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MACROBIOTUS ARIEKAMMENSIS GROENLANDICUS SUBSP. NOV. (TABLES 4, 5; FIGS 5–11) Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: 8A12E93C-8729-4B13-BD36-FC507DD117D3 Material examined: Altogether 110 animals and 78 eggs. Specimens mounted on microscope slides in Hoyer’s medium (83 animals + 68 eggs), fixed on SEM stubs (20 animals + ten eggs + four buccal apparatuses), processed for DNA sequencing (three animals). Etymology: The new subspecies is named after Greenland (from Danish Grønland), the territory where it was discovered. Type locality: 69°15’17’’N, 53°30’46’’W; 30 m a.s.l.: western coast of Greenland, Disko Island, Østerlien; moss on rock. Type depositories: Altogether 83 animals [slides: GL.018. 2–3, 9–17, SEM stubs: 9.06, 12.15 (buccal apparatus), 16.19] and 68 eggs (slides: GL.018. 1, 4–8, SEM stub: 16.19) are deposited at the Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387, Kraków, Poland. Description of the new subspecies Animals (measurements and statistics in Table 4): Body colourless in juveniles and whitish in adults, after fixation in Hoyer’s medium transparent (Fig. 5A). Eyes present, visible also after mounting the specimens on permanent slides in Hoyer’s medium. The entire cuticle covered with granulation visible in both PCM and SEM, arranged densely on the dorsum, and less densely on the venter and legs (Figs 5B–G, 6A, C, D, F, G, I). Only in some specimens the cuticular granulation can be less evident under PCM (Fig. 5D). Oval cuticular pores present (0.5–1.4 µm in diameter) (Fig. 5E–G). Patches of dense granulation present on internal and external surface of all legs I– III, as well as on legs IV and clearly visible (Fig. 6A, B, D, E). A pulvinus present on the internal surface of legs I– III (Fig. 6D, E). Granulation on legs IV is visible as a single large patch on dorsal and lateral leg surfaces (Fig. 6G–H). Claws slender, with flat and wide common tract, beginning with a visible stalk that connects the claws to the wide lunulae and ending with elongated branches (especially the primary branch; Fig. 7A–E). Primary branches with distinct accessory points, visible in PCM and SEM (Fig. 7A–E). Lunulae I– III smooth (Fig. 7A, C, D), whereas lunulae IV with clear dentation (Fig. 7B, E). A single continuous cuticular bar (Fig. 7A) and double muscle attachments visible on each leg I– III (Fig. 7A, C, D). Mouth anteroventral with ten peribuccal lamellae. Bucco-pharyngeal apparatus of the Macrobiotus - type (Figs 8A, 9A). Oral cavity armature extremely reduced to only one large tooth present in the dorsal portion of the third band of teeth, whereas other bands of teeth are absent (Figs 8A–D, 9F). Pharyngeal bulb spherical, with triangular apophyses, cuticular spikes, two rod-shaped macroplacoids (macroplacoid sequence: 2 Eggs (measurements and statistics in Table 5): Eggs laid freely, whitish, spherical or slightly oval (Figs 10A–D, 11A). The spaces between the processes are small and the surface of the egg between the processes is continuous and smooth, without any pores or reticulum, i.e. persimilis - type (Figs 10A–D, 11A–D). Between the processes on the egg surface, lightrefracting dots are usually visible in PCM, resembling micropores (Fig. 10A–D). Egg processes single-walled (without reticulation caused by labyrinthine layer) with dome-shaped basal part with distal part being thinner and elongated (Figs 10E–P, 11A–D). Internal septa are sometimes visible between basal and distal portion of the process in PCM (Fig. 10E–P). The basal portions of the processes are pierced by pores of uniform size (1.1– 1.8 µm in diameter) that are arranged alternately with dark thickenings around the process base (Figs 10A– D, 11B–D). In SEM, a reticulate internal structure is visible inside the pores and it seems to be a remnant of the reduced labyrinthine layer (Fig. 11B–D). The apical parts of the processes are flat but devoid of terminal discs and are covered with short, thin and flexible filaments (Figs 10E–P, 11E, F). Reproduction: The population is dioecious (the examination of specimens freshly mounted in Hoyer’s medium revealed testes filled with spermatozoa), but no secondary sexual dimorphism has been observed. DNA sequences: All obtained DNA sequences were represented by a single haplotype per each marker: 18S rRNA: MZ 463662, MZ 463663, MZ 463664. 28S rRNA: MZ 463677, MZ 463678, MZ 463679. ITS 2: MZ 463653, MZ 463654, MZ 463655. COI: MZ 461005, MZ 461006, MZ 461007. Differential diagnosis: Macrobiotus a. groenlandicus, known only from its locus typicus in Disko Island, Greenland, shares with M. a. ariekammensis the elongated primary branches of all claws, only one tooth in the third band of teeth in the oral cavity, and single-layer egg processes surrounded by a crown of pores and thickenings around their bases. However, it differs from M. a. ariekammensis, which is known only from a few localities in Svalbard (Norway) and Poland, by: the presence of a strong pronounced constriction in the first macroplacoid (first macroplacoid weakly constricted in M. a. ariekammensis), the presence of light-refracting dots resembling micropores on the egg surface (egg surface smooth in M. a. ariekammensis) and by the presence of fine granulation on the body cuticle visible in PCM and SEM (the body granulation absent or not visible in PCM in M. a. ariekammensis)., Published as part of Stec, Daniel, Vončina, Katarzyna, Kristensen, Reinhardt Møbjerg & Michalczyk, Łukasz, 2022, The Macrobiotus ariekammensis species complex provides evidence for parallel evolution of claw elongation in macrobiotid tardigrades, pp. 1067-1099 in Zoological Journal of the Linnean Society 195 on pages 1072-1076, DOI: 10.1093/zoolinnean/zlab101, http://zenodo.org/record/6994499

MACROBIOTUS KIRGHIZICUS TUMANOV, 2005 (TABLES 6, 7; FIGS 12–18) Material examined: Altogether 66 animals, and 15 eggs. Specimens mounted on microscope slides in Hoyer’s medium (53 animals + ten eggs), fixed on SEM stubs (ten + five), processed for DNA sequencing (three animals). Population locality: 41°32’37.98’’N, 75°10’2.28’’E; 2288 m a.s.l.: Kyrgyzstan, Chui, Kegeti, moss on rock. Specimens depositories: Altogether 53 animals (slides: KG.062.006. 1, 9–14, SEM stub: 18.07) and ten eggs (slides: KG.062. 5–8, SEM stub: 18.07) are deposited at the Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387, Kraków, Poland. Description of the Kyrgyz Republic population Animals (measurements and statistics in Table 6): Body whitish in adults and colourless in smaller individuals, after fixation in Hoyer’s medium transparent (Fig. 12A). After mounting in Hoyer’s medium eyes present in all specimens. Small, oval pores (0.5–0.8 µm in diameter), visible under PCM and SEM (Fig. 12B, C), scattered randomly on the entire body cuticle, including the external and internal surface of all legs (Fig. 13A–F). Extremely fine body granulation (c. 60 nm in diameter), visible only in SEM, present on the entire dorsocaudal cuticle (Fig. 12C). Patches of dense granulation present on the internal and external surfaces of all legs I– III and clearly visible both in PCM and SEM (Fig. 13A–D). A cuticular bulge, resembling a pulvinus, is present on the internal surfaces of legs I– III (Fig. 13C, D). Cuticular granulation on legs IV present and always clearly visible both in PCM and SEM (Fig. 13E, F). Claws slender, with flat and wide common tract, beginning with an evident stalk that connects the claws to the wide lunulae and ending with extremely elongated branches (especially the primary branch; Fig. 14A, B, D, E). Primary branches with indistinct accessory points, barely visible in PCM, but clearly visible in SEM (Fig. 14A, B, D, E). Lunulae I– III smooth (Fig. 14A, D), whereas lunulae IV with clear dentation (Fig. 14B, E). Mouth anteroventral with ten peribuccal lamellae (Fig. 16A, B). Bucco-pharyngeal apparatus of the Macrobiotus - type (Fig. 15A). Under PCM, only the second and third band of teeth visible, with the second band being faintly marked (Fig. 15B, C). However, under SEM, all of the three bands of teeth are visible, with the first band being situated at the base of peribuccal lamellae and composed of several irregular