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Mark S. Harvey - One of the best experts on this subject based on the ideXlab platform.
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the first fossil of the pseudoscorpion family ideoroncidae arachnida Pseudoscorpiones a new taxon from the mid cretaceous of northern myanmar
Cretaceous Research, 2021Co-Authors: Carolin Geisler, Mark S. Harvey, Ulrich Kotthoff, Jörg U. Hammel, Danilo HarmsAbstract:Abstract Pseudoscorpions have a sparse fossil record although they are among the oldest terrestrial lineages with origins that go back to the Devonian (ca. 385 Ma). Amongst the 25 extant families of pseudoscorpions, only 14 are known from fossils, most of which are preserved in European ambers from the Eocene. Burmese amber from the Cenomanian (mid-Cretaceous) of northern Myanmar is an important source of Mesozoic pseudoscorpion fossils but only six species have been described from this amber to date. In this paper, we establish the first fossil record for the pseudoscorpion family Ideoroncidae Chamberlin, 1930, which is coequally the oldest record of the pseudoscorpion superfamily Neobisioidea. The new genus Proalbiorix is established for the two species P. gracilis sp. nov. and P. compactus sp. nov. which already show all diagnostic features of members belonging to this family to date. Interestingly, Proalbiorix shows morphological features that align the fossils with present-day fauna from the Americas and Africa rather than Asia, which has biogeographical implications. Overall, the description provides another example of relative morphological stasis of pseudoscorpions compared to other arachnid lineages such as spiders, and that all major clades of pseudoscorpions were established long before the Cretaceous.
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taxonomic sampling and rare genomic changes overcome long branch attraction in the phylogenetic placement of pseudoscorpions
Molecular Biology and Evolution, 2021Co-Authors: Andrew Z Ontano, Mark S. Harvey, Guilherme Gainett, Shlomi Aharon, Jesus A Ballesteros, Ligia R Benavides, Kevin F Corbett, Efrat Gavishregev, Scott Monsma, Carlos E SantibanezlopezAbstract:Long-branch attraction is a systematic artifact that results in erroneous groupings of fast-evolving taxa. The combination of short, deep internodes in tandem with LBA artifacts has produced empirically intractable parts of the Tree of Life. One such group is the arthropod subphylum Chelicerata, whose backbone phylogeny has remained unstable despite improvements in phylogenetic methods and genome-scale datasets. Pseudoscorpion placement is particularly variable across datasets and analytical frameworks, with this group either clustering with other long-branch orders or with Arachnopulmonata (scorpions and tetrapulmonates). To surmount LBA, we investigated the effect of taxonomic sampling via sequential deletion of basally branching pseudoscorpion superfamilies, as well as varying gene occupancy thresholds in supermatrices. We show that concatenated supermatrices and coalescent-based summary species tree approaches support a sister group relationship of pseudoscorpions and scorpions, when more of the basally branching taxa are sampled. Matrix completeness had demonstrably less influence on tree topology. As an external arbiter of phylogenetic placement, we leveraged the recent discovery of an ancient genome duplication in the common ancestor of Arachnopulmonata as a litmus test for competing hypotheses of pseudoscorpion relationships. We generated a high-quality developmental transcriptome and the first genome for pseudoscorpions to assess the incidence of arachnopulmonate-specific duplications (e.g., homeobox genes and miRNAs). Our results support the inclusion of pseudoscorpions in Arachnopulmonata (new definition), as the sister group of scorpions. Panscorpiones (new name) is proposed for the clade uniting Scorpiones and Pseudoscorpiones.
