On the systematic allocation of Liomma Roewer, 1959 (Arachnida: Opiliones: Nomoclastidae) and discovery of a putative synapomorphy for Nomoclastinae

ABSTRACT

This study, based on the discovery and examination of male specimens of Liomma laeve Roewer, 1959, proposes the reclassification of the monotypic genus Liomma Roewer, 1959. Currently placed in Grassatores incertae sedis, we hereby transfer it to the Nomoclastidae family. In this work, we present a reevaluation of the genus and a comprehensive redescription of its type species. Additionally, we introduce a novel anatomical feature, seemingly exclusive to Nomoclastidae, which we term ‘metatarsal carinate setae (MtCS)’. MtCS comprises specialised striate setae organised in a comb-like structure located on the prolateral distal part of metatarsus I in males. The presence of MtCS has been observed not only in Liomma laeve but also in several as-yet-undescribed species within the Nomoclastidae family. These observations are part of a broader, ongoing project aimed at comprehensively understanding and classifying this taxonomic group.

KEYWORDS:

• Ecuador
• Andes
• Neotropics
• taxonomy
• Grassatores

Acknowledgements

Camila Messias, Beatriz Cordeiro and Amanda Garcez technically assisted in obtaining the SEM pictures. The research trip undertaken by MM to study material at SMF was made possible through the financial support of Synthesys+. MM extends heartfelt thanks for the warm hospitality provided by Peter Jäger and Julia Altmann during the visit to Frankfurt. Our taxonomic endeavours have encountered significant setbacks due to a series of unfortunate events. These include the devastating fire that consumed the splendid harvestmen collection at MNRJ (Museu Nacional, Rio de Janeiro), as well as the constraints imposed on scientific research in Brazil and the global impact of the COVID-19 pandemic. Despite these challenges, we remain committed to the task of rebuilding our collection, primarily through expeditions and generous donations. Repeated expeditions of the Brazilian National Museum to Ecuador benefitted from our collaboration with Álvaro Barragán, Fernanda Salazar and Taryn Ghia (QCAZ, Quito, Ecuador). We extend our heartfelt gratitude to Paula Cushing, Jürgen Gruber, Marcos Hara, and Alan Martin for their invaluable material support during these trying times.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study has been supported by (1) Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro – FAPERJ) (E-26/201.973/2020 to MM, E-26/200.085/2019 and E-26/210.148/2019 (249116) to ABK); (2) Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq (311531/2019-9; 430748/2018-3 to ABK) and (3) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – CAPES (Scholarships to MM).