Reptile Anatomy
Herpetoculture
Pensacola Jr College
Focal difference
in reptile anatomy:
w ABILITY TO CAPITALIZE ON A
TERRESTRIAL ENVIRONMENT
Integumentary
System
w Major reptile function is in
water conservation, as a protective barrier
w
Epidermis
w
Dermis
w
Glands
w
Pigmentation
Reptile Epidermis
w Thick strateum corneum (top
dead layer) with compacted layers of flat horny dead cells, filled with keratin
w Replaced by swelling/
pressure from diffusion of lymph between new and old layers
w Surface scales in varied
form
Other skin layers:
w Dermis well developed
May include bony plates or
armor, as in turtle plastron
w Glands
almost totally lacking in
reptile skin, a few have scent or recognition glands
w Pigmentation
4 types of chromatophores
Reptile Skin
(snake)
Skeletal System
w Differs from amphibians in:
Single occipital condyle
More ossification
Reduction / loss of some
bones
Higher and narrower shape
Closure of amphibian otic
notch
Quadrate articular jaw
joint
Reptile Skull
w Openings in temporal region
important in classification
No openings in turtles
One or two openings on each
side of skull in other reptiles
w Quadrate-articular jaw joint
w Skull kinesis
w Early secondary palate
Reptile Skull
(lizard)
Secondary Palate
(croc)
Reptile Vertebral
Column
w Cervical vertebrae neck
First two are atlas and axis
w Trunk vertebrae have ribs
w Sacral vertebrae at pelvis,
usually 2
w Caudal vertebrae tail
Many lizards and some snakes
can split these vertebrae
Reptile Limbs
w Usually short bones and with
a lot of associated muscle
w First patella (kneecap) in
lizards
w Turned out feet with usually
five digits
w Some groups lack limbs and
girdles entirely
Reptile Skeleton
(lizard)
Digestive System
w Increased complexity of
mouth
Lips
Protrusible tongue
Jacobsons organ
Beak (turtles)
Acrodont (surface) or
pleurodont (socketed) teeth in jaws
Reptile Teeth
Digestive System
(contd)
w Long esophagus
w Stomach with internal
folding
w Longer and more coiled
intestine than amphibians
w Caecum blind sac at
junction of large and small intestine
Reptile Digestive
Tract
Respiratory System
w Generally by lungs
Some aquatic turtles have
supplemental cloacal, pharyngeal, and cutaneous respiration
w Increased lung complexity
w Movement of ribs generates
active suction and exhalation
Comparative Lung
Structure
Circulatory System
w Heart shortened compared to
amphibians
w 3 chambered heart, but deoxygenated
blood stays on right side of ventricle and oxygenated blood stays on left side
of ventricle
w No conus arteriosus
Reptile Blood
w Red blood cells generally
similar but somewhat smaller than amphibians