Table of Contents

March 2026, Volume 64 Issue 2

Cover illustration: Representative taxa of the genus Mustela in China: a photograph of M. altaica taken in Lhasa, Xizang. Based on mitochondrialand nuclear genomic analyses, this species is the closest relative of the newly described M. mopbie, which was discovered in Mabian National NatureReserve. See Wei et al., pp. 186-202 in this issue. Cover credit: Lei Dong.

  

News and Views
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  Evolution’s role reversal: How seahorse dads evolved a “placenta”

  Xianghui Zhang, Chenguang Feng, and Wenyu Zhang

  J Syst Evol. 2026, 64(2): 179-180.
  https://doi.org/10.1111/jse.70053

  Abstract  |  Full Text PDF  |  Save

  Scientists discovered a special type of stem cell that forms the male seahorse's brood pouch, and found that similar cells in female mammalian placental tissue perform comparable reproductive functions, revealing a convergent evolutionary pathway for pregnancy. Future comparative studies of male pregnancy in seahorses and paternal brooding in sea spiders are demanded to provide crucial insights into the evolutionary convergence of this reproductive innovation between these two distantly related lineages.
Commentary
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  Molecular evolution of stem cell regulators driving powerful regenerative abilities in plants: Comment on Tang L et al. (2025) “Time-resolved reprogramming of single somatic cells into totipotent states during plant regeneration”

  Gui Cai, Zhanghui Zeng, Viola Willemsen, Wu Liu, Lin Xu

  J Syst Evol. 2026, 64(2): 181-185.
  https://doi.org/10.1111/jse.70055

  Abstract  |  Full Text PDF  |  Save

  Plants have evolved diverse regenerative strategies, such as somatic embryogenesis and de novo organ regeneration, governed by key transcription factors. This commentary summarizes the evolutionary trajectories of three conserved regulators—LEC2, WOX, and euANT—that orchestrate stem cell fate transitions during regeneration.
Research Article
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  Phylogenomics of the Genus Mustela with description of a new species from China

  Qiu-Jin Wei, Lei Cao, Xing-Cheng He, Alexei Abramov, Jin Wang, Jie Fu, Rui Li, Qi-Sen Yang, Li-Qiang Fu, Yao-Hua Huang, Cai-Quan Zhou, Zhi-Xin Wen, De-Yan Ge

  J Syst Evol. 2026, 64(2): 186-202.
  https://doi.org/10.1111/jse.70029

  Abstract  |  Full Text PDF  |  Save

  Weasels represent the most widely distributed and diverse lineage within the family Mustelidae. They have experienced adaptive radiation and have long been the subject of significant taxonomic debates. This study undertakes a comprehensive study of this group, employing morphological measurements, mitochondrial genomes, nuclear genes, and single copy orthologs extracted from whole genome data. Based on the outcomes of phylogenetic tree construction using orthologous genes, it is ultimately verified that the genera Mustela and Neogale are independent genera, thereby resolving the controversy regarding the species they encompass. Through molecular systematics and morphological studies, a putative Mustela species collected from Mabian Dafengding National Nature Reserve in Sichuan is confirmed as a new species, designated Mustela mopbie sp. nov. This new species exhibits molecular phylogenetic affinity with M. altaica and M. nivalis, yet shares morphological similarities with M. kathiah, M. nivalis and M. aistoodonnivalis. Notably, it is considerably smaller than these species and possesses distinctive body coloration and tail morphology. This study provides a detailed description of this new species and demonstrates that larger datasets yield more robust phylogenetic signal. Furthermore, we observed substantial incongruence between mitochondrial and nuclear gene trees, suggesting potential genomic introgression between this new species and its closely related congeners (M. altaica and M. nivalis).

  Phylogenetic reconstruction conducted by integrating thirteen protein coding genes obtained from the complete mitochondrial genome, cytochrome b (CYTB), a concatenated dataset of nuclear genes, single copy orthologs identified through whole genome sequences, along with habitat characteristics, external morphology, and cranial morphology of Mustela mopbie sp. nov.
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  Sex ratio variation in the populations of three submerged dioecious macrophytes of Vallisneria

