Posterior Gonopods Research Articles

Phylogenetic analysis of the millipede genus Argentocricus Verhoeff, 1941 (Spirobolida, Rhinocricidae) based on morphological characters

ABSTRACT This paper offers the first cladistic analysis of the genus Argentocricus Verhoeff, 1941 based on the most comprehensive morphological data matrix focusing on Rhinocricidae to date. We evaluated 50 morphological characters for 40 species as terminal taxa, representing all the nine species of Argentocricus and 31 outgroups. We performed a parsimony analysis under Implied Weighting (IW), obtaining one most parsimonious tree (K = 8.274, fit = 4.680). We obtained a monophyletic Argentocricus including two species of Rhinocricus supported by the following synapomorphies: sternite of anterior gonopod with median portion and very evident coxite; telopodite of anterior gonopod in posterior view with a membranous bulge; and external branch of the posterior gonopod digitiform. Expanded coxae of the male leg pairs 3, a character traditionally used to diagnose the genus, was not recovered as a synapomorphy. Based on the resulting topology, we propose transferring Rhinocricus boggianii Silvestri, 1898 and R. venefica Chamberlin, 1947 to Argentocricus resulting in a new combination of Argentocricus boggianii (Silvestri, 1898) comb. nov. and Argentocricus venefica comb. nov. In addition, a new diagnosis for the genus and a distribution map for all species are provided. We propose new characters potentially useful for future phylogenetic studies.

Two new species of Siphonorhinidae (Myriapoda: Diplopoda: Siphonophorida) from mid-Cretaceous Burmese amber

Two new species of the millipede family Siphonorhinidae, Siphonorhinus globosus sp. nov. and Siphonorhinus peculiaris sp. nov., are described from the mid-Cretaceous Burmese amber. Detailed morphological characters are provided on the basis of 22 specimens, mainly using confocal laser scanning microscopy. The new species can be confidently placed in the extant genus Siphonorhinus based on the head lacking a beak-like rostrum, antennae stout and elbowed; antennomeres 5 and 6 each with a field of basiconic sensilla, and gonopods leg-like, with apical podomere of posterior gonopod divided to two branches. A detailed comparison between the new and extant species is given.

Two new millipede species of the genus Coxobolellus Pimvichai, Enghoff, Panha & Backeljau, 2020 (Diplopoda, Spirobolida, Pseudospirobolellidae).

Two new millipede species of the genus Coxobolellus Pimvichai, Enghoff, Panha & Backeljau, 2020 from Thailand are described: Coxobolellussaratani sp. nov. from Loei Province and Coxobolellusserratoligulatus sp. nov. from Uttaradit Province. The descriptions are based on gonopod morphology and two mitochondrial gene fragments (COI and 16S rRNA). The phylogenetic mtDNA analysis assigned the two new species unequivocally to the consistently well-supported Coxobolellus clade, in which they form a fifth subclade that was well supported by maximum likelihood analysis of 16S rRNA, though neither by Bayesian inference nor by COI. The two new Coxobolellus species share four conspicuous gonopodal synapomorphies of the genus: (1) the protruding process on the coxae of the 3rd (and sometimes 4th) pair of male legs, (2) a large, triangular coxae on the 4th-5th pair of legs, (3) a short process of the preanal ring protruding as far as, or slightly beyond, the anal valves, and (4) the posterior gonopod telopodite divided into two parts, with a conspicuous pore opening at the mesal margin at the end of the coxal part of the posterior gonopod. Thus, the two new species provide further evidence of the well-defined monophyly of the genus Coxobolellus. Finally, the paper provides an updated morphological identification key to all currently described Coxobolellus species.

