Integrative Taxonomy of a New Thyropygus Pocock, 1894 Species from Thailand (Diplopoda: Spirostreptida: Harpagophoridae)

Authors

  • Piyatida Pimvichai Department of Biology, Faculty of Science, Mahasarakham University, Maha Sarakham 44150, THAILAND
  • Pongpun Prasankok School of Biology, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, THAILAND
  • Thierry Backeljau Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B-1000 Brussels, BELGIUM: Evolutionary Ecology Group, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, BELGIUM

DOI:

https://doi.org/10.58837/tnh.25.8.266935

Keywords:

COI, gonopod, phylogeny

Abstract

A new juliformian millipede species, Thyropygus sirindhornae sp. nov., is described from Chiang Rai Province, Thailand and assigned to the Thyropygus allevatus group based on two diagnostic gonopodal characters: (1) the gonopod telopodite with both tibial and femoral spines, and (2) a notably long tibial spine recurved toward the femoral spine. Despite its affiliation with the informal T. allevatus group, T. sirindhornae sp. nov. cannot be assigned to one of the four informal subgroups of the T. allevatus group because it lacks any of the diagnostic characters of these subgroups. Similarly, while the COI DNA barcode data support the distinctiveness of T. sirindhornae sp. nov. from other Thyropygus species within the T. allevatus group (mean interspecific sequence divergence of 0.16 ± 0.02, range: 0.12–0.19), they do not provide information about the sister group relationships or subgroup assignment of the new species. As a result, T. sirindhornae sp. nov. is tentatively assigned to the T. allevatus group, but is labelled as “incertae sedis” with respect to its sister group relations and subgroup classification. In fact, as the COI phylogeny only included species of the T. allevatus group, the assignment of T. sirindhornae sp. nov. to this informal species group needs to be confirmed by including representatives of other informal Thyropygus species groups.

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Published

2025-10-14

How to Cite

[1]
Pimvichai, P., Prasankok, P. and Backeljau, T. 2025. Integrative Taxonomy of a New Thyropygus Pocock, 1894 Species from Thailand (Diplopoda: Spirostreptida: Harpagophoridae). Tropical Natural History. 25, 8 (Oct. 2025), 108–120. DOI:https://doi.org/10.58837/tnh.25.8.266935.

Issue

No. 8 (2025): Supplement

Section

Original Articles

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Chulalongkorn University. All rights reserved. No part of this publication may be reproduced, translated, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior written permission of the publisher

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