taxonID	type	description	language	source
03CA41789C76D771FCB9F9FA1638F962.taxon	description	Despite the significant differences (especially dimensional) between the claws of E. ovezovae and the other two described species, it is noticeable that in all species of the genus, the internal claws of legs I – III typically have a wider angle compared to a typical Isohypsibius claw (as previously reported by Biserov, 1992). However, these claws cannot be considered of the Eremobiotus type for various reasons (see the discussion below regarding Eremobiotus claws) and therefore should be considered as modified Isohypsibius claws (as reported by Biserov, 1992). The external claws of legs I – III appear to be of the Isohypsibius type. Claws of the “ Eremobiotus type ” have never been defined formally. Biserov (1992), in describing the genus, mentioned claws of the fourth pairs of legs as “ significantly different from those of I – III legs, ” having a large basal part of the claws, longer than that of branches, primary branches slightly longer than secondary, and an angle of approximately 180 ° between the two branches. Upon revising the type material of E. alicatai, E. ginevrae, and E. ovezovae, we observed that (i) the basal portion of the claws I – III is not always longer than the primary / secondary branch, especially undivided distal buccal ring (white indented arrowhead), the circumoral sensory field without evident lobes (white arrowhead) and surrounding area forming the presumed “ second band of lobes ” (white arrows). Scale bars a 10 μm; b 5 μm in E. ginevrae; (ii) the claw branches of the fourth pair of legs do not always exhibit an angle of about 180 °, but rather a narrower angle (approximately starting from 140 °), varying even among specimens of the same population (Fig. 5 d, e). In particular, the anterior claws (homologous to the internal claws of legs I – III) exhibit an angle of 160 – 180 °, while the posterior claws (homologous to the external claws of legs I – III) display a narrower angle, of 140 – 180 °. The branches appear to be less divergent especially in larger specimens (Fig. 5). This variability may be dependent also on the claw orientation in the preparation. Despite this variation, the claws of the fourth pair of legs of Eremobiotus still differ from those of every leg pair of all Isohypsibioidea due to the following characters: (i) the primary and secondary branch share a large common portion of almost triangular shape; (ii) internal septa are almost invisible with PCM; (iii) accessory points are short, thick, and asymmetrical with respect to the main axis of the primary branch, appearing to point upwards with PCM. Thus, only those claws, i. e., the claws of the fourth pair of legs, should be treated as the “ Eremobiotus - type ” claws. Regarding this particular claw type, some problems arise when measurements are taken with the currently used methodology of measurement of the Isohypsibioidea claws, established by Beasley et al. (2008) (see also Fig. 6 a, b). Until 2002, parachelan claws with an asymmetrical arrangement were measured according to Pilato et al. (1982), i. e., from the base of the claw to the end of the primary branch (including the accessory points), not giving troubles even if Eremobiotus claws were measured. Pilato et al. (2002) introduced a new method but only for the external claws of the Hypsibius type. Beasley et al. (2008) introduced a ◂ Fig. 4 Bucco-pharyngeal apparatus of Eremobiotus alicatai (specimens from the topotypic population) (a SEM; b – d PCM). a Buccal opening showing the distal buccal ring (white indented arrowhead), a single band of teeth (black indented arrowhead) and the circumoral sensory field with lobes (white asterisk) and surrounding area forming the presumed “ second band of lobes ” (black asterisk). b Dorsoventral view of the bucco-pharyngeal apparatus. c Lateral view with Isohypsibius - type AISM (arrows). d Detail of the placoids; black arrowheads indicate constriction in the medial portion of the first placoids and in the final portion of the second placoid. Scale bars a 5 μm; b – d 10 μm new measurement method for claws of the Isohypsibius type (but subsequently applied to other asymmetrical claws as well) to take into consideration also the measurement of the “ basal claw height ” and “ secondary branch length. ” Up to date, this has not raised perplexities, but some difficulties are encountered if claws have primary and secondary branch diverging with an angle of approximately 180 °, and no septum or flexible connection is present to clearly indicate the border that separates primary and secondary branch bases, as those of the Eremobiotus type. Such a situation makes it impossible to obtain an objective