A new genus of Pseudospirobolellidae (Diplopoda, Spirobolida) from limestone karst areas in Thailand, with descriptions of three new species

A new genus of the millipede family Pseudospirobolellidae, Siliquobolellusgen. nov., is described from limestone mountains in Thailand, based on three new species, viz. Siliquobolellus amicusdraconisgen. et sp. nov. from Uthaithani Province, Siliquobolellus constrictusgen. et sp. nov. from Prachuap Khiri Khan Province and Siliquobolellus prasankokaegen. et sp. nov. (type species) from Lampang Province. The descriptions are based on gonopod morphology and mitochondrial DNA data (COI barcodes). The COI barcodes grouped the three new species in a well-supported Siliquobolellusgen. nov. clade. The mean interspecific COI sequence divergence among the three new species was 12% (range: 8–15%). The mean intergeneric COI sequence divergence between Siliquobolellusgen. nov., Coxobolellus Pimvichai, Enghoff, Panha & Backeljau, 2020, and Pseudospirobolellus Carl, 1912 was 19% (range: 14–23%). Three conspicuous gonopodal synapomorphies differentiate Siliquobolellusgen. nov. from other pseudospirobollellid genera: (1) the telopodital part of the posterior gonopod forms a deep concavity, (2) the telopodite of the anterior gonopod is directed distad and does not reach the tip of the coxal part of the anterior gonopod, and (3) the tip of the anterior gonopod coxa is narrowed, curving mesad. As such, the monophyly of the new genus is well supported by both morphological and mitochondrial DNA data. A distribution map and an identification key to the species are provided.

Carinobolus gen. nov. and Costabolus gen. nov., two new, remarkably crested, monospecific genera of spirobolidan millipedes from West Africa, with the proposal of a new tribe, Amblybolini tribus nova (Diplopoda, Spirobolida, Pachybolidae)

Two new genera, Carinobolus gen. nov. and Costabolus gen. nov., both belonging to the very large, widespread, pantropical family Pachybolidae, are described based on Carinobolus complex sp. nov. and Costabolus baculus sp. nov., respectively. Chiefly based on the posterior gonopod being distinctly articulated at midlength, both new genera seem to be especially similar to Amblybolus Keeton, 1964a (three species in western Africa) and Atlanticobolus Hoffman, 1979 (one species from an island off the Brazilian coast), all of them meriting a separate tribal category, Amblybolini tribus nova. A key is proposed to distinguish all four presently accepted genera of the new tribe. The new genera and species are clearly distinguished in showing unusually strongly crested/ribbed metazonae, a character that is only very seldom observed in Pachybolidae generally, and apparently unique among Afrotropical members. Being rather similar in many respects, both new genera and species differ from each other sufficiently well in gonopodal and leg structure, even though both come from forests in southeastern Nigeria close to the border to Cameroon.

Two new species of the previously monospecific genus Guipuzcosoma Vicente amp; Mauris, 1980 from Spain, with establishment of Guipuzcosomatidae fam. nov. (Diplopoda: Chordeumatida).

The present paper refers to the description of two new species of the previously monospecific genus Guipuzcosoma, viz., Guipuzcosoma karinae sp. nov. and G. reipi sp. nov. Given the unique combination of characters of this genus, we have established a higher taxonomic category, Guipuzcosomatidae fam. nov., which is clearly different from the family Vandeleumatidae, to which Guipuzcosoma was assigned earlier. Based on the structures of the anterior and posterior gonopods, we speculate that the new family may belong to the superfamilies Anthroleucosomatoidea or Cleidogonoidea. A diagnosis of the family, a brief description of the genus, as well as a diagnosis of all three species and detailed descriptions with illustrations of the two new species are presented. All three species were mapped. Additionally, some problems related to the taxonomy and classification within Chordeumatida, as well as the hypothetical association of the new family with some other chordeumatidans, are briefly discussed. Finally, the monospecific genus Miniusoma Mauris, 2014 is transferred here from the family Vandeleumatidae to the family Anthogonidae.

Combining mitochondrial DNA and morphological data to delineate four new millipede species and provisional assignment to the genus

Hitherto, the millipede genus Apeuthes (family Pachybolidae, subfamily Trigoniulinae) was only known from three species described in Vietnam based on morphological characters. The present study uses two partial mitochondrial gene fragments (cytochrome c oxidase I (COI) and 16S ribosomal RNA) and morphology to define four new Apeuthes species from Malaysia, Thailand and Vietnam: A. fimbriatus, sp. nov., A. longeligulatus, sp. nov., A. pollex, sp. nov. and ?A. spininavis, sp. nov. The intraspecific COI sequence divergence of two Apeuthes species is 3–7% (mean: 5%) and the interspecific divergence of five species is 11–16% (mean: 13.7%). All members of the genus share unique male characters, viz the posterior gonopod telopodite with several dentate, serrate or tuberculate lamellae in a boat-like cavity or a boat-like cavity covered with spines. The delimitation of the four new species is supported by the congruence between mitochondrial DNA and morphological data. However, while the monophyly of Trigoniulinae is well supported, the relationships within this subfamily, and particularly among Apeuthes species, including the monophyly of Apeuthes, lack strong support. Therefore assignment of the four new species, and particularly of ?A. spininavis sp. nov., to the genus Apeuthes is tentative and awaits a comprehensive revision of the group.

