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Reptile History
Dragon History


trexmuseumWhat Is A Reptile...


Class: Reptilia has over 6500 species in 48 families and 905 genera

*** This list is subject to change at the whims of new science***


Suborder: Serpentes or snakes has 2389 species in 11 families and 417 genera.

Skeleton: Snakes have generally between 200 and 400 vertebrae. Each is connected by at least articulated surfaces which give it that smooth and supple movement when combined with a set of interlocking muscles. The skull is very flexible and the bones of the upper and lower jaws are attached only with ligaments and muscle tissues and thus can be moved in just about any direction. Teeth are in reality simply inward curved sharp spikes designed to first impale, then hold, and finally to help move the prey back down the esophagus. Other adaptations is that snakes have evolved away from the pectoral girdle and sternum found in most animals with front limbs. This allows them to swallow larger prey.

Locomotion: It was originally thought that snakes "walked" on their ribs much like a millipede. However, what really happens is that they use their large ventral scutes (scales) which are found on their abdomens or bellies. These scutes are attached to the ribs with muscles and by simply moving them back and forth or pulling a snake can move in a fairly straight line. This is called the "rectilinear method" In addition snakes can "swim" either in the water or on the land. This is called the "lateral undulatory method" and is composed of a series of s curves. Where the curves hit the ground they "push off" and gain speed. Related to this is the "side winding method" used by a few snakes such as the desert dwelling American sidewinder. In this case the head is thrown in an arch forward while the body uses the LU method behind it. This allows much of the body to be off the often hot surface while still moving in a forward direction. The fourth style of locomotion is used by some species of tree snakes. It is called the "concertina method" and is somewhat like and inch worm's method. The prehensile tail tightly grips the tree and then the head quests upward until it has a firm grip or drape over another part of the tree. Then the tail is pulled up until it has another grip just below the head and the process continues to repeat itself as the snake progresses up the tree or bush.

Reproduction: All known snakes reproduce sexually with the male having two hemipenes which are inserted one at a time into the females cloaca to fertilize the eggs internally. Most snakes lay eggs but many species do have live young. Most eggs are laid in a crude nest of some kind and then leave but a few actually receive parental protection. Pythons are noted for coiling around their eggs and by bodily contractions actually keep the eggs warmer than the surrounding temperature. King Cobras are very protective of their nesting area and will attempt to chase anything that wanders too near away.

Sight: All snakes have some sort of vision, even the "blind snakes." Some only distinguish light and dark while others see only motion. A few like some of the tree snakes have vertically elliptical pupils that allow them to see when it is very dark while the day version of the same actually are thought to see quite well. No snake has any eyelids or eyelashes but instead rely on a transparent covering called the brille. Each time they shed they get a brand new brille and so even scratched or damaged eyes are often renewed in this manner.

Hearing: Snakes were likely to have developed under the ground and thus had very little need for acute hearing. The ear is basically internal and connected to the lower jaw. What they "hear" is in the range of low frequency sounds vibrated through the ground. Even the rattlesnake can not hear his own high pitched rattle.

Taste: Where snakes really excel is in their ability to explore their surroundings with taste. Snakes mostly explore their environment "chemically." The tongue waving in and out of the mouth is actually picking up molecules of "scent." These molecules are then inserted in their equivalent of a microprocessor called the "Jacobsons organs on the inside of the mouth. This allows a snake to make minute detection's about prey or enemies or even allow them to find mates far, far away.

Heat Sensing: Many of the Boas, pythons, and venomous snakes posses the ability to sense infrared heat coming from all living beings. The pits on the side of rattlesnakes head allows him to sense the difference between a mouse hiding behind a cactus. Or a green tree python to find a bird sleeping silently above him in a tree. Some snakes have such sensitive apparatus that they can detect differences down to .002 degrees Fahrenheit.


Suborder: Sauria or lizards have 3751 species in 16 families and 383 genera.

Skeleton: The skull of lizards is quite different from those of snakes. However, we believe that snakes did evolve from lizards so there are some similarities as well. Chief among them is the fact that the bones of their skulls are only loosely attached to one another. The lower jaw is composed of two halves and are united at the front. This tends to restrict the size of the meal that can be swallowed. At the back of the oral cavity the tongue is attached.

Lizards are called pleurodont meaning that the teeth are weakly attached to the inside of their jaws but not into the jaws themselves. The few exceptions to this are the group of acrodonts which are teeth attached somewhere on the jaw. The rest of the skeleton on lizards are variable and very unlike snakes primarily in that they have four functional appendages.

Skin: The skin of lizards are generally a hard horny substance that is folded together to make various types of scales. They can be small or large and all touch one another called "juxtaposed", are smooth with ridges called "keeled", or overlap and are called "imbricate." Scales have many purposes. Sometimes they are used as a way to absorb solar energy and warm up quicker. Other times they are used as armor or sexual display with many a bizarre crest or spines. And of course they differ from amphibians in that the scales prevent water loss.

Locomotion: Lizards as a species have explored it all. The typical lizard has four appendages with 5 toes on each. They may be barrel shaped, pipe shaped, flattened or you name it. In addition we have several species of lizards who have no limbs whatsoever and undulate side to side like primitive snakes. Still others have only vestigial legs front, back, or both. And then you have the many adaptations found throughout. Examples are the webbed feet of the Marine Iguana, Basilisks which can run on water, and Gecko feet that can climb up the smoothest glass. We even have prehensile tails that allow hanging from tree branches like Crocodile monitors. And perhaps the most unusual of all is the Flying Dragon from Asia that have the ability to glide just like flying squirrels. This group of reptiles is just plain versatile in ways to get around.

Reproduction: Again we see versatility. Most species use internal fertilization, but we also have unisex cloning such as Whiptails, Racerunners, and some other desert lizards. In addition their have been confirmed reports from some types of Chameleons, Geckos, Night Lizards, and Chisel-Teeth. The mechanism by which this happens is not completely understood nor the reason why it happens, but it is called "parthenogenesis."

Hearing: An external ear opening is present in most lizards and they likely hear much the same as other eared reptiles.

Behavior Adaptations: The adaptations of the many species of lizards is legendary. There are undoubtedly many, many we will never even know about as the lizards of smaller size do not fossilize well. But just looking around at the thousands of existing species gives a clue to the great diversity there was and still is. The very long and sticky tongues of the true chameleons which can snare prey more than a body length away are a good example. The ability to reproduce without males is another. Did some of the dinosaurs also employ this method"? It is not all that unlikely. Having an expendable tail, large colored tongue for defense, color changing for protection, large expandable frills, playing dead, and 360 degree independent eye movement are some of the other successful adaptation lizards are capable of

Hunting and Feeding: Lizards and their ancestors have been around for a very long time. The reason appears to be because of their adaptiveness. The first species to adapt to land in the earth's early history was the insects. And where plentiful prey is available the predators are soon to follow. Lizards started off eating insects and never had a real reason o change. True, there are some herbivores among the many lizard species, but it is in a minority.



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