Platicrista brunsoni Miller & J.D. Miller, 2021

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

publication ID	https://doi.org/ 10.1093/zoolinnean/zlad151
publication LSID	lsid:zoobank.org:pub:044A402-2A0F-4135-9410-7DE081CB11C4Corresponding
persistent identifier	https://treatment.plazi.org/id/03AF87C4-A625-FFAC-AD85-68EBFBDE8C07
treatment provided by	Plazi
scientific name	Platicrista brunsoni Miller & J.D. Miller, 2021
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Treatment

Platicrista brunsoni Miller & J.D. Miller, 2021 View in CoL

Material examined: Two individuals in total (originating from northern Wyoming; loaned by courtesy of Harry Meyer).

Amended description: Buccopharyngeal apparatus of the Platicrista type ( Fig. 22A View Figure 22 ): OCA not visible under PCM; simple pharyngeal annulation composed of tightly arranged single annuli; stylet supports inserted at the junction between the buccal and pharyngeal tubes; furcae of the Platicrista type (cochlear); pharyngeal apophyses not visible; pharynx oval, with two bar-like macroplacoids: the first much shorter than the second (1 <2).

Claws massive, of the Hypsibius type ( Fig. 22B–D View Figure 22 ). Accessory points divergent only on the primary branches of the posterior claws ( Fig. 22D View Figure 22 ). Septa between claw parts absent. Pseudolunulae present at the internal and anterior claw bases. Irregular granulation on legs IV. Internal cuticular bars II–III with irregular margins ( Fig. 22C View Figure 22 ). Internal, anterior, and posterior claw bases delicately indented ( Fig. 22B–D View Figure 22 ). Basal portion of the posterior claws greatly broadened ( Fig. 22D View Figure 22 ).

Dorsal cuticle with large polygonal granulation that extends to the lateral body parts (including legs). Granulation is most distinct in the cephalic ( Fig. 23A View Figure 23 ) to median and more caudal portions of the cuticle ( Fig. 23B View Figure 23 ). However, polygons may merge at the level of legs II–III, and form striae ( Fig. 23C View Figure 23 ). Polygons are different in shape in the caudalmost body portion, being more convex and irregular in shape ( Fig. 23D View Figure 23 ). Cribriform areas not visible under PCM.

Remarks: The original description contained several errors. The buccal tube width should not have been measured, at least not in the holotype, because it is evident from the photograph that the buccopharyngeal tube had collapsed ( Miller and Miller 2021: fig. 2B). This occurs frequently during mounting of Platicrista , Astatumen , and Itaquascon specimens on permanent slides (P. Gąsiorek, pers. obs.) and might be related to their shared similarities in the ultrastructure of the apparatus. The claws of P. brunsoni are of the Hypsibius type, not the Isohypsibius type. Finally, the dorsal sculpturing is not uniform across the dorsum, because the caudalmost polygonal tubercles are disparate in form. This makes P. brunsoni similar to P. cheleusis .

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 View Figure 24 ). Cuticle without pores, but with irregular wrinkling caudally and rudimentary granulation in the lateralmost portions of the dorsocaudal body part ( Fig. 25 View Figure 25 ). Cribriform areas not visible under PCM. Legs short and plump. Eyes absent in unmounted animals. Buccopharyngeal apparatus of the Platicrista type ( Fig. 26A View Figure 26 ): 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 View Figure 26 ). 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 View Figure 26 ).

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 View Figure 26 and 27B–D View Figure 27 );

• 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 ).