Two new species of the millipede genus Glyphiulus Gervais, 1847 (Diplopoda, Spirostreptida, Cambalopsidae) from caves in northern Thailand.

Two new species of the genus Glyphiulus Gervais, 1847 are described and illustrated. The first species, G.longussp. nov., is the second species of the javanicus-group to be found in Thailand. It resembles G.guangnanensis Jiang, Guo, Chen & Xie, 2018, from southern China, but is distinguished by a smaller size and the carinotaxic formula of the collum, combined with ♂ legs 1 bearing very strongly reduced telopodites, the anterior gonopods showing a pair of very long and slender apicomesal processes, and the denser plumose and stout flagella of the posterior gonopods. The second species, G.promdamisp. nov., the fifth member of the granulatus-group in Thailand, seems to be particularly similar to G.subbedosae Likhitrakarn, Golovatch & Panha, 2017, from Laos. However, it can be distinguished from the latter species mainly by showing a uniformly yellow collum and the posterior gonopod coxite bearing several strong setae in median and lateral views, coupled with the anterior gonopod coxosternum being microsetose in the anterior and medial parts in caudal view. An identification key to, and a distribution map of, all seven Glyphiulus species currently known to occur in Thailand are also provided.

Dichromatobolus, a new genus of spirobolidan millipedes from Madagascar (Spirobolida, Pachybolidae)

A new genus, Dichromatobolus gen. nov., belonging to the genus-rich mainly southern hemisphere family Pachybolidae of the order Spirobolida, is described based on D. elephantulus gen. et sp. nov., illustrated with color pictures, line drawings, and scanning electron micrographs. The species is recorded from the spiny bush of southwestern Madagascar. Dichromatobolus elephantulus gen. et sp. nov. shows an unusual color pattern, sexual dichromatism with males being red with black legs and females being grey. Males seem to be more surface active, as mainly males were collected with pitfall traps. Females mainly come from the pet trade. The body of this species is short and very wide, being only 8 times longer than wide in the males. Live observations show the species is a very slow mover, digging in loose soil almost as fast as walking on the surface. The posterior gonopods of Dichromatobolus gen. nov. are unusually simple and well-rounded, displaying some similarities to the genera Corallobolus Wesener, 2009 and Granitobolus Wesener, 2009, from which the new genus differs in numerous other characters, e.g., size, anterior gonopods and habitus. Despite several attempts with fresh tissue samples and different primers, molecular barcoding did not work for Dichromatobolus gen. nov. Any relationships to the other 15 genera of Pachybolidae indigenous to Madagascar remain unknown.

Two new species of the millipede genus Plusioglyphiulus Silvestri, 1923 from Cambodia (Diplopoda, Spirostreptida).

Two new species of Plusioglyphiulus are described from southern Cambodia. Plusioglyphiulus biserratussp. nov. is clearly distinguished from all congeners by the shape of the telopodites of the posterior gonopods which are distinctly serrate laterally and by the anterior gonopods showing only a pair of single, smooth and curved coxosternal processes. Plusioglyphiulus khmer sp. nov. is distinguished by having most crests on the collum being complete and male legs 1 showing long, prominent, one-segmented telopodites, coupled with the oblong-subtrapeziform, membranous, posterior gonopods with a small bifid process at about a third of the telopodite length. Notes on the variation of Plusioglyphiulus boutini Mauriès, 1970 are also given, including a colour photograph of fresh, live material. A key to all four species of Plusioglyphiulus currently known to occur in Cambodia is also presented.

