The origins of the giant pill-millipedes from Madagascar (Diplopoda: Sphaerotheriida: Arthrosphaeridae)

Integrative taxonomy reveals two new giant pill-millipedes of the genus Zephronia Gray, 1832 from eastern Thailand (Diplopoda, Sphaerotheriida, Zephroniidae)

A large amount of material of the millipede genus Zephronia Gray, 1832 was collected during 2014-2023 from many parts of eastern Thailand. An integrative study of morphological characters and genetic data (COI gene) revealed two new species: Z.chantaburiensis Srisonchai & Wesener, sp. nov. and Z.macula Srisonchai & Wesener, sp. nov. The two new species clearly differ from other congeners by their unique characteristics, especially in their colour pattern and telopod shape. The interspecific genetic distances of the 658 bp COI gene barcoding fragment between these new species and all other species of giant pill-millipede from Thailand, Laos and Cambodia are 12.01-23.49% for Z.chantaburiensis sp. nov. and 17.93-25.13% for Z.macula sp. nov. While relationships among species remain preliminary, the phylogenetic tree shows that species of Zephronia are interspersed with species of Sphaerobelum Verhoeff, 1924 and Prionobelum Verhoeff, 1924. Phylogenetic analyses place both new species in a clade termed Zephronia s.s., which receives support also from morphological data, showing a unique position of the organ of Tömösváry. Z.macula sp. nov. appears to occur over a broad distribution whereas Z.chantaburiensis sp. nov. was found only at the type locality. Given that all known records are in the eastern part of Thailand, we thus regard both species as endemic. Morphological illustrations based on SEM micrographs and a distribution map are also provided.

Novel mitochondrial gene rearrangements pattern in the millipede Polydesmus sp. GZCS-2019 and phylogenetic analysis of the Myriapoda

The subphylum Myriapoda included four extant classes (Chilopoda, Symphyla, Diplopoda, and Pauropoda). Due to the limitation of taxon sampling, the phylogenetic relationships within Myriapoda remained contentious, especially for Diplopoda. Herein, we determined the complete mitochondrial genome of Polydesmus sp. GZCS-2019 (Myriapoda: Polydesmida) and the mitochondrial genomes are circular molecules of 15,036 bp, with all genes encoded on + strand. The A+T content is 66.1%, making the chain asymmetric, and exhibits negative AT-skew (-0.236). Several genes rearrangements were detected and we propose a new rearrangement model: "TD (N\R) L + C" based on the genome-scale duplication + (non-random/random) loss + recombination. Phylogenetic analyses demonstrated that Chilopoda and Symphyla both were monophyletic group, whereas Pauropoda was embedded in Diplopoda to form the Dignatha. Divergence time showed the first split of Myriapoda occurred between the Chilopoda and other classes (Wenlock period of Silurian). We combine phylogenetic analysis, divergence time, and gene arrangement to yield valuable insights into the evolutionary history and classification relationship of Myriapoda and these results support a monophyletic Progoneata and the relationship (Chilopoda + (Symphyla + (Diplopoda + Pauropoda))) within myriapod. Our results help to better explain the gene rearrangement events of the invertebrate mitogenome and lay the foundation for further phylogenetic study of Myriapoda.

Ecotone shifts in southern Madagascar: first barcoding data and six new species of the endemic millipede genus Riotintobolus (Spirobolida, Pachybolidae)

Six new species of the Spirobolida millipede genus Riotintobolus Wesener, 2009, are described from the spiny forest in southern Madagascar utilising genetic barcoding, drawings and scanning electron microscopy: Riotintobolus tsimelahy sp. nov., R. mangatsiaka sp. nov., R. lavanono sp. nov., R. bovinus sp. nov., R. antafoky sp. nov. and R. makayi sp. nov. One other Riotintobolus population from the spiny forest might represent an additional species based on genetic data, but it cannot be described as no male specimens were collected. At present, the genus Riotintobolus Wesener, 2009 has eight species from the spiny forest and two species from the littoral rainforest. A determination key to all ten species of the genus is provided. Molecular data reveal that the two critically endangered species from the humid littoral rainforest are not closely related to one another, but have their closest relative in the dry spiny forest ecosystem. Riotintobolus mandenensis Wesener, 2009, only known from the southern littoral rainforest of Mandena is related to R. tsimelahy sp. nov. from the nearby spiny forest at Tsimelahy with a p-distance of 11%, while R. minutus Wesener, 2009 from the littoral forest of Sainte Luce is more distant to all other Riotintobolus species, but more closely related to R. bovinus sp. nov. from the southwestern forest of the Makay.

