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Introduction

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Selected reptile type

Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes (/sɜːrˈpɛntiːz/). Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with several more joints than their lizard ancestors, enabling them to swallow prey much larger than their heads (cranial kinesis). To accommodate their narrow bodies, snakes' paired organs (such as kidneys) appear one in front of the other instead of side by side, and most have only one functional lung. Some species retain a pelvic girdle with a pair of vestigial claws on either side of the cloaca. Lizards have independently evolved elongate bodies without limbs or with greatly reduced limbs at least twenty-five times via convergent evolution, leading to many lineages of legless lizards. These resemble snakes, but several common groups of legless lizards have eyelids and external ears, which snakes lack, although this rule is not universal (see Amphisbaenia, Dibamidae, and Pygopodidae).

Living snakes are found on every continent except Antarctica, and on most smaller land masses; exceptions include some large islands, such as Ireland, Iceland, Greenland, the Hawaiian archipelago, and the islands of New Zealand, as well as many small islands of the Atlantic and central Pacific oceans. Additionally, sea snakes are widespread throughout the Indian and Pacific oceans. Around thirty families are currently recognized, comprising about 520 genera and about 3,900 species. They range in size from the tiny, 10.4 cm-long (4.1 in) Barbados threadsnake to the reticulated python of 6.95 meters (22.8 ft) in length. The fossil species Titanoboa cerrejonensis was 12.8 meters (42 ft) long. Snakes are thought to have evolved from either burrowing or aquatic lizards, perhaps during the Jurassic period, with the earliest known fossils dating to between 143 and 167 Ma ago. The diversity of modern snakes appeared during the Paleocene epoch (c. 66 to 56 Ma ago, after the Cretaceous–Paleogene extinction event). The oldest preserved descriptions of snakes can be found in the Brooklyn Papyrus.

Most species of snake are nonvenomous and those that have venom use it primarily to kill and subdue prey rather than for self-defense. Some possess venom that is potent enough to cause painful injury or death to humans. Nonvenomous snakes either swallow prey alive or kill by constriction. (Full article...)

Selected Crocodilia article

In Llanos, Venezuela

The spectacled caiman (Caiman crocodilus), also known as the white caiman, common caiman, and speckled caiman, is a crocodilian in the family Alligatoridae. It is brownish-, greenish-, or yellowish-gray colored and has a spectacle-like ridge between its eyes, which is where its common name come from. It grows to a length of 1.4–2.5 m (4 ft 7 in – 8 ft 2 in) and a weight of 7–40 kg (15–88 lb), with males being both longer and heavier than females. Its diet varies seasonally, commonly consisting of crabs, fish, small mammals, amphibians and snails. Breeding occurs from May to August and 14–40 eggs are laid in July and August. This crocodilian has a large range and population; it is native to much of Latin America, and has been introduced to the United States, Cuba, and Puerto Rico. (Full article...)

Selected lizard article

Rhacodactylus leachianus

Rhacodactylus is a genus of medium to large geckos of the family Diplodactylidae. All species in this genus are found on the islands that make up New Caledonia.

Genus characteristics include long limbs and toes with well-developed lamellae. Some webbing occurs on the hind limbs and toes. Rhacodactylus possess prehensile tails which also have lamellae to assist in climbing. These are for the most part arboreal geckos. Rhacodactylus are nocturnal geckos.

The species are egg layers with the exception of Rhacodactylus trachyrhynchus and R. trachycephalus which gives live birth, a characteristic only otherwise found in New Zealand geckos. They also feed on lizards, more so than any of the family. Rhacodactylus geckos are sexually dimorphic, with the males possessing larger preanal pores than the females as well as a distinct hemipenis pocket. (Full article...)

Selected turtle article

Red-bellied short-necked turtle at Cologne Zoo

The red-bellied short-necked turtle (Emydura subglobosa), also known commonly as the pink-bellied side-necked turtle and the Jardine River turtle, is a species of turtle in the family Chelidae. The species is native to Australia and New Guinea. There are two recognized subspecies. (Full article...)

Picture slideshow

Image 1Plumed basilisk
Image 2Australian water dragon
Image 3Mexican beaded lizard
Image 4Cape skink - Trachylepis capensis. Close-up on purple Aster flowers.
Image 5Eastern bearded dragon
Image 6Gold dust day gecko
Image 7Gold dust day gecko close-up
Image 8Vipera xanthina
Image 9Leiocephalus personatus
Image 10Jackson's chameleon
Image 11 Albino alligator
Image 12Leiocephalus carinatus
Image 13Namaqua chameleon
Image 14Morelia spilota
Image 15Dwarf yellow-headed gecko
Image 16Phelsuma grandis
Image 17Green sea turtle
Image 18Mwanza flat-headed rock agama
Image 19Gold dust day gecko
Image 20Barracudasauroides
Image 21Trachylepis maculilabris mating
Image 22Bothriechis schlegelii
Image 23Red-headed Amazon River turtles
Image 24Common box turtle
Image 25Sicilian wall lizard
Image 26Niveoscincus metallicus
Image 27Anole at Polychrotinae
Image 28Trachylepis striata
Image 29Indian chameleon
Image 30Italian wall lizard
Image 31Yacare caiman
Image 32Carolina anole
Image 33Green sea turtle
Image 34Marine iguana
Image 35Rough chameleon
Image 36Plestiodon fasciatus
Image 37Cerastes cerastes
Image 38Namaqua chameleon
Image 39Thamnophis elegans terrestris at Western terrestrial garter snake
Image 40Bosc's fringe-toed lizards during courtship
Image 41Sinai agama
Image 42Aldabra giant tortoise
Image 43Ladder snake
Image 44Vipera dinniki
Image 45Eastern long-necked turtle
Image 46Species of Ceratopsia dinosaurs
Image 47Marginated tortoise hatchling
Image 48A green sea turtle swimming above a coral reef.
Image 49Common collared lizard
Image 50Asian vine snake Ahaetulla prasina. This snake has a wide distribution in Asia. It feeds on small reptiles and amphibians, particularly lizards and tree frogs. Adults may attain 1.8 m (6 feet) in total length, with a tail 0.6 m (2 feet) long. Its appearance is very much like those of South American vine snakes. It is a rear-fanged species and is mildly venomous but is not considered a threat to humans.
Image 51Steneosaurus
Image 52White-headed dwarf gecko
Image 53Green sea turtle

Selected snake article

Crotalus cerastes

Rattlesnakes are venomous snakes that form the genera Crotalus and Sistrurus of the subfamily Crotalinae (the pit vipers). All rattlesnakes are vipers. Rattlesnakes are predators that live in a wide array of habitats, hunting small animals such as birds and rodents.

Rattlesnakes receive their name from the rattle located at the end of their tails, which makes a loud rattling noise when vibrated that deters predators. Rattlesnakes are the leading contributor to snakebite injuries in North America, but rarely bite unless provoked or threatened; if treated promptly, the bites are seldom fatal.

The 36 known species of rattlesnakes have between 65 and 70 subspecies, all native to the Americas, ranging from central Argentina to southern Canada. The largest rattlesnake, the eastern diamondback, can measure up to 8 ft (2.4 m) in length. (Full article...)