  Yu Liang, Yin Zhou, Peng Nan, Yuguo Wang, Wenju Zhang, Ji Yang, Zhiping Song

  J Syst Evol. 2026, 64(2): 203-212.
  https://doi.org/10.1111/jse.70028

  Abstract  |  Full Text PDF  |  Save

  Sex ratio plays a critical role in population survival. Dioecious plants may simultaneously display sexual dimorphism and deviations from the equilibrium expectation of 1:1 sex ratio in populations, that is, biased sex ratio. However, whether biased sex ratios can be attributed to sexual dimorphism has not been well investigated. Here, we conducted experiments using a three-water-depth gradient to examine sexual dimorphism performance and population sex ratios for Vallisneria natans, and investigated the variations in natural population sex ratios for it and two other congeners V. spinulosa and V. denseserrulata along water depth changes. Females of V. natans had higher reproductive investment than males, and the degree of sexual dimorphism increased with increasing water depth. At greater water depths, increased reproductive expenditure led to higher mortality in females, resulting in a male-biased sex ratio. The sex ratios of natural V. natans and V. spinulosa populations did not significantly deviate from 1:1. In contrast, populations of V. denseserrulata exhibited markedly a female-biased sex ratio, which may be attributed to female plants producing more clonal ramets. Furthermore, no evidence was found for variation in sex ratios along water depth gradients in natural populations of any of the three species. These findings highlight the plasticity both of sexual dimorphism and sex ratios in dioecious plants, indicating that sex ratios are species-specific and depend on sex-specific life-history strategy shaped by their growth environments.

  Sex ratio plays a critical role in population survival. Dioecious plants may simultaneously display sexual dimorphism and deviations from the equilibrium expectation of 1:1 sex ratio in populations, that is, biased sex ratio. However, whether biased sex ratios can be attributed to sexual dimorphism has not been well investigated. Here, we conducted experiments using a three-water-depth gradient to examine sexual dimorphism performance and population sex ratios for Vallisneria natans, and investigated the variations of natural population sex ratios for it and two congeners Vallisneria spinulosa and Vallisneria denseserrulata along water depth changes. Females of V. natans had higher reproductive investment than males, and the degree of sexual dimorphism increased with water depth. At deep water more reproductive expenditure led to higher mortality of females, resulting in male bias. The sex ratios of natural V. natans and V. spinulosa populations did not deviate from 1:1, whereas that of V. denseserrulata was markedly female-biased, likely due to female plants producing more clonal ramets. There was no evidence for variation in sex ratios of natural populations along water depth changes for any of the three species. These findings indicate the plasticity both of sexual dimorphism and sex ratios of dioecious plants, reflecting that sex ratios are species-specific and based on sex-specific life-history strategies adopted in growth environments.
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  Phylogenetic and cytogenetic analyses reveal generic paraphyly and chromosome evolution in Bittacidae (Insecta: Mecoptera)

  Le-Le He, Bao-Zhen Hua

  J Syst Evol. 2026, 64(2): 213-228.
  https://doi.org/10.1111/jse.70019

  Abstract  |  Full Text PDF  |  Save

  Many genera were erected without phylogenetic validation in Bittacidae, a cosmopolitan family in Mecoptera, leaving their generic statuses contentious. Here, we investigated the phylogenetic relationships and reconstructed the ancestral states of chromosome numbers and key morphological characters for 26 species in three genera of Bittacidae using an integrative approach combining molecular, cytogenetic, and morphological data. The phylogenetic analyses reveal that all three genera studied are paraphyletic, but cytogenetic evidence supports the generic status of Terrobittacus Tan & Hua with haploid chromosome numbers ≥20. In contrast, the genus Bittacus Latreille, 1805 exhibits an extensive chromosomal variation from n = 8 to n = 22. Ancestral state reconstruction suggests that the diagnostic character of Bicaubittacus Tan & Hua may represent an apomorphy restricted to a few species. The cytogenetic investigation indicates that n = 22 was the ancestral chromosome number in Bittacidae. Chromosome fusions were likely responsible for numerical reduction in chromosomes of Terrobittacus, whereas more complex structural and numerical variations accounted for the chromosome diversity of Bittacus and Bicaubittacus. To satisfactorily resolve the generic problem of Bittacidae, taxon sampling should be greatly expanded at the global scale, and more attention should be paid to the integrative taxonomy.

