Guidettion prorsirostre ( Thulin, 1928 )
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.14536924 |
persistent identifier |
https://treatment.plazi.org/id/03AF87C4-A635-FFA1-AC5D-6EFBFBF38DB2 |
treatment provided by |
Plazi |
scientific name |
Guidettion prorsirostre ( Thulin, 1928 ) |
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Guidettion prorsirostre ( Thulin, 1928) View in CoL
Diphascon prorsirostre View in CoL ; terra typica: Sweden, Germany, Scotland; Thulin (1928). D. prorsirostre View in CoL ; Örnskoldsvik, Södertalje, Kila, Sweden; Durante Pasa and Maucci (1979).
D. cf. prorsirostre View in CoL ; Tranemåla, Sweden; Jönsson (2003).
Adropion prorsirostre ; Battle Hill, Huntly, Aberdeenshire; Invermoriston, Loch Ness, Highland; Slug Road, Stonehaven, Aberdeenshire, Scotland; Blagden et al. (2020). Guidettion prorsirostre View in CoL ; Scotland; Gąsiorek and Michalczyk (2020).
Material examined: 48 individuals in total (for details, see Supporting Information, Table S1 View Table 1 ) .
Neotype material: Neotype and 30 specimens (slides GB.062.01– 06) from Scotland, Little Oxen Craig, Bennachie (57°17 ʹ 35″N, 2°33 ʹ 40″W; 507 m a.s.l.), moss from rowan tree bark ( Sorbus aucuparia L.), 5 October 2015, Blagden coll., are deposited in the Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków. Seven specimens (slide GB.062.07 ; NHMD Catalogue number 1651665 ) are deposited in the Natural History Museum, University of Copenhagen, Denmark GoogleMaps .
Comparative material: Scotland, Insch (57°20 ʹ 32″N, 2°38 ʹ 44″W; 268 m a.s.l.), rural vicinity, lichen ( Cladonia ) from rock, 19 December 2014, Blagden coll. (three specimens) GoogleMaps ; Hill of Foudland (57°23 ʹ 15″N, 2°39 ʹ 39″W; 350 m a.s.l.), old slate quarry, moss from tree, 26 September 2015, Blagden coll. (10 specimens) GoogleMaps ; Cabrach , Foot of The Buck (57°18 ʹ 31″N, 2°57 ʹ 18″W; 427 m a.s.l.), pine needles from soil, 26 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 ) from soil, 5 September 2016, Blagden coll. (two specimens) GoogleMaps ; Creag Meagaidh (56°57 ʹ 03″N, 4°36 ʹ 09″ W; 1100 m a.s.l.), mountain grassland, lichen ( Peltigera Willd. ) from rock, 1 September 2016, Blagden coll. (seven specimens) GoogleMaps ; Norway, RingsvassØya , Hansnes (69°57 ʹ 37″N, 19°36 ʹ 23″E; 3 m a.s.l.), forest, moss from soil, 3 Septmeber 2015, Hlebowicz coll. (six specimens) GoogleMaps ; Poland, Kamienna Góra (50°46 ʹ 39″N, 16°03 ʹ 22″E; 490 m a.s.l.), urban park, moss from tree trunk, 5 September 2015, Przybycień coll. (six specimens) GoogleMaps .
Redescription: Body small to medium-sized ( Table 4 View Table 4 ), elongate and white; cuticle smooth, without pores, wrinkling or granulation ( Fig. 12A View Figure 12 ). Cribriform areas not visible under PCM. Legs short and plump. Eyes absent in live animals. Buccopharyngeal apparatus of the Adropion type ( Figs 12A View Figure 12 , 13A, B View Figure 13 ). The OCA invisible under PCM ( Fig. 13A View Figure 13 ), but visible in SEM as one row of conical teeth ( Fig. 13C View Figure 13 ). The AISMs flat, but rather narrow ( Fig. 13A, D View Figure 13 ). Furcae of the Hypsibius type ( Fig. 13E View Figure 13 ). Buccal tube transitions smoothly into the annulated pharyngeal tube ( Fig. 13A, B, F View Figure 13 ), with single, widely separated annuli ( Fig. 13F, G View Figure 13 ). In its posterior part, the pharyngeal tube is devoid of annulation ( Fig. 13H View Figure 13 ). Small pharyngeal apophyses present ( Fig. 13A, B, H View Figure 13 ). Pharynx oval ( Fig. 13A View Figure 13 ; non-deformed pharynx length-to-width ratio: 1.7–2.5). Macroplacoid length sequence 1 = 2 <3, all elongate and thin, with smooth margins. The third macroplacoid two times longer than the second ( Fig. 13H View Figure 13 ). Lacking microplacoid and septulum.
Claws of the Hypsibius type, small, with slightly widened bases and slightly protruding accessory points on the primary branches ( Fig. 14 View Figure 14 ). The primary branches are much longer than the secondary branches. Secondary branches markedly curved. Pseudolunulae and cuticular bars at the claw bases absent ( Fig. 14 View Figure 14 ).
Etymology: From Latin prorsus = having a forward projection, and rostrum = snout. The mouth opening is placed at the end of the snout, as a continuation of the main body axis in this species. An adjective in nominative singular.
Differential diagnosis: Depending on the position of a specimen (i.e. dorsoventral or lateral projection), the mouth opening may be described as terminally or more ventrally positioned in G. prorsirostre . In agreement with the observations and opinions of other tardigradologists ( Cuénot 1932, Marcus 1936, Ramazzotti and Maucci 1983), we do not recognize the distinction between Guidettion arduifrons ( Thulin, 1928) , described based on animals collected in Lapland and Siberia, and G. prorsirostre ( Fig. 12B, C View Figure 12 ), thus we designate the former as nomen inquirendum. It is possible that G. arduifrons is a valid species, but the current morphological data prevent its identification. Guidettion carolae ( Binda & Pilato,1969) is morphologically identical to G. prorsirostre , as redescribed above, thus it is designated as synonym novum. Of the remaining species with only macroplacoids in the pharynx, the most similar to G. prorsirostre are Guidettion clavatum ( Bartoš, 1935) and Guidettion modestum ( Binda et al., 1984) (see the key to Guidettion spp. ). However, G. clavatum exhibits granulated caudal cuticle and G. modestum lacks pharyngeal apophyses, characteristics sufficient to separate both taxa from G. prorsirostre . The recently described Guidettion vexatum ( Pilato et al., 2017) does not appear to be sufficiently differentiated from G. prorsirostre . Its description was based on a small number of individuals, and several of the morphometric characters, in addition to the ‘small dots on legs’ (as reported in the original description, i.e. a potential form of granulation), are not identifiable in any of the photomicrographs. These features, which were used to delimit G. vexatum from G. prorsirostre , can be questioned easily, owing to the increased accuracy of measurements provided in the present redescription of G. prorsirostre . Thus, we designate G. vexatum as nomen inquirendum, pending the verification of its validity.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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Itaquasconinae |
Genus |
Guidettion prorsirostre ( Thulin, 1928 )
Gąsiorek, Piotr, Blagden, Brian, Morek, Witold & Michalczyk, Łukasz 2024 |
Diphascon prorsirostre
Thulin 1928 |
D. prorsirostre
Thulin 1928 |
D. cf. prorsirostre
Thulin 1928 |
Adropion prorsirostre
Thulin 1928 |