rows of small granular teeth surrounding the oral cavity (Fig. 16A, C). The second band of teeth is situated between the ring fold and the third band of teeth, and is comprises of small cones, barely visible in PCM (Figs 15B, 16B; note: in Fig 16B, only distal portion of these teeth are visible from behind the ring fold; due to unsuitable positioned specimen it was impossible to get better image in SEM). The teeth of the third band are located within the posterior portion of the oral cavity, between the second band of teeth and the buccal tube opening (Figs 15B–D, 16A, B). The third band of teeth is discontinuous and divided into a dorsal and a ventral portion. Under PCM, the dorsal teeth form a transversal ridge weakly divided into two granular teeth, whereas the ventral teeth are smaller and faintly visible as two separate lateral transverse ridges with granular/roundish thickening at their medial extremities (Fig 15B–D). In SEM, both the dorsal and the ventral portion of the third band of teeth are visible as one fused ridge with two evident teeth extending from the medial portion of the ridge (Fig 16A, B). Pharyngeal bulb spherical, with triangular apophyses, cuticular spikes, two rodshaped macroplacoids (macroplacoid sequence: 2 Eggs (measurements and statistics in Table 7): Eggs laid freely, whitish, spherical or slightly oval (Figs 17A, B, 18A). Although the spaces between processes are small, the surface between processes is of the persimilis - type, i.e. with the continuous smooth chorion, with few, randomly distributed pores (Figs 17A, B, 18B–D). Egg processes single-walled (without reticulation caused by labyrinthine layer) with domeshaped basal part and rigid spine-like distal part (Figs 17A–F, 18A–F). In PCM, the basal and distal portions are clearly separated from with single internal septum (Fig 17C–F). The bases of egg processes are pierced with pores of uniform size (0.3–0.7 µm in diameter), distributed evenly around the base and most often arranged in two rows (Figs 17A, B, 18B–F). In PCM, short, dark thickenings are sometimes visible around the process bases below or at the same level as the lower ring of pores (Fig 17A, B). The apical part of the processes is devoid of terminal discs and is covered with short, thin and flexible filaments (Figs 17C–F, 18A–F). Reproduction: The population is dioecious (the examination of specimens freshly mounted in Hoyer’s medium revealed testes filled with spermatozoa), but no secondary sexual dimorphism has been observed. DNA sequences: All obtained DNA sequences were represented by a single haplotype per each marker: 18S rRNA: MZ 463665, MZ 463666, MZ 463667. 28S rRNA: MZ 463671, MZ 463672, MZ 463673. ITS 2: MZ 463659, MZ 463660, MZ 463661. COI: MZ 461002, MZ 461003, MZ 461004. PHYLOGENY The phylogenetic reconstruction (Fig. 19) shows three well-supported distinct lineages constituting three separate genera within superclade I (sensu Stec et al., 2021a) of the family Macrobiotidae: the clade comprising Macrobiotus species, and further two monophyletic groups: one corresponding to the genus Mesobiotus Vecchi et al., 2016, and the other representing Sisubiotus Stec et al., 2021a (Fig. 19). Macrobiotus is divided into three well-supported subclades: A, B and C, sensu Stec et al. (2021a). All of the three newly found populations investigated in this study, M. a. ariekammensis, M. a. groenlandicus and M. kirghizicus, are nested in subclade A, which contains species of the Macrobiotus hufelandi morphogroup sensu Stec et al. (2021a) and Macrobiotus basiatus Nelson et al., 2020, which exhibits unique egg morphology. Subclade B comprises three species complexes delineated by Stec et al. (2021a). As in Stec et al. (2021a) and Vecchi & Stec (2021), the Macrobiotus pallari complex and the Macrobiotus pseudohufelandi complex are monophyletic also in the present study (Fig. 19). However, the Macrobiotus persimilis complex, which was monophyletic in the two earlier studies, appears to be paraphyletic in the current analysis (Fig. 19). Thus, further studies are needed to clarify the phyletic character of the latter species complex. Subclade C comprises species of the Macrobiotus hufelandi morphogroup. SPECIES DELIMITATION AND GENETIC DISTANCES The PTP analysis identified 49 and 55 putative species in ML and BI approach, respectively. The ASAP analysis, on the other hand, identified 48 putative species. These results are in line with the general inspection of the tree terminals and the morphological information that would suggest also 48 species among the ingroup taxa. However, for two out of the three newly found populations analysed in this study, both PTP approaches were not congruent with ASAP results. The PTP approaches indicated that M. a. ariekammensis and M. a. groenlandicus constitute a single species, whereas the ASAP analysis identified them as separate entities. Uncorrected pairwise distances between the three newly found populations analysed in this study are as follows: • 18S rRNA: 0.2% for M. a. ariekammensis and M. a. groenlandicus; 0.1% for M. a. ariekammensis and M. kirghizicus; 0.3% for M. a. groenlandicus and M. kirghizicus. • 28S rRNA: 0.1% for M. a. ariekammensis and M. a. groenlandicus; 0.3% for M. a. ariekammensis in PCM (E) and SEM (F). Filled flat arrowheads indicate granulation patch on the external leg surface, empty indented arrowheads indicate cuticular bulge (pulvini), filled indented arrowhead indicates cuticular bar, empty flat arrowheads indicate granulation patch on the internal leg surface. Scale bars in µm. and M. kirghizicus; 0.1% for M. a. groenlandicus and M. kirghizicus. • ITS2: 0.3% to 0.8% for M. a. ariekammensis and M. a. groenlandicus; 6.1% for M. a. ariekammensis and M. kirghizicus; 6.3% for M. a. groenlandicus and M. kirghizicus. • COI: 3.3% for M. a. ariekammensis and M. a. groenlandicus; 16.3% for M. a. ariekammensis and M. kirghizicus; 16.4% for M. a. groenlandicus and M. kirghizicus. Given the discrepancies between the PTP and ASAP species delineation results, shallow genetic divergence and low p -distances in COI and ITS2 between M. a. ariekammensis and M. a. groenlandicus, we interpreted the morphological differences between the two taxa as intraspecific variability, hence the later taxon is described here as a subspecies rather than a separate species., Published as part of Stec, Daniel, Vončina, Katarzyna, Kristensen, Reinhardt Møbjerg & Michalczyk, Łukasz, 2022, The Macrobiotus ariekammensis species complex provides evidence for parallel evolution of claw elongation in macrobiotid tardigrades, pp. 1067-1099 in Zoological Journal of the Linnean Society 195 on pages 1076-1090, DOI: 10.1093/zoolinnean/zlab101, http://zenodo.org/record/6994499, {"references":["Tumanov DV. 2005. Two new species of Macrobiotus (Eutardigrada, Macrobiotidae) from Tien Shan (Kirghizia), with notes on Macrobiotus tenuis group. Zootaxa 1043: 33 - 46.","Stec D, Vecchi M, Calhim S, Michalczyk L. 2021 a. New multilocus phylogeny reorganises the family Macrobiotidae (Eutardigrada) and unveils complex morphological evolution of the Macrobiotus hufeland i group. Molecular Phylogenetics and Evolution 160: 106987.","Vecchi M, Cesari M, Bertolani R, Jonsson KI, Rebecchi L, Guidetti R. 2016. Integrative systematic studies on tardigrades from Antarctica identify new genera and new species within Macrobiotoidea and Echiniscoidea. Invertebrate Systematics 30: 303 - 322.","Nelson DR, Adkins Fletcher R, Guidetti R, Roszkowska M, Grobys D, Kaczmarek L. 2020. Two new species of Tardigrada from moss cushions (Grimmia sp.) in a xerothermic habitat in northeast Tennessee (USA, North America), with the first identification of males in the genus Viridiscus. PeerJ 8: e 10251.","Vecchi M, Stec D. 2021. Integrative descriptions of two new Macrobiotus species (Tardigrada, Eutardigrada, Macrobiotidae) from Mississippi (USA) and Crete (Greece). Zoosystematics and Evolution 97: 281 - 306."]}

