Revision of Disphaerobius Attems, 1926 (Chilopoda: Lithobiomorpha: Lithobiidae: Pterygoterginae), a centipede genus with remarkable sexual dimorphism

Abstract

Disphaerobius Attems, 1926, the sole constituent genus of the subfamily Pterygoterginae, is synonymized with Pterygotergum Verhoeff, 1934 syn. nov., and is shown to comprise only two species: D. svenhedini (Verhoeff, 1934) comb. nov. ex Pterygotergum, and D. loricatus (Sseliwanoff, 1881) (= Lithobius magnificus Trotzina, 1895), both syn. nov. and comb. nov. ex Lithobius Leach, 1814. Disphaerobius is rediagnosed, both of its basically Central Asian species are redescribed from fresh material of both sexes, and their distributions are mapped. Disphaerobius svenhedini is newly recorded from S Kazakhstan and W Mongolia. New material of D. loricatus is also recorded. Sexual dimorphic characters in Lithobiomorpha are briefly discussed, these being considered especially strongly pronounced and unique in Disphaerobius.

Morphology of the mandibles and the first maxillae in the family Lithobiidae (Myriapoda, Chilopoda), with remarks on their phylogenetic significance

“…Based on a number of striking similarities in the peristomatic structures, Ganske et al () inferred a close relationship between the genus Disphaerobius (= Pterygotergum ), on which the subfamily Pterygoterginae Verhoeff, 1933, is based, and the lithobiine (sub)genera Lithobius and Ezembius . These similarities are congruent with other shared characters from external morphology identified in a recent taxonomic work (Farzalieva et al, ). Here, we further compared the mandibular gnathal edge of Disphaerobius loricatus , Hessebius plumatus (Zalesskaja, ) and Lithobius ( Ezembius ) giganteus and noted strong similarities, especially in the presence of simple spines on the internal side; the low number of simple, triangular accessory denticles; and the similar pattern of the fringing bristles, these branching distally only and showing broad bases.…”

“…Phylogenetic analyses using maximum parsimony and maximum likelihood of the newly described characters together with characters from other morphological systems were performed, including characters extracted from other Lithobiidae, Henicopidae, and two representatives of Scutigeromorpha as outgroup. We further compared the mandibular gnathal edge of Disphaerobius loricatus (Sseliwanoff, ) and Lithobius ( Ezembius ) giganteus Sseliwanoff, and, together with the phylogenetic results, verified that it supports previous suggestions on their relationships based on external morphological and peristomatic characters (Farzalieva, Nefediev, & Tuf, ; Ganske et al, ). This is of particular systematic importance because Disphaerobius is usually classified separately from Lithobius , in the subfamilies Pterygoterginae and Lithobiinae, respectively.…”

“…We observed the presence of those setae in L. electus (Silvestri, , Figure and new observation) as well. Interestingly, these setae are absent in males of D. loricatus , but were described for its congener Disphaerobius svenhedini (Verhoeff, 1934) (Farzalieva et al, , Figure ).…”

“…State (0) is recorded in H. anodus (Koren, , p. 29) and L. mutabilis (Koren, , Figure 33a). Sulci on femora only (state (1)) are for example observed in L. forficatus (Koren, , Figure b), D. loricatus and L. giganteus (both Farzalieva & Zalesskaja, , p. 266 and Farzalieva et al, , Table ). State (2) applies to L. pelidnus (Matic, , p. 171) and E. grossipes (Koren, , p. 20).…”

New records of lithobiid centipedes (Chilopoda: Lithobiomorpha) from Western Mongolia

“…Six species are known from Xinjiang (China) (Ma et al, 2014) and 15 species from Altai Republic in Russia (Zalesskaja, 1978;Nefediev et al, 2016Nefediev et al, , 2017a. Ten species of centipedes are known from the best studied northern part of Mongolia (Poloczek et al, 2016), while only six species have been reported from western part of country, namely Disphaerobius svenhedini (Verhoeff, 1934) Loksa, 1978, Hessebius styliferus (Loksa, 1978) and Schizotergitius altajicus Loksa, 1978(Loksa, 1965Farzalieva et al, 2017). This paper is based on the material collected by A.A. DISTRIBUTION.…”