Download Reptiles

Reptiles
Advanced Life Science
Rainier Jr/Sr High School
Mr. Taylor
Reptiles
• Kingdom Animalia
– Phylum Chordata
• Subphylum Vertebrata
– Class Reptilia
Reptile Characteristics
1. Strong, bony skeleton with toes and claws.
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Claws allow for climbing, digging, prey
capture, etc.
2. Ectothermic metabolism
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"cold-blooded"
limits geographic distribution and activity
(many hibernate).
Reptile Characteristics
3. Dry, scaly skin.
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waterproof
allows for completely terrestrial lifestyle.
4. Improved lungs
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No cutaneous respiration, still need much O2
for land-based activities
Have alveoli (air sacs) surrounded by
numerous capillaries
Reptile Characteristics
5. AMNIOTIC EGG!!! (A "land egg")
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Amnion is a waterproof membrane that the
embryo is enclosed in…a "sea within a shell"
• Allantois: stores wastes from the embryo
• Yolk and albumen: feeds the embryo
• Chorion: provides O2/CO2 exchange.
 This is the adaptation that truly freed
reptiles from water and allowed them to
radiate into drier terrestrial biomes.
Reptile Characteristics
6. Cardiovascular system (heart)
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Ventricle (pumping chamber) either partly
divided or completely divided by a septum
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Gives increased to complete separation of
oxygen-rich and oxygen-poor blood in the body
Result is improved oxygen delivery to the tissues
7. Internal fertilization
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Oviparous or ovoviviparous
Born looking like parents and "ready to roll"
Orders of Reptiles
Order Squamata
– Lizards and snakes
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Have a hinged jaw
Periodically molt skin
Orders of Reptiles
Order Squamata
– Family Gekkonidae:
the geckos
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Excellent climbers
due to "velcro" feet
Easily lose tails
(escape strategy)
Western Banded Gecko
Orders of Reptiles
Order Squamata
– Family Iguanidae:
the iguanas
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Most North American
lizards in this group
Live in all biomes
Western Fence Lizard
Orders of Reptiles
Order Squamata
– Family Scincidae: the
skinks
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Slim bodies with shiny,
cycloid scales
Limbs are small (may
even be absent)
Western Skink
Orders of Reptiles
Order Squamata
– Family Anguidae: the
alligator lizards
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Have a lateral fold of
skin: allows for
respiration, eggs, etc.
Long bodies, short
limbs
Many lose tails easily
Northwestern Alligator Lizard
Orders of Reptiles
Order Squamata
– Family Colubridae: the
colubrids
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The most common type
of snake in N. America
No hollow fangs, only a
few are poisonous, not
dangerous in our area
California Mountain Kingsnake
Orders of Reptiles
Order Squamata
– Family Colubridae: the
colubrids
Northwest Garter Snake
Orders of Reptiles
Order Squamata
– Family Elapidae: the
Coral Snakes
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This family includes
cobras, mambas, and
coral snakes
Highly dangerous
neurotoxin
Non-moveable hollow
fangs
Texas Coral Snake a dangerous snake
looks a lot like the harmless
California Mountain Kingsnake
Orders of Reptiles
Western
Diamondback
Rattler
Order Squamata
– Family Viperidae: pit
vipers
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Rattlesnakes, cottonmouths, and
copperheads
Have moveable fangs
Inject hematoxin mix
Copperhead
Cottonmouth
Orders of Reptiles
Order Chelonia (old name Testudines)
– Turtles and Tortoises
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Have a protective shell
– Carapace is the top
– Plastron is the bottom
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Tortoise shell is dome shaped-land dwelling
Turtle shell is streamlined-water dwelling
Orders of Reptiles
Order Chelonia (old name Testudines)
Orders of Reptiles
Order Crocodylia
– Crocodiles, alligators, caimans, gavials
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Exhibit good parental care (including after
hatching)
Have a 4 chambered heart! resulting in
maximum oxygen delivery to tissues
Eyes and nostrils located "above the waterline"
allows them to stay almost completely
submerged while hunting
Orders of Reptiles
Order Crocodylia
– Crocodiles, alligators, caimans, gavials
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Have cardiac and respiratory adaptations that
allow them to take prey underwater for death
and dismemberment.
Have an adaptation in their hips that also is seen
in birds and mammals (possible common
ancestor) and allows bipedal movement.
Alligators have U-shaped snout
Crocodiles have narrow snout with lower "fangs"
showing
Orders of Reptiles
Order Crocodylia
Orders of Reptiles
Order Sphenodontida
– Tuataras
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Found only in New Zealand
An ancient order of reptiles
Nocturnal, active at lower temperatures
Slow reproducers
– May only incubate 6-10 eggs every 2-5 years
– Don't reach sexual maturity until 15-20 years old
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Very endangered due to loss of habitat to nonnative species (and man)
Orders of Reptiles
Order Sphenodontida