MACROBIOTUS ARIEKAMMENSIS ARIEKAMMENSIS WĘGLARSKA, 1965 (TABLES 2, 3; FIGS 1–4) Material examined: Seven animals and four eggs. Specimens mounted on microscope slides in Hoyer’s medium (four animals + four eggs), processed for DNA sequencing (three animals). Population locality: 78°40’33’’N, 16°38’49’’E; 208 m a.s.l.: Norway, Svalbard, Fortet; moss on soil. Specimen depositories: Four animals (slides: NO.393.393.2-4) and four eggs (slide: NO.393.01) are deposited at the Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387, Kraków, Poland. Description of the Norwegian population from Spitsbergen Animals (measurements and statistics in Table 2): Body transparent in smaller individuals (juveniles) and whitish in adults, after fixation in Hoyer’s medium transparent (Fig. 1A). Eyes present in all specimens, visible after mounting in Hoyer’s medium. Cuticular pores (0.7–1.2 µm in diameter) present, clearly visible under PCM (Fig. 1B–E) and scattered randomly on the entire body cuticle, including the external and internal surface of all legs. Patches of fine granulation present on internal and external surfaces of all legs I– III, as well as on legs IV and visible clearly in PCM (Fig. 1C–E). A pulvinus present on the internal surfaces of legs I– III (Fig. 1D). Granulation on legs IV is visible as a single large granulation patch on dorsal and lateral leg surfaces (Fig. 1E). Claws slender, with flat and wide common tract, beginning with a visible stalk that connects the claws to the wide lunulae and ending with elongated branches (especially the primary branch; Fig. 2A, B). Primary branches with distinct accessory points, visible in PCM (Fig. 2A, B). Lunulae I– III smooth (Fig. 2A), whereas lunulae IV with clear dentation (Fig. 2B, D). A single continuous cuticular bar and double muscle attachments visible on each leg I– III (Fig. 2C). Mouth anteroventral with ten peribuccal lamellae. Bucco-pharyngeal apparatus of the Macrobiotus - type (Fig. 3A). Under PCM, oral cavity armature extremely reduced to only one large tooth present in the dorsal portion of the third band of teeth, whereas other bands of teeth invisible or absent (Fig. 3A, B). Pharyngeal bulb spherical, with triangular apophyses, cuticular spikes, two rod-shaped macroplacoids (macroplacoid sequence: 2 Eggs (measurements and statistics in Table 3): Eggs laid freely, whitish, spherical or slightly oval (Fig. 4A, B). The spaces between processes are small, the surface between processes is of the persimilis - type, i.e. with the continuous smooth chorion, with no pores visible (Fig. 4A, B). Egg processes single-walled (without reticulation caused by the labyrinthine layer) with dome-shaped basal part and thinner and elongated distal portions (Fig. 4C–H). Internal septa are sometimes visible between the basal and the distal portion of the process in PCM (Fig. 4H). The basal portions of the processes are pierced by pores that are arranged alternately with dark thickenings and around the process base (Fig. 4A, B). The apical parts of the processes are flat but devoid of terminal discs, and are covered with short, thin and flexible filaments (Fig. 4C–H). Reproduction: The population is dioecious (the examination of specimens freshly mounted in Hoyer’s medium revealed testis filled with spermatozoa), but no secondary sexual dimorphism has been observed. DNA sequences: All obtained DNA sequences were represented by a single haplotype per each marker: 18S rRNA: MZ 463668, MZ 463669, MZ 463670. 28S rRNA: MZ 463674, MZ 463675, MZ 463676. ITS 2: MZ 463656, MZ 463657, MZ 463658. COI: MZ 460999, MZ 461000, MZ 461001., Published as part of Stec, Daniel, Vončina, Katarzyna, Kristensen, Reinhardt Møbjerg & Michalczyk, Łukasz, 2022, The Macrobiotus ariekammensis species complex provides evidence for parallel evolution of claw elongation in macrobiotid tardigrades, pp. 1067-1099 in Zoological Journal of the Linnean Society 195 on pages 1070-1072, DOI: 10.1093/zoolinnean/zlab101, http://zenodo.org/record/6994499, {"references":["Weglarska B. 1965. Die Tardigraden (Tardigrada) Spitzbergens. Acta Zoologica Cracoviensia 11: 43 - 52."]}

BARBARIA PAUCIGRANULATA WILAMOWSKI, VONČINA, GĄSIOREK & MICHALCZYK,SP. NOV. (FIGS 1–3, 7I, 8I, 9I, 10I, 11K, L; TABLES 3, 4) Zoobank registration: u r n: l s i d: z o o b a n k. org:act: A11E6BDF-7E2A-4F0A-BD6A-9BC87FCE147A Morphometric data: w w w. t a r d i g r a d a. n e t / register/0109.htm Type material: Holotype (adult female, slide AR.303.02) and 12 paratypes (eight adult females on slides AR.302.02, AR.303.01, 3, 5–6 and four juveniles on slides AR.303.03–4). Found together with B. ollantaytamboensis. Type locality: 24°47′14″S, 65°43 ′30″W, 2150 m asl: Argentina, Salta Province, Rosario de Lerma Department, vicinity of Río Rosario; lichen on rock in a shrubland (see also Table 1). Etymology: From Latin paucus, few, and granulatus, grained, alluding to the scarcity of epicuticular granulation on the dorsal plates. An adjective in nominative singular. Description: Adult females (i.e. from the third instar onwards, measurements in Table 3). Dark orange body with large red eyes; the pigment and eyes dissolve quickly after mounting in Hoyer’s medium. Body massive with stumpy limbs (Figs 1A, B, 2). Cylindrical, Echiniscus - type cephalic papillae (secondary clavae) and (primary) clavae; cirri embedded in bulbous cirrophores (Fig. 3D). Cirrus A is short ( Dorsal plate sculpturing of the bigranulata - type, comprising minute, poorly developed pillars (pseudogranulation) and pores (Figs 1C, 2, 3A–C, 7I, 8I, 9I, 10I). Pillars are densely packed and additionally interconnected by thin striae in the scapular (Fig. 7I) and caudal (terminal) plates (Fig. 10I). Pores are slightly larger in the scapular plate, median plate1, posterior portion of median plate 2 and centroposterior portions of paired segmental plates compared with posterolateral portions of paired segmental plates and the caudal plate (Figs 1, 2); pores of similar diameter are rarely present in the entire dorsum. Pores are always absent in the anterior portion of median plate 2 (Fig. 8I), paired segmental plates (Fig. 9I) and the entirety of median plate 3; and all these areas are covered with epicuticular, multangular granules. Lateralmost portions of the scapular and paired segmental plates can be poreless or with single minute pores (Figs 1A, B, 2). The cephalic plate is large, with a pronounced chalice-shaped anterior incision and with only pillars in the posterior portion of the plate. A broad and strongly sclerotized cervical plate is divided into sculptured anterior portion and smooth posterior portion bordering with the scapular plate (Figs 1A, 2A). Lateral sutures in the scapular plate demarcate lateralmost, trapezoidal portions (Figs 1A, B, 2B). Median plates 1 and 3 are unipartite (the latter with strongly developed granules), median plate 2 is bipartite (Fig. 8I). Paired segmental plates are without transverse unsculptured bands, as epicuticular granules of anterior portion transition gradually into pillars of the posterior portions (Fig. 9I). The caudal plate with short, poorly sclerotized incisions and no signs of faceting (Figs 1A, 2, 10I). Ventral cuticle with minute endocuticular pillars (Fig. 11K) distributed evenly throughout the entire venter, lacking plates, beside of rarely developed subcephalic plates (Fig. 3D). Sexpartite gonopore placed anteriorly to a trilobed anus between legs IV. Pedal plates without pores, their sculpturing consists of poorly developed endocuticular pillars formed as belts in the central portions of the legs (Figs 1A, B, 11K, L). Thick pulvini on outer side of all legs (Figs 1A, B, 2B). Dentate collar IV has numerous irregular short teeth (Fig. 11L). A small, elongated spine I and a tubby papilla IV (Figs 1B, 2B, 11K, L). Claws slightly heteronych with claws IV (Fig. 3F) higher and more robust than claws I–III (Fig. 3E). Internal claws IV have needle-like spurs more divergent from branches compared to spurs I– III (Fig. 11K, L). Cuticular bars below claw bases on the inner side of legs present. Buccal apparatus with a rigid tube and round pharynx containing placoids. Flexible stylet supports present. Juveniles (i.e. the second instar, measurements in Table 4). Clear morphometric gap between juveniles and adult females. Qualitatively alike adult females, excluding the lack of gonopore. Adult males, larvae or eggs not found. Differential diagnosis: The new species B. paucigranulata is distinguished from its congeners (alphabetically): • Barbaria bigranulata, by the distribution of pores in plates [absent in the anterior portion of median plate 2 (Fig. 8I), paired segmental plates (Fig. 9I) and the entirety of median plate 3 in B. paucigranulata vs. present in the anterior portion of m2 (Fig. 8A), paired segmental plates (Fig. 9A) and the entirety of m 3 in B. bigranulata], the shape of papilla IV [tubby in B. paucigranulata (Fig. 11L) vs. elongated in B. bigranulata (Fig. 11B)] and the primary spur morphology [needle-like and adjacent to the claw branch in B. paucigranulata (Fig. 11K, L) vs. robust, hook-shaped and divergent from the claw branch in B. bigranulata (Fig. 11A, B)]. • Barbaria charrua, by the shape of papilla IV [tubby in B. paucigranulata (Fig. 11L) vs. elongated in B. charrua (Fig. 11D)] and by the primary spurs [present in B. paucigranulata (Fig. 11K, L) vs. typically absent in B. charrua (Fig. 11C, D)]. • Barbaria danieli, by the shape of papilla IV [tubby in B. paucigranulata (Fig. 11L) vs. elongated in B. danieli (Fig. 12)] and by the primary spurs [present in B. paucigranulata (Fig. 11K, L) vs. absent in B. danieli (Fig. 11O)]. • Barbaria ganczareki, by the dorsal sculpturing [both pillars and pores easily identifiable in B. paucigranulata (Figs 7I, 8I, 9I, 10I) vs. pillars so poorly developed that pores become the dominant element of the sculpture in B. ganczareki (Figs 7C, 8D, 9C, 10C)], the pores in the subcephalic region (absent in B. paucigranulata vs. present in B. ganczareki) and in pedal plates (absent in B. paucigranulata vs. present in B. ganczareki) and by the primary spur morphology [needle-like and adjacent to the claw branch in B. paucigranulata (Fig. 11K, L) vs. robust, hook-shaped and divergent from the claw branch in B. ganczareki, fig. 21–22 in Michalczyk & Kaczmarek (2007)]. • Barbaria hannae, by the dorsal sculpturing [no smooth plate portions in B. paucigranulata (Figs 8I, 9I, 10I) vs. thickened plate portions devoid of sculpturing present in B. hannae (Figs 8E, 9D, E, 10D, E)] and the primary spur morphology [needle-like and adjacent to the claw branch in B. paucigranulata (Fig. 11K, L) vs. robust, hook-shaped and divergent from the claw branch in B. hannae (Fig. 11P)]. • Barbaria jenningsi, by the cirrus A length (B. paucigranulata vs.> 50% of the body length in B. jenningsi), the type of perforation in the dorsal plates [pores in B. paucigranulata (Fig. 7I) vs. pseudopores in B. jenningsi (Fig. 7E, F)] and by the primary spur morphology [slightly heteronych, needle-like and adjacent to the claw branch in B. paucigranulata (Fig. 11K, L) vs. fully heteronych, robust, hook-shaped and divergent from the claw branch in B. jenningsi (Fig. 11E, F)]. • Barbaria madonnae, by striae between pillars in the scapular and the caudal plate [present in B. paucigranulata (Figs 7I, 10I) vs. absent in B. madonnae (Figs 7G, 10G)], the shape of papilla IV [tubby in B. paucigranulata (Fig. 11L) vs. elongated in B. madonnae (Fig. 11H)] and the primary spur morphology [needle-like and adjacent to the claw branch in B. paucigranulata (Fig. 11K, L) vs. robust, hook-shaped and divergent from the claw branch in B. madonnae (Fig. 11G, H)]. • Barbaria ollantaytamboensis, by the distribution of pores in plates [absent in the anterior portion of median plate 2 (Fig. 8I), paired segmental plates (Fig. 9I) and the entirety of median plate 3 in B. paucigranulata vs. present in the anterior portion of m2 (Fig. 8H), paired segmental plates (Fig. 9H) and the entirety of m 3 in B. ollantaytamboensis] and claw isomorphy [slightly heteronych (heteromorphic) in B. paucigranulata (Fig. 11K, L) vs. isonych (homomorphic) in B. ollantaytamboensis (Fig. 11I, J)]. • Barbaria quitensis, by the type of perforation in the dorsal plates [pores in B. paucigranulata (Figs 7I, 8I, 9I, 10I) vs. pseudopores in B. quitensis (Figs 7J, 8J, 9J, 10J)] and the distribution of pores/pseudopores [scarcer on lateralmost portions of the caudal plate (Fig. 10I) in B. paucigranulata vs. roughly equally distributed in all portions of the caudal plate (Fig. 10J) in B. quitensis]. • Barbaria ranzii, by the cirrus A length (B. paucigranulata vs.> 50% of the body length in B. ranzii), the distribution of pores in plates [absent in the anterior portion of median plate 2 (Fig. 8I), paired segmental plates (Fig. 9I) and the entirety of median plate 3 in B. paucigranulata vs. present in the anterior portion of m2 (Fig. 8K), paired segmental plates (Fig. 9K) and the entirety of m 3 in B. ranzii] and the by secondary spurs directed upwards on external claws IV [absent in B. paucigranulata (Fig. 11L) vs. present in B. ranzii, Fig. 11R]. • Barbaria weglarskae, by the cirrus A length (B. paucigranulata vs.> 50% of the body length in B. weglarskae) and by the primary spur morphology [needle-like and adjacent to the claw branch in B. paucigranulata (Fig. 11K, L) vs. robust, hook-shaped and divergent from the claw branch in B. weglarskae (Fig. 11M, N)].

BARBARIA WEGLARSKAE GĄSIOREK, WILAMOWSKI, VONČINA & MICHALCZYK, SP. NOV. (FIGS 4, 7L, 8L, 9L, 10L, 11M, N; TABLE 5) Zoobank registration: u r n: l s i d: z o o b a n k. org:act: F083907B-741F-48C0-A127-2FC28482C9AA Morphometric data: w w w. t a r d i g r a d a. n e t / register/0110.htm Ty p e m a t e r i a l: Holotype (adult female, slide AR.059.04) and two paratypes (adult females, slides AR.059.01, 05). Type locality: 48°25′42″S, 71°44′48″W, 803 m asl: Argentina, Patagonia, Santa Cruz Province, Río Chico Department, vicinity of La Florida; lichen from on in the Andean Patagonian forest (see also Table 1). Etymology: A patronym honouring Professor Barbara Węglarska, 20.02.1922 – 02.10.2020, whose death left a void in the community of tardigradologists. A noun in the genitive case. Description: Adult females (i.e. from the third instar onwards, measurements in Table 5). Orange body with large, red eyes; the entire pigment and eyes dissolve quickly after mounting in Hoyer’s medium. Body massive (Fig. 4A). Cylindrical, Echiniscus - type cephalic papillae (secondary clavae) and (primary) clavae; cirri embedded in bulbous cirrophores. Cirrus A is long (> 50% of the body length) and with evident, conical cirrophore (Fig. 4A, B). Dorsal plate sculpturing of the bigranulata - type, composed of pillars present in all plate portions (pseudogranulation) and pores and pseudopores present in different elements of armour (Figs 4A, B, 7L, 8L, 9L, 10L). Pseudopores can be present or absent exclusively in the anterior portion of the median plate 2 and paired segmental plates and the entirety of median plate 3 (Fig. 4A, B). Minute pores of equal size are regularly distributed in the remaining plate portions (Figs 4A, B, 7L, 8L, 9L, 10L). The cephalic plate large, with a pronounced chalice-shaped anterior incision and lateral sutures demarcating roughly triangular lateralmost portions of the plate (Fig. 4A, B). Thin cervical plate with developed pillars and pseudopores. Lateral sutures in the scapular plate demarcate lateralmost, rectangular portions with identical sculpturing as on the rest of the plate (Fig. 4A, B). Median plates 1 and 3 unipartite (the latter strongly reduced and partially covered by the caudal plate), median plate 2 bipartite (Figs 4A, B, 8L). Paired segmental plates with broad, transverse, unsculptured bands (Figs 4A, B, 9L). The caudal plate with short, poorly sclerotized incisions clearly joined by a transversal suture (Figs 4A, B, 10L). Ventral cuticle with minute endocuticular pillars distributed evenly throughout the entire venter; a pair of small, subcephalic plates present (Fig. 4C–D). Sexpartite gonopore (Fig. 4E) placed anteriorly to a trilobed anus between legs IV. Pedal plates I–IV with evident pillars and pseudopores (Figs 4A, 11M, N). Evident pulvini on outer sides of all legs. Dentate collar IV with numerous irregular short teeth (Fig. 11N). A tiny spine I and a tubby papilla IV (Fig. 11N). Claws slightly heteronych, because primary spurs on internal claws IV are positioned higher than those on claws I–III (Fig. 11M, N). The shape and angle at which spurs diverge from branches are almost identical on all limbs. Cuticular bars below claw bases on the inner side of legs present. Buccal apparatus with a rigid