Reptiles are tetrapods and amniotes, animals whose embryos are surrounded by an amniotic membrane. Today they are represented by four surviving orders:

• Crocodilia (crocodiles, caimans and alligators): 23 species
• Rhynchocephalia (tuataras from New Zealand): 2 species
• Squamata (lizards, snakes and amphisbaenids ("worm-lizards")): approximately 7,600 species
• Testudines (turtles): approximately 300 species

Reptiles are found on every continent except for Antarctica, although their main distribution comprises the tropics and subtropics. Though all cellular metabolism produces some heat, modern species of reptiles do not generate enough to maintain a constant body temperature and are thus referred to as "cold-blooded" (ectothermic). (See the Leatherback Sea Turtle for an exception: a reptile that elevates its body temperature well above that of its surroundings.) Instead they rely on gathering and losing heat from the environment to regulate their internal temperature, e.g, by moving between sun and shade, or by preferential circulation — moving warmed blood into the body core, while pushing cool blood to the periphery. In their natural habitats, most species are adept at this, and can maintain core body temperatures within a fairly narrow range, comparable to that of mammals and birds, the two surviving groups of "warm-blooded" animals. While this lack of adequate internal heating imposes costs relative to temperature regulation through behavior, it also provides a large benefit by allowing reptiles to survive on much less food than comparably-sized mammals and birds, who burn much of their food for warmth. While warm-blooded animals move faster in general, an attacking lizard, snake or crocodile moves very quickly. A herpetologist is a zoologist who studies reptiles and amphibians.

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Reptiles and Amphibians - Twitter Search

RT @dvm360: Disney's Princess and Frog is coming. Stop your clients' kids from smooching their amphibians and reptiles:.http://bit.ly/7ublJH
PetDocsOnCall09 (Tom Dock) Mon, 14 Dec 2009 14:50:11 -0000
RT @dvm360: Disney's Princess and Frog is coming. Stop your clients' kids from smooching their amphibians and reptiles:.http://bit.ly/7ublJH
Disney's Princess and the Frog is coming. Stop your clients' kids from smooching their amphibians and reptiles:... http://bit.ly/7ublJH
dvm360 (dvm360.com) Mon, 14 Dec 2009 14:34:59 -0000
Disney's Princess and the Frog is coming. Stop your clients' kids from smooching their amphibians and reptiles:... http://bit.ly/7ublJH
@decibelle nah. i dont eat mammals, amphibians, or reptiles. only some bird. mostly fish and veggies.
lilel (Lil' El) Sun, 13 Dec 2009 20:55:31 -0000
@decibelle nah. i dont eat mammals, amphibians, or reptiles. only some bird. mostly fish and veggies.
NYC event: Hall of Reptiles and Amphibians - Amphibians were the first vertebrates to live on land. From them evolv... http://ow.ly/1696v6
nyccom (NYC.com) Sun, 13 Dec 2009 12:21:49 -0000
NYC event: Hall of Reptiles and Amphibians - Amphibians were the first vertebrates to live on land. From them evolv... http://ow.ly/1696v6
@dgdreamin Herpetoculture (keeping reptiles & amphibians) That's pretty much it actually, me my camera and my snakes haha, yourself?
erikpaterson (Erik Paterson) Sun, 13 Dec 2009 00:04:24 -0000
@dgdreamin Herpetoculture (keeping reptiles & amphibians) That's pretty much it actually, me my camera and my snakes haha, yourself?
reptiles, amphibians, and birds all my life, as well as a tendancy to not wash my hands after handling them.
JustinVal (Justin Val Rocha) Wed, 09 Dec 2009 21:19:47 -0000
reptiles, amphibians, and birds all my life, as well as a tendancy to not wash my hands after handling them.

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