Hidden biodiversity: total evidence phylogenetics and evolution of morphological traits in a highly diverse lineage of endogean ground beetles,TyphlocharisDieck, 1869 (Carabidae, Trechinae, Anillini)

Abstract

Typhlocharis is the most diverse eyeless endogean ground beetle genus known to date, with 62 species all endemic to the West Mediterranean region. The lineage is characterized by a conservative and singular body plan within Carabidae that contrasts with a high morphological diversity in many traits. We provide an exhaustive phylogeny of the lineage through the study of 92 morphological characters from all 62 described species and 45 potential new species from 70 additional populations, and the combination of morphological and available molecular data, in the first total evidence phylogenetic approach for a highly diverse endogean lineage. We tracked the evolution of morphological traits over the obtained phylogenies. Results suggest eight morphologically distinct clades, which do not correspond to the species groups proposed formerly. Ancestral state reconstructions and phylogenetic signal analyses of morphological traits revealed that some of the previously key characters to the classification of Typhlocharis, such as the umbilicate series or the apical denticles of elytra, are highly homoplasic, whereas other characters show stronger phylogenetic signal, including structures in the antennae, gula, pronotum and last abdominal ventrite. This evidence supports the split of Typhlocharis into three genera: Lusotyphlus gen. nov.; Typhlocharis Dieck, 1869 and Microcharidius Coiffait, 1969 (revalidated), forming the subtribe Typhlocharina Jeanne, 1973.

Speciation below ground: Tempo and mode of diversification in a radiation of endogean ground beetles

“…This study uses the subtribe Typhlocharina (Jeanne, 1973) as a model for the evolutionary biology of dispersal and speciation in the deep soil. Typhlocharina is a typical endogean group in the tribe Anillini (Jeannel, 1963;Coleoptera, Carabidae, Trechinae) consisting of three genera: Lusotyphlus, Typhlocharis and Microcharidius, and 62 known species: 59 restricted to the Iberian Peninsula and 2 distributed on both sides of the Gibraltar Strait and one endemic to Tunisia (P erez-Gonz alez, And ujar, & Zaballos, 2017;Zaballos, And ujar, & P erez-Gonz alez, 2016). All species show strong morphological adaptations to life in deep soil layers, including reduced size (from 0.9 to 2.9 mm), dorsoventrally flattened and parallel body shape, depigmentation and anophthalmia.…”

Hidden island endemic species and their implications for cryptic speciation within soil arthropods

“…However, inferences of broad distribution or disjunct distributions may be confounded by taxonomic inference, wherein traditional taxonomic approaches are challenged by cryptic species diversity. With regard to the speciesrich biodiversity fraction of flightless arthropods that inhabit soil, molecular genetic techniques are increasingly revealing patterns of subtle or cryptic morphological differentiation among otherwise genetically and often geographically discrete evolutionary entities (Andújar et al, 2015(Andújar et al, , 2017Cicconardi et al, 2013;Pérez-González et al, 2018;Szudarek-Trepto et al, 2021). Such studies point to the low dispersal potential of soil arthropods contributing to a limited spatial scale for speciation in soil (Paula Arribas et al, 2020;Kisel & Barraclough, 2010), occurring together with limited or no morphological change (Cicconardi et al, 2013).…”

Revision of the tribe Pogonini (Coleoptera, Carabidae, Trechinae) from the Ibero-Balearic region

“…Since these publications, and apart from faunistic works (Vives & Vives 1976, 1999Baehr 1986;Ortiz et al 1989;Serrano et al 1990;Vives 1998;among others), no further relevant contributions to the knowledge of the group in the Ibero-Balearic region have been made. On the contrary, more diverse Trechinae tribes in the territory have been widely studied in the last decades (for Anillini Jeannel, 1937, see Zaballos & Banda 2001;Ortuño & Sendra 2010Ortuño & Gilgado 2011;Serrano & Aguiar 2014;Pérez-González et al 2017;Pérez-González & Zaballos 2019; among others; for Bembidiini Stephens, 1827, see Ortuño & Toribio 2005; for Trechini Bonelli, 1810, see Faille et al 2011;Ortuño & Jiménez-Valverde 2011;Ortuño & Barranco 2015;Ortuño et al 2017;among others). Meanwhile, studies and revisions of Pogonini fauna have been published from the New Word (Bousquet & Laplante 1997), Korea (Choi et al 2015) and Iran (Azadbakhsh 2019).…”