1. Class Reptilia

2. Traditional Taxonomy Class Reptilia
Order Testudines – turtles, terrapins, tortoises
Order Crocodilia – crocs & gators
Order Squamata – snakes & lizards
Order Sphenodonta – tuatara

3. Fig. 26.1
Fig. 26.1

4. Fig. 26.2

5. Some Early Reptilians
Fig. 26.p547a

6. General Reptile Traits
Reproduction
Amniotic eggs with shell
Internal fertilization
Oviparous, ovoviviparous, viviparous (few)
Direct development
Epidermal scales & claws
5 digits on each limb
Thoracic ribs (except turtles)

7. Shelled Egg
Fig. 26.4

8. Epidermal Scales
Fig. 26.3

9. Order Testudines
Fig. 26.6

10. Fig. 26.8

13. Sex Determination in Turtles & Crocodilians
Males develop at low temps
Females develop at higher temps
Crocodilians
Males develop at higher temps
Females develop at lower temps

14. Order Crocodilia
Fig. 26.5

15. Crocodilians

16. Order Squamata
Shed their epidermal scales with growth

17. Gekkos
Fig

18. Chameleons
Fig

19. Iguanas
Fig

20. Snake Families Viperidae Elapidae Colubridae Hydrophiidae Boidae
Vipers
Sheathed fangs at front of mouth
Elapidae
Short, immovable fangs at front of mouth
Colubridae
Rear fanged (or no fangs)
Mostly non-poisonous
Hydrophiidae
Sea snakes
Extremely poisonous
Boidae
Constrictors
Many retain vestigial pelvic structures

21. Order Squamata, Suborder Serpentes
Cotton mouth or
water moccasin
Copper head
Rattlesnake
Fig
Viperidae

22. Snake Venoms Neurotoxins Hemorrhagins Paralysis Blindness
Digest tissues
Prevent clotting
Fasciotomy

23. Viperidae
Fig

24. Pit Organs of Pit Vipers
Family Viperidae
Subfamily Crotalidae
Fig

25. Red on yellow, kill a fellow
Red on black,
friend to jack
Coral snake or
King snake

26. Elapids

27. Temperature Regulation
Cold-blooded vs warm-blooded
Poikilothermy vs homeothermy
Ectothermy vs Endothermy