The millipede genus Sphaerobelum Verhoeff, 1924, in Thailand, with descriptions of three new species (Diplopoda, Sphaerotheriida, Zephroniidae)

By

Srikampha, Khanet
Wesener, Thomas
Likhitrakarn, Natdanai
Čhirasak Sutčharit
Srisonchai, Ruttapon

Type

Article

Date of Publication

2025-2-13

Original Publication

Zoosystematics and evolution

Volume

101

Series / Issue

Issue: 1

Pages

273--300

Subjects

Biodiversity , endemism , Limestone , Phylogeny , systematics

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia Pensoft

Identifiers

DOI: https://doi.org/10.3897/zse.101.143073

 

Abstract

Three new species of the giant pill-millipede genus Sphaerobelum Verhoeff, 1924, from Thailand and Laos, are described based on an integrative approach that combines morphological characters and COI data; these are S. nonghinensis Srikampha & Srisonchai, sp. nov., S. onyx Srikampha & Srisonchai, sp. nov., and S. petramurum Srikampha & Srisonchai, sp. nov. Additionally, new material of previously described species, S. aesculus Rosenmejer & Wesener, 2021, S. truncatum Wongthamwanich, 2012, and S. turcosa Srisonchai & Pimvichai, 2023, were collected and examined. The new species can be distinguished from all congeners by a combination of unique characters, including body colour, endotergum, vulva, and details of the telopods. The validity of these new species is further supported by high genetic distances from their congeners in the 658 base pairs of the COI barcoding fragment, ranging from 13.24–30.12%. Preliminary phylogenetic analyses using Bayesian inference and maximum likelihood indicate that each new species forms a distinct clade, supporting their morphological uniqueness, though the interrelationships with most other congeners remain unsupported. All new species are restricted to narrow distribution areas in Thailand and Laos, suggesting they are endemic to these regions. Morphological characters of the new species are illustrated, and an identification key and a distribution map for known Sphaerobelum species in Thailand are also provided.