RICHTERSIIDAE, Guidetti & Rebecchi & Bertolani & Jonsson & Kristensen & Cesari, 2016

Guidetti, Roberto, Rebecchi, Lorena, Bertolani, Roberto, Jonsson, Kjell Ingemar, Kristensen, Reinhardt Møbjerg & Cesari, Michele, 2016, Morphological and molecular analyses on Richtersius (Eutardigrada) diversity reveal its new systematic position and lead to the establishment of a new genus and a new family within Macrobiotoidea, Zoological Journal of the Linnean Society 178 (4), pp. 834-845 : 843

RICHTERSIIDAE FAM. NOV.

Description: Double claws Y-shaped, with the two branches forming an evident common tract of variable length. Large teeth on all lunules. Buccal tube with ventral lamina and a cuticular thick on the anterior, dorsal wall of the buccal tube (which can form a large apophysis). Absence of transverse crests in the buccal armature. Two macroplacoids in the pharynx. Cuticular pores (at least in a phase of the life cycle). Eggs laid freely with cuticular processes on their surface.

Type genus. Richtersius

Composition. Richtersius , Diaforobiotus gen. nov., Adorybiotus (provisionally, see Remarks).

Remarks. Based on molecular data, Richtersius , Diaforobiotus gen. nov., and Adorybiotus do not belong to Macrobiotidae , but the phylogenetic relationship of Adorybiotus with the other genera of the families Richtersiidae fam. nov. and Murrayidae needs to be clarified with further molecular data. Based on several morphological affinities with Richtersius and Diaforobiotus gen. nov. (i.e. a cuticular thickening on the anterior dorsal wall of the buccal tube, large teeth on all lunules, absence of transverse crests in the buccal armature, two macroplacoids in the pharynx, and presence of cuticular pores), we place Adorybiotus in this family.