Diphascon greveni, Dastych, 1984

Gąsiorek, Piotr, Blagden, Brian, Morek, Witold & Michalczyk, Łukasz, 2024, What is a ‘ strong’ synapomorphy? Redescriptions of Murray’s type species and descriptions of new taxa challenge the systematics of Hypsibiidae (Eutardigrada: Parachela), Zoological Journal of the Linnean Society 202 (1), pp. 1-63 : 5-6

Diphascon greveni ; King George Island; Dastych (1984).

Diphascon greveni ; King George Island; Tumanov and Tsvetkova (2023).

Material examined: 128 individuals in total (for details, see Supporting Information, Table S1).

Amended description: Large, body can exceed 500 μm ( Table 1), with a poorly demarcated, blunt cephalic region and a large interval between legs III and IV ( Fig. 5A). Lacking a DABT ( Figs 5B, 6A). The pharyngeal annulation simple in both PCM ( Fig. 5B) and SEM ( Fig. 6A, D, E), but occasional annular bifurcations present ( Fig. 6D, E). One band of teeth in the OCA ( Fig. 6B), not detectable in PCM ( Fig. 5B). Lateral porous areas in the walls of the buccal crown reduced and partly hidden under the apophyses for the insertion of stylet muscles (AISMs) ( Fig. 6C). Furca of the Hypsibius type ( Fig. 6F). Large pharyngeal apophyses. Three bar-shaped macroplacoids occasionally merged, but microplacoid and septulum always separate ( Fig. 6G). Claws of the Hypsibius type. Claw morphology ( Figs 7, 8) largely conforming to that described by Dastych (1984), but in rare cases the posterior claw bases were not broadened (almost all occurring asymmetrically on one leg, Fig. 7D) with respect to external claws I–III ( Fig. 7A–C). Some posterior claw bases so enlarged as to take almost a conical shape ( Fig. 7E). Claws of juveniles (probably hatchlings) delicate and with less well-developed indentation ( Fig. 7F). Rarely, this indentation may also be developed on the internal claw bases ( Fig. 8B). Internal bars visible under SEM as longitudinal thickenings adjacent to the internal claw bases

( Fig. 8A). Accessory points on claws IV more conspicuous and more widely divergent from the primary branches than on claws I–III (compare Fig. 8A, B with C, D).