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taxonomic sampling and rare genomic changes overcome long branch attraction in the phylogenetic placement of pseudoscorpions
bioRxiv, 2020Co-Authors: Andrew Z Ontano, Mark S. Harvey, Guilherme Gainett, Shlomi Aharon, Jesus A Ballesteros, Ligia R Benavides, Kevin F Corbett, Efrat Gavishregev, Scott Monsma, Carlos E SantibanezlopezAbstract:Abstract Long-branch attraction is a systematic artifact that results in erroneous groupings of fast-evolving taxa. The combination of short, deep internodes in tandem with LBA artifacts has produced empirically intractable parts of the Tree of Life. One such group is the arthropod subphylum Chelicerata, whose backbone phylogeny has remained unstable despite improvements in phylogenetic methods and genome-scale datasets. Pseudoscorpion placement is particularly variable across datasets and analytical frameworks, with this group either clustering with other long-branch orders or with Arachnopulmonata (scorpions and tetrapulmonates). To surmount LBA, we investigated the effect of taxonomic sampling via sequential deletion of basally branching pseudoscorpion superfamilies, as well as varying gene occupancy thresholds in supermatrices. We show that concatenated supermatrices and coalescent-based summary species tree approaches support a sister group relationship of pseudoscorpions and scorpions, when more of the basally branching taxa are sampled. Matrix completeness had demonstrably less influence on tree topology. As an external arbiter of phylogenetic placement, we leveraged the recent discovery of an ancient genome duplication in the common ancestor of Arachnopulmonata as a litmus test for competing hypotheses of pseudoscorpion relationships. We generated a high-quality developmental transcriptome and the first genome for pseudoscorpions to assess the incidence of arachnopulmonate-specific duplications (e.g., homeobox genes and miRNAs). Our results support the inclusion of pseudoscorpions in Arachnopulmonata, as the sister group of scorpions. Panscorpiones (new name) is proposed for the clade uniting Scorpiones and Pseudoscorpiones.
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supralittoral pseudoscorpions of the genus garypus Pseudoscorpiones garypidae from the indo west pacific region with a review of the subfamily classification of garypidae
Invertebrate Systematics, 2020Co-Authors: Mark S. Harvey, Mia J Hillyer, Joel A Huey, Jose I CarvajalAbstract:The pseudoscorpions of the genus Garypus L. Koch are restricted to seashore habitats where they occupy supralittoral and littoral zones primarily in tropical and subtropical areas. Few species have been recorded from the Indo-West Pacific region, and this project was devised to produce a review of the species found in museum collections and to test the relationships of the various garypid genera using a molecular analysis and an assessment of their morphology. A new subfamily classification is proposed with the subfamilies Garypinae, including Garypus and the new genus Anchigarypus Harvey (type species Garypus californicus Banks), and the Synsphyroninae for the other genera (Ammogarypus Beier, Anagarypus Chamberlin, Elattogarypus Beier, Eremogarypus Beier, Meiogarypus Beier, Neogarypus Vachon, Paragarypus Vachon, Neogarypus Vachon, Synsphyronus Chamberlin, and Thaumastogarypus Beier). The species-level revision of Garypus provides evidence for at least 14 species, most of which are known from only single localities. The following species are redescribed: G. insularis Tullgren from the Seychelles, G. krusadiensis Murthy & Ananthakrishnan from India and Sri Lanka, G. longidigitus Hoff from Queensland, Australia, G. maldivensis Pocock from the Maldives, G. nicobarensis Beier from the Nicobar Islands and G. ornatus Beier from the Marshall Islands. The holotype of G. insularis is a tritonymph, and not therefore readily identifiable. Nine new species are described: G. latens Harvey, sp. nov., G. malgaryungu Harvey, sp. nov., G. necopinus Harvey, sp. nov., G. postlei Harvey, sp. nov., G. ranalliorum Harvey, sp. nov. and G. weipa Harvey, sp. nov. from northern Australia, G. dissitus Harvey, sp. nov. from Cocos-Keeling Island, G. reong Harvey, sp. nov. and G. yeni Harvey, sp. nov. from Indonesia. A further possible new species from Queensland is described but not named, as it is represented by a single tritonymph. The subspecies of the Caribbean species G. bonairensis Beier are elevated to full species status: G. bonairensis, G. realini Hummelinck and G. withi Hoff. We supplement the descriptions with sequence data from five specimens from four species of Garypus and two species of Anchigarypus, and find COI divergence levels of 7–19% between Garypus species.
