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The delineation of zoogeographic regions is essential for understanding the evolution of biodiversity. Madagascar, characterized by high levels of endemism and habitat diversity, presents unique challenges and opportunities for such studies. Traditional global zoogeographic classifications, largely based on vertebrates, may overlook finer‐scale patterns of diversity. This study employs comprehensive ant distribution and phylogenomic datasets to propose a refined zoogeographic model for Madagascar. Utilizing phylogenetic Simpson's turnover, we identified three primary regions – Eastern, Northern, and Western – each characterized by distinct environmental and phylogenetic profiles. Further subdivision revealed nine subregions, reflecting variations in elevation, net primary productivity, and terrain ruggedness. Our findings highlight the importance of topographical and environmental barriers in shaping phylogenetic diversity and endemism. Notably, we observed significant phylogenetic clustering in lowland areas and distinct differences in net primary productivity and elevation across regions. This study underscores the value of integrating phylogenetic data in zoogeographic analyses and provides a nuanced framework for investigating biodiversity patterns in Madagascar, offering insights into the processes driving speciation and endemism on the island. 

Abstract While some relationships in phylogenomic studies have remained stable since the Sanger sequencing era, many challenging nodes remain, even with genome-scale data. Incongruence or lack of resolution in the phylogenomic era is frequently attributed to inadequate data modeling and analytical issues that lead to systematic biases. However, few studies investigate the potential for random error or establish expectations for the level of resolution achievable with a given empirical data set and integrate uncertainties across methods when faced with conflicting results. Ants are the most species-rich lineage of social insects and one of the most ecologically important terrestrial animals. Consequently, ants have garnered significant research attention, including their systematics. Despite this, there has been no comprehensive genus-level phylogeny of the ants inferred using genomic data that thoroughly evaluates both signal strength and incongruence. In this study, we provide insight into and quantify uncertainty across the ant tree of life by utilizing the most taxonomically comprehensive ultraconserved elements data set of ants to date, including 277 (81%) of recognized ant genera from all 16 extant subfamilies, and representing over 98% of described species. We use simulations to establish expectations for resolution, identify branches with less-than-expected concordance, and dissect the effects of data and model selection on recalcitrant nodes. Simulations show that hundreds of loci are needed to resolve recalcitrant nodes on our genus-level ant phylogeny. This demonstrates the continued role of random error in phylogenomic studies. Our analyses provide a comprehensive picture of support and incongruence across the ant phylogeny, while offering a more nuanced depiction of uncertainty and significantly expanding generic sampling. We use a consensus approach to integrate uncertainty across different analyses and find that assumptions about root age exert substantial influence on divergence dating. Our results suggest that advancing the understanding of ant phylogeny will require not only more data but also more refined phylogenetic models. We also provide a workflow for identifying under-supported nodes in concatenation analyses, outline a pragmatic way to reconcile conflicting results in phylogenomics, and introduce a user-friendly locus selection tool for divergence dating. 

Morphometric analyses of male genitalia are routinely used to distinguish genera and species in beetles, butterflies, and flies, but are rarely used in ants, where most morphometric analyses focus on the external morphology of the worker caste. In this work, we performed linear morphometric analysis of the male genitalia to distinguish Monomorium and Syllophopsis in Madagascar. For 80 specimens, we measured 10 morphometric characters, especially on the paramere, volsella, and penisvalvae. Three datasets were made from linear measurements: mean (raw data), the ratios of characters (ratio data), and the Removal of Allometric Variance (RAV data). The following quantitative methods were applied to these datasets: hierarchical clustering (Ward’s method), unconstrained ordination methods including Principal Component Analysis (PCA), Non-Metric Multidimensional Scaling analyses (NMDS), Linear Discriminant Analysis (LDA), and Conditional Inference Trees (CITs). The results from statistical analysis show that the ratios proved to be the most effective approach for genus-level differentiation. However, the RAV method exhibited overlap between the genera. Meanwhile, the raw data facilitated more nuanced distinctions at the species level compared with the ratios and RAV approaches. The CITs revealed that the ratios of denticle length of the valviceps (SeL) to the paramere height (PaH) effectively distinguished between genera and identified key variables for species-level differentiation. Overall, this study shows that linear morphometric analysis of male genitalia is a useful data source for taxonomic delimitation. 