measurement of the structures considered. Therefore, for those claws (Eremobiotus type, i. e., the fourth pair of claws, in which septa nor a clear division between primary and secondary branch is observable), we propose to not measure the claws according to Beasley et al. (2008) and reestablish the older method of claw measurement, i. e., the measurement taken from the basal portion of the claw to the end of primary branch according to Pilato et al. (1982), adding the same type of measurement also for the secondary branch (in Pilato et al. (1982) only the primary branch was measured) (Fig. 6 c). Moreover, we propose a third measurement for the claws of the Eremobiotus type. This measurement is taken from the tip of the primary branch to the tip of the secondary branch of the same claw, excluding the accessory points (Fig. 6 d). Moreover, since the “ Parachela ” template available from the Tardigrada Register (www. tardigrada. net / register, Michalczyk & Kaczmarek, 2013) was used, the line reporting the ratio between the posterior / anterior primary branch and the base was modified. The entry “ Anterior base / primary branch (cct) ” was replaced with “ Anterior branch distance / primary branch (cct), ” and the entry “ Posterior base / primary branch (cct) ” was replaced with “ Posterior branch distance / primary branch (cct). This new measurement was not adopted for internal claws of the legs I – III, even if the angle sometimes reaches the 180 °, due to the visibility of the insertion of the secondary branch on the primary branch, from which the measurement can be taken (Fig. 6). Taxonomic account	en	Camarda, Daniele, Frigieri, Federica, Guidetti, Roberto, Cesari, Michele, Lisi, Oscar (2025): Lights on tardigrade biodiversity: integrative redescription of Eremobiotus alicatai (Eutardigrada, Isohypsibiidae) with new insights on its morphology, phylogeny, and biogeography. Organisms Diversity & Evolution 25 (1): 55-80, DOI: 10.1007/s13127-024-00657-8, URL: https://doi.org/10.1007/s13127-024-00657-8
03CA41789C7BD771FCB9FF1413FAFCF1.taxon	description	Amended morphological description: Six peribuccal lobes, a buccal tube and apophyses for the insertion of the stylet muscles (AISM) of Isohypsibius type. Pharyngeal apophyses and two macroplacoids present in the pharynx, microplacoid, and / or septulum absent. Internal claws I – III of modified Isohypsibius type, forming a wide angle (about 160 – 180 °); external claws I – III of Isohypsibius - type. Claws of the hind legs of Eremobiotus type [= with branches having an angle of 140 – 180 °, with difficult-to-see internal septa, tendency to form a wide, triangular common tract (main body) of the claw, thick and asymmetrical accessory points], provided with indented lunulae.	en	Camarda, Daniele, Frigieri, Federica, Guidetti, Roberto, Cesari, Michele, Lisi, Oscar (2025): Lights on tardigrade biodiversity: integrative redescription of Eremobiotus alicatai (Eutardigrada, Isohypsibiidae) with new insights on its morphology, phylogeny, and biogeography. Organisms Diversity & Evolution 25 (1): 55-80, DOI: 10.1007/s13127-024-00657-8, URL: https://doi.org/10.1007/s13127-024-00657-8
03CA41789C7BD771FCB9FF1413FAFCF1.taxon	discussion	Remarks Buccal opening with apparently papular lamellae visible with PCM in all species; however, these correspond (SEM) to a continuous buccal ring with internal septa in Eremobiotus alicatai, and probably, but still to be verified with SEM, also in E. ginevrae and E. ovezovae.	en	Camarda, Daniele, Frigieri, Federica, Guidetti, Roberto, Cesari, Michele, Lisi, Oscar (2025): Lights on tardigrade biodiversity: integrative redescription of Eremobiotus alicatai (Eutardigrada, Isohypsibiidae) with new insights on its morphology, phylogeny, and biogeography. Organisms Diversity & Evolution 25 (1): 55-80, DOI: 10.1007/s13127-024-00657-8, URL: https://doi.org/10.1007/s13127-024-00657-8
03CA41789C7BD772FCB9FC2C125AFA10.taxon	materials_examined	Species: Eremobiotus alicatai (Binda, 1969) (Figs. 3 - 5, 7 - 10). Material examined Holotype and paratypes of E. alicatai: 10 specimens; slide nos. 956, 957, 959 – 963, 1339, 1875, 2017. Topotypic population of E. alicatai: 20 specimens; slide nos. 6023 – 6027, 6029, 6036, 6038 – 6039, 6046 – 6049, 6057, 6060, 6061. Three specimens; stub nos. DFG 2 - 19, DFG 2 - 20. Population of E. alicatai from Orbetello (Grosseto): 11 specimens; slide nos. C 3089 S 1 a _ 6062 – V 6 _ 6072. Type depositories: Holotype and paratypes of E. alicatai are preserved in the University of Catania, in the Pilato and Binda collection. Eighteen specimens of the topotypic population are preserved in the University of Catania, Pilato and Binda collection, while two are in the University of Modena and Reggio-Emilia, Bertolani collection. Specimens of the topotypic population which are mounted on SEM stub are preserved at the University of Catania (stub nos. DFG 2 - 19, DFG 2 - 20) in the Pilato and Binda collection. Samples of moss from which the additional specimens of E. alicatai were extracted are dry preserved in the University of Catania (sample UNICT-DFG 2) and University of Modena and Reggio Emilia (sample C 3089).	