Reptiles Flashcards
Amniotic development
Birds - calcareous egg
Reptile - leathery/flexible egg
Mammals - internal
4 extra embryonic membranes
Amnion - membranous sac - surrounds embryo in fluid filled sac
Chorion - outer membrane - surrounds embryo + yolk sac - gas exhange
Allantois - out growth of hind gut - storage of nitrogenous waste
Yolk sac - surrounds yolk - blood supply to embryo
Types of amniote skull
Anapsids - no hole/opening
Synapsids - 1 hole/opening
Diapsids - 2 holes/openings
Chelonians
Turtles + tortoises
Anapsids
crytodines - hidden neck - retracts in S shape into shell
Pleurodines - side neck - neck folds sideways - not into shell
Lepidosaurs
Tuataras + squamates
Diapsids
Archosaurs
Crocodilians, birds, dinosaurs
Diapsids
Tuataras
Lizard like but skull is heavier
Nocturnal - cool habitats - low BT
Shares burrows with sea birds - indirect and direct food from them
Slow reproduction - mature after 10-20 years - breed once every 4 years - embryo takes 11-14 months to hatch
Temp dependant sex determination
Squamata
Lizards + snakes
Kinetic skulls
Scaly
Legged + legless forms
Limb reduction
Worldwide distribution
Crocodilians
Archosaurs
Alligators + crocs
Alligatoridae
Crocdylidae
Gaviaaliadae
Modified salivary glads from excreting salt
All swallow gastroliths (stones) - aid digestion
2 stomachs - grinding prey + acidic
Respiration
All have lungs
Left reduced or absent in snakes
Use ventilation by rib movement
Turtles cannot ventilate - visceral muscles
Turtles have membrane lining mouth that can extract O2 from water - highly vascularised sacs off cloaca - allow gas exchange
Thermal regulation
Ectotherms
Behavioural regulation
Locomotion
limbs + girdles support body from underneath
Bipedal walking/running in some
Rapid
Flying gecko - webbed feet - high SA
Gliding lizard - flaps along ribs
Locomotion in legless
Lateral undulation - movements left - right with posterior moving waves
Sidewinding - modified lateral undulation - good with no solid contact points
Concertina - tunnels - one side grips while other extends
Rectilinear - no lateral movement - belly scales lifted and pulled forward - placed down - pulls forward - large snakes
Sea snakes - flattened paddle tails
Reproductive adaptations
Nesting in marine turtles - all turtles oviparous
Nests in sand
No parental care
Hatch at same time
Nesting in alligators
Nest made from layers of aquatic veg
rotting veg warms eggs
Lay above water level
female guards + carry young to waters edge
Predatory adaptions
Most carnivores (except tortoises/some lizards - M iguana))
Crocs - secondary palet - separates nasal + mouth passage - eat and breathe/not drown
Dermal receptors in crocs - every scale - alligators - jaws - sense slight disturbances in water surface
Vomeronasal/Jacobsons organ:
Snake tongues collects odour paraticles - transfer to olfactory chamber - processed by organ - sensitive to to compounds high molecular weight
nostrils for long range sense
Jacobsons for short range
Snake Jaws - do not detach - permanently hinged - elastic ligament allows them to spread - good for food manipulation as limbless - no pectoral girdle so prey size not restricted
Venom - Large prey - immobilisation - quick injection and withdraw - neurotoxic + haemolytic - most contain both with 1 being dormant