tube and round pharynx containing placoids. Lacking stylet supports. Adult males, juveniles, larvae or eggs not found. Differential diagnosis: There are only two other species of Barbaria with a cirrus A /body length ratio> 50% [the titles and values in the last five rows of table 1 in Michalczyk & Kaczmarek (2007) are mismatched in the case of sexes treated separately, but the ratio statistics for all measured specimens of B. ganczareki stands valid: min = 15%, max = 23%, mean = 19%]: B. jenningsi and B. ranzii, but B. weglarskae can be distinguished from: • Barbaria jenningsi, by the type of perforation in the dorsal plates [dominant pores in B. weglarskae (Fig. 7L) vs. pseudopores in B. jenningsi (Figs 7E, F, 8F, 9F, 10F)] and claw isomorphy [anisonych/ slightly heteronych in B. weglarskae (Fig. 11M, N) vs. strongly heteronych in B. jenningsi (Fig. 11E, F)]. • Barbaria ranzii, by the pedal plate sculpturing [with evident pillars in B. weglarskae (Fig. 11M, N) vs. without pillars in B. ranzii (Fig. 11R)], the shape of papilla IV [tubby in B. weglarskae (Fig. 11N) vs. elongated in B. ranzii] and by the presence of secondary spurs directed upwards on external claws IV [absent in B. weglarskae (Fig. 11N) vs. present in B. ranzii (Fig. 11R)]. MOLECULAR PHYLOGENY Phylogeny based on the five concatenated markers brought fully resolved relationships between all eight analysed species of Barbaria, which form clades characterized by low intraspecific and large interspecific genetic variability (Fig. 5). The topology is as follows: B. madonnae is a sisterspecies to all other sequenced Barbaria spp., which are clustered in two clades: the first comprising (B. paucigranulata (B. danieli + B. charrua)) and the second grouping ((B. weglarskae + B. jenningsi) + (B. ollantaytamboensis + B. bigranulata)). INTRA- AND INTERSPECIFIC GENETIC VARIABILITY Regarding COI sequences deposited in GenBank, the data are available only for B. bigranulata and B. jenningsi. COI p -distances between populations of B. bigranulata and the previously published data for a population from Chile (HM193406; Jørgensen et al., 2011) ranged between 2.6 and 2.9% (alignment length = 585 bp). Analogous index for the pair B. weglarskae – B. jenningsi (KP013596; Velasco-Castrillón et al., 2015) was 18.9% (alignment length = 472 bp). More than one haplotype per marker has been found for all markers, but only in a few species. The intraspecific p -distances are as follows: 18S rRNA: 0.1% (in B. bigranulata and B. charrua); 28S rRNA: 0.1–0.4% (B. bigranulata, B. ollantaytamboensis); ITS 1: 0.5 % (B. bigranulata), 0.1 – 1.0 % (B. charrua); ITS2: 0.2% (B. bigranulata), 0.2–0.4% (B.ollantaytamboensis); COI: 0.1–2.3% (B. bigranulata) and 0.7% (B. charrua). Interspecific p -distances in the analysed dataset are as follows: • 18S rRNA: 0.0–2.5% (1.2% on average), with the most similar being B. charrua (MZ820796) and B. danieli (MZ820800); and the least similar being B. madonnae (MZ820803) and B. ollantaytamboensis (MZ820804). • 28S rRNA: 0.0–4.3% (2.4% on average), with the most similar being B. charrua (MZ820814) and B. danieli (MZ820818); and the least similar being B. madonnae (MZ820821) and B. ollantaytamboensis (MZ820823). • ITS1: 0.3–10.3% (5.5% on average), with the most similar being B. charrua (MZ820833) and B. danieli (MZ820836); and the least similar being B. madonnae (MZ820839) and B. bigranulata (MZ820828). • ITS2: 1.6–10.8% (8.1% on average), with the most similar being B. charrua (MZ822380) and B. danieli (MZ822384); and the least similar being B. danieli + B. madonnae (MZ822384, MZ822387) and B. ollantaytamboensis (MZ822388 –91). • COI: 9.1–20.4% (16.0% on average), with the most similar being B. charrua (MZ820850) and B. danieli (MZ820853); and the least similar being B. ollantaytamboensis (MZ820855) and B. weglarskae (MZ820860). MORPHOLOGICAL EVOLUTION Mapping morphological traits on to the phylogeny suggests that the ancestor of Barbaria was most probably covered with uniform dorsal sculpturing comprising both pillars and pores (Fig. 6A) and welldelimited pedal plates on legs I–III with densely packed pillars and pseudopores (Fig. 6B). Its papillae on legs IV were elongated (Fig. 6C), meaning that they were much longer than wide. Internal claws were exhibiting heteronychy or lacking primary spurs (Fig. 6D). In other words, among the extant species, B. bigranulata is morphologically overall the most similar to the last common ancestor of the analysed species., Published as part of Gąsiorek, Piotr, Wilamowski, Andrzej, Vončina, Katarzyna & Michalczyk, Łukasz, 2022, Neotropical jewels in the moss: biodiversity, distribution and evolution of the genus Barbaria (Heterotardigrada: Echiniscidae), pp. 1037-1066 in Zoological Journal of the Linnean Society 195 on pages 1048-1054, DOI: 10.1093/zoolinnean/zlab087, http://zenodo.org/record/6993173, {"references":["Michalczyk L, Kaczmarek L. 2007. Echiniscus ganczareki, a new species of Tardigrada (Heterotardigrada: Echiniscidae, bigranulatus group) from Costa Rica. Zootaxa 1471: 15 - 25.","Jorgensen A, Mobjerg N, Kristensen RM. 2011. Phylogeny and evolution of the Echiniscidae (Echiniscoidea, Tardigrada) - an investigation of the congruence between molecules and morphology. Journal of Zoological Systematics and Evolutionary Research 49 (S 1): 6 - 16.","Velasco-Castrillon A, McInnes SJ, Schultz MB, Arroniz- Crespo M, D'Haese CA, Gibson JAE, Adams BJ, Page TJ, Austin AD, Cooper SJB, Stevens MI. 2015. Mitochondrial DNA analyses reveal widespread tardigrade diversity in Antarctica. Invertebrate Systematics 29: 578 - 590."]}

Mesobiotus dilimanensis, new species (Tables 3, 4, Figs. 1–5) Material examined: 65 animals (including eight simplex), 47 eggs, and 7 empty chorions mounted on microscope slides in Hoyer's medium, 5 eggs fixed on SEM stubs, and 8 specimens processed for DNA sequencing. Type locality: 14°39′40″N, 121°04′07″E; 76 m asl: Philippines, Quezon City, Diliman, University of the Philippines, A. Roces St.; moss on a rock; September 2015; coll. Lowelyn Itang. Etymology: The species is named after Diliman, the district in Quezon City, Philippines, where it was discovered. Type depositories: Holotype: slide PH.006.10 with six paratypes; 58 paratypes (slides: PH.006. *, where the asterisk can be substituted by any of the following numbers: 02–03, 11–16), 47 eggs (slides: PH.006. *: 5–9, 17); seven empty chorions (slides: PH.006. *: 01, 04) are deposited at the Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387, Kraków, Poland.

Itang, Lowelyn A. M., Stec, Daniel, Mapalo, Marc A., Mirano-Bascos, Denise, Michalczyk, Łukasz (2020): An integrative description of Mesobiotus dilimanensis, a new tardigrade species from the Philippines (Eutardigrada: Macrobiotidae: furciger group). Raffles Bulletin of Zoology 68: 19-31, DOI: 10.26107/RBZ-2020-0003

Genus Microhypsibius Thulin, 1928 DIAGNOSIS. ��� Same as for the family Microhypsibiidae. ETYMOLOGY (NOT PROVIDED IN THE ORIGINAL DESCRIPTION). ��� The name was most likely chosen to underline the minute size of the family members. COMPOSITION. ��� Microhypsibius bertolanii Kristensen, 1982, M. japonicus Ito, 1991, M. minimus Kristensen, 1982, M. truncatus Thulin, 1928 (type species). REMARKS See Kristensen (1982) for the most current depiction of the genus Microhypsibius., Published as part of G��siorek, Piotr, Morek, Witold, Stec, Daniel, Blagden, Brian & Michalczyk, ��ukasz, 2019, Revisiting Calohypsibiidae and Microhypsibiidae: Fractonotus Pilato, 1998 and its phylogenetic position within Isohypsibiidae (Eutardigrada: Parachela), pp. 71-89 in Zoosystema 41 (6) on page 84, DOI: 10.5252/zoosystema2019v41a6, http://zenodo.org/record/3718524, {"references":["THULIN G. 1928. - Uber die phylogenie und das system der tardigraden. Hereditas 11: 207 - 266.","KRISTENSEN R. M. 1982. - New aberrant eutardigrades from homothermic springs on Disko Island, West Greenland. In: Nelson, D. R. (ed.), Proceedings of the Third International Symposium on the Tardigrada, 1980, 203 - 220."]}

Fractonotus gilvus (Biserov, 1986) n. comb. Isohypsibius gilvus Biserov, 1986: 984. REMARK Elliptical organs not always visible due to developed sculpturing in the cephalic portion of the body.