en	Camarda, Daniele, Frigieri, Federica, Guidetti, Roberto, Cesari, Michele, Lisi, Oscar (2025): Lights on tardigrade biodiversity: integrative redescription of Eremobiotus alicatai (Eutardigrada, Isohypsibiidae) with new insights on its morphology, phylogeny, and biogeography. Organisms Diversity & Evolution 25 (1): 55-80, DOI: 10.1007/s13127-024-00657-8, URL: https://doi.org/10.1007/s13127-024-00657-8
03CA41789C7BD772FCB9FC2C125AFA10.taxon	description	Description Body whitish, eyespots absent. Dorsal and ventral cuticle with wrinkles (with PCM visible in exuviae and very rarely in specimens; well visible with SEM) almost invisible; cuticular pores absent. Distal portion of the buccal ring with internal septa (Fig. 3 a), which with PCM could give the impression of the presence of papular lamellae. Six peribuccal lobes visible with SEM (Fig. 4 a, b); the oral cavity armature of Isohypsibius type, showing a single band with two to five rows of teeth visible only with SEM (Fig. 4 a). Bucco-pharyngeal apparatus of Isohypsibius type; the AISM of the Isohypsibius - type; apophyses and two macroplacoids (length sequence 1> 2) in the pharynx, the first of which showing a central constriction (Fig. 4 b, d); microplacoid and septulum absent. cuticular thickening at the base of the lunula; asterisks indicate some claws with angles between primary and secondary branch visibly narrower than 180 °. Scale bars: 10 μm Internal claws of legs I – III of modified Isohypsibius - type; the angle between the primary and secondary branches is very wide (ca. 160 – 180 °) but the basal section of the claw and the insertion of the primary branch on the secondary branch still recognizable; secondary branch short, primary branch with very small and symmetrical accessory points (Fig. 7 b, d); distance between the insertion point of the main branch and the claw base very short; lunules at the base of the claws present with very small teeth almost impossible to observe with PCM (Fig. 7 c) but visible with SEM (Fig. 7 b, d). External claws of legs I – III of Isohypsibius - type, having a lesser wide angle between primary and secondary branches (ca. 130 °), secondary branch short, primary branch with very small and symmetrical accessory points (Fig. 7 b, c). A long and irregular singular cuticular thickening (single indented bar) develops from the lunula of the internal claws of legs I – III (Figs. 7 a, c, d and 9 c), with thick and evidently indented external margins, which teeth are positioned on the external cuticle (Fig. 7 d). Anterior and posterior claws IV of Eremobiotus - type, with primary and secondary branches fused forming a relatively long common triangular tract. The angle between primary and secondary branches very wide (ca. 170 – 180 °); primary branches with thick and asymmetrical (with respect to the main axis of the primary branch) accessory points, giving the impression, with PCM, of a primary branch with a secondary point pointing upwards (Figs. 9 d and 10); claw bases with small indented lunules which often present supernumerary small teeth (Fig. 10 a – c, e, f). A cuticular thickening present at the base of the lunulae of claw IV, bigger in anterior claws and smaller and slightly visible in posterior claws (Figs. 5 a – e and proposed here for the Eremobiotus - type claws (i. e., the fourth pair of claws in Eremobiotus species). c Posterior claws. d Anterior claws. sb, secondary branch; pb, primary branch; cb, claw base; bd, distance between branches 10 a, c). A furbelow structure present on all legs (i. e., an area surrounding the claws with fine but very dense granulation, visible with SEM (Figs. 7 b, d, 8 a, and 10 e) and, partially with PCM (Fig. 10 a, c). Eggs smooth laid in the exuviae.	en	Camarda, Daniele, Frigieri, Federica, Guidetti, Roberto, Cesari, Michele, Lisi, Oscar (2025): Lights on tardigrade biodiversity: integrative redescription of Eremobiotus alicatai (Eutardigrada, Isohypsibiidae) with new insights on its morphology, phylogeny, and biogeography. Organisms Diversity & Evolution 25 (1): 55-80, DOI: 10.1007/s13127-024-00657-8, URL: https://doi.org/10.1007/s13127-024-00657-8
