﻿An updated synthesis of the Geophilomorpha (Chilopoda) of Asian Russia

﻿Abstract A comprehensive overview of the state of knowledge on the ChilopodaGeophilomorpha of the Asian part of Russia is presented, based on the critical revision of all published morphological descriptions and all geographical records. Revised diagnoses for all the 38 nominal species so far reported from Asian Russia are given, with comments on their validity. Among them a total of 18 species are recorded only from this region and many of them from a single locality only. The species belong to Geophilidae s. l., (in the genera Arctogeophilus, Geophilus, Pachymerium, and Strigamia), Schendylidae (Escaryus), and Mecistocephalidae (Agnostrup, Arrup, and Tygarrup). At least two species have been introduced, namely Geophilusflavus and Tygarrupjavanicus. The history of studies on the Geophilomorpha in the Asian part of Russia are also summarized.


Introduction
The fauna of Chilopoda Geophilomorpha of large part of the Palearctic region, especially the Asian part of Russia, is still badly understood in comparison with other regions.While the species recorded from Europe, including the European part of Russia, have been recently reviewed (Bonato and Minelli 2014;Volkova 2016), available information and records on the Geophilomorpha living in the Asian part of Russia are still scattered in many and relatively old publications.Moreover, the overall knowledge of many species is largely incomplete, with brief descriptions hardly accessible or comparable.
The present paper aims to provide a comprehensive overview of the state of knowledge of Geophilomorpha from Asian Russia, in order to promote and facilitate further taxonomic and faunistic investigations.ZooKeys 1198: 17-54 (2024), DOI: 10.3897/zookeys.1198.119781Yurii V. Dyachkov & Lucio Bonato: An updated synthesis of the Geophilomorpha (Chilopoda) of Asian Russia
Diagnosis.A species of Arctogeophilus with first maxillary lappets relatively short; denticles on all forcipular articles; denticles on the forcipular intermediate articles only slightly shorter than those on trochanteroprefemur and tarsungulum; 39 leg-bearing segments, possibly invariably; ventral pore-fields absent; pretarsus of ultimate legs absent.
Remarks.The position of the locality "Nunamo" (indicated by Attems 1909) is uncertain: the original material was collected during the Vega expedition, and Nordenskiöld (1882: 565, 567) mentioned a tent-village "Nunamo" located in Chukotka, but he did not indicate the precise position of this place.Instead, Nordenskiöld (1882: 565) provided coordinates for "Konyam Bay" = Penkigney Bay.
Remarks.Zalesskaja et al. (1982: 189) suggested this species can be a junior synonym of A. glacialis (Attems, 1909), and this is still in doubt (Nefediev et al. 2017a).Because of this uncertainty, the actual taxonomic status of the populations of Arctogeophilus from the Far East remains to clarify.
The type locality for A. macrocephalus has been sometimes reported erroneously in previous publications (e.g., Bonato and Minelli 2014).

Diagnosis.
A species of Arctogeophilus with first maxillary lappets relatively long; forcipular denticles only on the trochanteroprefemur and tarsungulum, not on the intermediate articles; 39 leg-bearing segments, possibly invariably; ventral pore-fields on some anterior segments; pretarsus of ultimate legs absent.
Remarks.It has been suggested that A. sachalinus could be a junior synonym of A. glacialis (Attems, 1909) (Nefediev et al. 2017a).More generally, the actual taxonomic status of the populations of Arctogeophilus from the Far East remains to clarify.

