Orders
Order Crocodylia
Order Crocodylia contain the alligators, crocodiles, caimans, and gharials. There are only 21 species and 3 families in this order. They have triangular eyes along with a long snout with nostrils on the end. Their trachea has a flap of skin that can be used to cover it when crocodilians are underwater. Crocodilians also have a powerful tail that assists in swimming and can be used for defense. They and birds are the only two survivors of the Archosauria. Around 200 million years ago (Triassic) was when most or all of crocodilians' adaptions finished evolving. Crocodilians are considered the most advanced of the reptiles. The skin of a crocodilian is covered in heavy, non-overlapping scales. Crocodilians do not shed their skin all at once like snakes do, rather they individually shed their scales.
They typically avoid cooler climates because their skin doesn't provide good insulation. Crocodilians make their nests out of plant material and, or mud; they aggressively defend their nests and young against predators. The mothers might tend to their hatch-lings for many weeks and, in some species, fathers will do the same. Crocodilians are considered sexually mature once they reach a certain age and size. Even once they reach sexual maturity, they will continue to grow. The stomach acid of a crocodilian is considered the most powerful of any vertebrate; it is capable of digesting even the bones of a crocodilian's prey. Around 60% of a crocodilian's food intake can be converted into fat which allows it to survive for possibly up to two years without a meal.
Sources: http://animaldiversity.ummz.umich.edu/accounts/Crocodylia/, Google Drive notes
Order Crocodylia contain the alligators, crocodiles, caimans, and gharials. There are only 21 species and 3 families in this order. They have triangular eyes along with a long snout with nostrils on the end. Their trachea has a flap of skin that can be used to cover it when crocodilians are underwater. Crocodilians also have a powerful tail that assists in swimming and can be used for defense. They and birds are the only two survivors of the Archosauria. Around 200 million years ago (Triassic) was when most or all of crocodilians' adaptions finished evolving. Crocodilians are considered the most advanced of the reptiles. The skin of a crocodilian is covered in heavy, non-overlapping scales. Crocodilians do not shed their skin all at once like snakes do, rather they individually shed their scales.
They typically avoid cooler climates because their skin doesn't provide good insulation. Crocodilians make their nests out of plant material and, or mud; they aggressively defend their nests and young against predators. The mothers might tend to their hatch-lings for many weeks and, in some species, fathers will do the same. Crocodilians are considered sexually mature once they reach a certain age and size. Even once they reach sexual maturity, they will continue to grow. The stomach acid of a crocodilian is considered the most powerful of any vertebrate; it is capable of digesting even the bones of a crocodilian's prey. Around 60% of a crocodilian's food intake can be converted into fat which allows it to survive for possibly up to two years without a meal.
Sources: http://animaldiversity.ummz.umich.edu/accounts/Crocodylia/, Google Drive notes
Order Rhynchocephalia
The tuataras are rare for there are only two species of them left today. They can be found in New Zealand and only at night since they are nocturnal. Tuataras have a unique extra "eye" which they use to detect changes in light. They first appeared during the Mesozoic Era about 220 million years ago. This group of reptiles used to be more diverse and widespread and fossil evidence reflects this: Europe, Africa, South America, and Madagascar were all locations once inhabited by tuataras. Unfortunately, most species died out around 100 million years ago. Tuataras are burrowers and live in coastal forests where they eat bird eggs, chicks, invertebrates, amphibians, and and other smaller reptiles. Because they are cold-blooded and prefer cold environments, they have very slow metabolisms. As a result, they grow very slowly and live for many years. Tuataras are capable of reproducing until about the age of 60.
Sources: http://animals.about.com/od/reptiles/p/tuataras.htm, Google Drive notes
The tuataras are rare for there are only two species of them left today. They can be found in New Zealand and only at night since they are nocturnal. Tuataras have a unique extra "eye" which they use to detect changes in light. They first appeared during the Mesozoic Era about 220 million years ago. This group of reptiles used to be more diverse and widespread and fossil evidence reflects this: Europe, Africa, South America, and Madagascar were all locations once inhabited by tuataras. Unfortunately, most species died out around 100 million years ago. Tuataras are burrowers and live in coastal forests where they eat bird eggs, chicks, invertebrates, amphibians, and and other smaller reptiles. Because they are cold-blooded and prefer cold environments, they have very slow metabolisms. As a result, they grow very slowly and live for many years. Tuataras are capable of reproducing until about the age of 60.