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phylogenomic interrogation resolves the backbone of the Pseudoscorpiones tree of life
Molecular Phylogenetics and Evolution, 2019Co-Authors: Ligia R Benavides, Mark S. Harvey, Julia G Cosgrove, Gonzalo GiribetAbstract:Abstract Pseudoscorpiones, with nearly 3700 described species, are an ancient and globally distributed group of arachnids with a fossil record dating back to the Middle Devonian. Previous attempts to reconstruct their phylogenetic history have used morphology or a few amplicons, mostly of rRNAs and mitochondrial genes, which have not been able to completely resolve family-level relationships nor the earliest nodes in the pseudoscorpion tree—those which are most informative about the origins of key characters like venoms and silk. Here we undertake a phylogenetic approach using 41 pseudoscorpion transcriptomes and a series of analyses that account for many of the common pitfalls faced in large phylogenomic analyses. All analyses, using concatenation methods and coalescent approaches, supported monophyly of Iocheirata (the venomous pseudoscorpions), which diversified mostly during the Mesozoic, but paraphyly of Epiocheirata, with a sister group relationship of Feaelloidea to Iocheirata, with Chthonioidea as their sister group. These three main lineages were established during the mid-to-late Paleozoic. Our phylogenetic scheme is consistent with the prior hypothesis that the lack of venom in Pseudoscorpiones is plesiomorphic and not a synapomorphy of Epiocheirata. Based on the results of this study, a new classification is proposed for Pseudoscorpiones including the following new nomenclatural and taxonomic acts: the new suborders Palaeosphyronida Harvey and Atoposphyronida Harvey for Dracochelidae and Feaelloidea, respectively; the newly recognized superfamily Garypinoidea for Garypinidae and Larcidae; the revised rank for Lechytiidae and Tridenchthoniidae, which are regarded as subfamilies of Chthoniidae; the revised rank for Tridenchthoniini and Verrucadithini which are regarded as tribes of Tridenchthoniinae; and the elevation of Hesperolpiinae as a distinct family, Hesperolpiidae.
Joel A Huey - One of the best experts on this subject based on the ideXlab platform.
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supralittoral pseudoscorpions of the genus garypus Pseudoscorpiones garypidae from the indo west pacific region with a review of the subfamily classification of garypidae
Invertebrate Systematics, 2020Co-Authors: Mark S. Harvey, Mia J Hillyer, Joel A Huey, Jose I CarvajalAbstract:The pseudoscorpions of the genus Garypus L. Koch are restricted to seashore habitats where they occupy supralittoral and littoral zones primarily in tropical and subtropical areas. Few species have been recorded from the Indo-West Pacific region, and this project was devised to produce a review of the species found in museum collections and to test the relationships of the various garypid genera using a molecular analysis and an assessment of their morphology. A new subfamily classification is proposed with the subfamilies Garypinae, including Garypus and the new genus Anchigarypus Harvey (type species Garypus californicus Banks), and the Synsphyroninae for the other genera (Ammogarypus Beier, Anagarypus Chamberlin, Elattogarypus Beier, Eremogarypus Beier, Meiogarypus Beier, Neogarypus Vachon, Paragarypus Vachon, Neogarypus Vachon, Synsphyronus Chamberlin, and Thaumastogarypus Beier). The species-level revision of Garypus provides evidence for at least 14 species, most of which are known from only single localities. The following species are redescribed: G. insularis Tullgren from the Seychelles, G. krusadiensis Murthy & Ananthakrishnan from India and Sri Lanka, G. longidigitus Hoff from Queensland, Australia, G. maldivensis Pocock from the Maldives, G. nicobarensis Beier from the Nicobar Islands and G. ornatus Beier from the Marshall Islands. The holotype of G. insularis is a tritonymph, and not therefore readily identifiable. Nine new species are described: G. latens Harvey, sp. nov., G. malgaryungu Harvey, sp. nov., G. necopinus Harvey, sp. nov., G. postlei Harvey, sp. nov., G. ranalliorum Harvey, sp. nov. and G. weipa Harvey, sp. nov. from northern Australia, G. dissitus Harvey, sp. nov. from Cocos-Keeling Island, G. reong Harvey, sp. nov. and G. yeni Harvey, sp. nov. from Indonesia. A further possible new species from Queensland is described but not named, as it is represented by a single tritonymph. The subspecies of the Caribbean species G. bonairensis Beier are elevated to full species status: G. bonairensis, G. realini Hummelinck and G. withi Hoff. We supplement the descriptions with sequence data from five specimens from four species of Garypus and two species of Anchigarypus, and find COI divergence levels of 7–19% between Garypus species.