Genus Geophilus Leach, 1814
Diagnosis.Geophilids with head usually only slightly elongate; clypeal areas usually not distinct; labral side-pieces distinctly separated by an intermediate ZooKeys 1198: 17-54 (2024), DOI: 10.3897/zookeys.1198.119781Yurii V. Dyachkov & Lucio Bonato: An updated synthesis of the Geophilomorpha (Chilopoda) of Asian Russia part; second maxillary coxosternite medially long and sclerotized, without both statuminia and anterior inner processes; second maxillary pretarsus claw-like or reduced; forcipular tergite approximately as broad as the subsequent tergite, covering most part of the pleurites; forcipular coxosternite usually wider than long, gradually narrowing posteriorly, without anterior denticles, with chitin-lines, with coxopleural sutures diverging anteriorly also in their anterior half; forcipular trochanteroprefemur only moderately elongate, usually without denticles; forcipular tarsungulum with at most a small basal denticle; trunk sternites often with "carpophagus" pits and often with ventral pore-fields, usually a transverse band on the posterior part of the sternite; metasternite of the ultimate leg-bearing segment usually wider than long; coxopleura with sparse ventral pores, most of them close to metasternite; pretarsus of ultimate leg pair claw-like or reduced.See Table 3.
Diagnosis.A species of Geophilus with head slightly longer than wide, 35-39 leg-bearing segments; "carpophagus" pits present, up to as wide as the metasternites; ventral pore-fields present, an entire posterior diamond on the anterior metasternites, absent on most of the posterior metasternites, two paired posterior groups on the penultimate metasternite; metasternite of ultimate leg-bearing segment wider than long; a few coxal pores on each coxopleuron, all close to the margin of metasternite; pretarsus of ultimate leg pair claw-like; anal pores present.

Geophilus orientalis
Remarks.The species was originally described under the genus Geophilus, but its taxonomic position is considered uncertain since Attems (1929).The few morphological characters reported in the descriptions and keys by Sseliwanoff (1881Sseliwanoff ( , 1884) ) do not allow it to be assigned confidently to one of the known genera.
Diagnosis.A species of Geophilus with head slightly longer than wide; antennal articles ≤ ~ 1.5× as long as wide; second maxillary pretarsus claw-like, longer than surrounding setae; forcipular trochanteroprefemur slightly longer than wide; forcipular trochanteroprefemur, femur, and tibia without denticles; forcipular tarsungulum bearing a small basal denticle; 45-55 leg-bearing segments; "carpophagus" pits present, up to as wide as the metasternites; ventral pore-fields present, an entire posterior diamond on the anterior metasternites, absent on the posterior metasternites; metasternite of ultimate leg-bearing segment wider than long; up to a dozen coxal pores on each coxopleuron, all close to the margin of metasternite; pretarsus of ultimate leg pair claw-like; anal pores present.
Type series.Syntypes: unknown number of specimens, both sexes.Depository unknown.

Diagnosis.
A species of Geophilus with head approximately as long as wide; second maxillary pretarsus claw-like and relatively long; forcipular trochanteroprefemur, femur, and tibia without denticles; forcipular tarsungulum bearing a small basal denticle; 43-49 leg-bearing segments; "carpophagus" pits present, up to as wide as the metasternites; ventral pore-fields present, an entire posterior diamond on the anterior metasternites; metasternite of ultimate leg-bearing segment wider than long; a few coxal pores on each coxopleuron, most of them close to the margin of metasternite and one pore located separately; pretarsus of ultimate leg pair claw-like; anal pores present.

