Thomas Wesener

A first phylogenetic analysis of giant pill-millipedes (Diplopoda: Sphaerotheriida), a new model Gondwanan taxon, with special emphasis on island gigantism

The phylogeny of the Giant Pill‐Millipedes, order Sphaerotheriida, is investigated using a new morphological character matrix comprising 89 characters. The majority of these characters are employed for the first time in millipedes. All trees obtained agree on the monophyletic status of the Sphaerotheriida and several of its tribes, each restricted to a modern land mass. The species from Madagascar displaying island gigantism do not form a monophyletic group. The classic division of Giant Pill‐Millipedes into two families, Sphaerotheriidae and Zephronidae, was not reflected in the analysis. The genus Procyliosoma is the sister‐group to all other Sphaerotheriida, rendering the family Sphaerotheriidae paraphyletic. A new family‐level classification of Giant Pill‐Millipedes, based on the current phylogeny, is introduced. The new family Procyliosomatidae contains only the genus Procyliosoma, distributed in Australia and New Zealand. The family Zephronidae remains unchanged, while the family Sphaerotheriidae now incorporates only the African Giant Pill‐Millipede genera. All genera from southern India and Madagascar form a monophyletic group and are placed in the new family Arthrosphaeridae. The Malagasy genus Sphaeromimus is more closely related to the Indian Arthrosphaera species than to other genera from Madagascar. A biogeographical analysis identifies the group as a Gondwana taxon (with a notable absence from South America). The current phylogeny of Giant Pill‐Millipede families mirrors perfectly the suggested break‐up of Gondwana fragments 160–90 Ma. No evidence for a dispersal event could be found, highlighting the importance of Giant Pill‐Millipedes as a potential model taxon.

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

Giant pill-millipedes (order Sphaerotheriida) are large-bodied millipedes without poison glands which can roll-up into a complete ball. Their disconnected area of distribution spanning South Africa, Madagascar, India, SE Asia, Australia and New Zealand makes them interesting model organisms for biogeographic studies. The here presented phylogeny is based on a molecular dataset covering all areas of distribution with a special focus on Madagascar, where some species of giant pill-millipedes show island gigantism, reaching the size of a baseball. For our study, two mitochondrial genes (partial 16S rRNA and COI) as well as the complete nuclear 18S rDNA were sequenced. While many recent vertebrate studies hint that the ancestors of the recent Malagasy fauna crossed the >350 km wide Mozambique Channel several times, no such crossing was discovered in the Sphaerotheriida. For the first time in a molecular phylogenetic study of soil arthropods, a Madagascar-India group, the family Arthrosphaeridae, is recovered, hinting to a Gondwanan origin of the Sphaerotheriida. The Malagasy-Indian family Arthrosphaeridae forms a monophyletic, statistically well-supported group in all obtained trees. The giant pill-millipedes from Madagascar are paraphyletic because the Malagasy genus Sphaeromimus is the sister-taxon of the Indian Arthrosphaera. In Sphaeromimus, an ecotone shift occurred only once: the spiny forest species Sphaeromimus musicus forms the sister-clade to the species collected in rainforests and littoral rainforests. The two species of the Malagasy genus Zoosphaerium which express island gigantism form a monophyletic group in some trees, but these trees lack good statistical support. Deeper nodes inside the Sphaerotheriida, like the position of the Australian genera Procyliosoma and Epicyliosoma, the Southeast Asian family Zephroniidae and the South African genus Sphaerotherium could not be resolved. This study is the first genetic study inside the order Sphaerotheriida and provides a proper basis for future molecular biogeographic studies in millipedes and soil organisms from Madagascar.

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. rubrodorsalis n. sp. and A. jeekeli n. 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. rubrodorsalis n. 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.

Convergent Evolution of Unique Morphological Adaptations to a Subterranean Environment in Cave Millipedes (Diplopoda)

Animal life in caves has fascinated researchers and the public alike because of the unusual and sometimes bizarre morphological adaptations observed in numerous troglobitic species. Despite their worldwide diversity, the adaptations of cave millipedes (Diplopoda) to a troglobitic lifestyle have rarely been examined. In this study, morphological characters were analyzed in species belonging to four different orders (Glomerida, Polydesmida, Chordeumatida, and Spirostreptida) and six different families (Glomeridae, Paradoxosomatidae, Polydesmidae, Haplodesmidae, Megalotylidae, and Cambalopsidae) that represent the taxonomic diversity of class Diplopoda. We focused on the recently discovered millipede fauna of caves in southern China. Thirty different characters were used to compare cave troglobites and epigean species within the same genera. A character matrix was created to analyze convergent evolution of cave adaptations. Males and females were analyzed independently to examine sex differences in cave adaptations. While 10 characters only occurred in a few phylogenetic groups, 20 characters were scored for in all families. Of these, four characters were discovered to have evolved convergently in all troglobitic millipedes. The characters that represented potential morphological cave adaptations in troglobitic species were: (1) a longer body; (2) a lighter body color; (3) elongation of the femora; and (4) elongation of the tarsi of walking legs. Surprisingly, female, but not male, antennae were more elongated in troglobites than in epigean species. Our study clearly shows that morphological adaptations have evolved convergently in different, unrelated millipede orders and families, most likely as a direct adaptation to cave life.

Barcoding of Central European Cryptops centipedes reveals large interspecific distances with ghost lineages and new species records from Germany and Austria (Chilopoda, Scolopendromorpha).