Genus Fractonotus Pilato, 1998 Fractonotus Pilato, 1998: 132. AMENDED DIAGNOSIS. ��� Small isohypsibiid (rarely exceeding 200 ��m, Fig. 1). Cephalic elliptical organs present (Fig. 7 A). Dorsum and limbs covered with densely arranged, blunt protuberances. Six peribuccal lobes present (Fig. 6 A). Apophyses for the insertion of stylet muscles (AISM) asymmetrical with respect to the frontal plane ��� the dorsal apophysis subdivided into two portions: the anterior portion in the shape of a slightly convex longitudinal thickening (and the posterior portion as weakly developed blunt hook); the ventral apophysis in the shape of a mild and long ridge (Fig. 9 A). Very large pharyngeal apophyses and placoids in the muscle pharynx. Stylet furcae of the Fractonotus - type, i.e. with broad, trapezoid base, thin arms and rounded apices (Figs 8 D, 10 A). Claws of the modified Isohypsibius - type, with triangular bases and strongly curved claw branches (Fig. 12 A, B). Accessory points symmetrical or occasionally asymmetrical. Smooth eggs laid in exuviae. DIFFERENTIAL DIAGNOSIS. ��� Fractonotus shares pronounced cuticular sculpturing with some species of six other parachelan genera: Calohypsibius Thulin, 1928, some Ramazzottius Binda & Pilato, 1986, Hypsibius Ehrenberg, 1848, Pilatobius Bertolani, Guidetti, Marchioro, Altiero, Rebecchi, Cesari, 2014, Doryphoribius Pilato, 1969 and Isohypsibius Thulin, 1928, but it can be readily distinguished from these genera by the morphology of the stylet furcae (square/trapezoid in Fractonotus vs narrower and more rectangular in the latter genera; compare Figs 7 B, D; 10 A-C). Furthermore, Fractonotus differs from Ramazzottius, Hypsibius and Pilatobius by having Isohypsibius -like claws (claws of the latter genera are of the Hypsibius or of the modified Hypsibius- type). Moreover, the genus differs specifically from: ��� Calohypsibius Thulin, 1928 (Hypsibioidea: Calohypsibiidae), by having a different type of cuticular sculpture (roundish or oval tubercles covering the entire dorsum and limbs with smooth dorsal pebble-shaped plaques in Fractonotus, Fig. 5 A-D vs multangular or star-like tubercles and occasional spines arranged less densely in Calohypsibius, Fig. 5 E, F), different structures surrounding the mouth opening (six soft and large peribuccal lobes in Fractonotus, Fig. 6 A vs six small well defined papulae in Calohypsibius, Fig. 6 B), a reversed morphology of the dorsal apophysis for the insertion of stylet muscles (an anterior thickening and a tiny posterior hook in Fractonotus, Fig. 7 E-G vs an anterior large blunt hook and a slight posterior thickening in Calohypsibius, Fig. 9 A, B), and by claw morphology (modified Isohypsibius - type claws with pseudolunulae, triangular bases, and elongated, strongly curved branches with conspicuous accessory points in Fractonotus, Figs 11 A-D; 12 A, B vs very small, rigid, with the base width equal to the sum of the primary and secondary branch widths, with the vertical septum between the two branches, and without pseudolunulae in Calohypsibius, Figs 11 E; 12 C, D). ��� Doryphoribius Pilato, 1969 (Isohypsibioidea: Isohypsibiidae), by the presence of elliptical organs on the head (absent in Doryphoribius), and by the absence of the ventral lamina on the buccal tube (ventral lamina present in Doryphoribius). ��� Isohypsibius Thulin, 1928 (Isohypsibioidea: Isohypsibiidae), by the presence of elliptical organs on the head (absent in Isohypsibius), a different shape of AISM (asymmetrical with respect to the frontal plane in Fractonotus, Fig. 7 E vs ridges symmetrical with respect to the frontal plane Isohypsibius, Figs 7 H, I; 9 A, C), and by the claw morphology (modified Isohypsibius - type claws with triangular bases, especially well-marked on the fourth pair of legs, in Fractonotus vs Isohypsibius - type claws with stalk-like bases in Isohypsibius, Figs 11 H, I; 12 E, F). COMPOSITION AND REMARKS Currently only three species, Fractonotus caelatus (the nominal taxon), F. verrucosus n. comb. and F. gilvus n. comb., are assigned to the genus. The three species are placed in the single genus because they share a number of taxonomically important traits: AISM shape, the presence of elliptical cephalic organs, two granular macroplacoids in the pharynx, and the type of cuticular sculpturing. On the other hand, Pilato (1998) described the claws of F. caelatus as of the Microhypsibius type, whereas claws in F. verrucosus n. comb. and F. gilvus n. comb. are closer to Isohypsibius type claws. Therefore, given the differences in claw morphology, there is a possibility that F. verrucosus n. comb. and F. gilvus n. comb. belong to a new isohypsibioid genus, and are only delusively similar to Fractonotus due to convergent evolution in the remaining traits. Nevertheless, the majority of traits suggest that all three species should be placed in Fractonotus. Biserov (1986) misinterpreted the AISM of F.gilvus n. comb. (Fig. 3 therein) as Isohypsibius - type AISM, but our observations of the type material confirm that the species has the AISM of the Fractonotus - type. However, there are more Isohypsibius and Hypsibius species, that exhibit cuticular sculpturing similar to that of Fractonotus. Thus, they may in fact belong to Fractonotus rather than Isohypsibius or Hypsibius. Nevertheless, we refrained from enacting more transfers, as a careful examination of individuals is needed to confirm whether these species, in addition to cuticular sculpturing, also exhibit other characteristics of Fractonotus., Published as part of G��siorek, Piotr, Morek, Witold, Stec, Daniel, Blagden, Brian & Michalczyk, ��ukasz, 2019, Revisiting Calohypsibiidae and Microhypsibiidae: Fractonotus Pilato, 1998 and its phylogenetic position within Isohypsibiidae (Eutardigrada: Parachela), pp. 71-89 in Zoosystema 41 (6) on page 76, DOI: 10.5252/zoosystema2019v41a6, http://zenodo.org/record/3718524, {"references":["PILATO G. 1998. - Microhypsibiidae, new family of eutardigrades, and description of the new genus Fractonotus. Spixiana 21 (2): 129 - 134.","THULIN G. 1928. - Uber die phylogenie und das system der tardigraden. Hereditas 11: 207 - 266.","PILATO G. 1969 a. - Evoluzione e nuova sistemazione degli Eutardigrada. Bolletino di Zoologia 36: 327 - 345.","BISEROV V. I. 1986. - Terrestrial water bears from the North Caucasus. 2. Eutardigrada. Zoologicheskii Zhurnal 65 (7): 981 - 993."]}

Genus Calohypsibius Thulin, 1928 Calohypsibius Thulin, 1928: 238. DIAGNOSIS. ��� Same as for the family Calohypsibiidae. ETYMOLOGY (NOT PROVIDED IN THE ORIGINAL DESCRIPTION). ��� After Schuster et al. (1980), from Ancient Greek ����^��ς (k��llos) = beauty; derivatives calli-, callo- mean beautiful, pretty. Thulin most likely wanted to highlight the cuticular sculpturing, which is exceptionally complex, rich and unusual among Eutardigrada. COMPOSITION AND REMARKS Currently only three species, namely C. maliki Michalczyk & Kaczmarek, 2005 (Fig. 4 B), C. ornatus (Richters, 1900) (type species; Figs 3 C, D, 4 A), and C. schusteri Nelson & McGlothlin, 1996 (Fig. 4 C), are ascribed to the family. Nevertheless, Barto�� (1940) already described the remarkable variability within European records of the ornatus complex, which raises justifiable concerns as to whether C. ornatus encompasses only a single species. Further, as suggested by Pilato (1998), it is very likely that the genus comprises many more species than currently recognised. However, a systematic integrative study based on extensive sampling is needed to verify this hypothesis., Published as part of G��siorek, Piotr, Morek, Witold, Stec, Daniel, Blagden, Brian & Michalczyk, ��ukasz, 2019, Revisiting Calohypsibiidae and Microhypsibiidae: Fractonotus Pilato, 1998 and its phylogenetic position within Isohypsibiidae (Eutardigrada: Parachela), pp. 71-89 in Zoosystema 41 (6) on page 83, DOI: 10.5252/zoosystema2019v41a6, http://zenodo.org/record/3718524, {"references":["THULIN G. 1928. - Uber die phylogenie und das system der tardigraden. Hereditas 11: 207 - 266.","SCHUSTER R. O., NELSON D. R., GRIGARICK A. A. & CHRISTENBERRY D. 1980. - Systematic criteria of the Eutardigrada. Transactions of the American Microscopical Society 99: 284 - 303.","MICHALCZYK L. & KACZMAREK L. 2005. - The first record of the genus Calohypsibius Thulin, 1928 (Eutardigrada: Calohypsibiidae) from Chile (South America) with a description of a new species Calohypsibius maliki. New Zealand Journal of Zoology 32: 287 - 292. https: // doi. org / 10.1080 / 03014223.2005.9518420","RICHTERS F. 1900. - Beitrage zur Kenntnis der Fauna der Umgebung von Frankfurt a. M. Bericht der Senckenbergischen Naturforschenden gesellschaft in Frankfurt am Main 21 - 44.","NELSON D. R. & MCGLOTHLIN K. L. 1996. - A new species of Calohypsibius (Phylum Tardigrada, Eutardigrada) from Roan Mountain, Tennessee-North Carolina, U. S. A. Zoological Journal of the Linnean Society 116: 167 - 174. https: // doi. org / 10.1006 / zjls. 1996.0014","BARTOs E. 1940. - Uber die Variation der Art Hypsibius ornatus Richt. (Tardigrada). Zoologische Jahrbucher abteilung fur Systematik Okologie und Geographie der Tiere 73: 369 - 384.","PILATO G. 1998. - Microhypsibiidae, new family of eutardigrades, and description of the new genus Fractonotus. Spixiana 21 (2): 129 - 134."]}