Diagnosis.
A species of Geophilus with head ~ 1.2× as long as wide; tarsungulum without basal denticle; 57-59 leg-bearing segments; more than a dozen coxal pores on each coxopleuron, both on the ventral and lateral sides; pretarsus of ultimate leg pair claw-like; anal pores absent.
Remarks.The species was originally described under the genus Geophilus, but its taxonomic position was considered uncertain since Attems (1929).The few morphological characters reported in the descriptions by Stuxberg (1876aStuxberg ( , 1876b) ) do not allow to confidently assign it to one of the known genera.
Diagnosis.A species of Geophilus with second maxillary pretarsus claw-like, longer than surrounding setae; forcipular trochanteroprefemur slightly longer than wide; forcipular trochanteroprefemur, femur and tibia without denticles; forcipular tarsungulum bearing a small basal denticle; 55-57 leg-bearing segments; "carpophagus" pits present, up to as wide as the metasternites; ventral pore-fields present, an entire posterior band and other sparse pores on the anterior metasternites, absent on the posterior metasternites; metasternite of ultimate leg-bearing segment wider than long; a few coxal pores on each coxopleuron, most of them close to the margin of metasternite and one pore located separately; anal pores present.
Diagnosis.A species of Pachymerium with two paired clypeal areas; forcipular coxosternite with chitin-lines, which extend for most part of the length of the coxosternite, but do not reach the anterior margin; both forcipular trochanteroprefemur and tarsungulum with relatively small denticles; 41-69 leg-bearing segments; ventral pore-fields present, also on the posterior part of the trunk, where they are reduced to two paired posterior groups on each metasternite; ultimate metasternite trapezoidal, approximately as long as wide, distinctly tapering towards the posterior margin; all coxal pores sparse from the ventral to the dorsal sides of the coxopleura.
The assignment of this nominal species to the genus Pachymerium is only tentative (Bonato et al. 2016), and is suggested only by the following few characters described by Meinert (1870): head ~ 1.2× as long as wide, forcipular coxosternite very broad and with two anterior denticles, forcipules surpassing the anterior margin of the head, coxopleura elongate and with dense coxal pores not only on the ventral side but also on the lateral and dorsal ones, ultimate legs slightly longer than penultimate legs and bearing a claw.
The current identity and position of the locality "Sartung" (indicated by Meinert 1870) is uncertain.
Diagnosis.A species of Strigamia with clypeal setae arranged in an intermediate and two lateral groups; forcipular tarsungula not surpassing the anterior margin of the head; basal denticle of forcipular tarsungulum relatively short and with straight converging margins; 37-43 leg-bearing segments; metasternites of the anterior part of the trunk without a mid-longitudinal sclerotized stripe; ultimate leg-bearing segment with pleuropretergite entire, i.e., without distinct intercalary pleurites, and metasternite approximately as long as wide.
Diagnosis.A species of Strigamia with forcipular tarsungula not surpassing the anterior margin of the head; basal denticle of forcipular tarsungulum relatively large; internal and external margins of forcipular tarsungulum subparallel in their intermediate part; 51-67 leg-bearing segments; metasternites of the anterior part of the trunk with a mid-longitudinal sclerotized stripe; ultimate leg-bearing segment with distinct intercalary pleurites, and metasternite distinctly wider than long.
Diagnosis.A species of Strigamia with forcipular tarsungula not surpassing the anterior margin of the head; basal denticle of forcipular tarsungulum relatively short; internal and external margins of forcipular tarsungulum gradually converging through the entire length; 39-53 leg-bearing segments; ultimate leg-bearing segment with distinct intercalary pleurites and metasternite longer than wide.
Remarks.The taxonomic distinction of this nominal species from S. sacolinensis is uncertain.
Records from South-Eastern Asia are doubtful (Bonato et al. 2012).Diagnosis.A species of Strigamia with forcipular tarsungula not surpassing the anterior margin of the head; basal denticle of forcipular tarsungulum relatively short, pointed, and with straight outlines; internal and external margins of forcipular tarsungulum gradually converging through the entire length; 33-39 leg-bearing segments; metasternites of the anterior part of the trunk without a mid-longitudinal sclerotized stripe; ultimate leg-bearing segment with distinct intercalary pleurites and metasternite as long as wide or longer than wide.

