Class Reptilia

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Chordata

• Class Reptilia
• Class Amphibia

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CHORDATA

• Latin term for chord

http//universe-review.ca/R10-33-anatomy.htmamphi
bians
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Chordata- Urochordata, Cephlachordata, Agnatha,
Chondrichhyes,Osteichhyes, Aves, Mammalia The
best classes Reptilia and Amphibia

• Amphibia Latin meaning two lives water and
  land based
• Ex. Salamanders, frogs, toads

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http//webpages.charter.net/teefile/biognomen/phot
o/Amphibia.jpeg
Amphibia
http//news.siu.edu/news/May05/images/salamander.j
pg
Salamander
FROG
http//www.lemmykoopa.com/lk19/2_5.jpg
Toad
http//library.thinkquest.org/TQ0312042/Images/Ame
rican20Toad.jpg
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• Amphibians were the first vertebrates on land
• Early amphibians- lobe-finned fishes with lings,
  freshwater b/c of drought paired appendages to
  walk on land

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Types of Amphibians

• Urodeles- walk with lateral bending of the body
  i.e. salamanders
• Anurans- use legs for hopping i.e. toads/frogs
• Apodans- burrowing, legless, nearly blind,
  wormlike i.e. snake-type animals

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Amphibia

• Gas exchange- integuments (outer covering) allow
  gas exchange through skin Adults generally
  respire using lungs and through moist skin
• Skeletal- bony skeleton
• Reproduction- External fertilization requires
  aquatic environment 

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General CharacteristicsOf Phylum Chordata

• notochord
• dorsal hollow nerve chord
• pharynx slits
• muscular postanal tail

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• Body cavity-- coelom present heart inside
• Symmetry-- bilateral
• Nervous Brain reguates digestion and
  circulation muscular coordination
• Circulatory system 3-chamber lt3 mixed blood in
  single ventricle pulmonary veins only organ in
  coelom
• Sensory smell two holes and olfactory lobes
  crude eye cannot change focus, eyelid exposed
  ear

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• Digestion- mouth, weak teeth, sticky tongue to
  capture prey, esophagus, stomach, intestines,
  liver, pancreas, gall bladder
• Excretory liquid pass kidney to bladder liquid
  and solid exit through cloaca. Urea gets rid of
  nitrogenous waste
• Musco-skeletal walking legs w/ lt5 toes, flat
  skull, backbone, shoulders, leg bones

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Major Groupings

• Class Reptilia (Latin repere, "to creep").
• The 3 largest and most diverse orders
• Crocodilia (alligators crocodiles) 23 species
• Squamata (lizards snakes) approximately 7,600
  species
• Chelonia (turtles) approximately 300 species

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Crocodile http//www-biol.paisley.ac.uk/courses/Ta
tner/biomedia/subunits/order57.htm
Tuatara http//members.tripod.com/NZPhoto/animal/t
uatara.htm
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Green Sea Turtle http//www.nmfs.noaa.gov/pr/speci
es/turtles/green.html
Zebra-tailed lizard http//en.wikipedia.org/wiki/L
izard
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San Diego Alligator Lizard
http//www.yosemite.ca.us/library/reptiles/images/
thumbnail/lizards_22.jpg
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Gecko-Reptile this is some kind of local
reptile or something
Coleonyx variegatus abbotti
http//www.werc.usgs.gov/fieldguide/images/covajuv
.jpg
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Baby San Diego Gopher Snake
http//www.gregcooper.net/reptiles/sandiegogopher/
gallery/SDG009a.jpg
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Anatomy

• Extraembryonic membranes
• from embryonic tissue layers
• Consist of
• amnion (for protection),
• yolk sac (expands over yolk, where nutrients are
  stored)
• allantois (disposal sac functions as
  respiratory organ)
• chorion (functions as respiratory organ)
• involved in gas exchange, waste storage, and
  nutrient transfer from egg to embryo

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Amniotes!

• amniote a reptile whose eggs contain
  specialized membranes that allow them to develop
  out of water
• The first amniote reptile evolved from an
  amphibian about 300 million years ago.
• salamanders amphibians aren't amniotes eggs
  lack the shell.
• reptiles, birds, and mammals are amniotes

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• Amniotic egg
• Enclosed in a waterproof shell and permitted
  vertebrates to complete their life cycle
• The shell retains water and can therefore be laid
  in a dry place

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The Amniotic Egg
http//io.uwinnipeg.ca/simmons/16cm05/1116/chorda
te.htm
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Physiology

• Body Cavity coelom present
• Body Symmetry bilateral
• Circulatory System
• Ectotherms absorb external heat rather than
  generating their own (cold blooded)
• Exchange of oxygenated and deoxygenated blood
  between the ventricles in all reptiles but the
  crocodile

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• Digestive System All reptiles except snakes have
  a cecum, at the beginning of the large intestine
  gall bladder present caudal abdomen stores fat.
• Gas Exchange Reptiles have well-developed lungs
  enclosed within a protective rib cage.
• Locomotion/Musculature Most reptiles have legs
  with usually five clawed fingers or toes

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• Excretory System
• Crocodilians, snakes and some lizards do not have
  a urinary bladder
• those with a bladder, have it connected to the
  cloaca by a short urethra.
• Skeletal Type
• Vestigial pelvic and limb bones in primitive
  snakes are evidence that snakes evolved from
  reptiles with legs
• Scales contain the protein keratin which
  waterproof the skin

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• Sensory Structure/ Features
• Snakes have acute chemical sensors are
  sensitive to ground vibrations
• Heat-detecting organs between the eyes and
  nostrics of pit vipers rattlesnakes are
  sensitive to temperature changes
• Nervous System well developed especially within
  the brain and with regard to optic nerves visual
  sensory system
• Reproduction Some species lay shelled amniotic
  eggs and fertilization is internal

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Reptiles vs. Amphibians

• Amphibians have shell-less eggs, while reptiles
  have amniotic eggs that have a shell that retains
  water and can be laid in a dry place
• Reptiles have scales containing the protein
  keratin, which waterproof the skin to prevent
  dehydration in dry air

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Quiz

• Why do you think reptiles need fewer calories
  than mammals?
• Ectothermic
• Waterproof scales
• Amniotic egg
• More effecient respiratory system

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A

• What is true of amphibians?
• Amphibian's blood is blue-colored
• They have a 3-chambered heart
• They only respirate through skin
• Amphibians are green always

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B

• What are not amniotes?
• Amphibia
• Reptilia
• Aves
• mammalia

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A
What is not distinct about reptiles? a. reptiles
have amniotic eggs that have a shell that retains
water and can be laid in a dry place b. Reptiles
have scales containing the protein keratin c.
They have waterproof skin to prevent dehydration
in dry air d. They like cheetos E. All of the
above are true about reptiles

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• The answer is E, answer d gets ½ credit
• Now for some cool stuff

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Man-Eating Snake
http//www.reptileallsorts.com/snakefood.htm
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Gecko Hatching http//www.reptileallsorts.com/rep
tilemovies.htm
http//news.bbc.co.uk/1/hi/sci/tech/848629.stm
Odd deformities New Species
http//news.bbc.co.uk/1/hi/sci/tech/848629.stm