20. Class Reptilia Notes

1. ReptilesReptiles
Kingdom: AnimaliaKingdom: Animalia
Phylum: ChordataPhylum: Chordata
Class: ReptiliaClass: Reptilia
Order: TestudinesOrder: Testudines
Order: SquamataOrder: Squamata
Order: CrocodiliaOrder: Crocodilia

2. Class ReptiliaClass Reptilia
Herpetology Herpetology – study of – study of
reptilesreptiles
EctothermsEctotherms – cold – cold
blooded, must get heat blooded, must get heat
from environmentfrom environment
Skin is covered with Skin is covered with
scalesscales
Most are egg-layingMost are egg-laying
Tetrapods Tetrapods – land-– land-
dwelling vertebratesdwelling vertebrates

3. EctothermsEctotherms
Cold-blooded animals take Cold-blooded animals take
on the temperature of their on the temperature of their
surroundingssurroundings
More active in warm More active in warm
environments and very environments and very
sluggish in cold sluggish in cold
environmentsenvironments
Results of muscle activities Results of muscle activities
that work on chemical that work on chemical
reactions which speed up in reactions which speed up in
warmer temperatureswarmer temperatures

4. EctothermsEctotherms
Must bask in sun to Must bask in sun to
warm-up and speed-up warm-up and speed-up
metabolismmetabolism
Lie in certain directions Lie in certain directions
and expand rib cages to and expand rib cages to
absorb more heatabsorb more heat
If too hot they move to If too hot they move to
shade, burrow, open shade, burrow, open
their mouth wide, or their mouth wide, or
lighten skin colorlighten skin color

5. Advantages vs. DisadvantagesAdvantages vs. Disadvantages
Require less energy than Require less energy than
warm-blooded animalswarm-blooded animals
Therefore in food scarce Therefore in food scarce
environments such as the environments such as the
desert they do not have to desert they do not have to
burn energy to keep warmburn energy to keep warm
Can reduce body temperature Can reduce body temperature
to save energyto save energy
Immune system more Immune system more
efficient because bacteria efficient because bacteria
grows slower in the coldgrows slower in the cold
Must be warm out for them Must be warm out for them
to have a certain level of to have a certain level of
activity to hunt and defend activity to hunt and defend
themselvesthemselves
Also need it to be warm to Also need it to be warm to
find a mate and reproducefind a mate and reproduce

6. Class ReptiliaClass Reptilia
Breathe air using lungsBreathe air using lungs
Evolved from Evolved from
amphibiansamphibians

7. EvolutionEvolution
Evolved during the Evolved during the
Paleozoic Era from the Paleozoic Era from the
dinosaursdinosaurs
Included Icthyosaurs, Included Icthyosaurs,
plesiosaurs, placodonts, plesiosaurs, placodonts,
and mosasaursand mosasaurs

8. Order TestudinesOrder Testudines
Turtles, tortoises, and Turtles, tortoises, and
terrapinsterrapins
Bony or cartilaginous Bony or cartilaginous
shells are used for shells are used for
protectionprotection
Shell is fused to Shell is fused to
backbonebackbone

9. Sea TurtlesSea Turtles
Legs have been modified Legs have been modified
into flippersinto flippers
Cannot retract head into Cannot retract head into
shellshell
Lay eggs on landLay eggs on land
8 species who live 8 species who live
primarily in warm water, primarily in warm water,
all endangeredall endangered
Feed on sea grasses and Feed on sea grasses and
seaweedsseaweeds

10. BeakBeak
All turtles do not have All turtles do not have
teeth, instead they have a teeth, instead they have a
beak and strong biting beak and strong biting
jawsjaws
Eat everything from sea Eat everything from sea
weeds to sponges to weeds to sponges to
barnacles to jellyfishbarnacles to jellyfish

11. ExploitationExploitation
Nesting areas turned into Nesting areas turned into
resortsresorts
Eggs are taken by the Eggs are taken by the
bucketful to be eatenbucketful to be eaten
Adults meat considered a Adults meat considered a
delicacy and cartilage delicacy and cartilage
used in turtle soupused in turtle soup
Some shells are collected Some shells are collected
as jewelryas jewelry
Shrimp nets trap and killShrimp nets trap and kill

12. Order SquamataOrder Squamata
Includes sea snakes and Includes sea snakes and
marine iguanasmarine iguanas

13. Marine IguanasMarine Iguanas
Only lizard to feed Only lizard to feed
underwaterunderwater
Shorter snout to scrape Shorter snout to scrape
algae off of rocksalgae off of rocks
Long, curled claws to Long, curled claws to
hold onto rocks in hold onto rocks in
rougher watersrougher waters
Longer, flattened tails to Longer, flattened tails to
help swimminghelp swimming

14. Diving AbilityDiving Ability
Can withstand long Can withstand long
bouts of lactate for bouts of lactate for
periods of to two periods of to two
minutesminutes
Imagine being able to Imagine being able to
sprint as hard as you can sprint as hard as you can
for two minutes straightfor two minutes straight

15. Sea SnakesSea Snakes
Breath airBreath air
Flattened tail for Flattened tail for
swimmingswimming
Flap covers nostril while Flap covers nostril while
swimmingswimming
Eels have gills and no Eels have gills and no
scalesscales

16. Sea SnakesSea Snakes
Feed on fish, fish eggs, Feed on fish, fish eggs,
and eelsand eels
Stay in shallow waters Stay in shallow waters
and can be found in and can be found in
groupsgroups

17. VenomVenom
Venom used to immobilize not Venom used to immobilize not
kill preykill prey
Most toxic snakes on earthMost toxic snakes on earth
Bite is painless due to short fangsBite is painless due to short fangs
½ Hour Symptoms: stiffness, ½ Hour Symptoms: stiffness,
muscle aches, spasm of jaw, pain muscle aches, spasm of jaw, pain
in limbin limb
Eventual symptoms: Blurred Eventual symptoms: Blurred
vision, drowsiness, and vision, drowsiness, and
respiratory paralysisrespiratory paralysis

18. Order CrocodiliaOrder Crocodilia
Saltwater CrocodileSaltwater Crocodile
Found in estuaries and Found in estuaries and
along the coast of Indian along the coast of Indian
Ocean, Australia, and Ocean, Australia, and
Western Pacific IslandsWestern Pacific Islands

19. Evolution of CrocodileEvolution of Crocodile
Last of the types of Last of the types of
reptiles around during reptiles around during
the dinosaursthe dinosaurs

20. Saltwater CrocodileSaltwater Crocodile
Animal most likely to Animal most likely to
attack and eat a humanattack and eat a human
17-23 feet and 1000-2000 17-23 feet and 1000-2000
pounds in sizepounds in size
Some estimated at as Some estimated at as
much as 33 feetmuch as 33 feet