The millipedes collected by the Museum "La Specola" on Madagascar 1989/1991, with the description of three new species of giant pill-millipedes (Diplopoda, Sphaerotheriida, Arthrosphaeridae)

A large collection of millipedes (Diplopoda) from Madagascar, belonging to the Museum "La Specola" in Florence, Italy were investigated. The collection includes three new species of the giant pill-millipede genus Zoosphaerium Pocock, 1895 which are described here as Zoosphaerium mangabe Wesener, sp. nov., Z. bartolozzii Anilkumar & Wesener, sp. nov., and Z. taitii Anilkumar & Wesener, sp. nov., all belonging to the Z. coquerelianum species group. The latter two are currently only known from a single site. Other specimens belonging to eight orders (Polyxenida, Sphaerotheriida, Polyzoniida, Siphonophorida, Chordeumatida, Polydesmida, Spirobolida, and Spirostreptida) are listed. Three tropical tramp species, Pseudospirobolellus avernus (Butler, 1876), Glyphiulus granulatus Gervais, 1847, and Chondromorpha xanthotricha (Attems, 1898) are recorded for the first time from Madagascar. New locality data is provided for Zoosphaerium neptunus (Butler, 1872), Z. villosum Wesener & Sierwald, 2005, Z. blandum (de Saussure & Zehntner, 1897), Sphaeromimus musicus (de Saussure & Zehntner, 1897), Rhinotus purpureus (Pocock, 1894), Hylekobolus andasibensis Wesener, 2009, Aphistogoniulus infernalis Wesener, 2009, Ostinobolus rufus Wesener, 2009, Ostinobolus subterraneus Wesener, 2009, Dactylobolus bivirgatus (Karsch, 1881), and Eumekius antimena (de Saussure & Zehntner, 1901).

Intraspecific variation and phylogeography of the millipede model organism, the Black Pill Millipede Glomerismarginata (Villers, 1789) (Diplopoda, Glomerida, Glomeridae)

The Black Pill Millipede, Glomerismarginata, is the best studied millipede species and a model organism for Diplopoda. Glomerismarginata is widespread, with numerous colour morphs occurring across its range, especially in the south. This study investigates whether colour morphs might represent cryptic species as well as the haplotype diversity and biogeography of G.marginata. The results of the COI barcoding fragment analysis include 97 G.marginata, as well as 21 specimens from seven potentially related species: G.intermedia Latzel, 1884, G.klugii Brandt, 1833 (G.undulata C.L. Koch, 1844), G.connexa Koch, 1847, G.hexasticha Brandt, 1833, G.maerens Attems, 1927, G.annulata Brandt, 1833 and G.apuana Verhoeff, 1911. The majority of the barcoding data was obtained through the German Barcode of Life project (GBOL). Interspecifically, G.marginata is separated from its congeners by a minimum uncorrected genetic distance of 12.9 %, confirming its monophyly. Uncorrected intraspecific distances of G.marginata are comparable to those of other widespread Glomeris species, varying between 0–4.7%, with the largest genetic distances (>2.5 %) found at the Mediterranean coast. 97 sampled specimens of G.marginata yielded 47 different haplotypes, with identical haplotypes occurring at large distances from one another, and different haplotypes being present in populations occurring in close proximity. The highest number of haplotypes was found in the best-sampled area, western Germany. The English haplotype is identical to northern Spain; specimens from southern Spain are closer to French Mediterranean specimens. Analyses (CHAO1) show that approximately 400 different haplotypes can be expected in G.marginata. To cover all haplotypes, it is projected that up to 6,000 specimens would need to be sequenced, highlighting the impossibility of covering the whole genetic diversity in barcoding attempts of immobile soil arthropod species.