  Many genera were erected without phylogenetic validation in Bittacidae (Insecta: Mecoptera), leaving their generic statuses contentious. We investigated the phylogenetic relationships and reconstructed the ancestral states of chromosome numbers for hangingflies using an integrative approach combining molecular, cytogenetic, and morphological data. The phylogenetic analyses reveal that all three genera studied are paraphyletic. Chromosomal data likely play a critical role in the systematics of bittacids. Complex structural and numerical variations of chromosomes occurred in hangingflies during evolution.
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  Deep learning for Fabaceae identification by integrating molecular and morphological data and a solution for barcode selection

  Kawtar Lhayani, Karim Rabeh, Leila Medraoui

  J Syst Evol. 2026, 64(2): 229-239.
  https://doi.org/10.1111/jse.70021

  Abstract  |  Full Text PDF  |  Save

  Identification of Fabaceae family plants traditionally relies on either morphological traits or DNA barcoding, each with limitations in accuracy and efficiency. Deep learning has emerged as a promising tool for integrating multiple data sources, but its full potential remains underexplored. This study aimed to utilize a deep learning model that integrates morphological and molecular data for species identification within the Fabaceae family, bridging the gap between the two methods of identification. The research involved four main phases: (i) data collection; (ii) data preprocessing; (iii) training and testing the model; and (iv) analysis of results. The data comprised DNA barcode sequences retrieved from the BOLD database, and images were collected from different websites. The model was trained for identification on the genera and species levels, with two different barcodes: ITS2 and matK+rbcL. Only species with four available copies of ITS2, matK, and rbcL sequences were selected to ensure consistent input across samples. The final data set included seven genera and 21 species. While the model achieved high accuracy during training, test accuracy remained low (14%–19%), indicating overfitting, likely due to the limited data set size. However, the model demonstrated the ability to evaluate barcode discrimination across genera. Specifically, it highlighted ITS2 and matK+rbcL as having varying levels of effectiveness depending on the genus. These findings introduce a new application for deep learning in plant systematics not only for species identification but also for evaluating barcodes. This approach could help reduce the reliance on trial-and-error in barcode selection and enhance the efficiency of molecular taxonomy.

  This study proposes a deep learning framework integrating morphological traits and DNA barcodes (ITS2, matK, rbcL) to identify Fabaceae species. By combining image data and molecular sequences, a CNN artificial neural network (MMNet) enables automatic species identification and barcode evaluation. The model improves identification accuracy and suggests the most informative barcode per genus. This integrative approach enhances the reliability of plant taxonomy and supports large-scale biodiversity monitoring, providing a tool that bridges traditional and molecular identification methods through automation and intelligent feature fusion.
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  DNA barcoding and cryptic new species confirmation of Chimonocalamus (Poaceae: Bambusoideae)

  Yu-Xiao Zhang, Ru-Li Zhang, Xin-Yu Du, Gui-Liang Zhang, De-Zhu Li

  J Syst Evol. 2026, 64(2): 240-259.
  https://doi.org/10.1111/jse.70027

  Abstract  |  Full Text PDF  |  Save

  Chimonocalamus is distinguished by pachymorph rhizome, lower culm nodes with a ring of root thorns, and semelauctant inflorescence. However, species identification in this genus can be confused due to similar morphological features and overlapped geographical distribution. To confirm the identities of Chimonocalamus species in China, plastome and nuclear ribosomal (nrDNA) of 49 accessions of 10 known species and three putative new species were newly retrieved by genome skimming. Distance-based and tree-based methods were conducted to analyze the species discrimination rate of six datasets. The Skmer method was also applied. The results indicated that Skmer analyses had the highest discriminatory power with nine species identified (69.23%). The plastome showed much higher discriminatory success rate than the combination of three standard plastid DNA barcodes, which performed worst among the six datasets. The three potentially new species of Chimonocalamus were confirmed by the plastome and nrDNA datasets, and Skmer analysis, together with morphological differences. Herein, we describe and illustrate the three species as new to science, that is, Chimonocalamus hekouensis Y. X. Zhang, Gui L. Zhang & D. Z. Li, Chimonocalamus hsuehiorum D. Z. Li & Y. X. Zhang, and Chimonocalamus shuangjiangensis D. Z. Li & Y. X. Zhang. Moreover, the Chimonocalamus fimbriatus complex was designated, calling for further investigation. Taken together, plastome and nrDNA could serve as effective super-barcodes for species discrimination of Chimonocalamus, playing important roles in recognition of cryptic new species, and Skmer analysis can be adopted in molecular identification. Our study provides an empirical case for molecular discrimination of bamboos and can be meaningful for other plant groups.

