Integrative taxonomy uncovers hidden diversity in Romanian Geophilus Leach, 1814 (Geophilomorpha, Geophilidae)

Two new species of Geophilus Leach, 1814, are identified and described from Romania. The examined material is compared with morphologically similar congeners, suggesting the presence of a complex of closely related species within the highly diverse genus Geophilus, characterized by a unique combination of diagnostic morphological and molecular characters. Two nuclear (18 S, 28 S) and one mitochondrial (COI) markers are sequenced for Geophilus tenuis sp. nov., and COI sequence data are provided for Geophilus captiosus sp. nov.

Morphological data, phylogenetic reconstruction, and three molecular species delimitation tools (ASAP, bPTP, and GMYC) confirm their validity, with diagnostic nucleotide combinations, based on the COI barcode, additionally provided for them. Their placement in Geophilus is assessed through the most complete phylogeny of the genus hitherto constructed, using sequence data of 18 S, 28 S, and COI markers from all species present in public repositories.

The extent of potential undescribed species diversity in Geophilus is discussed, highlighting the need for comprehensive sampling of small endogeic members of this genus.