taxonID	type	description	language	source
0389879EFFDFCA4D34AAFF16FF2BF93D.taxon	description	Figs 2 – 17, Table 1 ‒ 2	en	Panina, Kseniya, Babenko, Anatoly, Potapov, Mikhail (2022): Two new « nosed » species of the genus Megalothorax (Collembola: Neelidae) from Russia. Zootaxa 5188 (4): 383-395, DOI: https://doi.org/10.11646/zootaxa.5188.4.6
0389879EFFDFCA4D34AAFF16FF2BF93D.taxon	materials_examined	Type material. Holotype, Russia (European part), Kanin Peninsula, outskirts of Shoina settlement [67 ° 53 ’ N, 44 ° 09 ’ E], birch forest with rich herbs, 24.07.2017, leg. A. Babenko. 4 paratypes, in the same location. The holotype and 4 paratypes deposited in the collection of the Department of Zoology & Ecology, Moscow State Pedagogical University. Other material. Russia (Asian part), Kemerovo region, Biyskaya Griva, Turachak-Tashtagol road [52 ° 52 ′ N, 87 ° 61 ′ E], pass, coniferous forest (Abies), 09.10.2020; Kemerovo region, Tashtagolsky district, Tashtagol-Kuzedeevo road [52 ° 97 ′ N, 87 ° 73 ′ E], Abies forest on slope, 08.10.2020; Kemerovo region, Novokuznetskiy district, Kuzedeevo settlement [53 ° 74 ′ N, 88 ° 09 ′ E], old pine forest along Kondoma river, 09.10.2020; Kemerovoregion, Kuznetsky Alatau ridge, near Raspadskaya mine [53 ° 74 ′ N, 88 ° 09 ′ E], mixed forest on slope (Fig. 36), 09.10.2020. All leg. M. Potapov and N. Kuznetsova.; Nenets Autonomous Okrug, Bolvanskaya Guba, left bank of the Yachay River [68 ° 05 ′ N, 54 ° 47 ′ E], willow grove (a strip of willow bushes between the meadow and the swamp), 18 – 24.07.2015, leg. O. Makarova & M. Bizin. All kept in MSPU. Two specimens from type locality kept in SMNG.	en	Panina, Kseniya, Babenko, Anatoly, Potapov, Mikhail (2022): Two new « nosed » species of the genus Megalothorax (Collembola: Neelidae) from Russia. Zootaxa 5188 (4): 383-395, DOI: https://doi.org/10.11646/zootaxa.5188.4.6
0389879EFFDFCA4D34AAFF16FF2BF93D.taxon	description	Description. General aspect. Habitus and segmentation typical of the genus. Body length up to 0.35 mm. Specimens whitish in alcohol. Body chaetotaxy sparse including chaetae, s-chaetae, trichobothria, neosminthuroid chaetae, wax-rods and inner sensilla within sensory fields 2 – 6. Chaetae ordinary on body, without any remarkable development. Integument. Secondary granulation made of the usual dorsal rough granules. Integumentary channels extending laterally and dorsally in anterior and posterior parts of head. Anterior canal branching. Channels connection with linea ventralis circular on the head (observation basing on one specimen). Detailed topology of channels not studied. Sensory fields and wax rods (Figs 5, 7, 9). Sensory field sf 1 with one wrc-chaeta (wrc) and without inner sensilla (s). Sf 2 with one s and one wrc, Sf 3 with three s and one wrc, Sf 4 and sf 5 with two s and one wrc. Sf 6 with one s and two wrc. All inner sensilla of sf 3 – 6 globular (Figs 7, 9). Inner sensilla of sf 2 broad flame-shaped. A total of 14 + 14 wrc (2 + 2 on head, 12 + 12 on body), including free 7 + 7 wrc not associated with sensory fields, notated as wrc 1 – wrc 7. Mouthparts. Labrum as typical for the genus (Fig. 3). Chaetae a 1 and a 2 not forked, with one or two teeth. Labium with 4 + 4 proximal chaetae (Fig. 4). Basomedian field with 3 + 3 chaetae. Basolateral field with 1 + 0 chaetae (one tubercle and no ventral chaeta). Labial palp (Fig. 4), as common for the genus (A, B, C, D, E, b 1, b 2, d 1, d 2, 2 e, H, h 1, h 2). Oral fold and maxillary outer lobe as typical for the genus, without sublobal hair. Maxillary head without strong