Platicrista angustata (Murray, 1905)

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 : 26-27

publication ID	https://doi.org/ 10.1093/zoolinnean/zlad151
publication LSID	lsid:zoobank.org:pub:044A402-2A0F-4135-9410-7DE081CB11C4Corresponding
DOI	https://doi.org/10.5281/zenodo.14536941
persistent identifier	https://treatment.plazi.org/id/03AF87C4-A620-FFA8-ADA4-6B08FBCB8830
treatment provided by	Plazi
scientific name	Platicrista angustata (Murray, 1905)
status

Treatment

Platicrista angustata (Murray, 1905) View in CoL

Diphascon angustatum ; terra typica: Loch Ness, Scotland; Murray (1905b).

D. angustatum ; Forth Valley, Scotland; Murray (1906b).

D. angustatum View in CoL ; Edinburgh, Killin, Scotland; Murray (1907) .

D. angustatum View in CoL ; Achill Island, Belclare, Ireland; Murray (1911). Hypsibius (D.) angustatus View in CoL ; Dartmoor, England, Isle of Man; Morgan and King (1976).

Platicrista aff. angustata View in CoL 4; Norway; Gąsiorek and Michalczyk (2020).

Material examined: 49 individuals in total (for details, see Supporting Information, Table S1 View Table 1 ).

Neotype material: Neotype and 28 specimens (slides GB.004.01– 06 , GB.012.19–25 , and GB.058.01–10 ) from Scotland, Hill of Foudland (57°23 ʹ 15″N, 2°39 ʹ 39″W; 451 m a.s.l.), lichen ( Cladonia ) from soil in abandoned slate quarry, 1 November 2014, Blagden coll., and Scotland, Creag Meagaidh, Lochan a’ Choire (56°57 ʹ 33″N, 4°34 ʹ 04″W; 624 m a.s.l.), moss from rock in alpine grassland, 24 March 2016, Blagden coll., are deposited in the Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków GoogleMaps .

Comparative material: Scotland, Gartly Forest , southern boundary (57°23 ʹ 2″N, 2°42 ʹ 52″W; 390 m a.s.l.), forest, lichen ( Parmelia ) from stone wall, 25 April 2015, Blagden coll. (five specimens) GoogleMaps ; Oxen Craig, Bennachie, Oyne , Aberdeenshire (57°17 ʹ 36″N, 2°33 ʹ 37″W; 520 m a.s.l.), heather moor, soil from rock crevice, 20 September 2015, Blagden coll. (one specimen) GoogleMaps ; Drum Castle, Drumoak (57°05 ʹ 42″N, 2°20 ʹ 16″W; 114 m a.s.l.), rural vicinity, leaf litter ( Quercus robur ) collected from soil, 5 September 2016, Blagden coll. (three specimens) GoogleMaps ; Fort Augustus, Loch Ness (57°08 ʹ 49″N, 4°40 ʹ 42″W; 20 m a.s.l.), lake shore, moss from rock, 5 November 2015, Blagden coll. (two specimens) GoogleMaps .

Redescription: Body medium-sized to very large ( Table 6 View Table 6 ), elongate and slightly narrowed in its anterior part ( Fig. 18A View Figure 18 ). Head blunt. Body white in smaller individuals, but brownish in the caudal part in large ones. Cuticle smooth, without pores or undulations, but with numerous irregular wrinkles intermingled with granulation in some individuals ( Fig. 19 View Figure 19 ). Cribriform areas not visible under PCM. Legs very short and plump; legs IV barely distinguishable from the posterior body end ( Fig. 18A View Figure 18 ). Eyes absent in live animals. Buccopharyngeal apparatus of the Platicrista type. The OCA absent ( Fig. 18B View Figure 18 ). Furcae of the Platicrista type, with branches pointing backwards. Pharyngeal apophyses absent; the pharyngeal tube is only slightly enlarged at its posterior end ( Fig. 18B View Figure 18 ). Pharynx oval and broad, with two thin macroplacoids, the second being at least two times longer than the first (1 <2). The macroplacoid margins are serrated ( Fig. 18B View Figure 18 ).

Claws of the Hypsibius type, large and robust, with thick but barely divergent accessory points, acute and slender at their tips. Primary branches of internal and anterior claws particularly massive ( Fig. 20 View Figure 20 ). Anterior and posterior claw bases with irregular margins under PCM ( Fig. 20B View Figure 20 ); delicate indentation visible in SEM ( Fig. 20E View Figure 20 ). Pseudolunulae present and well developed ( Fig. 20A, B View Figure 20 ). Cuticular bars absent.

Etymology: From the Latin angustatus = narrowed, most probably referring to the tendency, as described by Murray, of the animal to taper from legs III towards the anterior end of the body. An adjective in nominative singular.

Differential diagnosis: All species of Platicrista that also lack cuticular bars on their legs are compared with P. angustata , as follows:

• P. angustata View in CoL differs from P. aluna ( Lisi et al., 2019) by the absence of striation of the buccal tube;

• P. angustata View in CoL differs from P. carpathica sp. nov. by the absence of poorly developed indentation on all claw bases (compare Fig. 20A, B View Figure 20 with Fig. 25B, C View Figure 25 );

• P. angustata differs from P. horribilis by the presence of smooth pseudolunulae (compare Figs 20B View Figure 20 and 27D View Figure 27 );

• P. angustata differs from P. nivea sp. nov. by the presence of poorly developed indentation of claw IV bases (compare Figs 20B View Figure 20 and 28 View Figure 28 ).