Integrative taxonomy of the new millipede genus Coxobolellus, gen. nov. (Diplopoda : Spirobolida : Pseudospirobolellidae), with descriptions of ten new species

Pseudospirobolellidae is a poorly known family of spirobolidan millipedes with only two genera and five described species. Yet, the descriptive taxonomy and molecular systematics of this group have been largely neglected. Therefore, the present work presents an integrative taxonomic study of new pseudospirobolellid taxa in Thailand. To this end, two mitochondrial gene fragments (COI and 16S rRNA) combined with morphological characters were used to define the genus Coxobolellus, gen. nov. with 10 new species, viz. C. albiceps, sp. nov., C. compactogonus, sp. nov., C. fuscus, sp. nov., C. nodosus, sp. nov., C. serratus, sp. nov., C. simplex, sp. nov., C. tenebris, sp. nov., C. tigris, sp. nov., C. transversalis, sp. nov. and C. valvatus, sp. nov. The interspecific COI sequence divergences among the new species ranged from 6 to 15%. The intergeneric COI sequence divergence between species of Coxobolellus, gen. nov., Benoitolus birgitae and Pseudospirobolellus sp. ranged from 20 to 23%. Three major morphological differences separate Coxobolellus, gen. nov. from Benoitolus and Pseudospirobolellus, namely (1) the protruding process on the 3rd (and 4th) coxae on male legs, (2) the posterior gonopod telopodite divided into two parts, and (3) a conspicuous opening pore at the mesal margin at the end of the coxal part of the posterior gonopod. Thus, the new genus is well supported by both mtDNA and morphological evidence, while the delimitation of the 10 new species is supported by the congruence between mtDNA and morphological data. Yet, with respect to the relationships of Benoitolus birgitae, morphological data suggest a similarity with Coxobolellus, gen. nov. and Pseudospirobolellus, whereas mtDNA data place this species in the Pachybolidae. Further phylogenetic analyses are needed to explore this apparent incongruence and test the monophyly of Pseudospirobolellidae.

Two new species of the millipede family Cambalopsidae from Myanmar (Diplopoda, Spirostreptida).

Two new species of cave-dwelling millipedes are described from Myanmar, one each in the genera Plusioglyphiulus Silvestri, 1923 and Trachyjulus Peters, 1864. Plusioglyphiulus digitiformis sp. n. joins the small peculiar group of congeners from Thailand which is characterized by such plesiomorphies as the tergal crests on the collum and following metaterga being transversely divided into two, not three parts, as in species of the genus Glyphiulus Gervais, 1847. However, this new species differs by the 3-segmented telopodites of ♂ legs 1, the anterior gonopodal coxosternum showing higher and nearly straight apicomesal processes and very evident apicolateral teeth, as well as the higher and acuminate paramedian coxal processes of the posterior gonopods, the latter’s telopodites demonstrating an apical fovea bearing a group of microsetae at the bottom. Trachyjulus bifidus sp. n. is primarily distinguished by the telopodites of their anterior gonopods being strikingly and deeply bifid. A key to the five species of Cambalopsidae currently known to occur in Myanmar is presented, and a map showing their distributions given.

Dalmatosomatidae, a new monotypic family, and Dalmatosoma agaricum gen. et sp. nov. (Diplopoda: Chordeumatida: Craspedosomatidea) from Croatia, Balkan Peninsula.

A new millipede species, Dalmatosoma agaricum gen. et sp. nov., is described from a cave in Dalmatia (Croatia). The new taxon is clearly unique among chordeumatidans in both anterior and posterior gonopod structure and shows some noteworthy habitus features. We therefore here establish a new monotypic family, viz., Dalmatosomatidae, for the given taxon and place it within the suborder Craspedosomatidea. The new family is briefly discussed and compared with all other chordeumatidans.

Two new species of the millipede genus Glyphiulus Gervais, 1847 from Laos (Diplopoda, Spirostreptida, Cambalopsidae).

