Synonymisation of the male-based ant genus

Abstract

Although molecular data have proven indispensable in confidently resolving the phylogeny of many clades across the tree of life, these data may be inaccessible for certain taxa. The resolution of taxonomy in the ant subfamily Leptanillinae is made problematic by the absence of DNA sequence data for leptanilline taxa that are known only from male specimens, including the monotypic genus Phaulomyrma Wheeler & Wheeler. Focusing upon the considerable diversity of undescribed male leptanilline morphospecies, the phylogeny of 35 putative morphospecies sampled from across the Leptanillinae, plus an outgroup, is inferred from 11 nuclear loci and 41 discrete male morphological characters using a Bayesian total-evidence framework, with Phaulomyrma represented by morphological data only. Based upon the results of this analysis Phaulomyrma is synonymised with Leptanilla Emery, and male-based diagnoses for Leptanilla that are grounded in phylogeny are provided, under both broad and narrow circumscriptions of that genus. This demonstrates the potential utility of a total-evidence approach in inferring the phylogeny of rare extant taxa for which molecular data are unavailable and begins a long-overdue systematic revision of the Leptanillinae that is focused on male material.

Evolution and systematics of the Aculeata and kin (Hymenoptera), with emphasis on the ants (Formicoidea: †@@@idae fam. nov., Formicidae)

“…Distinguished from other Leptanillomorpha by the following likely autapomorphies (see Boudinot 2015 for male Martialis, Griebenow 2020, 2021 for Leptanillini, and Yamada et al 2020 for precise morphological depictions of Opamyrma) : (h) female mandibular teeth distinct in form, with a pointed apical tooth and a subrhomboidal and proximally directed subapical tooth, with these subtended by fine serration (vs. teeth spiniform and widely spaced [M] and teeth subtriangular and roughly equal in size [L], with [some L] or without [other L] teeth on the basal margin); (i) female mandible with a single median traction chaeta (vs. chaetae absent [M] or multiple [L]); (j) male antennal toruli situated distant from posterior clypeal margin (vs. toruli contacting or very nearly clypeus); (k) female occiput grossly enlarged such that it is distinctly visible behind the occipital carina in full-face view; (l) female petiole elongate, sessile and subrectangular, length ∼ 2 x width, excluding anterior and posterior constrictions (vs. petiole shorter [L, except for the bizarrely elongated, tubular condition in Yavnella laventa Griebenow et al ., submitted] or pedunculate [M]); (m) female petiolar sternum extremely long and narrow, vase-like in ventral view (vs. sternum shorter, wider, or with tergosternal fusion rendering abdominal sternum II undelimited laterally); (n) female abdominal segment III de-petiolated, i.e. , posterior margins not constricted, postsclerites tube-like (vs. AIII partially [M] to completely petiolated [L]; AIII is completely petiolate in workers and some queens of Leptanillini, with exceptional occurrence among certain Protanilla males, e.g.…”

“…Further, we synonymize Anomalomyrmini Taylor, 1990 with Leptanillini, 1910 syn. nov. based on consideration of worker and male morphology contextualized by phylogenomic inference (Griebenow 2020, 2021). To maintain reciprocally monophyletic genera that are diagnosable based on all adult castes Anomalomyrma and Protanilla will soon be synonymized, while all genera within the tribe Leptanillini will be subsumed into one (Griebenow, in prep.…”

A remarkable troglomorphic ant,

“…The genus is most diverse in mainland South-east Asia (this diversity remaining entirely undescribed), with additional representatives in the Indian subcontinent and the Arabian subcontinent as far south as Yemen (Collingwood and Agosti 1996). Borowiec et al (2019) also robustly recovered this clade, under a sampling regime overlapping with Griebenow (2020Griebenow ( , 2021, although Borowiec et al (2019) did not explicitly identify this clade as Yavnella.…”

“…Owing to collecting bias towards males, three genera in the tribe Leptanillini have been described solely from male specimens, as have some species of Leptanilla. Further, there is a large diversity of undescribed male morphospecies in the subfamily (Griebenow 2021). The Leptanillinae are therefore afflicted by parallel taxonomy.…”

“…Yavnella is the most recently described of the male-based leptanilline genera, established by Kugler (1986) for two species from Israel and Kerala (India), by original designation. The phylogenetic analyses of Griebenow (2020Griebenow ( , 2021 included a variety of undescribed male Yavnella morphospecies along with Yavnella argamani Kugler, 1987 and recovered the genus as monophyletic with high support, irrespective of data or inferential framework. The genus is most diverse in mainland South-east Asia (this diversity remaining entirely undescribed), with additional representatives in the Indian subcontinent and the Arabian subcontinent as far south as Yemen (Collingwood and Agosti 1996).…”