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Salientia
Salientia (Latin ''salere'' (''salio''), "to jump") is a total group of amphibians that includes the order Anura, the frogs and toads, and various extinct proto-frogs that are more closely related to the frogs than they are to the Urodela, the salamanders and newts. The oldest fossil "proto-frog" appeared in the early Triassic of Madagascar, but molecular clock dating suggests their origins may extend further back to the Permian, 265 million years ago.
== Characteristics ==
Very few fossils of early salientians have been found, which makes it difficult to define the characteristics of the group and their taxonomic relationships. The arrangement of pectoral elements and the number of vertebrae are some guide, but the degree of vertebral articulation and the arrangement of the bones in the leg have not been found to be reliable indicators. The early proto-frogs developed from temnospondylid ancestors in which some of the elements of their vertebrae remained separate. The structure of the salientian pelvis and hind limb was probably developed for swimming rather than jumping. From the structure of the vertebrae, the group appears not to be monophyletic. Evolution of salientians seems to have been rapid and radiative. The essential features of recent groupings seem to have been established during the Mesozoic or early Tertiary. The families Discoglossidae, Pipidae and Pelobatidae are ecologically isolated, the harlequin frogs, restricted to a neotropical range in Central and South America, and the Ranidae and Bufonidae probably radiated from tropical regions of Africa and Asia.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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