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pseudoscorpions of the family feaellidae Pseudoscorpiones feaelloidea from the pilbara region of western australia show extreme short range endemism
Invertebrate Systematics, 2016Co-Authors: Mark S. Harvey, Kym M Abrams, Amber S Beavis, Mia J Hillyer, Joel A HueyAbstract:Abstract. The phylogenetic relationships of the Australian species of Feaellidae are assessed with a molecular analysis using mitochondrial (CO1) and nuclear (ITS2) data. These results confirm the morphological analysis that three previously undescribed species occur in the Pilbara bioregion, which are named and described: Feaella (Tetrafeaella) callani, sp. nov., F. (T.) linetteae, sp. nov. and F. (T.) tealei, sp. nov. The males of these three species, as well as males of F. anderseni Harvey and other unnamed species from the Kimberley region of north-western Australia, have a pair of enlarged, thick-walled bursa that are not found in other feaellids. Despite numerous environmental impact surveys for short-range endemic invertebrates in the Pilbara, very few specimens have been collected, presumably due to their relictual distributions, restricted habitat preferences and low densities. http://zoobank.org/urn:lsid:zoobank.org:pub:131F0587-F2EE-405F-BE5A-772F072D9915
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the first troglobitic species of gymnobisiidae Pseudoscorpiones neobisioidea from table mountain western cape province south africa and its phylogenetic position
Invertebrate Systematics, 2016Co-Authors: Mark S. Harvey, Gonzalo Giribet, Mia J Hillyer, Joel A Huey, Erin McintyreAbstract:Fully troglobitic pseudoscorpions are rare in the Afrotropical Region, and we explored the identity and phylogenetic relationships of specimens of a highly modified troglobite of the family Gymnobisiidae in the dark zone of the Wynberg Cave system, on Table Mountain, South Africa. This large pseudoscorpion – described as Gymnobisium inukshuk Harvey & Giribet, sp. nov. – lacks eyes and has extremely long appendages, and has been found together with other troglobitic fauna endemic only to this cave system. Phylogenetic analyses using the nuclear ribosomal genes 18S rRNA and 28S rRNA and the mitochondrial protein-encoding gene cytochrome c oxidase subunit I unambiguously place the new species with other surface Gymnobisium from South Africa. This placement receives strong support and is stable to analytical treatments, including static and dynamic homology, parsimony and maximum likelihood, and data removal for ambiguously aligned sites. This species is the first troglobitic species of the family and one of the most highly modified pseudoscorpions from the Afrotropical Region. http://zoobank.org/urn:lsid:zoobank.org:pub:5227092B-A64B-4DB3-AD90-F474F0BA6AED
Gonzalo Giribet - One of the best experts on this subject based on the ideXlab platform.
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phylogenomic interrogation resolves the backbone of the Pseudoscorpiones tree of life
Molecular Phylogenetics and Evolution, 2019Co-Authors: Ligia R Benavides, Mark S. Harvey, Julia G Cosgrove, Gonzalo GiribetAbstract:Abstract Pseudoscorpiones, with nearly 3700 described species, are an ancient and globally distributed group of arachnids with a fossil record dating back to the Middle Devonian. Previous attempts to reconstruct their phylogenetic history have used morphology or a few amplicons, mostly of rRNAs and mitochondrial genes, which have not been able to completely resolve family-level relationships nor the earliest nodes in the pseudoscorpion tree—those which are most informative about the origins of key characters like venoms and silk. Here we undertake a phylogenetic approach using 41 pseudoscorpion transcriptomes and a series of analyses that account for many of the common pitfalls faced in large phylogenomic analyses. All analyses, using concatenation methods and coalescent approaches, supported monophyly of Iocheirata (the venomous pseudoscorpions), which diversified mostly during the Mesozoic, but paraphyly of Epiocheirata, with a sister group relationship of Feaelloidea to Iocheirata, with Chthonioidea as their sister group. These three main lineages were established during the mid-to-late Paleozoic. Our phylogenetic scheme is consistent with the prior hypothesis that the lack of venom in Pseudoscorpiones is plesiomorphic and not a synapomorphy of Epiocheirata. Based on the results of this study, a new classification is proposed for Pseudoscorpiones including the following new nomenclatural and taxonomic acts: the new suborders Palaeosphyronida Harvey and Atoposphyronida Harvey for Dracochelidae and Feaelloidea, respectively; the newly recognized superfamily Garypinoidea for Garypinidae and Larcidae; the revised rank for Lechytiidae and Tridenchthoniidae, which are regarded as subfamilies of Chthoniidae; the revised rank for Tridenchthoniini and Verrucadithini which are regarded as tribes of Tridenchthoniinae; and the elevation of Hesperolpiinae as a distinct family, Hesperolpiidae.