modification. Head chaetotaxy. Forehead chaetotaxy as on Figs 2, 5, 6. Clypeal-labral formula: a 0, 2, 2, 5, 4 / 5, 5, 4 (Fig. 2). Chaetae a 0 present. Head with four (rarely two) papillae grouped together forming a wart, the papillae devoid of secondary granules (Figs 2, 5, 6). Dorsal posterior area with 18 lanceolate chaetae (Fig. 5). Ventral side with three pairs of postlabial chaetae (Fig. 4). Trend for posterior chaetae to be longer and stronger than anterior chaetae. Antennal chaetotaxy (Fig. 8). Ant. I and II with one and four chaetae, respectively. Ant. III with 8 – 9 chaetae and two long S-chaetae (S 1 and S 4). Striations of Ant III sensory organ short sensilla (S 2 and S 3) distinguishable in light microscopy. Ant. IV with seven chaetae (including X-chaeta) and ten S-chaetae. Sensory organ with Sx, Sy, Or, a, Sa. Organite (Or) of Ant IV short, seems apically flared. Diagram of the chaetotaxy of the antenna nearly as for M. processus sp. nov. (Fig. 26). Summary on antennal chaetotaxy provided in Table 1. Body chaetotaxy. Th. II with 12 + 12 chaetae, 1 + 1 tubular and curved s 1 - sensilla (Figs 7, 9). Th. III with 11 + 11 chaetae, 6 + 6 free wax-rods (wrc 1 – 6). Chaetae p 4 not close to wrc 2 (Fig. 7). Chaeta a 5 slightly shorter than chaeta a 6. Abd I – V terga with 17 + 17 ordinary chaetae, 1 + 1 free wax-rods, 1 + 1 globular sensillum s 2. Globular sensillum s 3 absent (Figs 7, 9). Chaetae of body subequal, slightly thickened. Legs chaetotaxy. Typical of the genus (Table 2), consisting of ordinary chaetae of variable size (Figs 13 – 15). Claws. Claw III bulkier than claw I and II. Claws subequal in unguis length (with a trend as unguis I> unguis II> unguis III). Unguis basal and posterior auxiliary lamellae (la, lp and Bp) well developed (Figs 16 – 17). Unguiculus 0.5 - 0.6 as long as unguis. IV sternum and furca. Abd. IV sternum with 2 + 2 neosminthuroid chaetae and at least 2 + 2 chaetae (not 1 + 1, the observations are uncertain). Manubrium with 2 + 2 posterior chaetae and 1 + 1 pegs with convex tip articulated with a corresponding concavity of the dens (Figs 10, 12). Proximal subsegment of dens with a posterior chaeta (Figs 10, 12); distal subsegment posteriorly with two basal spines and one chaeta at the middle. Anterior side of dens with five apical spines, spines without elongated apex (Fig. 11). Mucro tri-edged, posteriorly gutter-like and with anterior crest (Figs 10 – 12). Mucro narrowing in the distal 2 / 5. Edges are entirely smooth with one notch. Chaetotaxy of Abd. V and VI not studied, looks generally as for the genus. Tenaculum and ventral tube. Tenaculum with 3 + 3 hook-like teeth (as in M. processus sp. nov., Fig. 35). Ventral tube bulky with two apical pairs of chaetae. Males not found. Name derivation. The name reflects the similarity of the wart on the forehead with a rose (flower).	en	Panina, Kseniya, Babenko, Anatoly, Potapov, Mikhail (2022): Two new « nosed » species of the genus Megalothorax (Collembola: Neelidae) from Russia. Zootaxa 5188 (4): 383-395, DOI: https://doi.org/10.11646/zootaxa.5188.4.6