Diagnosis.
A species of Strigamia with forcipular tarsungula surpassing the anterior margin of the head; 43-47 leg-bearing segments; metasternites of the anterior part of the trunk without a mid-longitudinal sclerotized stripe.
Distribution.Far East: Khabarovsk krai (Sseliwanoff 1881(Sseliwanoff , 1884) ) and Sakhalin oblast (Sakhalin Isl.) (Meinert 1870;Molodova 1973;Kurcheva 1977;Ganin 1997) Remarks.Bonato et al. (2012) suggested the putative projection of the forcipules in front of the anterior margin of the head can be due to some post-mortem displacement of the head with respect to the trunk.Based on the incomplete description provided by Meinert (1870), this nominal species could be a senior synonym of either S. hirsutipes or S. japonica (Verhoeff, 1935).
The current identity and position of the locality "Sartung" (indicated by Meinert 1870) is uncertain.Type series.Syntypes: 4 specimens, including 1 male and 3 females.Deposited in ZISP.
Diagnosis.A species of Strigamia with forcipular tarsungula not surpassing the anterior margin of the head; 33-35 leg-bearing segments.
Diagnosis.A species of Strigamia with forcipular tarsungula not surpassing the anterior margin of the head; 41-43 leg-bearing segments.
Diagnosis.A species of Strigamia with clypeal setae uniformly spaced in a continuous array, without recognizable gaps between intermediate and lateral groups of setae; forcipular tarsungula not surpassing the anterior margin of the head; basal denticle of forcipular tarsungulum relatively large and with distinctly curved outlines; internal and external margins of forcipular tarsungulum gradually converging through the entire length; 43-57 leg-bearing segments; metasternites of the anterior part of the trunk without a mid-longitudinal sclerotized stripe; ultimate leg-bearing segment with pleuropretergite entire, i.e., without distinct intercalary pleurites, and metasternite approximately as long as wide.
Remarks.Strigamia transsilvanica belongs to a species complex whose taxonomy is only partially resolved (Bonato et al. 2023).Bonato et al. (2012) suggested that the records from Russian Far East are probably due to misidentification of a different species.Nefediev et al. (2018) suggested the presence of a possible undescribed species similar in morphology to S. transsilvanica from Western Siberia, so that also the presence of S. transsilvanica in Western Siberia is doubtful.Doubtful are also the records from European Russia and Caucasus (Zuev and Evsyukov 2016;Dyachkov et al. 2022;Dyachkov and Zuev 2023), Eastern Kazakhstan (Dyachkov 2018b), Japan, and Taiwan (Bonato et al. 2012).
Diagnosis.An Agnostrup species with body length reaching ≥ 3 cm; clypeal plagulae with an irregular anterior margin and slightly smaller than the areolate part of the clypeus; many setae near the anterior margin of plagulae and on the center of the areolate part of the clypeus; forcipular trochanteroprefemur 1.3× as long as wide, both forcipular femur and tibia with small bulges.
Diagnosis.An Arrup species with body length reaching ≥ 3 cm; second maxillary pretarsi absent; forcipular trochanteroprefemur with a large distal denticle, both femur and tibia with small bulges, tarsungulum with pointed basal denticle.

Genus Tygarrup Chamberlin, 1914
Diagnosis.Mecistocephalids with head distinctly longer than wide; clypeus with an entire plagula, without mid-longitudinal areolate stripe and extending to the lateral margins of the clypeus; cephalic pleurites without both spiculum and setae; first maxillary coxosternite medially divided by a sulcus, without antero-lateral corners; second maxillary coxosternite medially undivided, with the grooves from the metameric pores reaching the lateral margins; second maxillary telopodites distinctly overreaching the first maxillary telopodites, with claw-like pretarsus; forcipular tergite only slightly wider than long, without a distinct mid-longitudinal sulcus; forcipular trochanteroprefemur with only a distal denticle, tarsungulum without denticle; invariably 43 or 45 leg-bearing segments; sternites with non-furcate mid-longitudinal sulcus and sometimes with pore-fields; legs of the ultimate pair ending with a short spine.See Table 6.
Diagnosis.A Tygarrup species with body length ≤ 2 cm; no distinct dark patches along the body; second maxillary pretarsus with a long slender point; both forcipular trochanteroprefemur and tibia with denticles; invariably 45 leg-bearing segments; ventral pore-fields absent in females, present in males; metasternite of the ultimate leg-bearing segment slightly wider than long.
Remarks.The species is regarded as an anthropochore introduction in Asian Russia (Nefediev 2019).