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the first troglobitic species of gymnobisiidae Pseudoscorpiones neobisioidea from table mountain western cape province south africa and its phylogenetic position
Invertebrate Systematics, 2016Co-Authors: Mark S. Harvey, Gonzalo Giribet, Mia J Hillyer, Joel A Huey, Erin McintyreAbstract:Fully troglobitic pseudoscorpions are rare in the Afrotropical Region, and we explored the identity and phylogenetic relationships of specimens of a highly modified troglobite of the family Gymnobisiidae in the dark zone of the Wynberg Cave system, on Table Mountain, South Africa. This large pseudoscorpion – described as Gymnobisium inukshuk Harvey & Giribet, sp. nov. – lacks eyes and has extremely long appendages, and has been found together with other troglobitic fauna endemic only to this cave system. Phylogenetic analyses using the nuclear ribosomal genes 18S rRNA and 28S rRNA and the mitochondrial protein-encoding gene cytochrome c oxidase subunit I unambiguously place the new species with other surface Gymnobisium from South Africa. This placement receives strong support and is stable to analytical treatments, including static and dynamic homology, parsimony and maximum likelihood, and data removal for ambiguously aligned sites. This species is the first troglobitic species of the family and one of the most highly modified pseudoscorpions from the Afrotropical Region. http://zoobank.org/urn:lsid:zoobank.org:pub:5227092B-A64B-4DB3-AD90-F474F0BA6AED
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first molecular phylogeny of the major clades of Pseudoscorpiones arthropoda chelicerata
Molecular Phylogenetics and Evolution, 2008Co-Authors: Jerome Murienne, Mark S. Harvey, Gonzalo GiribetAbstract:The phylogenetic relationships of the major lineages of the arachnid order Pseudoscorpiones are investigated for the first time using molecular sequence data from two nuclear ribosomal genes and one mitochondrial protein-encoding gene. The data were analyzed using a dynamic homology approach with the new program POY v.4 under parsimony as the optimality criterion. The data show monophyly of Pseudoscorpiones as well as many of its superfamilies (Feaelloidea, Chthonioidea, Cheiridioidea and Sternophoroidea), but not for Neobisiodea or Garypoidea. Cheliferoidea was not monophyletic either due to the position of Neochelanops, which grouped with some garypoids. In all the analyses, Feaelloidea constituted the sister group to all other pseudoscorpions; Chthonioidea is the sister group to the remaining families, which constitute the group Iocheirata sensu Harvey—a clade including pseudoscorpions with venom glands within the pedipalpal fingers. This phylogenetic pattern suggests that venom glands evolved just once within this order of arachnids.
Carlos E Santibanezlopez - One of the best experts on this subject based on the ideXlab platform.
