Morphological and molecular analysis of ‘Melania’ jacqueti Dautzenberg and Fischer, 1906: from anonymous orphan to critical basal offshoot of the Semisulcospiridae (Gastropoda: Cerithioidea)

摘要: Morphological and molecular studies have been inconclusive in assessing monophyly of the Pleuroceridae s.l affinity western North American Juga to Asian members family currently grouped Semisulcospirinae. In part, this has hampered by rarity anatomical accounts for pleurocerids (s.l.). The present study provides a comprehensive description ‘Melania’jacqueti— Vietnamese species uncertain generic placement forgotten scientific literature over 100 years. This investigation confirmed that ‘Melania’jacqueti possess number features differentiate them from eastern species, including kidney, prostate pallial oviduct. However, comparative data remain inadequate allow phylogenetic analysis based on morphological alone. Consequently, set partial mitochondrial 16S ribosomal RNA gene sequences 51 (s.l.) five outgroups (Melanopsidae, Thiaridae), was assembled. Parsimony, Bayesian Maximum Likelihood analyses are largely congruent support s.l., two large clades: (i) clade (ii) an Asian–American with as critical basal offshoot, decisively anchoring within Semisulcospirinae sister all remaining forms. Given disparity between these clades, result is consistent restriction concept s.s. elevation rank — Semisulcospiridae. Examination available genus-group names Oriental semisulcospirids supports genus Hua. Molecular calibration split Semisulcospiridae suggests they diverged Cretaceous (approximately 90 million years ago). origin diversification clades roughly coincident subdivision Laurasia epicontinental seas opening Atlantic basin, primarily vicariant explanation their modern biogeographical distributions modified dispersal Juga.