Fractonotus verrucosus (Richters, 1900) n. comb. Macrobiotus ornatus var. verrucosus Richters, 1900: 41 (terra typica: Taunus, Germany). Macrobiotus scabrosus Murray, 1911: 10 (locus typicus: Clare Island, Ireland). Hypsibius verrucosus – Thulin 1911: 29 (Kiruna, Lapland, Sweden). — Marcus 1928: 180 (Vannsee, Berlin, Germany). — Cuénot 1932: 77 (the Vosges, France and Switzerland). — da Cunha 1947, 1948: 6, 2 (Serra d’Arga, Serra do Buçaco, Serra da Estrela, Serra da Lousã, Portugal). Calohypsibius verrucosus – Thulin 1928: 239 (Sweden). Calohypsibius scabrosus Thulin, 1928: 239 (Sweden). Hypsibius scabrosus Cuénot, 1932: 77 (the Vosges, France and Switzerland). — da Cunha 1947, 1948: 6, 2 (Serra d’Arga, Serra do Buçaco, Serra da Estrela, Serra da Lousã, Portugal). Hypsibius (Calohypsibius) verrucosus – Marcus 1936: 285 (Schwarzwald, Germany). — Franceschi 1951-1952: 12 (Val Camonica, Italy). — Mihelčič 1953: 247 (Tirol, Austria). — Fontoura 1981: 18 (Viseu, Arga, Amarante, Portugal). Hypsibius placophorus da Cunha, 1943: 1 (locus typicus: Cabril do Ceira, Portugal); 1947, 1948: 2, 2 (Serra d’Arga, Serra do Buçaco, Serra da Estrela, Serra da Lousã, Portugal) n. syn. LOCALITIES. — Scotland. Creag Meagaidh (56°57’10’’ N, 4°30’35’’ W; 291 m a.s.l.; collection date: 1.X.2014), lichens from moorland rocks; Scotland, Hebrides, Isle of Lewis, Loch nan Muilne (58°21’08’’ N, 6°35’14’’ W; 27 m a.s.l.; collection date: 29.VII.2015), moss and lichen mix from stones on the lakeshores; Invermoriston, Loch Ness (57°12’39’’ N, 4°35’59’’ W; 20 m a.s.l.; 25.X.2015; Brian Blagden leg.), moss and lichen mix from stones on the lakeshores. MATERIAL EXAMINED. — 23 individuals, UJ (19 specimens, including one simplex, on slides GB.005.03-12, GB.008.01-3, GB.028.01- 2 and 4 specimens on two SEM stubs); 2 individuals, MNHN (slides GB.005.01-2); 3 individuals, NHMD (slides GB.008.04- 5); 2 individuals, UAM (slides GB.028.03-4); 1 individual, CU (slide GB.028.02). ETYMOLOGY (NOT PROVIDED IN THE ORIGINAL DESCRIPTION). — The name most likely refers to the rugged cuticular surface of the species (from Latin verruca = wart). DIFFERENTIAL DIAGNOSIS. — Fractonotus verrucosus n. comb. can be distinguished from F. caelatus and F. gilvus n. comb. (Fig. 2 A, B) by the presence of plaques (absent in the latter species). It also differs from F. gilvus n. comb. by shorter, stouter claws (anterior and posterior primary branches 4.1-6.4 μm [N =10] and 4.3-7.4 μm long [N =18], respectively, in Fractonotus verrucosus n. comb. vs 7.0- 13.0 μm [N =21] and 10.5-16.5 μm long [N =21], respectively, in F. gilvus n. comb.; compare Fig. 11 A-D). INTEGRATIVE DESCRIPTION Animals (see Table 3 for measurements) Body stubby, typically slightly rose in live animals, transparent in mounted specimens. Dorsum strongly sculptured from the first instar, although with substantial ontogenetic quantitative and qualitative variability in this trait (Fig. 1 A- F). Juveniles with ten transverse bands of numerous tu- bercles that increase in size towards the caudal end of the body, but fully formed plaques never present, legs covered with fine tubercles (Fig. 1 A). All ten bands not always easily identifiable under PCM in juveniles. In young adults, plaques present in bands 6-10, with the most prominent plaques in bands 8-10 (Fig. 1 B). In older adults, smooth spaces between the transverse bands becoming narrow and sometimes merge into larger areas (Fig. 1 C-F). Plaques larger and more numerous than in young adults, and typically developping in bands 4-10, but the most evident plaques present in the caudal part of the body (Fig.1 C-F). Tubercles more or less round or oval (Figs 3 A, B; 5 A, B), gradually increasing in size from juveniles to adults, and becoming scabrous with age (compare Figs 1 A-F; 5 A, B). Plaques, on the other hand, typically smooth and only sometimes slightly rough (Fig. 5 C, D, arrowheads); under stereomicroscope strongly opalescent. Plaques arranged symmetrically in respect to the longitudinal body axis, although deviations A from symmetry are not rare (Fig. 1 C, D). In adults, seven pairs of central plaques and four lateral plaque pairs. Central plaques triangular in shape, with their apices directed laterally and outwards. In rows where only central plaques are present, plaques slimmer and longer than in rows with lateral plaques. Central plaques present in bands aligned with legs I-III as well as in bands between those legs. First three pairs of lateral plaques in line with legs I-III and the last pair of double lateral plaques situated between legs III and IV (Fig. 1 E). Plaque configuration VII:4-2-4-2-4-2-6. Cephalic elliptical organs present but not easy to identify, given the rich cuticular sculpturing (Fig. 7 A). Eyes absent in live animals. Buccal apparatus of the Fractonotus - type (Fig. 7 B, C, E), i.e. with a long ventral AISM, and the dorsal AISM subdivided into the proximal, weakly developed thickening, and the distal, small blunt hook (Fig. 9 A). Mouth opening surrounded by six large and soft peribuccal lobes (visible only under SEM, Fig. 6 A). Oral cavity armature, visible only under SEM, consisting of a single row of minute conical teeth located on the ring fold (Fig. 8 A). Two distinct porous areas on the lateral sides of the buccal crown are visible in SEM only (Fig. 8 B). Stylet furcae of the modified Hypsibius shape, i.e. with very broad and trapezoid bases, thick arms and rounded apices (Figs 7 B, 8 D, 10 A). Buccal tube with slight lateral thickenings posterior to the stylets supports (Figs 7 B, C, E; 8 C). Round bulbus with large pharyngeal apophyses (almost as large as the placoids), and two granular macroplacoids (Figs 7 B, C, E; 8 E, F). In PCM, macroplacoids without constrictions, however slight central constrictions in both macroplacoids detectable under SEM (Fig. 8 E, F). Claws of the modified Isohypsibius - type (Figs 11 A-C; 12 A, B). Specifically, claw bases triangular, especially pronounced in claws IV (Figs 11 C, 12 B). Claw branches V-shaped, elongated and strongly curved. Apparent accessory points on the primary branches (Figs 11 A-C; 12 A, B). Weakly developed pseudolunulae present, particularly visible under the internal and anterior claws (Fig. 11 A, C). Claw septa and cuticular bars on legs absent. Eggs Roundish and smooth, deposited in exuviae (up to two eggs per exuvia recorded). MOLECULAR MARKERS The sequences for all DNA markers were of a good quality. The sequenced fragments were of the following lengths: 1.727 bp (18 S rRNA; MG 800855), 819 bp (28 S rRNA; MG 800856), and 499 bp (ITS-2; MG 800857). All markers, including the specimen without cuticular plaques, were represented by single haplotypes. The p-distances between 18S haplotypes of all available isohypsibioid species and Fractonotus verrucosus n. comb. ranged from 2.0% (I. prosostomus Thulin, 1928, EF 620404 from Denmark) to 7.1% (Hexapodibius micronyx Pilato, 1969, HQ 604915 from Italy), with an average distance of 5.2%. As our 28S rRNA primers obtain a different gene fragment to the one sequenced by previous authors, comparisons of this gene were not possible. Matrices with p-distances are provided in the Supplementary Material 2. REMARKS The vast part of the Richters Collection has been lost, thus the type material (if ever existed) is not available for examination. Moreover, no specimens from Germany were examined in this study, therefore the neotype series is not established. Hence, until the redescription from the terra typica in Germany is available, we propose to consider the description of the Scottish specimens only as the current perception of the species. PHYLOGENETIC POSITION OF FRACTONOTUS AMONG OTHER ISOHYPSIBIIDAE Both Bayesian Inference and Maximum Likelihood methods unreservedly located Fractonotus within Isohypsibioidea (Fig. 13), thus corroborating the phenotypic analysis (see above). The genus Isohypsibius s.s. (i.e. I. prosostomus and its closest relatives) appears paraphyletic with respect to Fractonotus. However, in general, all isohypsibioid lineages clearly remain in polytomy, with only the occasional sound Bayesian posterior probabilities characterising clades with morphologically similar taxa. Therefore, the exact relationships between different isohypsibioid clades remain unsolved.

