1. Non Avian Diapsid Amonites
Reptiles
Non Avian Diapsid Amonites

2. Evolutionary Perspective
350 million years ago during the Carboniferous period primitive Amnoites emerged who developed into reptiles, birds and mammals
Amniota (amnion)- membrane around a fetus, was an egg adapted for life on land
Amniotic eggs- extraembryonic membranes that protect the embryo from dessication, cushion, promote gas transfer and store waste material
surrounded by a tough leathery or hard shell

3. Diapsids 4 living orders
Order Testudines- Turtles approx 300 living species
Characterized by a bony shell, limbs articulating internally to ribs and a keratinized beak (no teeth)
Carapace- dorsal portion of shell, formed from fusion of vertebrae, ribs, bones and skin. Keratin covers bone of the carapace
Plastron- Ventral portion of shell, formed from bones of pectoral girdle, dermal bone and keratin

4. Painted Turtle

5. Green Sea Turtle

6. Sea Turtle Shell interior

7. Sea Turtle with Barnacles

8. Aldabra Giant Tortoise

9. Turtles
On some shells the plastron has flexible areas which allows the shell openings to close when the turtle withdraws
S shaped neck vertebrae allow head to be withdrawn
Turtles have long life spans 14 years or more
Tortoises (terrestrial) can live 100 years
Oviparous- lay eggs which hatch outside mother, young are independent of parents
Slow growth rates make turtles vulnerable to extinction

10. Order Crocodylia Alligators, crocodilians, gavials and caimans
Characterized by triangular eye orbits, openings in skull in front of eye and laterally compressed teeth
Have not changed much in 170 million years
Elongated snout used to catch food
Nostrils at tip of snout, eyes high on head
Air passages lead to back of mouth, sealed from throat by flap of tissue

11. Crocodylia Muscular and elongated tail used for swimming
Teeth for seizing prey, swallow prey whole
If prey too large, bite and spin body to tear off large chunks
Swallow rocks as abrasives to help break down food
Oviparous, nesting behavior, parental care

12. Alligator

13. Alligator

14. Mother transporting Young

15. Crocodile

16. Crocodile Running

17. Gavialovy

18. Order Sphenodontida
Tuatarans- distinguished from other reptiles by two rows of upper teeth and a single row on lower jaw, produce a shearing bite
Unchanged in 200 million years, Mesozoic period
Found only in New Zealand
Oviparous, use underground burrows

19. Tuatara

20. Parietal Eye

21. Order Squamata, 3 suborders
Suborder Sauria- Lizards- 4,500 species- two pairs of legs and jaws unite, legless lizards still have sternum and pectoral girdle
Vary in length from few cm to 3 meters
Most are oviparous, some ovoviviparous, and few viviparous
Usually hide for protection under rocks, live in trees, some burrowers

22. Lizards
Geckos- semitropical areas, short and stout bodies, nocturnal, large eyes and adhesive disks on digits to climb trees, walls
Iguania- robust bodies, short necks, distinct heads, includes marine iguanas of galapagos, and flying dragons of southeast Asia
Chameleons- Africa and Asia, adapted to arboreal life, long sticky tongue, ability to change color
Gila Monster- only venomous lizards, southwest U.S., venom released from grooves in teeth

23. Gecko

24. Leopard Gecko

25. Iguana

26. Marine Iguana

27. Marine Iguana

28. Flying Dragon, Iguana

29. Chameleon

30. Chameleon

31. Chameleon

32. Gila Monster

33. Suborder Serpentes Snakes- 2,900 species, about 300 species venomous
30,000 people die worldwide each year, 9-15 die in U.S. due to emergency health care
Snakes have elongate bodies and lack limbs, vestigial appendages in pythons and boas
Skeleton may have 200 vertebrae and pairs of ribs, joints between vertebrae very flexible

34. Snakes Skull adaptations to swallow prey whole
Upper and lower jaws loosely joined, move independently
Elongation (narrowing) of body resulted in loss of left lung, displacement of gall bladder, right kidney and gonads
Most snakes oviparous, many vipers, boas and cobras give birth to live young
Snakes evolved 135 mya, Cretaceous period

35. Diamond back Rattlesnake

36. Python

37. Python Swallowing

38. Python with Alligator protruding from midsection

39. Snake Swallowing Egg

40. Snake Evolution
Originally snakes were thought to have evolved to burrow but recent findings of 90 million year old fossils indicate snakes were aquatic or lived in densely tangled vegetation
Elapsids- fixed fangs- Cobra, mambas, Kraits, taipans, and coral snakes. Neurotoxin produces paralysis of lungs and heart
Viperid- copperhead, rattlesnake, water moccasin(cottonmouth), Bushmaster and fer-de-lance .Retractable fangs hemotoxin
24 kinds of snake venom known to exist

41. Coral Snake

42. Reptile Skin Reptilian skin is thick, dry, keratinized
Scales modified for various functions, belly scales
Ecdysis- shedding skin(scales) as body grows
Phermones-secretions function in sex recognition and defense
Chromatophores-dermal cells produce cryptic coloration, mimmicry, aposematic and used for thermal regulation

43. Suborder Amphisbaenia
Worm Lizards- 135 species, specialized burrowers, live in Africa, south America, Caribbean and Midwest U.S.
Some legless, skull wedge shaped
Single median tooth in upper jaw, forms nipper with two lower teeth
Skin has ring like folds used to bulge out against burrow walls
Move easily forward and backward, feed on worms

44. Worm Lizard

45. Worm Lizard

46. Support and Movement
Reptilian skeleton inherited from ancient Amphibians
Highly ossified, very strong
Secondary Palate- plate of bone separates nasal passages from mouth
Have Atlas and axis vertebrae at base of skull
Ribs may be highly modified, turtles, flying dragon
Snake ribs have a muscular connection to belly scales

47. Support and Locomotion
Autotomy- caudal vertebrae in many lizards contain a vertical fracture plane to sever tail
Primitive reptiles walk similar to salamanders
Modern reptiles have longer slender legs, hold body higher
Many prehistoric reptiles were bipedal which freed front appendages to adapt for capturing prey and flight

48. Nutrition and Digestion
Most reptiles carnivores, turtles may be carnivores, herbivores or omnivores
Tongues of some lizards and Tuatara sticky to capture prey
Chameleons tongue exceeds body length
Reptiles possess peg teeth some angled back to aid in holding and swallowing prey