Two new species of Glyphiulus are described and illustrated from northern Laos. The epigean Glyphiulus subbedosae Likhitrakarn, Golovatch & Panha, sp. n. is the second member of the granulatus-group to be found in that country and it seems to be especially similar to G. bedosae Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2007. However, it differs from the latter species by a row of several strong setae near the median marginal ridge on the paraprocts, combined with the gnathochilarium being considerably less densely setose on the caudal face, and the anterior gonopods showing a pair of smaller, apical, but larger lateral teeth on the coxosternal plate. Glyphiulus semicostulifer Likhitrakarn, Golovatch & Panha, sp. n. is the fourth member of the javanicus-group to be discovered in Laos, taken from a cave. It seems to be particularly similar to G. costulifer Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2007, but is distinguished by the more sparsely alveolate background fine structure of the metazonae, coupled with the gnathochilarium being considerably less densely setose on the caudal face, much stronger paramedian prongs and 4-segmented telopodites on ♂ coxae 1, the slightly longer and more slender apicoparamedian sternal projections on the anterior gonopods, and the much longer flagella of the posterior gonopods. An identification key to and a distribution map of Glyphiulus species in Laos are also presented.

Review of the genus Ommatoiulus in Andalusia, Spain (Diplopoda: Julida) with description of ten new species and notes on a remarkable gonopod struc-ture, the fovea

A comprehensive revision of the species of the genus Ommatoiulus in Andalusia, southern Spain, is carried out for thefirst time, revealing the presence of a total of 19 species, among which are one new record for the country, one for con-tinental Spain, two new records for Andalusia and 10 species new to science: Ommatoiulus baenai, O. baileyi, O. hoff-mani, O. jaenensis, O. kimei, O. pseudoflagellatus, O. recueroi, O. reipi, O. sabinarensis, O. schubarti n.spp. Thefollowing taxa are synonymised: Schizophyllum hoplites Verhoeff, 1910, S. diplurum appendiculatum Brolemann,1925, and Ommatoiulus diplurus mauriesi Hoffman, 1975, are regarded as junior synonyms of Ommatoiulus diplurus(Attems, 1903), n.syn. Schizophyllum dorsovittatum estrellanum Verhoeff, 1910, and S. calatravanum Brolemann,1920, are junior synonyms of Ommatoiulus dorsovittatus (Verhoeff, 1893), n.syn. Schizophyllum nivale Schubart,1959, is a junior synonym of Omnmatoiulus ilicis (Brölemann, 1896), n.syn. Full descriptions and diagnostic notes areprovided for all the species with accounts on their distributions, habitats, and notes discussing their taxonomy. A di-chotomous identification key, based on gonopod structures, is presented to facilitate species identification. In the dis-cussion section, the general patterns of species distribution are underlined, showing a clear tendency to ‘endemism’ forthe majority of species and to polymorphism for species with broader distribution ranges, especially O. diplurus. A dis-junct distribution Andalusia/Pyrenees is registered for O. ilicis. A comprehensive comparison of gonopods is attempt-ed, and three main types of gonopod configuration are delimited, denoting a wide range of structural complexity. Thefovea, a cavity in the posterior gonopods, is explored for the first time with scanning electron microscopy, revealing anagglutination of spermatozoa and confirming Verhoeff’s original observation dating back nearly 120 years. The con-stancy of the fovea in all Schizophyllini, combined with its absence in the rest of the julids, provides an additional apomorphy for the tribe.

The millipede genus Plusioglyphiulus Silvestri, 1923 in Thailand (Diplopoda, Spirostreptida, Cambalopsidae)

The basically southeast Asian genus Plusioglyphiulus is shown to currently comprise 27 species, all keyed, of which 13 are new, stemming from Thailand, and mapped: P. panhai sp. n., P. antiquior sp. n., P. sutchariti sp. n., P. likhitrakarni sp. n., P. pimvichaiae sp. n., P. erawan sp. n., P. wat sp. n., P. tham sp. n., P. phra sp. n., P. jaydee sp. n., P. puttakun sp. n., P. saksit sp. n. and P. samakkee sp. n. Although the new species have mainly been collected in caves, none seems to actually represent a troglobiont. A second record of P. ampullifer Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009 is provided in southern Vietnam, as well as new illustrations are presented for P. bessoni Golovatch, Geoffroy, Mauriès & VandenSpiegel, 2009, prepared from strictly topotypic samples in northern Thailand. With the discovery of P. panhai sp. n. and, especially, P. antiquior sp. n., both from southern Thailand, and both markedly transitional to the more northerly diversified javanicus-group of Glyphiulus, the genus Plusioglyphiulus is reconfirmed as being heterogeneous. Its diagnosis seems to be based now only on a single, rather weak apomorphy in posterior gonopod structure. Some evolutionary and zoogeographical considerations are presented to substantiate the predominantly eastward and/or southward speciation events in typical Plusioglyphiulus which have reached northern and eastern Borneo in the east and southeast.

