreal hypothesis
Trees-down
Reptilian features: Archaeopteryx
Skull with teeth
* Lacked fused structures like
the keel, pygostyle
* Long bony tail * Forearms with clawed digits
characterised by:
Reduced body sizes – Feathers – Streamlining – Skeletal modifications to
reduce weight – beak with no teeth (ancient
birds had teeth) – Internal fertilization and hardshelled amniotic egg – high metabolic rate – endothermic – four-chambered heart – reduced tail – breathing by lungs and
associated air sacs
Functions
feather
Flight
2. Heat Conservation
* Reduced convective and
evaporative heat loss
* Increased insulation
3. Camouflage
4. Protection
5. Behaviors (courtship, defense)
(pterylae)
Arranged in tracts
(apteria)
separated by regions of
unfeathered skin
Five standard types: Feathers
Contour
Semiplumes:
Down
Bristles:
Filoplumes
Molting
the process of feather replacemen
Structural Requirements for Flight
Rigid vertebral column
synsacrum
pygostyle
furculum
uncinate processes on ribs
To fly: both horizontal
thrust and vertical lift
are required
- Gravity & Lift - airfoil
- Drag & Thrust
Pectoralis major
Adducts and depresses wing
Suprocoracoideus major -
Abducts and elevates the wing
Triosseal canal
coracoid, scapula and furcula
supracoracoideus tendon
inserts on the dorsal face
of the humerus
Anisodacyl foot
four moderately
long toes
Zygodactyl foot
two toes forward, two
toes back for climbing
Uropygial Gland
Large preen gland for oil
production
“crop milk
fat
laden cells in fluid; high lipid/protein
but no sugar
Foregut Fermentation
crop as a fermentation
chamber.
Anterior glandular stomach = Proventriculus
Posterior muscular stomach = Gizzard
Avian lung
Anterior air sacs – Posterior air sacs
proportionally much larger tympanic membranes
enhances sensitivity to sound
