New Species of Glomeridae Discovered in Dinghushan, Guangdong, Filling a Zoogeographic Gap for Millipedes in China

On May 20, 2026, the international zoological taxonomy journal ZooKeys published online a research result by a team from the South China Botanical Garden (Chinese Academy of Sciences), South China Agricultural University, Sun Yat-sen University, and other institutions. During biodiversity surveys and monitoring in Dinghushan National Nature Reserve, the research team first discovered and photographed a species of the family Glomeridae (order Glomerida). Through morphological comparison, genetic distance analysis, and phylogenetic verification, the species was confirmed as a new species of the genus Rhopalomeris, named Rhopalomeris dinghushan after its type locality, Dinghushan.

Pill Millipedes: Ancient and Vital Soil Detritivores

Pill millipedes belong to the order Glomerida, class Diplopoda, and are soil invertebrates of great ecological and taxonomic significance. As key detritivores in forest ecosystems, they play an irreplaceable role in nutrient cycling and soil formation. With weak dispersal ability, pill millipedes are highly dependent on forest and woodland habitats, making them important indicators for assessing habitat integrity and environmental change.

Taxonomically, the order Glomerida comprises only three families: Glomeridae, Protoglomeridae, and Glomeridellidae, with Glomeridae being the most species-rich group. Globally, Glomerida is mainly distributed in the Holarctic region. The genus Rhopalomeris discovered in this study is endemic to the Oriental Realm, with 14 known species previously recorded across the Indochinese Peninsula, ranging from northern Vietnam in the north to the Malay Peninsula in the south and Myanmar in the west.

Long-Standing Lag in Glomerida Research in China

China is one of the world’s most biodiverse countries, yet research on its Glomerida fauna has long lagged behind. To date, only 39 species have been documented in China: 37 species of Hyleoglomeris (Glomeridae), 1 species of Mauriesia (Glomeridae), and 1 species of Tonkinomeris (Glomeridellidae). As China’s first nature reserve and one of the first sites in China to join UNESCO’s Man and the Biosphere Programme, Dinghushan has been systematically surveyed for vascular plants, mammals, birds, reptiles, amphibians, butterflies, and macrofungi—but the species composition and distribution of its millipede fauna remain poorly understood.

Discovery: A Midnight Field Encounter

On Sunday, September 14, 2025, Mr. Fan Zongji, a senior engineer at Dinghushan National Nature Reserve, led a research monitoring team to conduct wildlife surveys in the core zone of the reserve. At around 3 a.m., they discovered and photographed a brightly colored millipede in the leaf litter of a montane evergreen broad-leaved forest at 708 m a.s.l. The millipede was large (15.0–21.0 mm in body length), blackish-brown with distinctive yellowish-brown marbled patterns. Diagnostic morphological features included approximately 12 superficial transverse striae on the thoracic shield, a triangular apicolateral process on each coxa of male legs 4–16, and a median syncoxital lobe of the telopods distinctly lower than the lateral horns.

Using an integrative taxonomic approach combining traditional morphological examination and mitochondrial COI gene barcoding, the team confirmed the specimen represents a new, undescribed species of Glomeridae. The paper provides a detailed morphological description of the new species, its male reproductive structures, and a phylogenetic tree based on COI sequences to clarify its systematic position within the genus.

Multiple Scientific Significances

1. Filling a zoogeographic gap

This is the first formal record of the genus Rhopalomeris in China, extending its known distribution northward and eastward from the Indochinese Peninsula to southern China. It fills a critical zoogeographic gap for this Oriental endemic genus and provides key evidence for understanding its biogeographic evolutionary history.

2. Enriching China’s pill millipede diversity

The discovery raises the total number of Glomerida species recorded in China to 40, greatly advancing knowledge of China’s pill millipede fauna. It underscores the conservation value of Dinghushan National Nature Reserve as a biodiversity hotspot.

3. Challenging current generic delimitation

Molecular phylogenetic analyses reveal that the genus Rhopalomeris is likely polyphyletic as currently defined. Rhopalomeris dinghushan forms a strongly supported monophyletic clade with the Vietnamese species Peplomeris magna, rather than with other Rhopalomeris species. This indicates the need for a comprehensive revision of the genus and raises new scientific questions for high-level taxonomic research in Glomeridae.

Author Information & Funding

The co-first authors of the paper are Fan Zongji (Senior Engineer, South China Botanical Garden, Chinese Academy of Sciences) and Huang Hengjie (Graduate Student, South China Agricultural University). The corresponding author is Liu Weixin (Associate Professor, South China Agricultural University).

This research was supported by the Central Forestry and Grassland Ecological Protection and Restoration Fund Project of the Guangdong Forestry Bureau: Assessment of Ecosystem Service Functions and Construction of Bird Song Background Monitoring in Dinghushan National Nature Reserve.

The team received strong support from experts at the Institute of Biology (Vietnam Academy of Science and Technology), the Institute of Ecology and Evolution (Russian Academy of Sciences), and staff and volunteers of Dinghushan National Nature Reserve.

Citation: FAN Zongji, HUANG H, ZHANG Zekun, ZHANG L, LIU Weixin (2026) The pill millipede genus Rhopalomeris Verhoeff, 1906 new to the fauna of China, with an integrative description of a new species from Guangdong Province (Diplopoda, Glomerida, Glomeridae). ZooKeys 1280: 45-61. Article link：https://doi.org/10.3897/zookeys.1280.190182

Figure 1. Rhopalomeris dinghushan.（Photo by FAN Zongji）

Figure 2. Phylogenetic tree of pill millipedes. （Image by LIU Weixin）