More reptile anatomy and physiology Flashcards
What are the 2 Chelonian sub-orders? What is the main comparison between them?
- Pleurodira: can flex neck at 3 points (S-shape horizontally)
- Cryptodira: can flex neck at 2 points (S-shape vertically)
How do chelonia gain heat?
Heliothermic - by basking in the sun
What is the shell composed of?
Keratinised plates called scutes.
Scutes overlie dermal bone plates
What are the names given to the dorsal dome part and ventral flattened parts of the shell?
Dorsal = carapace Ventral = Plastron
How is the skeleton of chelonia modified?
- limbs project laterally
- spine and ribs fused
- pectoral and pelvic girdle vertical within the ribcage
Describe the respiratory system of chelonia
- Nasal breathers
- Trachea short
- No diaphragm
- lungs lie dorsally and under carapace
- can switch to anaerobic respiration
Where does the heart lie in chelonia?
Posterior to the pelvic girdle
How many chambers does a chelonia heart have?
3 - 2 atria and one ventricle
Where in chelonia would you take a blood sample?
Jugular vein
Dorsal coccygeal vein - in tail
How do chelonia grasp and chew food?
No teeth so use sharp beak instead
Thick fleshy tongue
What are the 2 methods of urine excretion in chelonia
- directly into urodeum
- refluxed into bladder or colon for further water conservation
How can a male chelonia be identified from a female?
- Concave plastron to assist with mounting
- Presence of phallus
- Longer distance from caudal edge of plastron to cloaca
- Longer, broader tails than females
Give a definition of oviparous
Females produce young by means of eggs which are hatched after they have been laid by the parent
What are the 3 thermoregulation methods of lizards?
- Colour change: melanin pigment
- Body posture/position
- Behaviour
In lizards which muscle is responsible as the main jaw opener?
Depressor mandible
