1. REPTILES Scientific Classification of Reptiles To creep
Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Reptilia

2. REPTILES REPTILES tetrapods - 4 legs adapted for land, hip/girdle
Amniotes - animals whose embryos are surrounded by a fluid filled amniotic membrane
Four surviving orders:

3. Crocodilia (crocodiles, caimans and alligators): 23 species
Sphenodonta (tuataras from New Zealand): 2 species - Wedge Tooth
Squamata (lizards, snakes and Worm lizards) approximately 7,600 species - scaly skin
Testudines (Tortoise) Chelonia (Turtles : approximately 300 species – to seize

4. Firs known reptile fossil
350 MYA
Carboniferous period
Drier conditions gave rise to the first adaptive radiation of reptiles
by late Triassic and Jurassic periods
Age of Reptiles – Mesozoic
245 MYA

5. REPTILES Reptiles are found on every continent except for Antarctica,
main distribution comprises the tropics and subtropics.
modern species of reptiles do not generate enough heat to maintain a constant body temperature and are thus referred to as "cold-blooded" (ectothermic).

6. REPTILES
Sea Turtle an exception: a reptile that elevates its body temperature well above that of its surroundings.

7. REPTILES
Reptiles evolved from tailed amphibian ancestors. There are nearly 8000
A reptile has the following features;
ectothermic
dry, scaly skin
tough shell on eggs
eggs are laid on land - “enclosed the pond”

8. REPTILES The Rise of Amniotes - Reptiles
During the late Carboniferous, amphibians
gave rise to the amniotes (birds, reptiles, mammals).
A. Four features were critical to amniotes’
escape from water dependency:
1. They produce amniote eggs with internal
covering membranes and a shell, which allow
the eggs to survive in dry habitats.

9. REPTILES
Amniote egg contains a membraneous sac that surrounds and protects the embryo.

10. REPTILES Allantois Greek word for sausage respiration and excretion
webbed with blood vessels.
liquid waste from the embryo.

11. REPTILES
The allantois functions similarly in monotremes, which are egg-laying mammals.

12. REPTILES 3 They have internal fertilization.
4 Their kidneys are good at conserving
water.
5 scaly skin water conservation

13. REPTILES
“Reptiles” demonstrate certain advantageous features compared to amphibians.
Modification of limb bones, teeth, and
jaw bones allowed greater exploitation
of the insect life
Development of the cerebral cortex permitted
greater integration of sensory input and motor
response.
Well developed lungs

14. REPTILES Descendants of the surviving dinosaurs
became the lineage of reptiles.
4 living orders

15. REPTILES
Circulatory systems
Fish Bird, Mammal Reptile
Amphibian

16. REPTILES
Humans, birds, and mammals have a 4-chambered heart that completely separates oxygen-rich and oxygen-depleted blood.
Fish have a 2-chambered heart in which a single-loop circulatory pattern takes blood from the heart to the gills and then to the body.
Amphibians have a 3-chambered heart with two atria and one ventricle.

17. REPTILES
The disadvantage of the three-chambered heart is the mixing of oxygenated and deoxygenated blood.
Most reptiles have an incomplete division in the ventricle
“ 3 ½ chambers”
Crocodiles and alligators have 4 complete chambers

18. REPTILES A Sampling of Existing Reptiles – (Latin, to creep)
A. Turtles – Testudines
1. The distinctive shell offers protection while
conserving water and body heat.

19. REPTILES
2. The shell is connected to the skeleton Their teeth are tough, horny plates designed for gripping & chewing
food.
3. Turtles lay their eggs on land, where
predation is high.

20. REPTILES
Anatomy of a Box Turtle

21. REPTILES
Turtle shell structure

22. REPTILES
Turtle eggs and newborn

23. REPTILES Lizards 1. Most lizards are small-bodied insect
eaters; their most usual habitats are deserts
and tropical forests.
2. Lizards are also prey for many other animals,
but are quick in movement and have the
unique ability to sever their own tails if it is
grabbed by a predator.

24. REPTILES
Lizards

25. REPTILES & AMPHIBIANS Scientific classification Order: Squamata
95% of all living reptiles are in this group

26. REPTILES & AMPHIBIANS Snakes
1. Snakes are limbless but retain vestiges
of hind limbs; they are excellent
predators.
2. Snakes have the ability to swallow prey
larger than they are due to flexible skull
and jaw bones.
3. All snakes are carnivores. Some suffocate their
prey, and some kill their prey with venom.

27. REPTILES & AMPHIBIANS
95% of all living reptiles are composed of Lizards and Snakes.

28. REPTILES & AMPHIBIANS Tuataras 1. Although they resemble lizards, they
are evolutionarily more ancient. They
resemble amphibians with the brain
and the way they walk.
2. They do not engage in sex until they
are twenty years old!.

29. REPTILES & AMPHIBIANS 3. Only two species remain today;
they live on islands off the shore of
New Zealand.
4. Like lizards, tuatarus have a 3rd eye
under the skin with a retina, a lens,
and nerves to the brain. They also
may live to be 60 years old.

30. REPTILES & AMPHIBIANS Scientific Classification of Tuataras
Order: Sphenodontia

31. REPTILES & AMPHIBIANS Crocodilians
1. Crocodiles and alligators all live in or
near water.
2. They are the largest living reptiles.
3. The body plan includes a long snout;
body temperature is regulated behavior-
ally (ectothermic).

32. REPTILES & AMPHIBIANS 4. The ventricle of the heart is divided
into right and left chambers – more
like the heart of birds than that of
other reptiles.

33. REPTILES & AMPHIBIANS
4. Like other reptiles and birds, crocodilians adjust body temperature with behavioral and physiological mechanisms.
5. They are like birds in displaying complex social behaviors, such as parents guarding nests
and assisting hatchlings into water. This trait
and others suggest that crocodilians and birds
share a common ancestor.

34. REPTILES & AMPHIBIANS Reptilian Orders Procolophonida (extinct)
Araeoscelidia (extinct)
Avicephala (extinct)
Younginiformes (extinct)
Ichthyopterygia (extinct)
Placodontia (extinct)
Nothosauria (extinct)

35. REPTILES & AMPHIBIANS Orders (cont.) Plesiosauria (extinct)
Prolacertiformes (extinct)
Pterosauria (extinct)
Saurischia (extinct)
Ornithischia (extinct)

36. REPTILES & AMPHIBIANS Reptilian Orders (cont.) Testudines Squamata
Sphenodontia
Crocodilia