REPTILES- SPECIES ADAPTATIONS Flashcards
What class do reptiles belong to
Sauropsida
What are the 4 orders of reptiles
- Crocodilia
- Sphenodontia
- Squamata
- Testudines
What are crocodilia
Crocodiles
Gharials
Caimans
Alligators
What are sphenodontia
Tuataras from New Zealand one 2 species
What are Squamata
Has 2 suborders
Sauria - lizards
Serpentes - snakes
What are testudines
Also know as chelonians
Turtles, tortoises and terrapins
What are the main differences between tortoises, turtles and terrapins
Tortoise- terrestrial
Turtle- marine
Terrapin- freshwater
This is for the uk in North America all are known as turtles and terrapins are any water chelonians
What are the 2 types of reptile growth
Determinate
Indeterminate
Outline determinate growth
Genetically predetermined growth - stops after maturity
Outline indeterminate reptile growth
Fast growing to a Turing- continue to grow after maturity just slower
Reliant on adequate nutrition and conditions
Describe the axial skeleton of lizards
Atlas and axis
8 cervical vertebrae (doe have ribs - tend to be caudal 4-5)
11-18 (variable ) trunk vertebrae with ribs - some also have gastralia
Variable caudal vertebrae
What is gastralia
Dermal ribs
Formed via intramembranous ossification
Attaches to the sides of ventral body wall- sternum and pelvis
Lizards and crocodiles - accessory muscle attachment
What is caudal tail autonomy in lizards
Is an anti-predator defence
Lizard drops tail, which trashes around and is brightly coloured so attracts thee predator
Hat allows caudal tail autonomy to occur
The lizards have:
Fracture plates
Sphincters to prevent blood loss
Does the tail regrow after caudal tail autonomy
Yes
So no stitching/tight bandaging.
Regrows as cartilage
What a the problem with caudal tail autonomy
Is vey costly as the tail contains fat stores and energy diverted t regrow
May affect locomotion, reproduction
Can make the lizard slower, more vulnerable less able to fight
Can a lizard undergo caudal tail autonomy again
Yes however can’t occur in the same place - has to be higher up
Describe the sternal and pectoral girdles of lizards
Interclavicle - unpaired dermal bone
Sternum - cartilage or bone that isn’t fully ossified . Links the ribs
May have gastralia
Pelvic girdle - very similar to other species
Describe the axial skeleton of snakes
Atlas and axis Single occipital condyle 100-300 preclinical vertebrae - with ribs 2-10 lumbar/ cloacal vertebrae - no ribs 10-20 caudal vertebrae - no ribs
What is the advantage of snakes only having a single occipital condyle
Supports the body
Can lunate neck more easily
Describe how the vertebrae of snakes are adapted to allow flexibility of the body without damage to the spinal cord
Zygosphene and zygantrum
- provide stability
Allows vertebrae to move together and lock vertebrae together = less movement and therefore damage of the spinal cord
Describe the pectoral and girdles of snakes
No pectoral girdle
No pelvic girdle most snakes
Pelvic spurs
What is the advantage of sakes not having a pectoralgirdle
More flexibility to move ad expand (eating prey )
Which type of snake does have a pelvic girdle
Boidae (pythons , Boa constrictors )
What are pelvic spurs
Pelvic remnants
Short bones covered in keratin, muscles flex and extend the spurs
Only males
Outline the main muscular anatomy of the snake
Intervertebral muscles are complex
Intercostal and hypaxial muscles- interlocking system of muscle chains and tendons for locomotion, passage of prey and respiration
Describe the main axial skeletons of chelonians
Atlas and axis 8 cervical vertebrae Shell 10 trunk/ dorsal vertebrae Trunk ribs are fused with costal bones 2 sacral vertebrae - fused to neural bones of the carapace <24 caudal vertebrae
What allows for variable neck length in chelonians
Varied length of the cervical vertebrae
What makes up the shell of chelonians
Osteoderms ( dermal bone ) and endochondral bones which are fused
How do you tell male and female chelonians apart
Ales have a longer tail than females therefore have more caudal vertebrae
What are the 2 suborders of chelonians
Cryptodira
Pleurodira
What is the difference between cryptodira and pleurodira chelonians
Cryptodira = hidden neck into shell- retract neck , majority of speecies Pleuurodira = side neck - turn neck to the side, small suborder
Does a chelonians shell contain blood vessels
Yes it also contains nerves so needs to be included in drug dose calculations
Describe the pectoral and pelvic girdles of chelonians
Within ribcage
Vertical orientation of ones - greater stability within the shell. Scapula articulates with shell- ventral
Outline the main muscular anatomy of the chelonians
Large muscle mass
Head and neck retraction
No trunk muscles
Pectoral/ pelvic bones to plastron