0389879EFFDFCA4D34AAFF16FF2BF93D.taxon	discussion	Discussion. Megalothorax roseus sp. nov. can be attributed to neither minimus - nor incertus - group in understanding of Schneider & D’Haese (2013). The new species shows all characters of the former group, except for globular sensilla inside the trunk sensory fields which are the characteristic of the incertus - group. The unique character of M. roseus sp. nov. is the four papilla wart which was unknown among congeners so far. M. potapovi and M. sanctistephani also have a process on forehead though its shape is completely different. Both species also differ in the form of inner sensilla (flame-shaped vs. globular in M. roseus) and the number of chaetae on the forehead and body (more complete in M. potapovi, and regretfully unknown for body of M. sanctistephani). From the widespread M. willemi and M. minimus, M. roseus sp. nov. clearly differs notably by the shape of the inner sensilla (globular vs. flame shapes). Among species not fully described the new species can be compared with M. interruptus Hüther, 1967 (Sudan), which is also close to M. laevis Schneider, Zon & d’Haese, 2018. Apart from the wart, M. roseus sp. nov. differs from M. interruptus by the absence (vs. presence in M. interruptus) of the second pair of dorsal globular sensillum s 3. The shape of the sensilla of sensory fields depends on location in new species: from flamed-shape in sf 2 on head to globular on body. The same pattern is observed in M. laevis. See also the Discussion part to M. processus sp. nov.	en	Panina, Kseniya, Babenko, Anatoly, Potapov, Mikhail (2022): Two new « nosed » species of the genus Megalothorax (Collembola: Neelidae) from Russia. Zootaxa 5188 (4): 383-395, DOI: https://doi.org/10.11646/zootaxa.5188.4.6
0389879EFFDFCA4D34AAFF16FF2BF93D.taxon	distribution	Distribution and ecology. Megalothorax roseus sp. nov., previously recorded from the East-European tundra as Megalothorax sp. 3 (Babenko et al. 2017), seems to be widespread in the Central Palaearctic being found from northern (Kanin Peninsula) to relatively southern (Altai Mts) areas. It mostly occurs in different types of forest floor.	en	Panina, Kseniya, Babenko, Anatoly, Potapov, Mikhail (2022): Two new « nosed » species of the genus Megalothorax (Collembola: Neelidae) from Russia. Zootaxa 5188 (4): 383-395, DOI: https://doi.org/10.11646/zootaxa.5188.4.6
0389879EFFDACA4334AAFF16FC4AFB72.taxon	description	Figs 18 – 35, Table 1 ‒ 2	en	Panina, Kseniya, Babenko, Anatoly, Potapov, Mikhail (2022): Two new « nosed » species of the genus Megalothorax (Collembola: Neelidae) from Russia. Zootaxa 5188 (4): 383-395, DOI: https://doi.org/10.11646/zootaxa.5188.4.6
0389879EFFDACA4334AAFF16FC4AFB72.taxon	materials_examined	Type Material. Holotype, Russia (European part), Nenets Autonomous Okrug, Yugorsky Peninsula, surroundings of Amderma [69075 ′ N, 610 67 ′ E], meadow with dryad, 15 – 16.07.2018, leg. M. Bizin and B. Efeikin. 10 paratypes, in same location. The holotype and 8 paratypes deposited in the collection of the Department of Zoology & Ecology, Moscow State Pedagogical University. 2 paratypes deposited in SMNG. Other material. Russia (Asian part), Republic of Altai, Chuysky tract, Kosh-Agachsky district, at the exit from the Chuysky basin [50 ° 10 ′ N, 88 ° 34 ′ E], floodplain forest (larch with willow undergrowth), 06.10.2020 (Fig. 37); Altai Republic, Chuisky tract, Ongudai district, Seminsky pass [50 ° 99 ′ N, 85 ° 65 ′ E], meadow with Betula nana in brook valley, mosses on a bump, 04.10.2020. All leg. M. Potapov and N. Kuznetsova. Novaya Zemlya, South Island, Bezymyannaya River Valley [72050 ′ N, 53045 ′ E], willow-herb thickets, 20 – 26.07.2017, leg. V. Spitsin; Nenets Autonomous Okrug, Pakhanchenskaya Guba [68029 ′ N, 570 12 ′ E], forb meadow on slope, 26.07. – 05.08.2015, leg. O. Makarova and M. Bizin. All kept in MSPU.	en	Panina, Kseniya, Babenko, Anatoly, Potapov, Mikhail (2022): Two new « nosed » species of the genus Megalothorax (Collembola: Neelidae) from Russia. Zootaxa 5188 (4): 383-395, DOI: https://doi.org/10.11646/zootaxa.5188.4.6