Two new Lophoturus species (Diplopoda, Polyxenida, Lophoproctidae) from Queensland, Australia

Lophoturusqueenslandicus Verhoeff, 1924 was the first penicillate millipede in the family Lophoproctidae collected from Cairns, a tropical region in Queensland, Australia, to be formally described. Specimens collected from this region in a recent study had the morphological characters known to define this genus. However, their body form and length, as well as dorsal colouration proved to be different, suggesting the possibility of more than one Lophoturus species. This assertion was supported by the results of a phylogenetic analysis of DNA extracted and sequenced using 18S and COI regions from L.queenslandicus and two undescribed species from this genus. Specimens preserved in ethanol can prove difficult to confidently identify to species level because their colour gradually fades. Examination of live specimens with their body colour visible, together with morphological characters and DNA analysis is the most reliable way of correctly distinguishing between these three species. Two new species, L.boondallussp. n. and L.molloyensissp. n. collected in Queensland, Australia are described.

An apparently non-swinging tentorium in the Diplopoda (Myriapoda): comparative morphology of the tentorial complex in giant pill-millipedes (Sphaerotheriida)

The presence of a swinging tentorium is a key apomorphy of Myriapoda, but this character has been studied in detail in only few species. Here the tentorium, i.e., the peristomatic skeleton of the preoral chamber, is comparatively studied in three species of the millipede order Sphaerotheriida Brandt, 1833. Since dissections of the fragile tentorial components proved to be difficult, despite the large head size, they were analysed mainly in situ via micro-computed tomography. Our results confirm previous observations of large differences in the tentorial construction in the giant pill-millipedes compared to chilognathan diplopods. The tentorium of Sphaerotheriida consists of a curved, plate-like epipharyngeal bar with distal projections, an elongate and thin hypopharyngeal bar, and a plate-like triangular posterior process; a transverse bar is absent. Only seven muscles attach at the tentorium in giant pill-millipedes, including two antennal muscles and two muscles of the gnathochilarium. Within the order Sphaerotheriida, the composition of the tentorium and its muscular equipment seems to be conserved, except for some variability in the shape of the epipharyngeal bar. As the transverse bar has been considered essential for the mobility of the tentorium in myriapods, its absence in Sphaerotheriida may indicate that their tentorium is not capable of performing a swing. Loss of tentorial mobility may also pertain to the order Glomerida Brandt, 1833, inferred here from the absence of a posterior process. An apparently immobile tentorium in Glomerida and Sphaerotheriida can straightforwardly be correlated with transformations of the head related to their ability of volvation. The different transformations of the tentorium, here hypothesised to cause immobility, may support current assumptions that the ability of volvation evolved convergently in Glomerida and Sphaerotheriida. This conclusion, however, still requires more detailed studies of the head anatomy in Glomerida and Glomeridesmida Cook, 1895.

Four new species of the millipede genus Eutrichodesmus Silvestri, 1910 from Laos, including two with reduced ozopores (Diplopoda, Polydesmida, Haplodesmidae)

Laos has large areas of primary forest with a largely unexplored fauna. This is evidenced by millipedes, class Diplopoda, with fewer than 60 species being recorded from the country. In the widespread Southeast Asian “Star Millipede” genus Eutrichodesmus Silvestri, 1910 (family Haplodesmidae), only two of 49 recorded species have been found in Laos. Four new species of Star Millipedes are here described from caves in Laos: Eutrichodesmussteineri Liu & Wesener, sp. n., Eutrichodesmusdeporatus Liu & Wesener, sp. n., Eutrichodesmusparaster Liu & Wesener, sp. n. and Eutrichodesmusparvus Liu & Wesener, sp. n.. A fifth species, for which only a female is available, remains unnamed. The defensive glands (ozopores) are found to be strongly or entirely suppressed in two of the new species, Eutrichodesmusdeporatus Liu & Wesener, sp. n. and Eutrichodesmusparaster Liu & Wesener, sp. n., both troglobionts, which is new to the family. All of the Star Millipedes were collected during Northern Lao-European Cave Project faunal surveys conducted by the Senckenberg Museum, Frankfurt. A key to the six species of Eutrichodesmus currently known to occur in Laos is provided.

