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''Pelophylax'' is a genus of true frogs widespread in Eurasia, with a few species ranging into northern Africa. This genus was erected by Leopold Fitzinger in 1843 to accommodate the green frogs of the Old World, which he considered distinct from the brown pond frogs of Carl Linnaeus' genus ''Rana''. They are also known as water frogs, as they spend much of the summer living in aquatic habitat; the pond frogs can be found more often, by comparison, on dry land, as long as there is sufficient humidity. Yet there are species of Eurasian green frogs – the Central Asian ''P. terentievi'', or the Sahara frog (''P. saharicus'') – which inhabit waterholes in the desert. ==Systematics and taxonomy== Most authors throughout the 19th and 20th century disagreed with Fitzinger's assessment. The green frogs were included again with the brown frogs, in line with the tendency to place any frog similar in habitus to the common frog (''R. temporaria'') in ''Rana''. That genus, in the loose circumscription, eventually became a sort of "wastebin taxon". Around the year 2000, with molecular phylogenetic studies becoming commonplace, it was discovered that Fitzinger's assessment was correct after all – not only is ''Pelophylax'' an independent genus, but it does in fact belong to a lineage of Raninae not particularly close to ''Rana''. But it also turned out that these Eurasian green frogs might not form a monophyletic lineage. The sheer number of species involved in the group of ''Pelophylax'' and its closest relatives means that it will probably be some time until the definite circumscription of this genus is resolved. In any case, it can by now be said that the ''Pelophylax'' frogs belong to a group of moderately advanced Raninae – possibly a clade – that also includes such genera as ''Babina'', ''Glandirana'', ''Hylarana'', ''Pulchrana'', ''Sanguirana'', ''Sylvirana'', as well as ''Hydrophylax'' which like ''Pelophylax'' is suspected of being not monophyletic. These genera were formerly also included in ''Rana'' by most authors, and several of them have in fact only been established in the 1990s. And as regards the possible paraphyly of ''Pelophylax'', it seems that some species assigned here are very close to ''Hylarana'', and thus it might simply be a matter of moving them to that genus. But hybridogenic speciation is running rampant in the Old World green frogs, and this obfuscates the data gained from DNA sequence analyses.〔〔〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Pelophylax」の詳細全文を読む スポンサード リンク
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