What are the main groups of amphibian?

amphibians, class amphibians, are an ancient line that developed directly from the fish with a lobe in the late Devonian period, about 365 million years ago. At one point it contained three subclass: Labyrinthodonts, Leposponyls and Lissamphibians. Today, there are only Lissamphiani, who count all surviving amphibians among members: salamanders and salamans (command called Caudata or ), frogs and toad (orders ) and obo ).

Among the surviving groups of amphibians are the most successful frogs and toads (5,453 species), followed by registers and registers (560 species) and Caecilians (171 species). It is assumed that all these amphibians share a common predecessor, although some workers say that the pleasure and the sales come from a different ancient ancestor than the others. The number of species of amphibians is roughly comparable to the number of mammal and MDash species; Both have about 6,000 - but of course mammals are much more numerous and more successful.

The common predecessor Lissamphia probably lived about 290 million years ago. One fossil from that time, Gerobatrachus , is referred to as frogamander due to a clear combination of frogs and a newt. In 2004, the rediscovery of this fossil called the "shaken salamander with frog ears" showed that the common predecessor of the frogs and salamanders lived recently before it was otherwise thought. The common predecessor of the Caecilians and other amphibians could have been 10-20 million years old. The discovery of Gerobatchus proved that modern amphibians came from an ancient group called Temnosponyls. The controversy of the descent of the amphibian was considered one of the most important in the evolution of vertebrates before the discovery of Frogamuander Fossil.

Although ancient amphibians were relatively large and today they occupied many niches that have taken reptiles and mammals, today's reptiles are relatively small. By one kind that turns on this long losingAcena amphibian, is a Chinese giant salamander ( Andrias Davidianus ), a Torweller, which reaches a size of 64 kg (140 lb) and 1.83 m (6 ft). Like many other amphibians, the Chinese giant salamander is critically endangered, today it lives only in the most remote mountain streams. Other species of amphibians, which are currently endangered by extinction, include the Malagasis Rainbow Frog, Chile Darwin, Frog Ghosts, Seychelles of Frogs, Caecilian Sagalla, Mexican Mlados without lungs and a Betic midwife.