Search results
Results from the WOW.Com Content Network
The origins and evolutionary relationships between the three main groups of amphibians is a matter of debate. A 2005 molecular phylogeny, based on rDNA analysis, suggests that salamanders and caecilians are more closely related to each other than they are to frogs.
Amphibians are ectothermic, anamniotic, four-limbed vertebrate animals that constitute the class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all tetrapods excluding the amniotes (tetrapods with an amniotic membrane , such as modern reptiles , birds and mammals ).
The largest living amphibian is the 1.8 m (5 ft 11 in) South China giant salamander (Andrias sligoi), but this is dwarfed by prehistoric temnospondyls such as Mastodonsaurus which could reach up to 6 m (20 ft) in length. The study of amphibians is called batrachology, while the study of both reptiles and amphibians is called herpetology.
Habitat shifts also occur in the developmental life history of amphibians, and in insects that transition from aquatic to terrestrial habitats. Biotope and habitat are sometimes used interchangeably, but the former applies to a community's environment, whereas the latter applies to a species' environment. [24] [26] [27]
Warty frog species tend to be called toads, but the distinction between frogs and toads is informal, not from taxonomy or evolutionary history. An adult frog has a stout body, protruding eyes , anteriorly-attached tongue , limbs folded underneath, and no tail (the tail of tailed frogs is an extension of the male cloaca).
It belongs to a lineage believed to have given rise to the three living branches of amphibians - frogs, salamanders and limbless caecilians. Creature named for Kermit the Frog offers clues on ...
The spermatophore has a packet of sperm supported on a conical gelatinous base, and often an elaborate courtship behavior is involved in its deposition and collection. Once inside the cloaca, the spermatozoa move to the spermatheca , one or more chambers in the roof of the cloaca, where they are stored for sometimes lengthy periods until the ...
The Caudata ("urodeles"; salamanders and newts), an order of tailed amphibians, is possibly the most adept vertebrate group at regeneration, given their capability of regenerating limbs, tails, jaws, eyes and a variety of internal structures. [2] The regeneration of organs is a common and widespread adaptive capability among metazoan creatures ...