Taxonomic revision and evolution of Cambrian mollusks of the genus Aldanella Vostokova, 1962 (Gastropoda: Archaeobranchia)

摘要

The species composition of the Early Cambrian genus Aldanella is revised based on extensive fossil material. Among 14 nominal species assigned to this genus, five are regarded as valid taxa, i. e., A. attleborensis (type), A. crassa, A. golubevi, A. utchurica, and A. operosa; the sixth species, A. sibirica sp. nov., is described as a new taxon. Eight species names are treated as junior synonyms of valid species, one species is excluded from the generic composition. The monographic description is given for all valid species, accompanied by refined data on their stratigraphic and geographic ranges. Based on the revised morphology and taxonomy of species and taking into account refined stratigraphic and geographic distribution, the taxonomic position and origin of the genus Aldanella are discussed, and its phylogenetic scenario is reconstructed.