  In order to better exploit the nuclear reads from genome skimming data, an assembly-free and alignment-free analysis method, Skmer analysis, was adopted in a DNA barcoding study of the bamboo genus Chimonocalamus. It showed the highest discriminatory power compared with standard DNA barcodes and super-barcodes, with nine species (69.23%) successfully identified. Skmer analysis was recommended in DNA barcoding and taxonomic (including taxonomic revision, and cryptic and/or new species confirmation) studies of bamboos.
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  Chromosome-level genome assembly of the endangered Magnolia sinostellata: Insights into genome evolution, cold stress resistance, and terpenoid biosynthesis

  Huijuan Zhou, Fan Wu, Hengzhao Liu, Jiayu Ma, Huiling Yan, Renna Li, Lu Fan, Fangbing Ding, Yuwei Linghu, Bin Xie, Xiaoai Fang, Shu Yang, Ming Yue, Peng Zhao, Yaling Wang

  J Syst Evol. 2026, 64(2): 260-282.
  https://doi.org/10.1111/jse.70025

  Abstract  |  Full Text PDF  |  Save

  The genus Magnolia belongs to Magnoliaceae, an early diverging lineage of the Magnoliales, and is cultivated globally for its high ornamental and commercial values. As a large genus in the family Magnoliaceae, Magnolia species are regarded as highly valuable in phylogenetic and conservation biological studies. However, the whole genome data of Magnolia is still relatively insufficient. Here, we present a high-quality, chromosome-level genome sequence of Magnolia sinostellata (1.86 Gb) with a scaffold N50 of 85.33 Mb. The 19 M. sinostellata genome chromosomes revealed 11 main duplications representing the subgenome. Comparative genomics analysis revealed that the variance in the number of abiotic stress resistance genes among Magnoliid species are related to different environmental adaptations. Most of the genes related to MAPK signaling and stress resistance pathways in the investigated M. sinostellata species are expanded, compared to the other species. Furthermore, the comparative genomics analysis of three Magnolia assemblies, M. sinostellata, Magnolia biondii, and Magnolia sieboldii revealed that large inversions were enriched in terpenoid metabolic pathways, stress resistance and flavonoid biosynthesis, and DNA replication proteins. Using transcriptome sequencing data, we analyzed the expression levels of genes related to terpenoid biosynthesis (terpene synthase) and ICE–CBF–COR gene models related to cold tolerance in various tissues and the buds under different temperature conditions. The high-quality assembly of M. sinostellata and the ICE–CBF–COR bioinformatic analysis cascade provide valuable resources for studying the phylogeny and evolution of Magnoliaceae and angiosperms, while the candidate genes will provide foundational support for molecular breeding in Magnolia species.

  A valuable genomic resource for understanding the evolution, stress resistance, and terpenoid biosynthesis in Magnolia sinostellata. The high-quality genome assembly and detailed analysis offer insights into the adaptive evolution of this endangered species and lay the foundation for future conservation and molecular breeding efforts. The findings highlight the importance of M. sinostellata as a model for studying the evolutionary dynamics and functional genomics of the Magnoliaceae family.
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  Convergent evolution of glutathione metabolism pathway genes in marine mammals

  Zhihong Jin, Jie Jiang, Tinghui Li, Simin Chai, Ran Tian

  J Syst Evol. 2026, 64(2): 283-294.
  https://doi.org/10.1111/jse.70031

  Abstract  |  Full Text PDF  |  Save

  Oxidative stress, triggered by hypoxia during repetitive diving, represents a notable environmental adaptation of marine mammals. Glutathione (GSH) is a widely acknowledged antioxidant that protects crucial cellular elements from damage by reactive oxygen species (ROS). Nevertheless, the role of the glutathione metabolism pathway in shaping the adaptation to oxidative stress in marine mammals is not fully elucidated. In this study, we conducted evolutionary analyses on 37 genes related to the GSH metabolism pathway in marine and terrestrial mammals. We found that in comparison with their terrestrial relatives, marine mammals showed convergently accelerated evolution on the core modules of GSH metabolism. Specifically, we identified a total of 16 genes with significant evolution signals unique to marine mammals, and several genes (e.g., accelerated evolution genes: RRM1 and SMS, positively selected genes: ANPEP and GCLC) were shared in marine mammal lineages. Eight genes were discovered to possess specific amino acid modifications that are common among all marine mammals. Functional assays of marine mammal GCLC showed a downregulation of HIF-1α and enhanced GSH levels under hypoxic conditions, suggesting heightened protection of marine mammals against oxidative stress induced by hypoxia. Our study identified key genes with significant evolutionary signals in marine mammals, providing genomic and functional support for convergent hypoxia adaptation mechanisms within this taxon.