Family Schendylidae Cook, 1896 Genus Escaryus Cook & Collins, 1891
Diagnosis.Schendylids with head slightly longer than wide; antennae gradually tapering; labrum with distinct denticles in the intermediate part; first maxillae with lappets; second maxillary pretarsi fringed by two rows of filaments; forcipular tergite narrower than subsequent tergite; ventral pore-fields absent; coxal pores numerous and scattered; legs of the ultimate pair with two tarsal articles and claw-like pretarsus, swollen in adult males and slender in females; gonopods biarticulated in both sexes.See Table 7.
Type series.Syntypes: unknown number of specimens, both sexes.Depository unknown.
Diagnosis.An Escaryus species with body length reaching ≥ 2 cm; clypeus with small plagulae; labral arc relatively shallow, with denticles short and obtuse; first maxillae with one pair of lappets; forcipular trochanteroprefemur, femur, and tibia with small bulges, tarsungulum without bulge; 35-39 leg-bearing segments; metasternites with relatively sparse setae; metasternite of the ultimate leg-bearing segment trapezoid, approximately as long as wide; coxal pores on both ventral and lateral sides of coxopleura; anal pores present.
Diagnosis.An Escaryus species with body length reaching ≥ 2 cm; clypeus without plagulae (polygonal structure poorly visible, but recognizable); labral arc relatively shallow, with denticles short and obtuse; first maxillae with one pair of lappets; forcipular trochanteroprefemur and tarsungulum with large denticles, femur and tibia with small denticles; 37-39 leg-bearing segments; metasternites with relatively sparse setae; metasternite of the ultimate leg-bearing segment trapezoid, slightly longer than wide; coxal pores on both ventral and lateral sides of coxopleura; anal pores present.
Remarks.Titova (1973) indicated that the type series was from two localities ("Suputinsky zapovednik" and "Kedrovaya Pad"), but she did not state explicitly which is the locality of the holotype.
Diagnosis.An Escaryus species with body length reaching ≥ 2.5 cm; clypeus with large plagulae; labral arc relatively deep, with denticles long and obtuse; first maxillae with one pair of lappets; all forcipular articles with large bulges; 37-39 leg-bearing segments; metasternites with relatively dense setae; metasternite of the ultimate leg-bearing segment almost rectangular, ~ 1.5× as long as wide; coxal pores on both ventral and lateral sides of coxopleura; anal pores present.
Diagnosis.An Escaryus species with body length reaching ≥ 4.3 cm; clypeus with large plagulae; labral arc relatively shallow, with denticles long and obtuse; first maxillae with one pair of lappets; forcipular trochanteroprefemur with a small distal denticle, all other articles with very small bulges; 43-55 leg-bearing segments; metasternites with relatively sparse setae; metasternite of the ultimate leg-bearing segment rectangular, ~ 2× as long as wide; coxal pores of similar size, on both ventral and lateral sides of coxopleura; anal pores present.
Diagnosis.An Escaryus species with body length reaching ≥ 6.5 cm; clypeus with large plagulae; labral arc relatively shallow, with long denticles, the middle denticles obtuse, the lateral ones pointed; first maxillae with one pair of lappets; forcipular trochanteroprefemur with an small obtuse denticle, femur and tibia without denticles, tarsungulum with a small basal bulge; 43-55 leg-bearing segments; metasternites with relatively dense setae; metasternite of the ultimate leg-bearing segment rectangular, ~ 2× as long as wide; coxal pores of different size, on both ventral and lateral sides of coxopleura, including a pair of much larger pores on each coxopleuron; anal pores present.
Diagnosis.An Escaryus species with body length reaching ≥ 2 cm; clypeus without plagulae; labral arc relatively deep, with denticles short and obtuse; first maxillae with one pair of lappets; forcipular trochanteroprefemur and tibia with large bulges, femur and tarsungulum with small bulges; 45-49 leg-bearing segments; metasternite of the ultimate leg-bearing segment trapezoid, approximately as long as wide; coxal pores on both ventral and lateral sides of coxopleura, the pair of largest pores close to inner edge of coxopleura; anal pores present.