The genus-level classification of the ant subfamily Ponerinae (Hymenoptera: Formicidae) is revised based on a comprehensive phylogenomic analysis of more than 2,300 ultraconserved element (UCE) loci across 1,170 sampled specimens representing 1,020 taxa (600 valid species and 420 morphospecies) and all described ponerine genera known from workers. While most previously defined genus groups are recovered as monophyletic, several genera are shown to be polyphyletic or paraphyletic. To resolve these inconsistencies, four new genera are described:Boltonoponegen. nov.,Makebaponegen. nov.,Subiridoponegen. nov., andSritoponeragen. nov.Xiphopeltastat. rev.is revalidated andEuponerais restricted by expandingFisheroponeto absorb a paraphyletic assemblage.Mesoponerais split into four lineages, resulting in transfers toMakebapone,Subiridopone, andXiphopelta.Iroponerasyn. nov.is synonymized underCryptoponeand additional new synonymies at both the generic and species levels are established. Morphological diagnoses are revised for each affected genus, and updated species lists and new combinations are provided. The updated classification recognizes 54 valid genera within Ponerinae and acknowledges an additional lineage that will be formally described in a subsequent publication. To support identification and comparative studies, revised keys to all extant Ponerinae genera are provided, presented by biogeographic region (African and Malagasy, Palearctic–Indomalaya–Australasia, and New World). This classification is intended to provide a stable, phylogenetically informed framework for future research on ponerine ants. 

Abstract The genus Ponera includes over 60 extant species worldwide. These tiny, endogeic predator ants are predominantly distributed in the Indomalaya and Australasia regions, with a few additional Holarctic species. Herein, we explore and describe the diversity of the Malagasy Ponera fauna through an integrative taxonomic approach. We obtained our morphological species hypotheses from multivariate analyses of ten continuous morphometric characters. Species boundaries and reliability of morphological clusters were tested via confirmatory Linear Discriminant Analysis (LDA), cross-validation (LOOCV), and analyses of a mitochondrial COI gene fragment. According to the combined application of the analyses, altogether, three species are inferred in the Malagasy region, Ponera petila Wilson (1957), P. swezeyi Wheeler (1933), and P. adumbrans Csősz & Fisher sp. n. Ponera petila and P. swezeyi belong to the Indo-Australian Ponera tenuis group; the third species, P. adumbrans sp. n., is morphologically similar to the Papua New Guinean P. clavicornis Emery (1900). Furthermore, Linear Discriminant Analysis classified the type specimens of P. bableti Perrault (1993), along with a P. petila cluster with posterior p  = 1. Therefore, we propose the new junior synonymy of P. bableti with P. petila . Madagascar’s extant biodiversity is predominantly explained by colonization events from the African continent across the Mozambique channel via rafting. However, since no native Ponera species are known from the Afrotropical continent, and the closest congeners have an almost exclusively Indo-Australian distribution, the likelihood of an Indo-Australian origin of the Malagasy Ponera fauna is implied. 

The male of the myrmicine genus Erromyrma is described for the first time on the basis of two specimens of Erromyrma latinodis (Mayr, 1872) collected in northern Madagascar. We used COI barcoding to confirm the identification of the male specimens as conspecific with Erromyrma latinodis . We provide an illustrated male-based key to the four Myrmicinae tribes (Attini, Crematogastrini, Solenopsidini, Stenammini) and to the Solenopsidini genera ( Adelomyrmex , Erromyrma , Solenopsis , Syllophopsis and Monomorium ) for the Malagasy region. 

Abstract The classification of ants (Hymenoptera: Formicidae) has progressed in waves since the first 17 species were described by Linnaeus in the 1758 edition of Systema Naturae. Since then, over 18,000 species-rank names have accumulated for the global myrmecofauna, of which ~14,260 living and ~810 fossil species are valid. Here, we provide a synopsis of ant biodiversity and review the history and classification of the family, while highlighting the massive growth of the field in the new millennium. We observe that major transformation has occurred for ant classification due to advances in DNA sequencing technologies, model-based hypothesis testing, and imaging technologies. We therefore provide a revised and illustrated list of diagnostic character states for the higher clades of Formicidae, recognizing that vastly more work is to be done. To facilitate discussion and the systematic accumulation of evolutionary knowledge for the early evolution of the ants, we suggest an informal nomenclatural system for the higher clades of ants, based on names currently in use and a set of names that have been democratically selected by the authors. To guide future work on ant systematics, we summarize currently available databases and present perspectives on regions in need of biodiversity exploration, challenges facing the field, and the future of ant taxonomy. 

The collection of Volodymyr Opanasovych Karawajew, stored at the Schmalhausen Institute of Zoology of the National Academy of Sciences of Ukraine (SIZK, Kiev), is one of the richest ant collections of the world. It contains more than 20,000 dry mounted specimens, collected mostly in Southeast Asia and the Palaearctic, as well as in the Afrotropics, Australia, and North and South America. Among them, we found type specimens of 509 taxa, described by Karawajew and other myrmecologists. The compiled Catalogue includes data on types of 80 taxa belonging to the subfamilies Dorylinae, Amblyoponinae, Ectatomminae, Ponerinae, Proceratiinae and Pseudomyrmecinae.