Myrmecol. News 36: 215-229
- DOI: https://doi.org/10.25849/myrmecol.news_036:215
- Open Access: CC BY 4.0
- Year: 2026
- Title: Reconstructed phylogeny and morphometry suggest the European rock ant Temnothorax sordidulus (Müller, 1923) forms a ring species around the Dinaric Alps (Hymenoptera, Formicidae)
- Journal: Myrmecological News
- Volume: 36
- Zoobank: urn:lsid:zoobank.org:pub:1B47F9E4-3243-4FB7-AB9B-083FA860CCE2
- Pages: 215-229
- Type of contribution: Original Article
- Supplementary material: yes
- Abstract: The spatial variation observed within a species often leads to clines or ring-species formation, presenting a challenging puzzle in taxonomy. In this gray zone of classifcation, interconnected populations obscure the clear boundaries that taxonomists rely on. Taxonomy of the European Temnothorax sordidulus complex has long been presenting a challenge for myrmecologists. Previous revisions have identifed diferent species boundaries within the complex, shedding light on the complexity of this lineage. To address these challenges, we explored the phylogenetic and morphological patterns of the species complex using high-resolution ultraconserved elements and multivariate analyses of morphometric data within an integrative taxonomic framework. Our fndings suggest that the European T. sordidulus complex represents a ring species around the Dinaric Alps, with populations exhibiting continuous morphological and genetic variation along a C-shaped geographic continuum. The “C-shaped” descriptor refects that the two terminal populations approach each other geographically but do not form a closed ring, remaining reproductively isolated despite their proximity – a pattern analogous to, yet more descriptive than, the classical ring-species metaphor. Concatenated populations maintain gene fow, yet terminal populations exhibit weak-to-insignifcant gene fow and remarkable morphological diferentiation despite their geographic proximity. Consequently, we confrm synonymy of Temnothorax mulleri (Santschi, 1926) and Temnothorax carinthiacus (Bernard, 1957) and propose synonymy of Temnothorax tergestinus (Finzi, 1928) syn.n. and Temnothorax saxonicus (Seifert, 1995) syn.n. under Temnothorax sordidulus (Müller, 1923), treating the complex as a single polytypic species with pronounced geographic variation. Our research demonstrates that in ring-species systems, applying rigid species boundaries is impractical due to the continuous nature of evolutionary processes across geographic space. This study enhances our understanding of how geographic barriers can drive population divergence while maintaining species connectivity through intermediate populations, exemplifying speciation as a gradual, spatially-mediated process rather than a discrete temporal event.
- Key words: Ultraconserved elements, morphometrics, hybrid zone, spatial cline, speciation, synonymy.
- Publisher: The Austrian Society of Entomofaunistics
- ISSN: 1997-3500
Myrmecol. News 36: 215-229 Supplement
- Open Access: CC BY 4.0
- Year: 2026
- Journal: Myrmecological News
- Volume: 36
- Pages: 215-229
- Type of contribution: Supplement
- Supplementary material: no
- Key words: Ultraconserved elements, morphometrics, hybrid zone, spatial cline, speciation, synonymy
- Publisher: The Austrian Society of Entomofaunistics
- ISSN: 1997-3500
Myrmecol. News 36: 215-229, Table S1
- Open Access: CC BY 4.0
- Year: 2026
- Journal: Myrmecological News
- Volume: 36
- Pages: 215-229
- Type of contribution: Supplement
- Supplementary material: no
- Key words: Ultraconserved elements, morphometrics, hybrid zone, spatial cline, speciation, synonymy
- Publisher: The Austrian Society of Entomofaunistics
- ISSN: 1997-3500
Myrmecol. News 36: 215-229, Table S2
- Open Access: CC BY 4.0
- Year: 2026
- Journal: Myrmecological News
- Volume: 36
- Pages: 215-229
- Type of contribution: Supplement
- Supplementary material: no
- Key words: Ultraconserved elements, morphometrics, hybrid zone, spatial cline, speciation, synonymy
- Publisher: The Austrian Society of Entomofaunistics
- ISSN: 1997-3500
Myrmecol. News 36: 215-229, Table S3
- Open Access: CC BY 4.0
- Year: 2026
- Journal: Myrmecological News
- Volume: 36
- Pages: 215-229
- Type of contribution: Supplement
- Supplementary material: no
- Key words: Ultraconserved elements, morphometrics, hybrid zone, spatial cline, speciation, synonymy
- Publisher: The Austrian Society of Entomofaunistics
- ISSN: 1997-3500
Myrmecol. News 36: 215-229 Table S4
- Open Access: CC BY 4.0
- Year: 2026
- Journal: Myrmecological News
- Volume: 36
- Pages: 215-229
- Type of contribution: Supplement
- Supplementary material: no
- Key words: Ultraconserved elements, morphometrics, hybrid zone, spatial cline, speciation, synonymy
- Publisher: The Austrian Society of Entomofaunistics
- ISSN: 1997-3500