Revision of the genus Pseudodiphascon (Tardigrada,Macrobiotidae), with the erection of three new genera

A flexible but non-annulated buccal tube was used to erect the subgenus Pseudodiphascon, later raised to genus level (type species Macrobiotus inflexus). However, the presence of a flexible (but non-annulated) buccal tube in the holotype and paratype is due to the moulting simplex stage of both animals. Therefore Macrobiotus inflexus must be considered species dubia. The other species to date attributed to Pseudodiphascon differ from the type species of the genus in the presence of a pharyngeal tube that appears annulated. Because of this and other characters, they do not conform to the definition of Pseudodiphascon and cannot be attributed to this genus, which must be considered genus dubium. The characters of the claws and of the buccal—pharyngeal apparatuses led us to describe three new genera: Biserovus gen. n.: claws without a differentiated basal portion, annulated pharyngeal tube, peribuccal lamellae present; Minilentus gen. n.: claws of ‘hufelandi type’, annulated pharyngeal tube, peribuccal lamellae absent; Insuetifurca gen. n.: claws of modified' hufelandi type, annulated pharyngeal tube, peribuccal lamellae present, stylet furcae of a peculiar shape. Pseudodiphascon diphasconides lacks annulation in the buccal tube and is transferred to the genus Minibiotus.