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Amphibians (class Amphibia) are a taxon of animals that include all tetrapods, four-legged vertebrates, that do not have amniotic eggs.(from Greek αμφις "both" and βιος "life") are ectotherms, and generally spend part of their time on land, but most do not have the adaptations to an entirely terrestrial existence found in most other modern tetrapods (amniotes). There are around 6,000 described, living species of amphibians. The study of amphibians and reptiles is known as herpetology.
History of amphibians
Amphibians developed with the characteristics of pharyngeal slits/gills, a dorsal nerve cord, a notochord, and a post-anal tail at different stages of their life. Though early tetrapods (which appeared 390 million years ago in the Devonian period) are often referred to as "amphibians", the first true amphibians (of the order Temnospondyli) appeared during the early Carboniferous period. During the late Carboniferous, Permian and Triassic periods, amphibians were extremely diverse, including many large and small forms, some newt and salamander-like, others resembling snakes or eels, and some large-snouted forms that were very like small (about 1.5 meter long) crocodiles (e.g. Archegosaurus). The drying out of the coal swamps during the latest Carboniferous and again at the end of the Early Permian diminished many of the environments of these Paleozoic amphibians, with the result that many types died out, and they were supplanted by reptiles. However both large and small amphibians still continued to flourish in rivers and lakes of the Late Permian, alongside the diverse therapsids or mammal-like reptiles that were the dominant land animals of that time. During the following, Triassic period, there were many genera with large, sometimes very flattened heads and very weak limbs; some of these, like Paracyclotosaurus, Cyclotosaurus and Mastodonsaurus were several meters in length. Apart from a few stragglers, all these large amphibians died out at the Triassic-Jurassic extinction event, and the majority of Jurassic amphibians belonged to modern groups, and would look familiar today.
Throughout their history, amphibians have ranged in size from large forms, such as the above mentioned Triassic genera, the 5 foot (150cm) long Eryops of the Permian period, and the Giant Japanese and Chinese Salamanders of today, down to the tiny Brachycephalus didactylus (Brazilian Gold Frog) and Eleutherodactylus iberia (leptodactylid frog) from Cuba, with a total length of 9.6-9.8 millimeters (0.4 inches). Amphibians have mastered almost every climate on earth from the hottest deserts to the frozen arctic.
More on [ Amphibian ]
science channel has rekindled my love of amphibians. i'm suddenly missing my frogs, salamanders and turtles. i need a slimy pet in my life.
caro__ (caroline beard) Thu, 10 Dec 2009 21:09:59 -0000
science channel has rekindled my love of amphibians. i'm suddenly missing my frogs, salamanders and turtles. i need a slimy pet in my life.
climate change ," from musk oxen in the Arctic to amphibians in Peru. http://bit.ly/5Fx6XV
all_about_warm (allaboutwarm) Thu, 10 Dec 2009 20:57:58 -0000
climate change ," from musk oxen in the Arctic to amphibians in Peru. http://bit.ly/5Fx6XV
would like to know why there is a wild mammals protection act but not to protect amphibians, reptiles or birds. Answers on a postcard please
toni_pearce (toni pearce) Thu, 10 Dec 2009 16:24:53 -0000
would like to know why there is a wild mammals protection act but not to protect amphibians, reptiles or birds. Answers on a postcard please
After eating,do amphibians need to wait an hour before getting OUT of the water?
HoraceOchoa (Horace Ochoa) Thu, 10 Dec 2009 15:44:11 -0000
After eating,do amphibians need to wait an hour before getting OUT of the water?
TZ: Carnivorous, worm-like amphibians invade London: 'The Secret World of Naked Snakes', part I: On Monday 7th De... http://bit.ly/6zaXDl
cryptozoology (Cryptozoology Shop) Thu, 10 Dec 2009 13:38:46 -0000
TZ: Carnivorous, worm-like amphibians invade London: 'The Secret World of Naked Snakes', part I: On Monday 7th De... http://bit.ly/6zaXDl
Carnivorous, worm-like amphibians invade London: 'The Secret World of Naked Snakes', part I: On Monday 7th Decemb... http://bit.ly/8m3E9L
JPResearchLab (JP - Research Lab) Thu, 10 Dec 2009 13:38:46 -0000
Carnivorous, worm-like amphibians invade London: 'The Secret World of Naked Snakes', part I: On Monday 7th Decemb... http://bit.ly/8m3E9L
Amphibian - Article from Encarta Encyclopedia provides a basic introduction to these creatures. Includes a look at their physical characteristics, range and habitat, behavior, and life cycle.
Amphibians of Canada - Provides descriptions and pictures of amphibians that live in Canada.
CGEE: Amphibian Facts - Basic facts, a look at global population decline, and information about and photos of malformed amphibians.
Frogs and Amphibians - Pictures, sounds, animation, links, and fun. Created by 11 year old Daniel Contreras.
Meta Description: [ Frogs,toads,tadpoles,games,teachers welcome, pictures,sound, animation,coloring pages,live tadpoles for sale and more!!!!!! ]
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