Sources: http://animals.about.com/od/reptiles/p/tuataras.htm, Google Drive notes
Order Squamata
This order is composed of the lizards, snakes, and worm-lizards. It is considered the most diverse reptiles group and with about 7,400 species. All squamates have two universal traits: they shed their skin and they have pointed jaws and skulls. Squamates appeared in fossils during the mid Jurassic period but most likely were around before that time. Modern squamates popped up around 160 million years ago during the late Jurassic period. Suborder sauria contains the lizards and there are about 4,500 species. They have two pairs of legs, two jaws that completely connect closed, and most species are oviparous. Suborder serpentes are the snakes with about 2,000 species and around 300 of those species are venomous. They have long bodies without limbs and more than 200 vertebrae and ribs. Their skulls are adapted for swallowing large prey whole. Most snakes are oviparous but some vipers, boas, and cobras give live birth. Suborder serpentes also contains the worm-lizards and there are around 135 species. They are legless and burrow in the ground, they have shovel-shaped skulls to help with this. They have a single tooth in their upper and lower jaws.
Sources: http://animals.about.com/od/lizardsandsnakes/p/squamata.htm, Google Drive notes
This order is composed of the lizards, snakes, and worm-lizards. It is considered the most diverse reptiles group and with about 7,400 species. All squamates have two universal traits: they shed their skin and they have pointed jaws and skulls. Squamates appeared in fossils during the mid Jurassic period but most likely were around before that time. Modern squamates popped up around 160 million years ago during the late Jurassic period. Suborder sauria contains the lizards and there are about 4,500 species. They have two pairs of legs, two jaws that completely connect closed, and most species are oviparous. Suborder serpentes are the snakes with about 2,000 species and around 300 of those species are venomous. They have long bodies without limbs and more than 200 vertebrae and ribs. Their skulls are adapted for swallowing large prey whole. Most snakes are oviparous but some vipers, boas, and cobras give live birth. Suborder serpentes also contains the worm-lizards and there are around 135 species. They are legless and burrow in the ground, they have shovel-shaped skulls to help with this. They have a single tooth in their upper and lower jaws.
Sources: http://animals.about.com/od/lizardsandsnakes/p/squamata.htm, Google Drive notes
Order Testudines
This order contains the turtles and the tortoises. There are around 300 species. They are a very unique animal because of their shells. Most aspects of their bodies are modified to accommodate the shell. They also have a "beak" rather than teeth. The top of the shell is called the carapace and the bottom is called the plastron. Turtles reach sexual maturity at about age 7 or 8. Most live to be over 14 and some tortoises and sea turtles can live to be over 100 years old. Turtle and tortoises are oviparous. Some eggs can take up to a year to develop. Most turtles and tortoises are not very protective of their eggs.
Sources: http://animaldiversity.ummz.umich.edu/accounts/Testudines/, Google Drive notes
This order contains the turtles and the tortoises. There are around 300 species. They are a very unique animal because of their shells. Most aspects of their bodies are modified to accommodate the shell. They also have a "beak" rather than teeth. The top of the shell is called the carapace and the bottom is called the plastron. Turtles reach sexual maturity at about age 7 or 8. Most live to be over 14 and some tortoises and sea turtles can live to be over 100 years old. Turtle and tortoises are oviparous. Some eggs can take up to a year to develop. Most turtles and tortoises are not very protective of their eggs.
Sources: http://animaldiversity.ummz.umich.edu/accounts/Testudines/, Google Drive notes
Representative organism: Armadillo Girdled Lizard
- Scientific name: Cordylus cataphractus
- Part of Order Squamata
- Named after the armadillo because of its ability to roll into a ball that is almost completely impregnable
- Can be found along the west coast of South Africa and from the Orange River to the Piketberg Mountains
- They prefer temperate habitats
- The outer body of an armadillo lizard is covered in spiky scales that protect it against virtually all of its predators with the exception of birds of prey
- As a last resort, armadillo lizards are capable of "dropping" their tails from their bodies. A new tail slowly grows back over time. But an armadillo lizard will not so easily part with its tail as it relies on it to help keep it in its curled position
- Their jaws are extremely powerful, powerful enough to sever small limbs. They sometimes roll their bodies while biting, which can cause terrible damage
- Unlike many other lizards, armadillo lizards are sociable (they can be kept as pets) and between 1 and 30 lizards might share a rock crevice together in the wild
- Armadillo lizards feed mostly on insects, their main prey being the southern harvester termite
Sources: http://www.arkive.org/armadillo-girdled-lizard/cordylus-cataphractus/, http://animaldiversity.ummz.umich.edu/accounts/Cordylus_cataphractus/