A phylogeny of West Palearctic Salamandridae based on 1208 bp of mtDNA sequences (300 bp of cytb, 346 bp of 12S rRNA and 562 bp of 16S rRNA) indicates the European brook newts (Euproctus) are polyphyletic. To reflect revised relationships, the Tyrrhenian species (E. montanus (Savi, 1838) and E. platycephalus (Gravenhorst, 1829)) are retained in EuproctusGenè, 1839, while the genus CalotritonGray, 1858 is resurrected to include the Pyrenean brook newt (Calotriton asper (Dugès, 1852) comb. nov.) and a new species from the massif of El Montseny, Catalonia, Spain, described herein as Calotriton arnoldi sp. nov., which is both morphologically and genetically distinct. Although according to the principle of priority MegapternaSavi, 1838 should take precedence over EuproctusGenè, 1839, for the sake of nomenclatural stability and in line with Art. 23.9.1 of the International Code of Zoological Nomenclature, Megapterna is considered a nomen oblitum and Euproctus a nomen protectum. The polyphyly of Euproctus (s.l.) contradicts previous, well-accepted, biogeographical hypotheses and represents a clear case of convergence, involving several morphological traits and a unique reproductive behaviour that is advantageous in stream situations. Molecular dating suggests the Western brook newt lineage (C. asper+C. arnoldi) originated towards the end of the Miocene (8.3 ± 0.11 Mya) and is part of a well-supported monophyletic assemblage, which also includes Neurergus kaiseri (Schmidt, 1952) and a clade formed by Triturus karelinii (Strauch, 1870), T. carnifex (Laurenti, 1768), T. pygmaeus (Wolterstoff, 1905) and T. marmoratus (Latreille, 1800). Speciation separating E. montanus and E. platycephalus might have coincided with the onset of the Messinian salinity crisis. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society, 2005, 145, 555–582.