03CA41789C7BD772FCB9FC2C125AFA10.taxon	discussion	Remarks Binda (1969) reported the presence of cuticular pores (“ cuticola cosparsa di perle, ” meaning “ cuticle sprinkled with pores ”); however, our analysis of types through LM, and analysis of the two investigated populations of E. alicatai through LM and SEM, revealed the absence of cuticular pores.	en	Camarda, Daniele, Frigieri, Federica, Guidetti, Roberto, Cesari, Michele, Lisi, Oscar (2025): Lights on tardigrade biodiversity: integrative redescription of Eremobiotus alicatai (Eutardigrada, Isohypsibiidae) with new insights on its morphology, phylogeny, and biogeography. Organisms Diversity & Evolution 25 (1): 55-80, DOI: 10.1007/s13127-024-00657-8, URL: https://doi.org/10.1007/s13127-024-00657-8
03CA41789C7BD772FCB9FC2C125AFA10.taxon	diagnosis	Differential diagnosis Given that the main characters to differentiate E. alicatai from E. ginevrae are not constant and well visible in all specimens of the former species (indentation of the lunulae of the legs I – III), the two species differs only in the dimension and indentation of the lunulae of the IV pair of legs and in morphometric characters. Eremobiotus alicatai differs from E. ginevrae in having bigger lunulae of the fourth pair of legs; those have a well-developed indentation in E. alicatai while they are only slightly indented in E. ginevrae. The species are also differentiated based on certain morphometric traits (Tables 2, 3, 4, and 5; see also remarks paragraph of E. ginevrae). Eremobiotus alicatai differs from E. ovezovae by different dimension and shape of claws on all legs (i. e., bigger and more slender in E. alicatai); the external claws of legs I – III more closely resemble Isohypsibius - type claws, whereas in E. ovezovae, all claws more closely resemble Eremobiotus - type claws. The species differ also in morphometric characters (pt of all claws). arrowheads indicate a well-developed single, indented cuticular bar. White indented arrowheads indicate short accessory points; white arrowheads indicate the furbelow-like structure; black arrowheads indicate the poorly indented lunula of the internal (c, d) and external (b) claws. (a, c, PCM; b, d, SEM). Scale bars: 10 μm	en	Camarda, Daniele, Frigieri, Federica, Guidetti, Roberto, Cesari, Michele, Lisi, Oscar (2025): Lights on tardigrade biodiversity: integrative redescription of Eremobiotus alicatai (Eutardigrada, Isohypsibiidae) with new insights on its morphology, phylogeny, and biogeography. Organisms Diversity & Evolution 25 (1): 55-80, DOI: 10.1007/s13127-024-00657-8, URL: https://doi.org/10.1007/s13127-024-00657-8
03CA41789C67D76DFF01FD4114CAFEC4.taxon	materials_examined	Material examined A single paratype of E. ovezovae (slide No. 3358), donated by Biserov, was examined and measured (SM. 07). Remarks The species, only reported from Turkmenistan, exhibits a distinctive claw morphology, markedly different from the other known Eremobiotus species. The examination of the paratype with PCM revealed a likely similar situation to the other two species of Eremobiotus concerning peribuccal structures and claws. A circular sensory field is visible with PCM; peribuccal structures look like papular lamellae with PCM, but it is essential to check the morphology through SEM analysis to verify the presence of a continuous buccal ring (as in E. alicatai). Internal claws of legs I – III of modified Isohypsibius - type (with an angle between branches of ca. 160 – 180 °) do not always exhibit a clear 180 ° angle between branches; instead, they often have a narrower angle. The redescription of E. ovezovae may lead to different scenarios on the peribuccal structures, including: 1. Confirmation of the hypothesis that E. ovezovae possesses a continuous buccal ring and 6 peribuccal lobes with SEM, alongside maintaining all three species within the Eremobiotus genus, if supported by molecular data 2. Confirmation of the hypothesis that E. ovezovae has a continuous buccal ring and 6 papular peribuccal lobes with SEM (similarly to the Calohypsibius peribuccal structures arrangement), but leading to the establishment of a new genus for E. alicatai and E. ginevrae, if supported by molecular data 3. Confirmation of Biserov’s description, i. e., the presence of papular lamellae and 6 peribuccal lobes, which might prompt the erection of a new genus for E. alicatai and E. ginevrae, if also supported by molecular data Depending on further analysis on this interesting species, the scenario concerning Eremobiotus composition could change.	en	Camarda, Daniele, Frigieri, Federica, Guidetti, Roberto, Cesari, Michele, Lisi, Oscar (2025): Lights on tardigrade biodiversity: integrative redescription of Eremobiotus alicatai (Eutardigrada, Isohypsibiidae) with new insights on its morphology, phylogeny, and biogeography. Organisms Diversity & Evolution 25 (1): 55-80, DOI: 10.1007/s13127-024-00657-8, URL: https://doi.org/10.1007/s13127-024-00657-8
