Mitogenomic phylogenetics of Diochus occultus n. sp., a palaeoendemic endogean species within the tribe Diochini (Coleoptera: Staphylinidae: Staphylininae)

• Main Authors: Hernando, Carles, Andújar, Carmelo
• Other Authors: Ministerio de Economía y Competitividad (España), Junta de Andalucía
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley-VCH 2020
• Subjects: Mitochondrial metagenomics; Mitogenome; Betic-Rifean plate; Soil Biodiversity; Abies pinsapo; Antarc*
• Online Access: http://hdl.handle.net/10261/219389; https://doi.org/10.1111/jzs.12425; https://doi.org/10.13039/501100003329; https://doi.org/10.13039/501100011011

The tribe Diochini has a worldwide distribution, with 2 and 74 epigean species within the genera Antarctothius and Diochus respectively. Recent phylogenetic studies suggest a sister relationship of Diochini and a lineage formed by Xantholinini, Maorothiini, and Othiini, within the subfamily Staphylininae. Here we describe the first known endogean representative of Diochini, Diochus occultus n. sp., and provide the first two complete mitogenomes for the tribe, corresponding to the two European Diochus species: Diochus occultus n. sp. and Diochus staudingeri. These sequences were combined with 40 additional mitogenomes from representatives within Staphylininae, Paederinae, Silphidae, and Aleocharinae, and COI sequences from 5 additional species of Diochus to conduct a series of mitogenomic phylogenetic and dating analyses. The estimated molecular phylogeny is fully consistent with previous studies based on morphology and molecular data, finding a sister relationship of Diochini with a clade formed by Xantholinini and Othiini (Maorothiini not sampled). Dating analyses inferred an early split of the tribe Diochini at 140-156 Mya. Morphology shows clear differences in the aedeagal and external morphology of D. occultus n. sp. and D. staudingeri, whereas a sister relationship of these taxa is found in the phylogenetic analyses, with the split dated at 48-61 Mya. Although the study of additional Palaearctic Diochus species will be required to conclusively establish that D. occultus n. sp. is a palaeoendemic taxon sister to D. staudingeri, associated to forests of Abies pinsapo in the south of the Iberian Peninsula, this conclusion is consistent with the ancient estimated age of speciation, endogean habitat specificity, low dispersal capacity (flightless species), and microendemicity of D. occultus. This is also consistent with the continued emersion of the Betic sub-plate along its tectonic evolution. The estimated ages of diversification of the Paederinae-Staphylininae lineage are also discussed. CA was supported by ...