The Giant Pill-Millipedes of Madagascar: Revision of the Genus Sphaeromimus, with a Review of the Morphological Terminology (Diplopoda, Sphaerotheriida, Sphaerotheriidae).

Proceedings of the California Academy of Sciences, Fourth Series 12/2005; 56(29):557-599.


The Malagasy sphaerotheriid genus Sphaeromimus DeSaussure and Zehntner, 1902 is revised. Known heretofore from a single male specimen, the genus now contains three species, Sphaeromimus musicus (DeSaussure and Zehntner, 1897), Sphaeromimus splendidus sp. nov. and Sphaeromimus inexpectatus sp. nov. The female of S. musicus is described here for the first time. The mouthparts of giant pill millipedes were observed for the first time using scanning electron microscopy and species- and genus-level characters are illustrated. Intraspecific variation of the female stridulatory organ, the ‘washboard’ is described. For the first time in Malagasy Sphaerotheriida, some ecological comments are given. Characters found in the male
telopods and the female stridulatory organ (the washboard) indicate that characters employed previously for the definition of subfamilies and tribes cannot be maintained and the monophyly of such groups remains questionable.

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    • "aridus). This speciation model was coined “ecotone shift” in other Malagasy animals, including amphibians and lemurs [12], while in Malagasy giant pill-millipedes such an ecotone shift seems to have occurred in the opposite direction from Aphistogoniulus: within the genera Zoosphaerium [52] and Sphaeromimus [53], the most basal species are distributed in the dry spiny forest ecosystem [10], [11]. "
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    ABSTRACT: 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.
    Full-text · Article · Dec 2011 · PLoS ONE
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    • "Other authors previously observed the morphological similarity of Sphaeromimus and Arthrosphaera and suggested that S. musicus (at this point only known from the holotype) represents in fact a ''mislabeled or an introduced Indian sphaerotheriid " (Jeekel, 1999). This theory was, however, refuted with the later discovery of several Sphaeromimus species on Madagascar (Wesener and Sierwald, 2005b). Timing the nodes in the Sphaerotheriida phylogeny is difficult without any fossil data (Shear and Edgecombe, 2010). "
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    ABSTRACT: 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.
    Full-text · Article · Dec 2010 · Molecular Phylogenetics and Evolution
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    ABSTRACT: This paper describes the second species of sphaerotheriid millipede to be recorded from Western Australia, Epicyliosoma (Epicyliosoma) sarahae sp. nov. It is restricted to low rainfall biotopes in the southeast coastal province of Western Australia and may be under threat from climate change and fire. Epicyliosoma sarahae is more restricted within its range than the other Western Australian species, the threatened Cynotelopus notabilis Jeekel, and both species are short-range endemics.
    Full-text · Article · Jan 2008
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