Two new species of Phryssonotus (Diplopoda : Synxenidae) from southern and western Australia

For many years Phryssonotus novaehollandiae Silvestri, 1923 was thought to be the only species of this genus present in Australia. Specimens collected from three geographically separated populations had similar taxonomically important morphological characters and body lengths. However, their body scale trichomes exhibited three distinctive patterns: a trapezoid, T-shape, or dark banding, and the length-to-width ratios of their trichomes also differed. These differences, as well as results of phylogenetic analysis using 18S and COI gene regions from representatives of the three populations, suggested that more than one Phryssonotus species were present. Specimens of Phryssonotus preserved in ethanol can prove difficult to distinguish because the colour patterning gradually fades. Examination of the colour patterns of live specimens, other morphological characters and DNA analysis together, were found to be the most reliable method of correctly distinguishing between these three species. P. novaehollandiae Silvestri, 1923, the first described species collected from South Australia, remains, with its range extended to inland Victoria, and two new species (P. australis, sp. nov. and P. occidentalis, sp. nov.) are described.

Biochemical composition of two giant pill-millipedes of the Western Ghats of India

Many invertebrates have an unexpected nutraceutical potential and are of nutritional or ethnomedicinal significance to many tribals throughout the world. The giant pill-millipedes of the genus Arthrosphaera are traditionally used as natural medicines by tribals in the Western Ghats of India. In this study, two species of pill-millipedes (Arthrosphaera fumosa and A. magna) were subjected to proximate and biochemical analysis to ascertain their nutritional potential. Bodies of A. fumosa and A. magna (after removal of their intestines) had a low protein content (8-15%) and high quantity of carbohydrates (40-41%). They were rich in many essential elements, especially in calcium. The essential amino acids of pillmillipedes were in high quantities. The level of glycine was the highest, followed by lysine and serine. The fatty acid methyl esters (FAMEs) of males and females consist of high quantities of unsaturated fatty acids. The mono-unsaturated fatty acids were more abundant than poly-unsaturated fatty acids. Palmitic and oleic acids were dominant saturated and unsaturated fatty acids, respectively. The study has revealed for the first time that pill-millipedes of the Western Ghats of India constitute a good source of essential minerals, essential fatty acids, and essential amino acids. Being valuable contributors of organic manure by processing recalcitrant plant lignocellulosic wastes, pill-millipedes become part and parcel of organic farming as well as future nutraceutical sources.

Steps towards a phylogeny of the pill millipedes: non-monophyly of the family Protoglomeridae, with an integrative redescription of Eupeyerimhoffiaarchimedis (Diplopoda, Glomerida)

Eupeyerimhoffiaarchimedis (Strasser, 1965) is redescribed based on several specimens collected at a number of sites close to the type locality on Sicily, Italy. Scanning electron microscopy is used to illustrate several unusual morphological characters for a member of the Glomerida for the first time. A fragment of the mitochondrial COI gene (668bp) is sequenced for the first time in Eupeyerimhoffia to provide a species-specific barcode and to gain first insights into the genetic distances between the genera in the widespread family Protoglomeridae. The novel sequences are compared to representatives of all other genera of the family: Protoglomerisvasconica (Brölemann, 1897) from northern Spain, the dwarfed Glomerellinalaurae Silvestri, 1908 from Italy and Glomeroidesprimus (Silvestri, 1929) from western North America. The addition of COI sequences from the two other families of the Glomerida renders the family Protoglomeridae paraphyletic with Glomeroidesprimus being more closely related to Glomeridellaminima (Latzel, 1884) than to the other genera in the family. The large genetic distances (13.2–16.8%) between Eupeyerimhoffia and the other genera in the order, as well as its unusual morphological characters, including unique morphological adaptations to roll into a ball, are probably an indication of the old age of the group.

