Platicrista carpathica Gąsiorek, 2024

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 : 29-31

Platicrista carpathica Gąsiorek sp. nov.

ZooBank registration: urn:lsid:zoobank.org:act:4D82EEA5-92A6-4061-A43E-F4C09B97F307

Material examined: 24 individuals in total (for details, see Supporting Information, Table S1 ).

Type material: Holotype (slide PL.188.01 ) and 18 paratypes (slides PL.088.01 , PL.188.02 , PL.201.01 , PL.245.01–3 , PL.249.01 , PL.287.03 , PL.296.01 , and PL.373.01 ) from Poland, various locales in the Tatra Mountains (Supporting Information, Table S1 ), are deposited in the Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków.

Description: Body massive ( Table 8 ), white and elongate, with a blunt cephalic part ( Fig. 24 ). Cuticle without pores, but with irregular wrinkling caudally and rudimentary granulation in the lateralmost portions of the dorsocaudal body part ( Fig. 25 ). Cribriform areas not visible under PCM. Legs short and plump. Eyes absent in unmounted animals. Buccopharyngeal apparatus of the Platicrista type ( Fig. 26A ): OCA not visible under PCM; annulation of the pharyngeal tube simple and comprising tightly merged annuli; stylet supports inserted at the junction between the buccal and pharyngeal tubes; furcae of the Platicrista type; pharyngeal apophyses absent; pharynx oval, with two bar-like macroplacoids: the first much shorter than the second (1 <2).

Claws of the Hypsibius type, large and slender ( Fig. 26B–D ). Accessory points tightly adjacent to primary branches of the external/posterior claws, but with tips divergent from the primary branches of the internal/anterior claws. A weakly developed indentation on all claw bases. Septa between claw parts absent. Pseudolunulae smooth. Cuticular bars absent. Pulvini visible when legs are oriented suitably ( Fig. 26C ).

Etymology: The name signifies terra typica. An adjective in nominative singular.

Differential diagnosis: There are four congeneric species characterized by an absence of cuticular bars on their legs and the presence of a poorly developed or entirely absent dorsal granulation: P. aluna , P. angustata , P. nivea and P. horribilis (granulation absent). Platicrista carpathica can be differentiated from them based on: • P. aluna , the absence of striation of the buccal tube;

• P. angustata , see above;

• P. horribilis , the indentation of the pseudolunulae under claws IV (absent in P. carpathica vs. present in P. horribilis ) and the divergence of accessory points from the primary branches of the external and posterior claws (not divergent in P. carpathica vs. clearly divergent in P.horribilis ; compare Figs 26B–D and 27B–D );

• P. nivea , the presence and form of the caudal granulation (weakly developed only in the lateralmost part of caudal trunk in P. carpathica vs. strongly developed on the entire caudal trunk in P. nivea ).

Figures

Figure 24. General morphology of Platicrista carpathica sp. nov. (holotype in ventral view, PCM). Scale bar is in micrometres.

Figure 25. Caudal wrinkling of Platicrista carpathica sp. nov. (paratype, PCM). Scale bar is in micrometres.

Figure 26. Detailed morphology of Platicrista carpathica sp. nov. (paratypes, PCM): A, buccopharyngeal apparatus in toto; B, claws I; C, claws II; D, claws III. Empty white arrowheads indicate pseudolunulae; white asterisk indicates internal pulvinus; and black asterisk indicates external pulvinus. Scale bars are in micrometres.

Figure 27. Detailed morphology of Platicrista horribilis Kaczmarek & Michalczyk, 2003 (PCM): A, buccopharyngeal apparatus in toto; B, claws I (white asterisk indicates internal pulvinus); C, claws III; D, claws IV (empty white arrowhead indicates pseudolunule). Scale bars are in micrometres.