  In this study, we conducted evolutionary analyses and functional verification on glutathione (GSH) metabolism genes across marine mammals. Marine mammals showed convergent evolution in core modules, including rapidly evolving, positively selected genes and proteins with marine mammal-specific amino acid modifications. Functional assays showed that marine mammal GCLCs downregulate HIF-1α and elevate GSH under hypoxia, suggesting heightened oxidative stress protection in marine mammals.
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  Integrative phylogenomics and morphology reveal the evolution and biogeography of Encephalartos (Zamiaceae)

  Sadaf Habib, Anders Lindstrom, James A.R. Clugston, Yiqing Gong, Shanshan Dong, Yunhua Wang, Dennis Stevenson, Chen Feng, Shouzhou Zhang

  J Syst Evol. 2026, 64(2): 295-312.
  https://doi.org/10.1111/jse.70034

  Abstract  |  Full Text PDF  |  Save

  Encephalartos, an African endemic genus within the Zamiaceae, comprises 65 extant species whose phylogenetic relationships have remained unresolved due to limited genetic differentiation observed in previous studies. This research reconstructs the evolutionary history of Encephalartos utilizing 3545 single-copy nuclear genes derived from transcriptomes of 64 species. The study estimates divergence times and reconstructs ancestral states for 12 key morphological traits. Phylogenetic analyses definitively resolve eight major clades, supported by both molecular and morphological evidence. Although these clades partially align with previous morphology and geography based classifications, the genomic data provide novel insights, necessitating a revised infrageneric system. Biogeographic reconstructions indicate that Encephalartos originated in southern Africa during the Oligocene (~26.3 Ma), subsequently dispersing into eastern and northern Africa through the Zimbabwe–Mozambique corridor during the Miocene, followed by expansion into Central Africa. Speciation rates decreased markedly during the Pliocene and Pleistocene, potentially due to intensified climatic drying and cooling. Morphological character mapping identified ancestral traits, including aerial stems, green leaves, and red sarcotesta. Specific transitions such as subterranean stems in clade IV and bluish-green leaves in clades II and V, further substantiate clade differentiation. These findings resolve long-standing taxonomic uncertainties and emphasize the Oligocene-Miocene as a crucial period for Encephalartos diversification, influenced by Cenozoic climate change. This research establishes a robust framework for future systematic and conservation studies while demonstrating the effectiveness of transcriptome data in resolving phylogenies of slowly evolving lineages.

  We aimed to conduct phylogenetic analyses of Encephalartos, a cycad genus endemic to Africa, using 3545 single-copy nuclear genes extracted from transcriptome data, covering 64/65 of the recognized species, along with inference of divergence times using two secondary calibration points. Integrating analyses of phylogenomics, spatio-temporal distribution, and morphology, the eight major clades within the genus were resolved. Dated analyses to estimate the origins and diversification patterns for the genus Encephalartos species yielded divergence age estimates corresponding to the Oligo-Miocene. Comprehensive phylogenetic analyses reveal new higher level phylogenetic relationships among taxa in Encephalartos, providing a stable framework for clarifying the evolutionary history of this cycad group.
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  Molecular phylogenetics and trait-dependent biogeography offer insights on the dispersal of Meiogyne (Annonaceae) across the Australasia–Pacific region

  Ming-Fai Liu, Jérôme Munzinger, Piya Chalermglin, Junhao Chen, Bine Xue, Richard M. K. Saunders