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taxonomic sampling and rare genomic changes overcome long branch attraction in the phylogenetic placement of pseudoscorpions
Molecular Biology and Evolution, 2021Co-Authors: Andrew Z Ontano, Mark S. Harvey, Guilherme Gainett, Shlomi Aharon, Jesus A Ballesteros, Ligia R Benavides, Kevin F Corbett, Efrat Gavishregev, Scott Monsma, Carlos E SantibanezlopezAbstract:Long-branch attraction is a systematic artifact that results in erroneous groupings of fast-evolving taxa. The combination of short, deep internodes in tandem with LBA artifacts has produced empirically intractable parts of the Tree of Life. One such group is the arthropod subphylum Chelicerata, whose backbone phylogeny has remained unstable despite improvements in phylogenetic methods and genome-scale datasets. Pseudoscorpion placement is particularly variable across datasets and analytical frameworks, with this group either clustering with other long-branch orders or with Arachnopulmonata (scorpions and tetrapulmonates). To surmount LBA, we investigated the effect of taxonomic sampling via sequential deletion of basally branching pseudoscorpion superfamilies, as well as varying gene occupancy thresholds in supermatrices. We show that concatenated supermatrices and coalescent-based summary species tree approaches support a sister group relationship of pseudoscorpions and scorpions, when more of the basally branching taxa are sampled. Matrix completeness had demonstrably less influence on tree topology. As an external arbiter of phylogenetic placement, we leveraged the recent discovery of an ancient genome duplication in the common ancestor of Arachnopulmonata as a litmus test for competing hypotheses of pseudoscorpion relationships. We generated a high-quality developmental transcriptome and the first genome for pseudoscorpions to assess the incidence of arachnopulmonate-specific duplications (e.g., homeobox genes and miRNAs). Our results support the inclusion of pseudoscorpions in Arachnopulmonata (new definition), as the sister group of scorpions. Panscorpiones (new name) is proposed for the clade uniting Scorpiones and Pseudoscorpiones.
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taxonomic sampling and rare genomic changes overcome long branch attraction in the phylogenetic placement of pseudoscorpions
bioRxiv, 2020Co-Authors: Andrew Z Ontano, Mark S. Harvey, Guilherme Gainett, Shlomi Aharon, Jesus A Ballesteros, Ligia R Benavides, Kevin F Corbett, Efrat Gavishregev, Scott Monsma, Carlos E SantibanezlopezAbstract:Abstract Long-branch attraction is a systematic artifact that results in erroneous groupings of fast-evolving taxa. The combination of short, deep internodes in tandem with LBA artifacts has produced empirically intractable parts of the Tree of Life. One such group is the arthropod subphylum Chelicerata, whose backbone phylogeny has remained unstable despite improvements in phylogenetic methods and genome-scale datasets. Pseudoscorpion placement is particularly variable across datasets and analytical frameworks, with this group either clustering with other long-branch orders or with Arachnopulmonata (scorpions and tetrapulmonates). To surmount LBA, we investigated the effect of taxonomic sampling via sequential deletion of basally branching pseudoscorpion superfamilies, as well as varying gene occupancy thresholds in supermatrices. We show that concatenated supermatrices and coalescent-based summary species tree approaches support a sister group relationship of pseudoscorpions and scorpions, when more of the basally branching taxa are sampled. Matrix completeness had demonstrably less influence on tree topology. As an external arbiter of phylogenetic placement, we leveraged the recent discovery of an ancient genome duplication in the common ancestor of Arachnopulmonata as a litmus test for competing hypotheses of pseudoscorpion relationships. We generated a high-quality developmental transcriptome and the first genome for pseudoscorpions to assess the incidence of arachnopulmonate-specific duplications (e.g., homeobox genes and miRNAs). Our results support the inclusion of pseudoscorpions in Arachnopulmonata, as the sister group of scorpions. Panscorpiones (new name) is proposed for the clade uniting Scorpiones and Pseudoscorpiones.
Ligia R Benavides - One of the best experts on this subject based on the ideXlab platform.