A new species of <i>Tarracoblaniulus</i> Mauriès & Vicente, 1977: description, postembryonic development, life cycle, and spatial distribution (Diplopoda, Julida, Blaniulidae)

Tarracoblaniulus phantasmanus n. sp. is described from Tarragona province, Spain and compared with the only known other species known in the genus, T. lagari Mauries & Vicente, 1977, from which it differs mainly in having only 5, instead of 15 or more, straight spines on the posterior gonopod. The female vulva (unknown in T. lagari ) is very different from all known blaniulid vulvae. Based on a large number of specimens, the postembryonic development (euanamorphosis) from stadium II onward is described. This is highly variable, with three to six apodous body rings in stadium IV, which is the most variable number so far recorded in Blaniulidae. Accordingly, specimens beyond stadium VIII could not be assigned to a specific stadium. At least some males are morphologically distinguishable in stadium IV, morphologically mature males appear in stadium VIII, possibly already in stadium VII. The life cycle of the new species is tentatively suggested to involve at least three years. The monthly mean density of the total population was 28.82 ind/m2 across the whole soil profile. Statistically significant differences in density values between months and Spearman’s rank correlation analyses between the monthly mean values of density and temperature show that T. phantasmanus presents a maximum density in the coldest months and a minimum one in the summer. Significant differences between monthly mean densities of different soil levels and the Usher index values show that during the spring and summer T. phantasmanus is concentrated in the mineral horizon A. In autumn, during winter and up to early spring, the population shows a clear tendency to move up towards horizon H and horizon L/F. Concerning horizontal distribution, Morisita index monthly values for each of the horizons indicate that the species is distributed in patches.

A new species and new records of millipedes of the family Diplomaragnidae (Diplopoda, Chordeumatida) from Altai

Altajosoma corniferum sp. n. is described from the Republic of Altai, Siberia, Russia. The new species differs from congeners mainly by the large, horn-shaped lateral sheath processes of the posterior gonopod colpocoxites. New faunistic records for Altai are given for other species of the family Diplomaragnidae. All currently known members of Diplomaragnidae from Altai are keyed, including the new species.

Arvechamboides ocala, n. gen., n. sp., a new aniulinine milliped from peninsular Florida, USA (Julida: Parajulidae)

Arvechamboides ocala, n. gen., n. sp., is proposed for a male aniulinine milliped in Marion County, Florida; no females are available. The genus is the fourth in the Parajulidae recorded from Florida, all representatives of the Aniulini, and the second known only from the state, the other being Gyniulus Loomis, 1963. The posterior gonopods of Arvechamboides possess both true and accessory prefemoral processes, the former being a feature of Pseudojulus Bollman, 1887, and the latter, a trait of Arvechambus Causey, 1963. The 8th sternum expands laterally into broad lobes as in Arvechambus, and the generic name reflects the shared anatomical features with this genus. "Sphaerotrichomes" are observed on the tibiae & tarsi of the 1st legs and are reported in retrospect for previously studied aniulinine genera.

Ommatoiulus malleatus n. sp., a new Tunisian millipede, with notes on the punicus species group of Ommatoiulus (Diplopoda, Julidae)

A new millipede species, Ommatoiulus malleatus n. sp. (Diplopoda, Julidae), is described from the Ichkeul National Park, Tunisia. The gonopod structure of the species indicates the punicus-group which includes Ommatoiulus punicus (Brölemann, 1894), Ommatoiulus seurati (Brolemann, 1925), Ommatoiulus aumalensis (Brolemann, 1925), Ommatoiulus atlanteus Schubart, 1960, Ommatoiulus quadridentatus Schubart, 1960 recorded from North Africa and Ommatoiulus brandti (Berlese, 1885) from Sicily. The new species is, however, well differentiated by a particular “hammer-like structure” on the mesomerite process of the posterior gonopod.