  J Syst Evol. 2026, 64(2): 313-329.
  https://doi.org/10.1111/jse.70017

  Abstract  |  Full Text PDF  |  Save

  Meiogyne is a genus of shrubs, trees and treelets occurring in India, tropical Southeast Asia, and Australasia–Pacific, an unusually wide distribution across Australasia and the Western Pacific compared to other genera of Annonaceae. Previous chloroplast phylogenies of the genus offered poor resolution and support. Here, a molecular phylogeny was reconstructed based on 27 described Meiogyne species (ca. 70% sampling) using seven chloroplast and 11 nuclear markers. The combined data set generated a well-resolved and well-supported phylogeny. Estimation of divergence time utilized two fossil calibrations and an uncorrelated log-normal relaxed clock model. Trait-dependent and trait-independent biogeographical models in BioGeoBEARS were compared using corrected Akaike information criterion weight and the likelihood ratio test. The results suggest that narrow monocarp width is correlated with increased macroevolutionary dispersal. Under the best-fitting trait-dependent DEC + j + t₁₂ + t₂₁ + m₂ model, a single colonization event from Sunda to Sahul during the middle Miocene and two dispersal events from New Guinea and Australia into the Pacific during the late Miocene to early Pliocene were detected. BayesTraits analysis strongly supports a correlation between narrow monocarp width and bright fruit colors. Bird dispersal and the associated traits (narrow monocarp width) may have driven macroevolutionary dispersal for Meiogyne in Australasia–Pacific.

  Molecular phylogeny based on 11 nDNA and seven cpDNA markers and ancestral range reconstruction sugges that the genus Meiogyne dispersed from tropical Southeast Asia to Sahul and the Western Pacific. Trait-dependent biogeographical models and correlated evolution analysis reveal that the bird dispersal trait narrow fruitlet width may have aided the colonization of Meiogyne in the Australasia–Pacific region.
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  A new Late Permian species of Curvicubitidae illuminates the phylogeny and palaobiogeography of Pereborioidea (Insecta: Hemiptera)

  Ziqiang Xu, ChungKun Shih, Chenxin Zhou, Wei Yuan, Yu Liu, Dong Ren, Ying Wang

  J Syst Evol. 2026, 64(2): 330-343.
  https://doi.org/10.1111/jse.70016

  Abstract  |  Full Text PDF  |  Save

  A new species, Sinocurvicubitus haotianus Xu, Shih, Ren & Wang, sp. nov. (Curvicubitidae), is described from the Upper Permian Leping Formation in Jiangxi Province, South China. This constitutes the second definitive occurrence of Curvicubitidae in the Late Permian. Through comparative wing morphology and cladistic analyses, we resolved phylogenetic relationships within the superfamily as ((Ignotalidae + Pereboriidae*) + Curvicubitidae) and validated the exclusion of Scytophara extensa from Pereboriidae. Additionally, we estimated divergence times across Pereborioidea lineages, reconstructed ancestral distribution ranges, and elucidated the origin centers and dispersal routes for Curvicubitidae. Wing eyespots and bands suggested predator mimicry, a novel defense strategy in Permian insects.

  This study revised the generic diagnosis based on Sinocurvicubitus haotianus Xu, Shih, Ren & Wang, sp. nov., a new species from Jiangxi Province, and interpreted the color bands and eyespot on the forewing as defensive mimicry in early insects. By constructing a phylogenetic tree using phenotypic wing data, we clarified the relationships within the superfamily and reconstructed both divergence times and ancestral distribution ranges for key nodes.
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  The first Cheliferidae (Pseudoscorpiones: Cheliferoidea) from mid-Cretaceous Kachin amber

  Chen Feng, Xiangbo Guo, Yuhui Zhuang, Qingqing Zhang, Corentin Jouault, Edmund Aleksander Jarzembowski, Yu Liu

  J Syst Evol. 2026, 64(2): 344-353.
  https://doi.org/10.1111/jse.70018

  Abstract  |  Full Text PDF  |  Save

  Pseudoscorpiones are a group of small-sized to medium-sized arachnids under the species-rich Chelicerata. They are found in many terrestrial habitats, normally cryptic, including leaf litter and soil, under tree bark or rocks. The fossil record of pseudoscorpions is mainly composed of species belonging to extinct genera in extant families, with a small number of taxa described from the famous Kachin amber, sometimes referred to as Burmese amber or Burmite (12 species in six families). Here, we describe a well preserved male specimen of pseudoscorpion from mid-Cretaceous Kachin amber, representing the first fossil record of Cheliferidae from Burmese amber. This new taxon, Echinochelifer curvatus gen. & sp. nov., is characterized by elongate tubercle-bearing pedipalps and several trichobothrial features. Based on these, we discuss the systematic placement and palaeoecological implications of the new taxon in Burmese amber.

