Reptiles Flashcards
Were Dinosaurs fluffy or scaled?
Fluffy
2 Lineages of Reptiles
1) Para-reptilia
2) Eu-reptilia
Eureptilia can be devided into two groups + examples
1) Lepidosauromorpha (snakes, lizards, sphenodon)
2) Archosauromorpha (dinos, crocs, birds)
4 orders of reptiles + examples
1) Tetrudines (turtles/tortoises)
2) Rhynsocephilia/Sphenodonta
3) Squamata (lizards, snakes)
4) Crocodilia (crocs, aligators)
What distinguished between the two groups of Tetrudines?
How they retract their necks:
Cryptodira: Contract neck backwards
Pleurodira: Flex neck laterally
Two groups of Tetrudines
1) Cryptodira
2) Pleurodira
Testudines (general information)
Leatherback turtle is largest Unique to turtles: positioning of limbs within shell Marine and saltwater Herbivorous and Carnivorous Lack teeth - have keratinized ridges
Rhyncocephalia/Sphenodanta (general info.)
Lifespan ~100 years (sexually mature ~20yrs and females breed ~4-5yrs
Redevelopment of diapsid skull
Teeth:
Fuse to bone
Double row (maxilla), single row (mandible)
All have stapes, incus, malleus - Reptiles only have stapes between incus(quadrate) and inner ear
What is the difference between the human ear and reptilian ear?
Humans: Eardrum, malleus(articular), Incus(quadrate), stapes, Inner Ear
Reptiles: Eardrum, Stapes, Inner Ear
NO OUTER MEMBRANE, OR TYMPANIC MEMBRANE
Contain Incus and Quadrate as bones of the skull
Squamates (general info.)
Evolution of venom early on
60% of squamates have venom
Movable Quadrate Bone* (back part of the jaws)
Which to lizards have venom?
Gila Monster [heloderma suspectum] (usa)
Mexican beaded lizard [heloderma horridum]
Who are the closest living relatives to birds?
Crocodilia
Crocodilia
Closest living relative to birds
Semi-sprawled posture
Ability to high-walk
Ancestors were bipedal - sprawled gait is a derived trait
Dinosaurs lived during what period?
Triassic Period (~250mya) Dominant is Jurassoc period (210mya)
Main lineages of Dinosaurs (2)
1) Ornithischia
2) Saurichia
*Ischia refers to pelvic region
Ornithischia
“bird-hipped”
Herbivore
Ex) Stegosaurus
Saurischia
"Lizard-Hipped" Sauropods: Herbivores Theropods: Carnivores - Ex: Tyrannosaurus - Birds
Reptiles (General info.)
All must return to lad to lay eggs or live young (except sea snakes)
Thick keratinized stratum corneum
Epidermal scales
Scutes
Distribution limited by being ectothermic
Specialized atlas and axis cervical vertebrae
Thoracic/lumbar vertebrae not clearly different from rest
Many caudal vertebrae (tail)