The evolutionary history of the rediscovered Austrian population of the giant centipede Scolopendra cingulata Latreille 1829 (Chilopoda, Scolopendromorpha)

The thermophilous giant centipede Scolopendra cingulata is a voracious terrestrial predator, which uses its modified first leg pair and potent venom to capture prey. The highly variable species is the most common of the genus in Europe, occurring from Portugal in the west to Iran in the east. The northernmost occurrences are in Hungary and Romania, where it abides in small isolated fringe populations. We report the rediscovery of an isolated Austrian population of Scolopendra cingulata with the first explicit specimen records for more than 80 years and provide insights into the evolutionary history of the northernmost populations utilizing fragments of two mitochondrial genes, COI and 16S, comprising 1,155 base pairs. We test the previously proposed hypothesis of a speciation by distance scenario, which argued for a simple range expansion of the species from the southeast, via Romania, Hungary and finally to Austria, based on a comprehensive taxon sampling from seven countries, including the first European mainland samples. We argue that more complex patterns must have shaped the current distribution of S. cingulata and that the Austrian population should be viewed as an important biogeographical relict in a possible microrefugium. The unique haplotype of the Austrian population could constitute an important part of the species genetic diversity and we hope that this discovery will initiate protective measures not only for S. cingulata, but also for its habitat, since microrefugia are likely to host further rare thermophilous species. Furthermore, we take advantage of the unprecedented sampling to provide the first basic insights into the suitability of the COI fragment as a species identifying barcode within the centipede genus Scolopendra.

Integrative revision of the giant pill-millipede genus Sphaeromimus from Madagascar, with the description of seven new species (Diplopoda, Sphaerotheriida, Arthrosphaeridae)

The Malagasy giant pill-millipede genus Sphaeromimus de Saussure & Zehntner, 1902 is revised. Seven new species, S. titanus sp. n., S. vatovavy sp. n., S. lavasoa sp. n., S. andohahela sp. n., S. ivohibe sp. n., S. saintelucei sp. n., and S. andrahomana sp. n. were discovered, in one case with the help of sequence data, in the rainforests of southeastern Madagascar. The species are described using light- and scanning electron microscopy. A key to all 10 species of the genus is presented. All but one (S. andohahela) of the newly discovered species are microendemics each occurring in isolated forest fragments. The mitochondrial COI barcoding gene was amplified and sequenced for 18 Sphaeromimus specimens, and a dataset containing COI sequences of 28 specimens representing all Sphaeromimus species (except S. vatovavy) was analyzed. All species are genetically monophyletic. Interspecific uncorrected genetic distances were moderate (4-10%) to high (18-25%), whereas intraspecific variation is low (0-3.5%). Sequence data allowed the correct identification of three colour morphs of S. musicus, as well as the identity of a cave specimen, which although aberrant in its morphology and colouration, was genetically identical to the holotype of S. andrahoma.

Strong phylogeographic structure in a millipede indicates Pleistocene Vicariance between populations on banded iron formations in semi-arid Australia

The Yilgarn Banded Iron Formations of Western Australia are topographical features that behave as terrestrial islands within the otherwise flat, semi-arid landscape. The formations are characterised by a high number of endemic species, some of which are distributed across multiple formations without inhabiting the intervening landscape. These species provide an ideal context for phylogeographic analysis, to investigate patterns of genetic variation at both spatial and temporal scales. We examined genetic variation in the spirostreptid millipede, Atelomastix bamfordi, found on five of these Banded Iron Formations at two mitochondrial loci and 11 microsatellite loci. Strong phylogeographic structuring indicated the five populations became isolated during the Pleistocene, a period of intensifying aridity in this landscape, when it appears populations have been restricted to pockets of moist habitat provided by the formations. The pattern of reciprocal monophyly identified within the mtDNA and strong differentiation within the nuclear microsatellite data highlight the evolutionary significance of these divergent populations and we suggest the degree of differentiation warrants designation of each as a conservation unit.