  This study presents the first fossil record of Cheliferidae from mid-Cretaceous Kachin amber, specifically a well preserved male specimen (Echinochelifer curvatus gen. et sp. nov.) from amber mines near Noije Bum, Hukawng Valley, Kachin State, northern Myanmar (26°20′N, 96°36′E). The new taxon is distinguished by unique features such as elongate tubercle-bearing pedipalps and specific trichobothrial traits. Using advanced techniques like micro-CT scanning and wide-field fluorescence imaging, we elucidate its systematic placement and explore its ecological role within the Burmese amber biota.
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  Divergent defense strategies and niche partitioning in Cretaceous micro-beetles

  Yan‑Da Li, Zhi-Hao Qi, Di‑Ying Huang, Chen‑Yang Cai

  J Syst Evol. 2026, 64(2): 354-362.
  https://doi.org/10.1111/jse.70032

  Abstract  |  Full Text PDF  |  Save

  The evolutionary arms race between insects and their predators has fueled remarkable defensive adaptations, offering insights into ecological dynamics across deep time. Fossils provide critical evidence for studying the evolution of defense strategies. Here, we describe a new lineage of Clambidae from mid-Cretaceous Kachin amber, Scutacalyptus kolibaci gen. et sp. nov. Scutacalyptus stands out within the family due to the flattened body and fully explanate body margins. The diversity of defensive morphotypes in Cretaceous Clambidae, including conglobators like Sphaerothorax, semi-flattened forms like Acalyptomerus, and shield-formers like Scutacalyptus, highlights their developmental plasticity and suggests ecological differentiation in response to varied predation pressures during the late Mesozoic. This morphological divergence reflects niche partitioning in the Cretaceous forest floor ecosystem, driven by a diverse predator array including spiders, ants, lizards, and birds. The coexistence of clambids with spines or explanate margins parallels adaptations in the modern, unrelated Cassidinae, where tortoise beetles use explanate margins and some leaf-mining beetles use spines, each tailored to counter specific predation pressures. These parallel strategies reveal how different defenses likely addressed distinct ecological challenges in the mid-Cretaceous.

  We report a new clambid beetle from mid-Cretaceous Kachin amber, Scutacalyptus kolibaci gen. et sp. nov., characterized by a flattened body and explanate margins. Alongside spiny and conglobating clambid forms, this diversity reflects niche partitioning and varied antipredator strategies in the Cretaceous forest floor. These defenses parallel those of modern Cassidinae, highlighting convergent adaptations to different predation pressures.
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  Genome-based polyphasic taxonomy of desert-derived Kineococcus reveals nine novel species with plant growth-promoting traits

  Jie Huang, Shuai Li, Zhuo-Huan Zheng, Jun Liu, Yi-Jun Mo, Ting-Ting She, Li-Jia Huang, Wen-Sheng Shu, Lei Dong, Wen-Jun Li

  J Syst Evol. 2026, 64(2): 363-386.
  https://doi.org/10.1111/jse.70020

  Abstract  |  Full Text PDF  |  Save

  The genus Kineococcus is primarily found in extreme environments and plant-associated habitats, suggesting its potential for stress tolerance and plant growth promotion. However, the diversity and functional potential of this genus remain largely unexplored, mainly due to the limited availability of strains and genomic resources. In this study, 33 Kineococcus strains were isolated from the Gurbantunggut Desert and Shanshan Kumtag Desert in Xinjiang, China. Based on the overall genome-relatedness indices (OGRI) and sampling origins, 12 representative Kineococcus strains were selected for polyphasic taxonomy and assessment of plant growth-promoting traits. By integrating phylogenetic, morphological, physiological, chemotaxonomic, and genomic analyses, these strains were classified into nine novel species (one with two subspecies). The representative isolates exhibited various key plant growth-promoting traits, including siderophore production, cellulose degradation, organophosphate solubilization, and indole-3-acetic acid (IAA) production. This study significantly expands the strains, species, and genome resources of the genus Kineococcus, providing valuable insight into its ecological adaptation, particularly in saline–alkali tolerance, and growth-promoting potential for sustainable agriculture.

