Reptile species adaptations

Question 1

Explain some features of reptile skeleton

Answer 1

Skull:
Snakes have quadrate bone which allows them to have flexible jaw & open widely

Vertebrae:
Reptile skeleton built for flexibility
Single occipital condyle which articulates with first vertebrae = allows for greater skull flexibility
Don’t have same need to stability as they have stomach on ground
Nomenclature:
Mammals: cervical, thoracic, lumbar, coccygeal
Reptiles: pre-sacral, pre-cloacal, trunk

Ribs:
True endochondral ribs
Some have gastralia (Caudal to sternum) - Do not articulate with vertebrae - More superficial than true ribs - Muscle attachment & abdominal support

Chelonian neck types:
Cryptodira (hidden neck)

Plurodira (side neck)

Chelonian shell:
3 parts:
Epidermal – scutes, keratinised structures (skin)
Dermal – mineralised bones within dermis (dermal bones)
Endochondral – ribs, vertebrae, clavicles, interclavicle (fused to shell)
Carapace – domed part
Plastron – underside

Question 2

Explain caudal tail autotomy

Answer 2

Anti-predator defence

Not all species

Tail keeps thrashing so predator will go for tail instead of lizard

Very costly
Fat stores in tail
Divert energy away from other processes to heal tail
Tail grows back as cartilage (not bone)
May affect locomotion & reproduction

If tail drops again it is always proximal to original site

Question 3

Describe unique features of snake locomotion

Answer 3

Ribs are very flexible & have 5 different articulations which gives flexibility to spine

Zygosphene & zygantrum (vertebrae articulations) fit into each other which prevents twisting of spine

Hypaxial & epaxial muscles have interlocking system which gives flexibility

Individualised contractions of muscles for passage of prey

Question 4

Explain some rabbit MSK adaptations

Answer 4

Longer & more muscular hindlimbs to run & jump

Hop & land on forelimbs which allows them to move quickly

High muscle mass to generate power & speed when jumping

Mobile hip joints

Pronounced curvature of spine allowing them to compress body & fit through tight spaces

Question 5

What are the causes, signs and treatment of metabolic bone disease

Answer 5

Causes:
Poor nutrition (high phosphorus, low calcium, low vitamin D)
Kidney disease
Inadequate UV B light (causes calcium & vitamin D deficiency)

Signs:
Softening carapace of turtles
Bumps along bones of leg (lizards)
Softening of jaw (lizards)
Arched spine (lizards)

Treatment:
Aims are to improve calcium intake & improve access to UV light
Pain relief
Improvements to husbandry