0389879EFFDACA4334AAFF16FC4AFB72.taxon	description	Description. General aspect. Habitus and segmentation typical of the genus. Body length up to 0.35 mm. Specimens whitish in alcohol. Body chaetotaxy sparse including chaetae, s-chaetae, trichobothria, neosminthuroid chaetae, wax-rods and inner sensilla within sensory fields 2 – 6. Chaetae ordinary on body, without any remarkable development. Integument. As in M. roseus sp. nov. Connection of channels with linea ventralis circular on the head. Sensory fields and wax rods (Figs 22, 27, 31). Sensory field sf 1 without inner sensilla (s) and with one wrcchaeta. Sf 2 with one inner s and one wrc-chaeta (wrc). Sf 3 with three s and one wrc. Sf 4 and sf 5 with two s and one wrc. Sf 6 with one s and two wrc. Each s of sf 2 – 6 broad flame-shaped (Figs 27, 31). A total of 14 + 14 wrc (2 + 2 on head, 12 + 12 on body), including free 7 + 7 wrc (not associated with sensory fields, notated as wrc 1 – wrc 7). Mouthparts. Labrum typical of the genus (Fig. 20). Chaetae a 1 and a 2 not forked, with one or two teeth. Labium with 4 + 4 proximal chaetae (Fig. 21). Basomedian field with 3 + 3 chaetae. Basolateral field with 1 + 0 chaetae (one tubercle and no ventral chaeta). Labial palp as in Fig. 21, as common for the genus (A, B, C, D, E, b 1, b 2, d 1, d 2, 2 e, H, h 1, h 2). Oral fold and maxillary outer lobe typical of the genus, with one sublobal hair (sh). Maxillary head without strong modification. Head chaetotaxy. Forehead chaetotaxy as on Figs 18, 22, 23. Clypeo-labral formula: 2, 5, 5, 4 / 5, 5, 4 (Fig. 18). Chaetae a 0 absent, replaced by a long cuticular process extended at the tip (Figs 18, 22, 23). Dorsal posterior area with 18 lanceolate chaetae (Fig. 22). Ventral side with three pairs of postlabial chaetae. Trend for posterior chaetae to be longer and stronger than anterior chaetae. Antennal chaetotaxy (Figs 24 – 25). Pattern diagram in Fig. 26. Ant. I and II with one and four chaetae, respectively. Dorsal chaeta on the Ant. II bigger than others. Ant. III with 8 – 9 chaetae, two long S-chaetae (S 1 and S 4). Striations of Ant III sensory organ short sensilla (S 2 and S 3) distinguishable in light microscopy. Ant. IV with seven chaetae (including X-chaeta) and ten S-chaetae. Sensory organ with Sx, Sy, Or, a, Sa. Organite (Or) of Ant IV short, seems apically flared. Summary on antennal chaetotaxy provided in Table 1. Body chaetotaxy. Th. II with 12 + 12 chaetae, 1 + 1 tubular and curved s 1 - sensilla (Figs 27, 31). Th. III with 11 + 11 chaetae, 6 + 6 free wax-rods (wrc 1 – 6). Chaetae p 4 not close to wrc 2 (Figs 27, 31). Chaeta a 5 slightly shorter than chaeta a 6. Abd I – V terga with 17 + 17 ordinary chaetae, 1 + 1 free wax-rods, 1 + 1 globular sensillum s 2. Globular sensillum s 3 absent (Figs 27). Chaetae of body subequal, slightly thickened. Legs chaetotaxy. Leg chaetotaxy consist of ordinary chaetae of variable size, about as in Figs 13 – 15. Chaetotaxy leg typical of the genus. Number of chaetae for each segment is summed up in Table 2. Claws. Claw III bulkier than claw I and II (Figs 32 – 34). Claws subequal in unguis length (with a trend as unguis I> unguis II> unguis III). Unguis basal and posterior auxiliary lamellae (la, lp and Bp) well developed (Figs 32 – 34). Unguiculus about 0.6 as long as unguis. Abd. IV sternum and furca. Abd. IV sternum with 2 + 2 neosminthuroid chaetae and at least 2 + 2 chaetae (the observations are uncertain). Manubrium with 2 + 2 posterior chaetae and 1 + 1 pegs with convex tip articulated with a corresponding concavity of the dens (Fig. 28). Dens as in M. roseus sp. nov. (Figs 28 – 30). Mucro narrowing in the distal 2 / 5. Edges are entirely smooth with one notch. Chaetotaxy of Abd. V and VI not studied, looks generally as for the genus. Tenaculum and ventral tube. Tenaculum with 3 + 3 hook-like teeth (Fig. 35). Ventral tube bulky with two apical pairs of chaetae. Males not found. Name derivation. The name reflects the presence of a process on the forehead.	