  Thirty-three new Kineococcus strains were isolated from a desert habitat. By integrating phylogenetic, morphological, physiological, chemotaxonomic, and genomic analyses, these strains were classified into nine novel species (one with two subspecies). The representative isolates exhibited various key plant growth-promoting traits. This study expands the resources of the genus Kineococcus and enhances our understanding of its potential applications in sustainable agriculture.
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  Benthoplanidae, a new family of benthic ctenophores (Platyctenida), based on morphological and genetic data

  Nicholas Bezio, Gustav Paulay, Allen Collins

  J Syst Evol. 2026, 64(2): 387-400.
  https://doi.org/10.1111/jse.70023

  Abstract  |  Full Text PDF  |  Save

  We present a phylogenetic analysis of benthic ctenophores of the order Platyctenida, sampling all but one genus. Using complete mitochondrial genomes and nuclear ribosomal data and a reassessment of anatomy, our integrated analysis uncovers an unexpectedly close relationship between two unusual members of the Coeloplanidae: Coeloplana (Benthoplana) meteoris and Vallicula multiformis. These two species form a well-supported clade, deriving at or near the base of the tree of Platyctenida, distantly related to other Coeloplana, rendering Coeloplana and Coeloplanidae non-monophyletic. A unique mitochondrial gene order and a tentacle bulb with four extensions are newly identified synapomorphies of this lineage. We elevate the subgenus Benthoplana to the generic level, erect the new family Benthoplanidae for Benthoplana and Vallicula, and provide diagnoses for these taxa and their accepted species. We also show that planktonic Ctenoplana (Diploctena) neritica is the early life stage of Benthoplana meteoris, and suggest that the remaining Ctenoplanidae likely represent early life history stages of Coeloplanidae and perhaps other platyctenes. While both the nuclear ribosomal (18S and 28S) and mitochondrial protein-coding genes suggest a deep phylogenetic divergence between Benthoplanidae and Coeloplanidae, we detect conflicting phylogenetic signal between these markers, suggesting nuclear-mitochondrial discordance, leaving the placement of Tjalfiellidae and Lyroctenidae uncertain.

  The benthic ctenophore Benthoplana meteoris (adults left and bottom, planktonic juveniles to the top right), type species for the genus, which in turn is type for the newly erected family: Benthoplanidae (Ctenophora, Platyctenida).
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  Hidden Lineages in the African Sky Islands: A taxonomic reevaluation of Afrocarduus (Compositae)

  Lucía D. Moreyra, Juan Antonio Calleja, Cristina Roquet, Siri Birkeland, Carme Blanco-Gavaldà, Mercè Galbany-Casals, Abel Gizaw, Frederik Leliaert, Christian Brochmann, Alfonso Susanna

  J Syst Evol. 2026, 64(2): 401-420.
  https://doi.org/10.1111/jse.70024

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  Accurate species delimitation is crucial for biodiversity research, as it significantly impacts taxonomy, ecology, and conservation. Recent advances in molecular phylogenetics and integrative taxonomy have improved classifications and resolved long-standing taxonomic uncertainties. Here, we use Hyb-Seq (489 nuclear loci) and phylogenomic approaches to investigate Afrocarduus, a genus endemic to tropical Afromontane and Afroalpine regions. Our analyses reveal 16 evolutionary lineages within this relatively young genus (crown age 2.3 Mya), with new morphological data strongly supporting the recognition of each lineage as a distinct species. We demonstrate that the stemless habit evolved independently in species from the Ethiopian Highlands and the East African Rift System (EARS). Notably, we show that the concept of the stemless Afrocarduus schimperi adopted by the Flora of Tropical East Africa, in fact, comprises seven clearly recognizable species, which we formally reinstate. Unexpectedly, the stemmed Afrocarduus nyassanus was recovered as paraphyletic with Afrocarduus ruwenzoriensis nested within it, probably due to incomplete lineage sorting or hybridization. Additionally, the stemmed Afrocarduus keniensis may represent a complex of cryptic species, and we describe a new stemmed species from southern Ethiopia, Afrocarduus kazmi sp. nov. We expand the number of accepted species in Afrocarduus from eight, as recognized in the Flora of Tropical East Africa, to 18 (including two species for which we were not able to obtain molecular data). Our study thus highlights a substantial prior underestimation of the diversity of Afrocarduus in Afromontane and Afroalpine habitats.

  Species delimitation is crucial for biodiversity studies. Using Hyb-Seq and phylogenomics, we reassessed Afrocarduus, endemic to Afromontane and Afroalpine regions, uncovering 16 evolutionary lineages (2.3 Mya). Morphological data support their distinctiveness, with acaulescence evolving independently twice. The traditionally broad A. schimperi includes seven species, now reinstated, and we describe A. kazmi sp. nov., expanding Afrocarduus from eight to 18 species.