Abstract In order to evaluate the diversity of Central European Myriapoda species in the course of the German Barcode of Life project, 61 cytochrome c oxidase I sequences of the genus Cryptops Leach, 1815, a centipede genus of the order Scolopendromorpha, were successfully sequenced and analyzed. One sequence of Scolopendra cingulata Latreille, 1829 and one of Theatops erythrocephalus Koch, 1847 were utilized as outgroups. Instead of the expected three species (Cryptops parisi Brolemann, 1920; Cryptops anomalans Newport, 1844; Cryptops hortensis (Donovan, 1810)), analyzed samples included eight to ten species. Of the eight clearly distinguishable morphospecies of Cryptops, five (Cryptops parisi; Cryptops croaticus Verhoeff, 1931; Cryptops anomalans; Cryptops umbricus Verhoeff, 1931; Cryptops hortensis) could be tentatively determined to species level, while a further three remain undetermined (one each from Germany, Austria and Croatia, and Slovenia). Cryptops croaticus is recorded for the first time from Austria. A single specimen (previously suspected as being Cryptops anomalans), was redetermined as Cryptops umbricus Verhoeff, 1931, a first record for Germany. All analyzed Cryptops species are monophyletic and show large genetic distances from one another (p-distances of 13.7–22.2%). Clear barcoding gaps are present in lineages represented by >10 specimens, highlighting the usefulness of the barcoding method for evaluating species diversity in centipedes. German specimens formally assigned to Cryptops parisi are divided into three clades differing by 8.4–11.3% from one another; their intra-lineage genetic distance is much lower at 0–1.1%. The three clades are geographically separate, indicating that they might represent distinct species. Aside from Cryptops parisi, intraspecific distances of Cryptops spp. in Central Europe are low (<3.3%).

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.

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

Abstract. 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.

Revision of the endemic giant fire millipedes of Madagascar, genus Aphistogoniulus (Diplopoda: Spirobolida: Pachybolidae)

The Malagasy fire millipede genus Aphistogoniulus (Silvestri, 1897) is revised. All previously described species, A. cowani (Butler, 1882), A. erythrocephalus (Pocock, 1893), A. hova (de Saussure & Zehntner, 1897), A. corallipes (de Saussure & Zehntner, 1902), A. sakalava (de Saussure & Zehntner, 1897), are redescribed. Four new synonyms are confirmed: Aphistogoniulus sanguinemaculatus (Silvestri, 1897) new synonym of A. cowani, A. quadridentatus (Attems, 1910) new synonym of A. erythrocephalus, A. polleni Jeekel, 1971 and A. brolemanni Jeekel, 1971 new synonyms of A. hova. Scanning electron microscopy is utilized to investigate the sexual differences on the antenna, mandible and gnathochilarium in A. cowani. The intraspecific variation of the taxonomic characters within and between different populations of A. erythrocephalus (Pocock, 1893) is examined. Five new species (A. sanguineus Wesener, n. sp., A. infernalis Wesener, n. sp., A. diabolicus Wesener, n. sp., A. aridus Wesener, n. sp., A. vampyrus Wesener, n. sp.) are described, including the first records of the genus from the Malagasy spiny forest and azonal Western deciduous forest ecosystem. A key to Aphistogoniulus species is provided.

Pachybolini – a tribe of giant Afrotropical millipedes: arguments for monophyly and the description of a new genus from Madagascar (Diplopoda : Spirobolida : Pachybolidae)

Madabolus, gen. nov. is described to accommodate M. maximus, sp. nov. (type species) from several localities in western Madagascar. A phylogenetic analysis of 26 spirobolidan taxa, based on morphological characters, places Madabolus, gen. nov. with the Afrotropical genera Pelmatojulus de Saussure, 1860; Pachybolus Cook, 1897; Hadrobolus Cook, 1897 and Epibolus Cook, 1897. The tribe Pachybolini is proposed to include Madabolus, gen. nov. and the four abovementioned genera. Putative autapomorphies of Pachybolini are: a closed incisura lateralis; setae of gnathochilarial lamella lingualis apical; vulva kidney- or crescent-shaped, with valves meeting in a sinuous fissure and crest protruding. Within Pachybolini, Pelmatojulus (West Africa) stands out by virtue of an increased number of apical antennal sensory cones, with great probability an apomorphy. Madabolus, gen. nov. and east African genera of the tribe share another potential synapomorphy, namely, an increased number of setae on the gnathochilarial lamellae linguales. Other Malagasy genera of Pachybolidae do not seem to be related to Afrotropical genera.

First results of the German Barcode of Life (GBOL) - Myriapoda project: Cryptic lineages in German Stenotaenialinearis (Koch, 1835) (Chilopoda, Geophilomorpha).

Abstract As part of the German Barcode of Life (GBOL) Myriapoda program, which aims to sequence the COI barcoding fragment for 2000 specimens of Germany’s 200 myriapod species in the near future, 44 sequences of the centipede order Geophilomorpha are analyzed. The analyses are limited to the genera Geophilus Leach, 1814 and Stenotaenia Koch, 1847 and include a total of six species. A special focus is Stenotaenia, of which 19 specimens from southern, western and eastern Germany could be successfully sequenced. The Stenotaenia data shows the presence of three to four vastly different (13.7–16.7% p-distance) lineages of the genus in Germany. At least two of the three lineages show a wide distribution across Germany, only the lineage including topotypes of Stenotaenia linearis shows a more restricted distribution in southern Germany. In a maximum likelihood phylogenetic analysis the Italian species Stenotaenia ‘sorrentina’ (Attems, 1903) groups with the different German Stenotaenia linearis clades. The strongly different Stenotaenia linearis lineages within Germany, independent of geography, are a strong hint for the presence of additional, cryptic Stenotaenia species in Germany.