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Class Reptilia Class Amphibia

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1 Class Reptilia Class Amphibia
Chordata Class Reptilia Class Amphibia

2 CHORDATA Latin term for “chord”

3 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

4 Amphibia Salamander FROG Toad
Amphibia Salamander FROG Toad

5 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

6 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

7 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 

8 General Characteristics Of Phylum Chordata
notochord dorsal hollow nerve chord pharynx slits muscular postanal tail

9 Body cavity-- coelom present; heart inside
Symmetry-- bilateral Nervous– Brain reguates digestion and circulation; muscular coordination Circulatory system– 3-chamber <3; 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

10 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/ <5 toes, flat skull, backbone, “shoulders,” leg bones

11 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

12 Crocodile Tuatara

13 Green Sea Turtle Zebra-tailed lizard

14 San Diego Alligator Lizard

15 Gecko-Reptile; this is some kind of local reptile… or something
Coleonyx variegatus abbotti

16 Baby San Diego Gopher Snake

17 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

18 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

19 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

20 The Amniotic Egg

21 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

22 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

23 Excretory System: Skeletal Type:
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

24 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

25 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

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

27 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

28 B What are not amniotes? Amphibia Reptilia Aves mammalia

29 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

30 The answer is E, [answer d gets ½ credit]
Now for some cool stuff…

31 Man-Eating Snake

32 Gecko Hatching:
Odd deformities & New Species

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