Remarks.Titova (1973) indicated that the type series was from three localities ("Suputinsky zapovednik", "Kangauz", and "Kedrovaya Pad"), but she did not state explicitly which is the locality of the holotype.
Diagnosis.An Escaryus species with body length reaching ≥ 1.4 cm: clypeus with small plagulae; labral arc relatively shallow, with denticles short and obtuse; first maxillae with one pair of lappets; forcipular trochanteroprefemur, femur and tibia with small denticles; forcipular tarsungulum with a large, pointed basal denticle; 35 leg-bearing segments; metasternites with relatively sparse setae; metasternite of the ultimate leg-bearing segment trapezoid, approximately as long as wide; coxal pores only on the ventral side of coxopleura; anal pores present.
Diagnosis.An Escaryus species with body length reaching ≥ 2 cm; clypeus with small plagulae; labral arc relatively shallow, with denticles short and obtuse; first maxillae with one pair of lappets; forcipular trochanteroprefemur and tibia with small denticles, femur without denticle, tarsungulum with a large basal denticle; 39-43 leg-bearing segments; metasternite of the ultimate leg-bearing segment trapezoid, distinctly wider than long; most of coxal pores on the ventral side of coxopleura, mostly close to metasternite; anal pores present.
Remarks.Titova (1973) indicated that the type series was from two localities ("Suputinsky zapovednik" and "Rayon r.Sinancha"), but she did not state explicitly which is the locality of the holotype.
Diagnosis.An Escaryus species with body length reaching ≥ 2.8 cm; clypeus with small plagulae; labral arc relatively deep, with denticles short and obtuse; first maxillae with one pair of lappets; forcipular trochanteroprefemur, femur, and tibia with small bulges; forcipular tarsungulum without denticle; 39 leg-bearing segments; metasternites with relatively sparse setae; metasternite of the ultimate leg-bearing segment trapezoid, ~ 1.5× as long as wide; coxal pores of different size, on both ventral and lateral sides of coxopleura; anal pores present.
Remarks.Titova (1973) indicated that the type series was from two localities ("Suputinsky zapovednik" and "Kedrovaya Pad"), but she did not state explicitly which is the locality of the holotype.
Diagnosis.An Escaryus species with body length reaching ≥ 4 cm; clypeus with small plagulae; labral arc relatively deep, with denticles long and obtuse; first maxillae with one pair of lappets; forcipular trochanteroprefemur, femur, and tibia with small denticles, tarsungulum with a small bulge; 49-55 leg-bearing segments; metasternites with relatively sparse setae; metasternite of the ultimate leg-bearing segment trapezoid, approximately as long as wide; coxal pores on both ventral and lateral sides of coxopleura; anal pores absent.
Diagnosis.An Escaryus species with body length reaching ≥ 3 cm; clypeus without plagulae; labral arc relatively deep, with denticles short and obtuse; first maxillae with lappets; all forcipular articles with small denticles, except tarsungulum; 35-39 leg-bearing segments; metasternite of the ultimate leg-bearing segment rectangular, ~ 1.5× as long as wide; numerous coxal pores on ventral side of coxopleuron; anal pores present.
Diagnosis.An Escaryus species with body length reaching 6.5 cm; labral arc relatively shallow, with middle denticles obtuse and lateral ones long and pointed; first maxillae with two pairs of lappets; forcipular trochanteroprefemur with a small distal bulge, other forcipular articles without denticles; 49-51 leg-bearing segments; metasternite of the ultimate leg-bearing segment rectangular, ~ 2× as long as wide; coxal pores of different size, on both ventral and lateral sides, including a pair of much larger ventral pores on each coxopleuron; anal pores absent.
Remarks.Titova (1969) reported this species from Western Siberia (Kemerovo oblast) but later (Titova 1973) she regarded the same record as E. koreanus, even though she also suggested that the latter species can be a junior synonym of E. sibiricus.The anal pores were indicated as absent by Cook (1899) and Attems (1904) but illustrated as present in specimens identified as E. sibiricus by Thofern et al. (2021), and they are known to be present in E. koreanus.Type series.Holotype: female.Paratypes: 3 specimens, including 1 male and 2 females.Deposited in ZMMU (S.Golovatch andA. Schileyko, pers. comm., 13.II.2023 andXII.2023).