Autapomorphies of Testechiniscus meridionalis (Murray, 1906) and T. macronyx (Richters, 1907) (measurements and statistics of juveniles and adult specimens of both sexes of T. meridionalis in Tables 10–12) Both species assigned to the genus Testechiniscus by Kristensen (1987) and McInnes (1994a), respectively, exhibit unique phenotypic traits. Given that works on their systematic position are in progress (McInnes, personal communication), we do not designate them as new genera, but, instead, we present their autapomorphies, which exclude their affiliation within the revised Testechiniscus. Both species have brown lipoid or red eyes and are dioecious whereas Testechiniscus s.s. exhibits black crystalline eyes and parthenogenetic reproduction (although the presence of males was suggested in T. laterculus by Kathman & Dastych (1990)). Moreover, T. meridionalis resembles Testechiniscus s.s. in having eight rows of ventral plates, however it differs from Testechiniscus s.s. by: a smaller body size, i.e. with adults not exceeding 200 µm (compare Figs 1A–B, 6A–B, 10A–C and 12A–B, see Tables 10–11), whereas adults of Testechiniscus spp. are typically 300–450 µm long; smaller ventral plates (Figs 12C–D) with minute cuticular pillars that are more like in the Bryodelphax weglarskae group (see Dastych 1984, Kaczmarek et al. 2012) rather than in Testechiniscus spp.; the dorsal sculpture consisting solely of granules (Fig. 14E) and never polygonal pores typical for Testechiniscus (e.g. Fig. 14A); evident sexual dimorphism, i.e. cephalic papillae and primary clavae are significantly longer in males than in females (one-tailed Welch t -test for: cephalic papillae: t 3=4.07, p=0.013, and primary clavae: t 3=4.14, p=0.013, compare also Figs 12A, D, arrowheads). Finally, T. macronyx differs from the revised Testechiniscus by: a smaller body size (i.e. below 200 µm); the presence of only lateral, exceptionally long cirri A (Fig. 13A); nine (instead of eight) rows of small ventral plates (configuration IX:2-5-5-2-4-4-4-1-2, Fig. 13B); dorsal sculpture in the form of an irregular reticulum/pseudopores (see McInnes 1994a), that look like dark margins of minute bright depressions on the cuticle surface (Fig. 14F); and by considerably longer claws, curved slightly only in their terminal parts., Published as part of Gąsiorek, Piotr, Stec, Daniel, Zawierucha, Krzysztof, Kristensen, Reinhardt Møbjerg & Michalczyk, Łukasz, 2018, Revision of Testechiniscus Kristensen, 1987 (Heterotardigrada: Echiniscidae) refutes the polar-temperate distribution of the genus, pp. 261-297 in Zootaxa 4472 (2) on page 285, DOI: 10.11646/zootaxa.4472.2.3, http://zenodo.org/record/1440175, {"references":["Murray, J. (1906) Scottish National Antarctic Expedition: Tardigrada of the South Orkneys. Transactions of the Royal Society of Edinburgh, 45 (12), 323 - 334. https: // doi. org / 10.1017 / S 0080456800022754","Richters, F. (1907) Antarktische Tardigraden. Zoologischer Anzeiger, 31, 915 - 916.","Kristensen, R. M. (1987) Generic revision of the Echiniscidae (Heterotardigrada), with a discussion of the origin of the family. In: Bertolani, R. (Ed.), Biology of Tardigrada. Selected Symposia and Monographs. U. Z. I. Mucci, Modena, pp. 261 - 335.","McInnes, S. J. (1994 a) Rediscovery of the species Echiniscus macronyx Richters, 1907 on South Georgia, South Atlantic, its new systematic position and redescription within the genus Testechiniscus. Bollettino di Zoologia, 61, 83 - 87. https: // doi. org / 10.1080 / 11250009409355863","Kathman, R. D. & Dastych, H. (1990) Some Echiniscidae (Tardigrada: Heterotardigrada) from Vancouver Island, British Columbia, Canada. Canadian Journal of Zoology, 68, 699 - 706. https: // doi. org / 10.1139 / z 90 - 102","Dastych, H. (1984) The Tardigrada from Antarctica with descriptions of several new species. Acta Zoologica Cracoviensia, 27 (19), 377 - 436.","Kaczmarek, L., Zawierucha, K., Smykla, J. & Michalczyk, L. (2012) Tardigrada of the Revdalen (Spitsbergen) with the descriptions of two new species: Bryodelphax parvuspolaris (Heterotardigrada) and Isohypsibius coulsoni (Eutardigrada). Polar Biology, 35, 1013 - 1026. https: // doi. org / 10.1007 / s 00300 - 011 - 1149 - 0"]}

Genus: Testechiniscus Kristensen, 1987 Amended genus diagnosis: Medium-sized echiniscids with black, crystalline eyes. Rigid buccal tube with large cuticular stylet supports. Appendaged, i.e. having both cephalic and trunk cirri. Two pairs of segmental plates, unpaired scapular and caudal plates. Three median plates. Cuticular sculpture composed of large true round or polygonal pores that gradually become reticulum. Incisions (notches) on caudal (terminal) plate. Eight rows of ventral plates. No pseudosegmental plates. Differential diagnosis. Phenotypic. Testechiniscus differs from Bryodelphax, Bryochoerus Marcus, 1936 and Echiniscus in having black eyes. Moreover, Testechiniscus can be separated from Bryodelphax and Bryochoerus by the presence of incisions on the caudal plate and cirri in positions other than A, and from Echiniscus by the presence of ventral armature covering the entire venter. Furthermore, Diploechiniscus has only two rows of ventral plates (subcephalic and genital) and double cuticular sculpture absent in Testechiniscus. Finally, Hypechiniscus Thulin, 1928 lacks trunk cirri (sometimes only an autapomorphic mediodorsal cirrus is present) and ventral plates; dorsal armature is very weakly sclerotised compared to large and strongly sclerotised plates in Testechiniscus. Genotypic. Based on the currently available sequences, the 18S rRNA p-distances within the genus Testechiniscus vary from 0.2% to 0.8%, and between Testechiniscus spp. and other currently recognised echiniscid genera they vary from 4.6% (E. granulatus (Doyère, 1840), MG016454) to 15.7% (Bryodelphax parvulus Thulin, 1928, HM193371, and B. maculatus Gąsiorek et al., 2017, KY609137). The corresponding comparisons for the 28S rRNA fragment yield higher minimal but lower maximal p-values between genera; respectively from 6.3% (E. trisetosus Cuénot, 1932 and E. canadensis Murray, 1910, FJ435781 and FJ435784, FJ435786) to 13.9% (Pseudechiniscus facettalis Petersen, 1951, FJ435788). Full p-distance matrices are provided in the Supplementary Materials (SM.2). Composition: Testechiniscus sensu stricto: T. spitsbergensis spitsbergensis, T. spitsbergensis tropicalis ssp. nov. and T. laterculus. Testechiniscus sensu lato includes T. macronyx and T. meridionalis (our analyses described below show that the two last species do not belong to the genus. However, their taxonomic status remains unchanged, pending formal taxonomic designations). Etymology: From Latin testa = shell, armour. The name refers to well-developed plates covering both dorsum and venter of animals (Kristensen 1987)., Published as part of Gąsiorek, Piotr, Stec, Daniel, Zawierucha, Krzysztof, Kristensen, Reinhardt Møbjerg & Michalczyk, Łukasz, 2018, Revision of Testechiniscus Kristensen, 1987 (Heterotardigrada: Echiniscidae) refutes the polar-temperate distribution of the genus, pp. 261-297 in Zootaxa 4472 (2) on pages 265-266, DOI: 10.11646/zootaxa.4472.2.3, http://zenodo.org/record/1440175, {"references":["Kristensen, R. M. (1987) Generic revision of the Echiniscidae (Heterotardigrada), with a discussion of the origin of the family. In: Bertolani, R. (Ed.), Biology of Tardigrada. Selected Symposia and Monographs. U. Z. I. Mucci, Modena, pp. 261 - 335.","Marcus, E. (1936) Tardigrada. Das Tierreich, 66, 1 - 340.","Thulin, G. (1928) Uber die Phylogenie und das System der Tardigraden. Hereditas, 11, 207 - 266. https: // doi. org / 10.1111 / j. 1601 - 5223.1928. tb 02488. x","Doyere, M. L. (1840) Memorie sur les Tardigrades. Annales des Sciences Naturelles. Zoologie, 14, 269 - 362.","Cuenot, L. (1932) Tardigrades. In: Lechevalier, P. (Ed.), Faune de France, 24, pp. 1 - 96.","Murray, J. (1910) Tardigrada. British Antarctic Expedition 1907 - 1909. Reports on the Scientific Investigations, 1, Biology (Part V), 83 - 187.","Petersen, B. (1951) The Tardigrade Fauna of Greenland. Meddelelser om GrOnland, 150 (5), 1 - 94."]}