Reptile Information



The word "reptile" means "to creep"; a reference to the fact that except for snakes, all reptiles have four legs and creep when walking. Zoologists, scientists who study animals, have divided reptiles into four main groups: lizards and snakes, turtles, crocodilians, and the tuatara (a lizard-like creature of New Zealand).

All reptiles reproduce by laying eggs. Females lay their eggs in decayed wood, a nest of leaves and mud, or elsewhere on land. Reptiles do not sit on their eggs to incubate them like birds do. Instead, they abandon their eggs and rely on the heat from the sun to hatch them. Unlike newborn mammals which cared for by their parents, new-born reptiles are left to fend for themselves.

Reptiles have dry scaley or scale-like skin. The scales are made of keratin, the same material that makes hair, feathers and fingernails in other classes of animal. Some species of reptiles, like snakes, shed their scaly skin as they grow. Turtles are the only reptiles with a shell. Some turtles can pull their head, legs, and tail into the shell for protection. There are about 250 species of turtles. They live on land, in fresh water, and in the ocean.

Reptiles breathe air with their lungs just as mammals. This means that reptiles who live in water must at some time come to the surface to breathe.

Reptiles are often called "cold-blooded". This doesn't mean that their blood is cold though. It means that they can change their body temperature to match their surroundings. If the temperature of the air goes up, reptiles will raise their body temperature. If the air temperature goes down, they will lower their body temperature. In hot climates, reptiles usually seek shaded shelter during the day and are eat or search for prey mainly in the night. If air temperatures do not suit them, some reptiles can hibernate until the temperatures are right again.

Another unique characteristic of reptiles is their eyes. The shape of a reptile's pupil, the black spot in the center of the eye, indicates whether the animal is active at night or during the day. Most reptiles active at night have slit-like pupils that can close tightly in bright light. Reptiles active in daytime have round pupils just like ours. Most reptiles have good vision. Some can see in colour.

Reptiles live on every continent except Antarctica and in all the oceans except those of the polar regions. They are most abundant in the tropics. There are more than 7,100 species of reptiles. Most of them live on land. Some, like the sea turtle, make their home in the ocean and others, like crocodiles, live in fresh water.



Characteristics

cold-bloodedness
the presence of lungs
direct development, without larval forms as in amphibians
a dry skin with scales but not feathers (a characteristic of birds) or hair (a characteristic of mammals)
an amniote egg
internal fertilization
a three- or four-chambered heart
two aortic arches (blood vessels) carrying blood from the heart to the body; mammals have only one  aorta, the left; birds also have but one, the right
a metanephric kidney
twelve pairs of head (cranial) nerves; amphibians have ten)
skeletal features such as (a) limbs with usually five clawed fingers or toes, third eye," or parietal body, is present in the upper skull of some lizards. It has a cornea, lens, and retina and is able to respond to light and dark, but it cannot distinguish shapes.

























REPTILE CLASSIFICATION

Subclass Anapsida Lepidosauria Lepidosauria Archosauria
Order Chelonia
(Turtles)
Rhynchocephalia
(Tuatara)
Squamata  Crocodylia
(crocodilians)
Suborder Cryptodira   Amphisbaenia
(worm lizards)
 
Suborder Pleurodira   Sauria (lizards)  
Suborder     Serpentes (snakes)  




NUMBER OF REPTILE SPECIES

Snakes 2700 species
Lizards 2400-3000 species
Turtles 200 species
Crocodilians 23 species
Tuatara 1 species




 Lizard Characteristics

Movable eyelid; some can close their eyes
External ear: good hearing
Most have 4 legs with claws; 2-legged lizard  p.30 Reptiles
Molt; Shed skin
Non-posionous; Gila monster & Mexican beaded lizard are exceptions
                                a. Poison is a form of saliva
                                b. Drips down grooves in teeth
                                c. Bite and hang on so poison gets into prey
Male has 2 sexual organs; called hemipenis (uses the closest one)
Male lizards identify females by sight
Most lizards don't brood (watch over eggs)
     American skink is an exception
      a. Ward off intruders
      b. Turn eggs
      c. Provides warmth
Climb, glide, swim in sand, run on hind legs, slither
Food: Reptiles, insects, spiders, worms, mammals; some eat fruit flowers and leaves
Danger: Escape, puff up and act tough, camouflage, use tail as a decoy
Tail: Used for balance and storehouse of fat
Well-developed tongue: clean eyes, smell, scare
Lizards have great vision and use their tongues to taste their  surroundings.
 



3 Types of Snakes

Constrictors Reticulated  Python
 Longest reptile 33' 
Can kill 3 rabbits at a time
Vipers Rattlesnake Have extra fangs that will take the place of missing fangs
Poison is modified saliva that affects the circulatory system
Cobras   Fangs have grooves
Some spit
Poison affects the nervous system by paralyzing the prey


Snake Characteristics

No legs, eyelids, ear openings, bladder; can't close eyes; cobra has remnants of ancient legs
Has one lung; sea snakes can breathe through skin
100-400 Vertebrae
See close up; Blind snake: eyes under scales
Excellent sense of smell, use tingue
Eats prey whole by dislocating its jaw; 4' Rattlesnake can swallow a full sized rabbit, in 84 hours the hind legs are gone and the spine is disolving
Food: snakes, lizards, birds, insects, worms, mammals; One snake sucks the juice from the abdomen of termites
Molts: sheds skin
Move in a straight line or in a serpentine motion
Male identifies female by smell
14' python lays 20 eggs; 20' python lays 100 eggs
  Snakes can go a long time without eating, but when they do, their meal is usually another animal.
 




Turtle Information

Evolved 175 mya; Unchanged for 150 million years
Shelled reptile
Breathe with lungs; Musk Turtle can breathe through skin (Trionyx)
No teeth; Use feet and beaks to rip up food
Food: Insects, worms, fish, fruit, mushrooms, plant material; Can go without food for one year
2 Types of Turtles: Hidden Neck and Side Neck
All sea turtles migrate; Green Turtles migrate 1400 miles
Lays eggs on the beach where it was born; Boreneo allowed to take 1-2 million eggs a year
Leatherback: Heaviest 1600lbs
Turtles spend most of their lives in the water and have plated shells covering their bodies
 



Crocidilian Information

4 Chambered heart; only reptile to have this
Unchanged for 150 million years
Alligators take care of babies for 2-3 months;  Then she may eat as many as she can catch
Crocodiles lose their teeth chomping on prey, but new sets always grow in.
Can live for a century
Can wait a year between meals
Their hearts are equipped to slow down and divert blood away from the lungs while the animal is under water.



Tuatara Information

Evolved 200 mya
Lives on 20 islands around New Zeland
100 year life span
3rd eye on top of head covered with skin; May have something to do with temperature regulation; Has a cornea, lens, retina. It responds to light and dark, but it cannot distinguish shapes.
Nocturnal animal
Will crawl out of hole if music is played
Food: Insects
Lays 8-15 eggs; Takes 15 months to hatch
The tuatara is similar to a lizard, but the tuatara has a third eye and an extra row of teeth.
 



Dinosaur Information

(1) Evolved 200 mya during Triassic Period
(2) Chicken sized at the beginning
(3) Walked or hopped on hind legs
(4) Saurischians       Lizard hipped     Herbivore or Carnivore
     Ornithischians     Bird hipped        Herbivore