Escaryus vitimicus
Diagnosis.An Escaryus species with body length reaching ≥ 2.7 cm; clypeus with large plagulae; labral arc relatively shallow, with denticles long and obtuse; first maxillae with one pair of lappets; all forcipular articles with small bulges; 37 leg-bearing segments; metasternites with relatively sparse setae; metasternite of the ultimate leg-bearing segment rectangular, ~ 1.5× as long as wide; coxal pores on both ventral and lateral sides of coxopleura, the largest pores near the metasternite; anal pores present.

Other records of uncertain species
During ecological studies (Ghilarov and Perel 1973;Molodova 1973;Kurcheva 1977;Markelov and Mineeva 1981;Ganin 1997) some specimens of Geophilomorpha were not identified at the species level.These records are listed below.

State of knowledge
The published records of Geophilomorpha from Asian Russia refer to 38 nominal species, arranged in eight genera (Table 1).However, the taxonomic validity of ≥ 19 species is uncertain, including 14 species that are known from Asian Russia only (Table 1).The taxonomic status of most of these species has never been revised since they were originally described.Of all the species reported from Asian Russia, only nine are also known from European Russia, where, a total of 41 species from 17 genera have been reported so far (Volkova 2016;Zuev and Evsyukov 2016;Dyachkov and Bonato 2022).
The records of Tygarrup javanicus and Geophilus flavus from hothouses in Western Siberia by Nefediev et al. (2017a;Nefediev 2019) seems to be due to anthropochore introduction.However, the occurrence of Geophilus flavus outside hothouses in Asian Russia requires confirmation.Gerstfeldt (1859) identified a sole specimen from Eastern Siberia (Zabaykalsky krai) as Arthronomalus longicornis (= Geophilus flavus), but Sseliwanoff (1884: 90) questioned this identification.Moreover, the nominal species Schizotaenia ornata Folkmanová & Dobroruka, 1960 was mentioned by Zalesskaja et al. (1982) from Western Siberia, however without providing information on specimens or published sources.This nominal species was considered a junior synonym of Geophilus proximus by Zalesskaja et al. (1982), but was later synonymized under G. flavus by Bonato and Minelli (2014).Nefediev et al. (2017a) suggested that some previous records of G. flavus from the former USSR may be reported under the name G. proximus.
Other species require confirmation from Asian Russia.The records of Strigamia acuminata from Far East and S. transsilvanica from Western Siberia and Far East are dubious because of possible confusion with other species (Bonato et al. 2012(Bonato et al. , 2023)).Moreover, Titova (1972Titova ( , 1973) ) indicated the presence of Escaryus retusidens from the Russian Far East, but she did not mention material from that region when she listed the studied specimens.Nefediev et al. (2017aNefediev et al. ( , 2017cNefediev et al. ( , 2018) ) indicated this species from the Far East with reference to Titova (1972Titova ( , 1973)).It is worth noting that E. retusidens has never been recorded during ecological studies in Eastern Siberia (Alekseeva 1974;Vorobiova 1999;Vorobiova et al. 2002;Rybalov 2002) or the Far East (Kurcheva 1977;Ganin 1997Ganin , 2006Ganin , 2011)).
Our synthesis of all published information on Geophilomorpha from Asian Russia shows that the knowledge of this fauna is very far from being satisfactory.We hope that this work may provide a background reference and will prompt further investigations.

Table 1 .
Nominal species of Geophilomorpha reported from Asian Russia: i -anthropochore introduction, * -uncertain taxonomic validity, !-known from Asian Russia only.

Table 2 .
Differences between species of the genus Arctogeophilus Attems, 1909 known from Asian Russia and adjacent territories.Arctogeophilus with first maxillary lappets relatively long; denticles on all forcipular articles, those on intermediate articles smaller than those on trochanteroprefemur and tarsungulum; 35-43 leg-bearing segments; ventral pore-fields on some anterior segments; pretarsus of ultimate legs absent.

Table 3 .
Differences between species of the genus Geophilus Leach, 1814 known from Asian Russia.

Table 4 .
Differences between species of the genus Pachymerium C.L. Koch, 1847 known from Asian Russia.

Table 5 .
Differences between species of the genus Strigamia Gray, 1843 known from Asian Russia.

Table 6 .
Differences between members of the family Mecistocephalidae Bollman, 1893 known from Asian Russia.

Table 7 .
Differences between species of the genus Escaryus Cook & Collins, 1891 known from Asian Russia.