en	Panina, Kseniya, Babenko, Anatoly, Potapov, Mikhail (2022): Two new « nosed » species of the genus Megalothorax (Collembola: Neelidae) from Russia. Zootaxa 5188 (4): 383-395, DOI: https://doi.org/10.11646/zootaxa.5188.4.6
0389879EFFDACA4334AAFF16FC4AFB72.taxon	discussion	Discussion. Megalothorax processus sp. nov. belongs to the minimus - group (Schneider & D’Haese 2013). Specific cuticular process is usually well visible and easy defines this species. Formally, M. potapovi and M. sanctistephani also have the front head process, albeit fold- and coffee bean-shaped, respectively (vs. long and extended at the tip in M. processus sp. nov.). M. potapovi also differs in number of chaetae on the forehead, including chaeta a 0 (present in M. potapovi vs. absent in M. processus sp. nov.) and body (more chaetae in M. potapovi). M. sanctistephani lacks chaeta X on Ant. IV (present in M. processus sp. nov.) and has 2 sublobal hairs on maxilary outer lobe (vs. 1 in M. processus sp. nov.). M. processus sp. nov., M. roseus sp. nov. and M. laevis share the reduced chaetotaxy. Both new species differ from M. laevis by the presence of process, the absence (vs. presence) of sensilla s 3 on body and 3 + 3 (vs. 4 + 4) teeth on tenaculum. The new species differs from widely distributed M. willemi and M. minimus by many characters, including the process and smaller flame-shaped inner sensilla. M. processus sp. nov. differs from M. roseus sp. nov. with shape of the process, chaetotaxy of forehead, number of sublobal hairs, and shape of inner sensilla in sensory field. The four species (M. sanctistephani, M. potapovi, M. roseus sp. nov., M. processus sp. nov.) belong to minimus - group (in spite of doubts on M. roseus sp. nov.) Their “ nose ”, however, is unlikely homologous if considering its shape and location. The independent appearance of this process probably indicates its importance to these species. The function of small unpaired “ nose ” is, presumably, delicate unlike, e. g., in stiff epistome in Acari (which protects mouth parts). In Collembola with similar position of head (Symphypleona), specific equipment on head front appear in sexually dimorphic taxa only (e. g., " nasal " organ in Nasosminthurus Stach) which cannot be associated to mentioned congeners of Megalothorax at all because of parthenogenesis.	en	Panina, Kseniya, Babenko, Anatoly, Potapov, Mikhail (2022): Two new « nosed » species of the genus Megalothorax (Collembola: Neelidae) from Russia. Zootaxa 5188 (4): 383-395, DOI: https://doi.org/10.11646/zootaxa.5188.4.6
0389879EFFDACA4334AAFF16FC4AFB72.taxon	distribution	Distribution and ecology. Megalothorax processus sp. nov. is recorded from the arctic deserts to the mountains of Southern Siberia. It occurs in meadows, floodplain forests, and thickets along rivers. It is probably noted as Megalothorax sp. 2 in the East-European tundra (Babenko et al. 2017).	en	Panina, Kseniya, Babenko, Anatoly, Potapov, Mikhail (2022): Two new « nosed » species of the genus Megalothorax (Collembola: Neelidae) from Russia. Zootaxa 5188 (4): 383-395, DOI: https://doi.org/10.11646/zootaxa.5188.4.6
