Reptiles Flashcards
4 extant species
Tuatara
Squamata - worm like lizard
Chelonia - turtles and tortoises
Crocodylia - crocodiles, alligators, caimans and gharials
Squamata family
Amphisbaenia - worm like lizard
Sauria - lizards
Serpents - snakes
Tuatara (Rynchocephalia)
Primitive features
Nocturnal
Perietal eye - regulated day/night cycles
No external ear
Heart is closer to amphibians
Amphisbaenia
Worm like lizard
Legless
Tunnelling lizards
Keratinised hear
Rings on annuli
Europe, Africa, America
Sauria
Lizards
Variation in size and shape
Iguania, gekkonodia, scincomorphia, platynota
Some venomous
Venomous lizards
Gila monster
Komodo dragon
Serpents
Snakes
Lack of ears
Colubroidea - most living species
Elapsids and viperids
Elapsids and viperids
Snakes that posses hollow fangs at the front of the mouth and have highly toxic venom
Aglyphous (serpents)
Without fangs
Opisthoglyphous (serpent)
Fangs in the rear of the maxilla
Solenoglyphous (serpents)
Fangs on rotating maxilla
Viper
Proteroglyphous (serpents)
Permanently erect fangs in the front of the maxilla (cobra)
Chelonia
Turtles and tortoises
Two part shell:
Dorsal = carapace
Ventral = plastron
Omnivores- beak
Crocodylia
Crocodiles, alligators, caimans, gharial
Gharial - endangered
Skull fenestration in reptiles
Two
Reptiles skin
Dry and scaly
This limits water loss
Teeth in reptilians
All except turtles
Powerful as fenestration makes room for more muscle
Homodont dentition
Partial heterodonty in snakes and some lizards
Orientation of limbs in reptiles
Appendages rotated towards the body
Long axis of limbs parallel to main body’s axis
Limbs are straighter provides better support and greater agility
Reproduction in reptiles
Amniotic egg
Temperature dependent sex determination
Parthenogenesis - absence of male
Respiration in reptiles
Lungs
Faveoli- increases surface area
No diaphragm
Negative pressure
Pulmonary circulation in reptiles
3 chambers except from crocodilians
Septum dividing chambers
Vision in reptiles
Day vision
= multiple cones, block ultraviolet
Night vision
= large pupillary and lens apertures
= allows more uv light in
Jacobs organ
Inside mouth to detect chemicals via tongue
Smell rerouted from the nose to the tongue
Pit organ
Touch, temperature and pain
Organ has a membrane that converts changes in thermal radiation to an electrical signal