A new phylogenetic analysis of the Sphaerotheriida (Diplopoda) with a revision of the Australian giant pill-millipedes

Cyliosoma Pocock, 1895, the oldest available genus name for Australian giant pill-millipedes, is revised with a redescription of its type species, Sphaerotherium angulatum Butler, 1878. All 16 species of Epicyliosoma Silvestri, 1917 are transferred to Cyliosoma, together with two species, Sphaerotherium fraternum Butler, 1872 and S. marginepunctatum Karsch, 1881, which are redescribed here. A new phylogenetic analysis of the Sphaerotheriida was conducted using 100 morphological characters and including two Cyliosoma species and four recently described or redescribed species of the family Zephroniidae. Most character states are illustrated for Cyliosoma, including the first SEM images of a member of the genus. Cyliosoma is neither closely related to the South African Sphaerotherium, nor to the other Australian genus, Procyliosoma, and is here placed in a new family, Cyliosomatidae. The monotypic Australian genus Cynotelopus Jeekel, 1986 is also referred to the Cyliosomatidae. The current position of the Cyliosomatidae is in a trichotomy including the South African Sphaerotheriidae and the Malagasy–Indian Arthrosphaeridae.

Molecular phylogeny of the Thyropygus allevatus group of giant millipedes and some closely related groups

Giant cylindrical millipedes of the family Harpagophoridae, especially species of the genus Thyropygus, are broadly distributed in Thailand and nearby countries. They show a great deal of variation in body size, color patterns and gonopodal characters. Phylogenetic analyses of 26 nominate species from six genera in the subfamilies Harpagophorinae and Rhynchoproctinae, as well as nine new morphotypes (regarded as new species), were performed with the DNA sequences from two mitochondrial gene fragments (16S rRNA and COI). The genus Thyropygus (Harpagophorinae) was recovered as monophyletic under all analyses, whilst the representatives of Rhynchoproctinae also formed a monophyletic group. However, the analyses suggested that the tribe Gonoplectini should be elevated to a separate subfamily, Gonoplectinae. The molecular analyses were largely (but not totally) congruent with, and so supported the usefulness of, gonopodal characters for the classification and identification of harpagophorid millipedes, and additionally supported previous studies on the delimitation of species and subgroups. This is the first molecular study inside the family Harpagophoridae and provides the basis for further studies of the evolutionary processes and biogeographic patterns of millipedes in Southeast Asia.

Mountain refugia play a role in soil arthropod speciation on Madagascar: a case study of the endemic giant fire-millipede genus Aphistogoniulus

To elucidate the speciation mechanisms prevalent within hotspots of biodiversity, and the evolutionary processes behind the rise of their species-rich and endemic biota, we investigated the phylogeny of the giant fire-millipede genus Aphistogoniulus Silvestri, 1897, a Malagasy endemic. This study is the first comprehensive (molecular and morphological) phylogenetic study focusing on millipede (class Diplopoda) speciation on Madagascar. The morphological analysis is based on 35 morphological characters and incorporates ten described as well as two newly described species (A. rubrodorsalisn. sp. and A. jeekelin. sp.) of Aphistogoniulus. The molecular analysis is based on both mitochondrial (COI and 16S), and nuclear genes (complete 18S rDNA), together comprised of 3031 base pairs, which were successfully sequenced for 31 individual specimens and eight species of Aphistogoniulus. In addition to the null-model (speciation by distance), two diversification models, mountain refugia and ecotone shift, were discovered to play a role in the speciation of soil arthropods on Madagascar. Mountain refugia were important in the speciation of the A. cowani clade, with three species occurring in the Andringitra and Ranomafana Mountains in the southeast (A. cowani), the Ambohijanahary and Ambohitantely Mountains in the mid-west (A. sanguineus), and the Marojejy Mountain in the northeast (A. rubrodorsalisn. sp.). An ecotone shift from the eastern rainforest to the unique subarid spiny forest of Mahavelo was discovered in the A. vampyrus-A. aridus species-pair. In the monophyletic A. diabolicus clade, evidence for divergent evolution of sexual morphology was detected: species with greatly enlarged gonopods are sister-taxa to species with normal sized gonopods. Among the large-bodied Spirobolida genera of Madagascar, Colossobolus and Sanguinobolus were found to be close sister-genera to Aphistogoniulus. Forest destruction has caused forest corridors between populations to disappear, which might limit the possible resolution of biogeographic analyses on Madagascar.