Dwarfs under dinosaur legs: a new millipede of the order Callipodida (Diplopoda) from Cretaceous amber of Burma

A new species of Paracortina from a Vietnamese cave, with remarkable secondary sexual characters in males (Callipodida, Paracortinidae)

A new millipede species, Paracortina kyrangsp. nov., is described from a cave in Cao Bang Province, northern Vietnam. The new species is diagnosed by having an extraordinarily long projection on the head of males, reduced eyes, a gonocoxite with two processes, a long and slender gonotelopodite with two long, clavate prefemoroidal processes densely covered with long macrosetae apically, and with a distal, reverse, short spine on mesal side, and a rather sinuous distal part of the telopodite. This is the third species of the genus that is known from Vietnam. A brief comparison of some secondary sexual characters is made.

Re-evaluating and dating myriapod diversification with phylotranscriptomics under a regime of dense taxon sampling

Recent transcriptomic studies of myriapod phylogeny have been based on relatively small datasets with <40 myriapod terminals and variably supported or contradicted the traditional morphological groupings of Progoneata and Dignatha. Here we amassed a large dataset of 104 myriapod terminals, including multiple species for each of the four myriapod classes. Across the tree, most nodes are stable and well supported. Most analyses across a range of gene occupancy levels provide moderate to strong support for a deep split of Myriapoda into Symphyla + Pauropoda (=Edafopoda) and an uncontradicted grouping of Chilopoda + Diplopoda (=Pectinopoda nov.), as in other recent transcriptome-based analyses; no analysis recovers Progoneata or Dignatha as clades. As in all recent multi-locus and phylogenomic studies, chilopod interrelationships resolve with Craterostigmus excluded from Amalpighiata rather than uniting with other centipedes with maternal brood care in Phylactometria. Diplopod ordinal interrelationships are largely congruent with morphology-based classifications. Chilognathan clades that are not invariably advocated by morphologists include Glomerida + Glomeridesmida, such that the volvation-related characters of pill millipedes may be convergent, and Stemmiulida + Polydesmida more closely allied to Juliformia than to Callipodida + Chordeumatida. The latter relationship implies homoplasy in spinnerets and contradicts Nematophora. A time-tree with nodes calibrated by 25 myriapod and six outgroup fossil terminals recovers Cambrian-Ordovician divergences for the deepest splits in Myriapoda, Edafopoda and Pectinopoda, predating the terrestrial fossil record of myriapods as in other published chronograms, whereas age estimates within Chilopoda and Diplopoda overlap with or do not appreciably predate the calibration fossils. The grouping of Chilopoda and Diplopoda is recovered in all our analyses and is formalized as Pectinopoda nov., named for the shared presence of mandibular comb lamellae. New taxonomic proposals for Chilopoda based on uncontradicted clades are Tykhepoda nov. for the three blind families of Scolopendromorpha that share a "sieve-type" gizzard, and Taktikospina nov. for Scolopendromorpha to the exclusion of Mimopidae.

Diversity, distribution patterns, and fauno-genesis of the millipedes (Diplopoda) of mainland China

Based on all available information, 339 species from 71 genera, 26 families, and eleven orders of Diplopoda have hitherto been recorded from mainland China, the fauna thus being very rich, albeit far from completely known, comprising various zoogeographic elements and populating very different environments. Diplopods mainly occur in various woodlands, in caves, and high in the mountains. Most species (> 90 %, usually highly localised, including 160 cavernicoles), 18 genera, and one family are strictly endemic to continental China. Mapping not only the horizontal, but also the vertical distributions of Diplopoda in China shows the bulk of the fauna to be expectedly restricted to forested lowland and mountain biomes or their remnants. Yet some Chordeumatida, Callipodida, Polydesmida, Julida, and even Spirobolida seem to occur only in the subalpine to alpine environments and thus may provisionally be considered as truly high-montane. The long-acknowledged notions of China being a great biogeographic zone transitional between the Palaearctic and Oriental regions generally find good support in millipede distributions, in particular at the higher taxonomic levels (generic, familial, and ordinal). While the Palaearctic/Holarctic components expectedly dominate the fauna of the northern parts of the country, the Oriental ones prevail in its south and along the Pacific coast. Both realms are increasingly mixed and intermingled towards China’s centre. However, in addition to the above traditional views, based on distribution patterns alone, southern China seems to harbour a rather small, but highly peculiar faunal nucleus or origin centre of its own, whence Himalaya, Myanmar, Thailand, Indochina and/or Taiwan could have become populated by younger lineages. The millipede fauna of continental China is thus a tangled mixture of zoogeographic elements of various origins and ages, both relict and more advanced. The few anthropochores must have been the latest faunal “layer” to populate China.

Genital morphology and the mechanics of copulation in the millipede genus Pseudopolydesmus (Diplopoda: Polydesmida: Polydesmidae)

Mate choice, copulation, genital morphology, and sperm storage are not very well understood in millipedes. The use of three-dimensional x-ray computed tomography (μCT) provides new morphological data regarding millipede reproductive systems in both the female and male, including chitinous sclerites and membranes, muscles, glands, oviducts, and sperm conduits. Here we present a complete integrated account of the morphology and function of the female genital organs in the family Polydesmidae (Diplopoda: Polydesmida) using μCT, UV fluorescence imaging, and scanning electron microscopy. These data allow us to consider competing hypotheses regarding millipede vulva formation. We additionally present the morphology of copulatory interface in Pseudopolydesmus Attems, 1898 using images of a mating pair in copula and by simulating the interface of the organs using 3D models from μCT, allowing us to tentatively identify a lock-and-key-like mechanism. Finally, we use μCT to reveal the topology of the seminal canal in the gonopod of male Pseudopolydesmus, a topic that has remained unresolved for nearly 80 years.