Hope in Homoplasy Hell - Demosponge classifications clarified with type (and other) sequences
Demosponge classification is notoriously challenged by the paucity of informative morphological characters with sufficient complexity to discriminate between apomorphies and convergences. Molecular data, preferably from type material, helps shedding light on the correct phylogenetic relationships. In the following we review the classification of several demosponge species and genera with eminent (or previously) uncertain classification using molecular tools. We report that the aster-bearing genus Leptosastra Topsent, 1904, has a poecilosclerid origin, unlike Clathria faviformis Lehnert & van Soest, 1996, which should be classified as Raspailiidae. The genus transfers of Prosuberites laughlini (Díaz, Alvarez & van Soest, 1987) from Eurypon Gray, and Leucophloeus lewisi Van Soest and Stentoft, 1988, to Axinyssa Lendenfeld are supported, unlike the transfer of Halichondria almae (Carballo et al.) from Ciocalapata de Laubenfels. We again highlight the benefits of historic (type) material sequencing, even if it is centuries old, and underline that type material should always be considered in answering systematic questions particularly with challenging taxa such as sponges.