Turtle shell Carapace (dorsal shell) Composed of 55-60 bones
Fused to ribs Fused to vertebrae Plastron (ventral shell) Composed
of 9 bones Bones covered by epidermal "scales"
Slide 8
Slide 9
Life with a shell Protection from predators Constrained
morphology Affects physiology, ecology, selective response Shell
shape often reflects ecology ("ecomorphology") Terrestrial: domed
Aquatic: flattened, streamlined Storage of calcium Breathing
adaptations
Slide 10
Turtle respiration Ribs (shell) are rigid, so can't use costal
muscles to breathe like other vertebrates Lungs are dorsal,
attached to carapace Sheets of muscle attach internal organs to
shell One set of muscles pulls internal organs distally in body
cavity (inspiration) Other set pulls organs inwards and upwards
towards lungs, forcing air out Some cutaneous, buccal respiration
Cloacal breathing
Turtle Life History Carnivorous, Omnivorous, or Herbivorous
Generally long-lived Internal fertilization All species oviparous
Nest in soil or sand Temperature dependent sex determination No
parental care