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taxonomic sampling and rare genomic changes overcome long branch attraction in the phylogenetic placement of pseudoscorpions
Molecular Biology and Evolution, 2021Co-Authors: Andrew Z Ontano, Mark S. Harvey, Guilherme Gainett, Shlomi Aharon, Jesus A Ballesteros, Ligia R Benavides, Kevin F Corbett, Efrat Gavishregev, Scott Monsma, Carlos E SantibanezlopezAbstract:Long-branch attraction is a systematic artifact that results in erroneous groupings of fast-evolving taxa. The combination of short, deep internodes in tandem with LBA artifacts has produced empirically intractable parts of the Tree of Life. One such group is the arthropod subphylum Chelicerata, whose backbone phylogeny has remained unstable despite improvements in phylogenetic methods and genome-scale datasets. Pseudoscorpion placement is particularly variable across datasets and analytical frameworks, with this group either clustering with other long-branch orders or with Arachnopulmonata (scorpions and tetrapulmonates). To surmount LBA, we investigated the effect of taxonomic sampling via sequential deletion of basally branching pseudoscorpion superfamilies, as well as varying gene occupancy thresholds in supermatrices. We show that concatenated supermatrices and coalescent-based summary species tree approaches support a sister group relationship of pseudoscorpions and scorpions, when more of the basally branching taxa are sampled. Matrix completeness had demonstrably less influence on tree topology. As an external arbiter of phylogenetic placement, we leveraged the recent discovery of an ancient genome duplication in the common ancestor of Arachnopulmonata as a litmus test for competing hypotheses of pseudoscorpion relationships. We generated a high-quality developmental transcriptome and the first genome for pseudoscorpions to assess the incidence of arachnopulmonate-specific duplications (e.g., homeobox genes and miRNAs). Our results support the inclusion of pseudoscorpions in Arachnopulmonata (new definition), as the sister group of scorpions. Panscorpiones (new name) is proposed for the clade uniting Scorpiones and Pseudoscorpiones.
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taxonomic sampling and rare genomic changes overcome long branch attraction in the phylogenetic placement of pseudoscorpions
bioRxiv, 2020Co-Authors: Andrew Z Ontano, Mark S. Harvey, Guilherme Gainett, Shlomi Aharon, Jesus A Ballesteros, Ligia R Benavides, Kevin F Corbett, Efrat Gavishregev, Scott Monsma, Carlos E SantibanezlopezAbstract:Abstract Long-branch attraction is a systematic artifact that results in erroneous groupings of fast-evolving taxa. The combination of short, deep internodes in tandem with LBA artifacts has produced empirically intractable parts of the Tree of Life. One such group is the arthropod subphylum Chelicerata, whose backbone phylogeny has remained unstable despite improvements in phylogenetic methods and genome-scale datasets. Pseudoscorpion placement is particularly variable across datasets and analytical frameworks, with this group either clustering with other long-branch orders or with Arachnopulmonata (scorpions and tetrapulmonates). To surmount LBA, we investigated the effect of taxonomic sampling via sequential deletion of basally branching pseudoscorpion superfamilies, as well as varying gene occupancy thresholds in supermatrices. We show that concatenated supermatrices and coalescent-based summary species tree approaches support a sister group relationship of pseudoscorpions and scorpions, when more of the basally branching taxa are sampled. Matrix completeness had demonstrably less influence on tree topology. As an external arbiter of phylogenetic placement, we leveraged the recent discovery of an ancient genome duplication in the common ancestor of Arachnopulmonata as a litmus test for competing hypotheses of pseudoscorpion relationships. We generated a high-quality developmental transcriptome and the first genome for pseudoscorpions to assess the incidence of arachnopulmonate-specific duplications (e.g., homeobox genes and miRNAs). Our results support the inclusion of pseudoscorpions in Arachnopulmonata, as the sister group of scorpions. Panscorpiones (new name) is proposed for the clade uniting Scorpiones and Pseudoscorpiones.
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phylogenomic interrogation resolves the backbone of the Pseudoscorpiones tree of life
Molecular Phylogenetics and Evolution, 2019Co-Authors: Ligia R Benavides, Mark S. Harvey, Julia G Cosgrove, Gonzalo GiribetAbstract:Abstract Pseudoscorpiones, with nearly 3700 described species, are an ancient and globally distributed group of arachnids with a fossil record dating back to the Middle Devonian. Previous attempts to reconstruct their phylogenetic history have used morphology or a few amplicons, mostly of rRNAs and mitochondrial genes, which have not been able to completely resolve family-level relationships nor the earliest nodes in the pseudoscorpion tree—those which are most informative about the origins of key characters like venoms and silk. Here we undertake a phylogenetic approach using 41 pseudoscorpion transcriptomes and a series of analyses that account for many of the common pitfalls faced in large phylogenomic analyses. All analyses, using concatenation methods and coalescent approaches, supported monophyly of Iocheirata (the venomous pseudoscorpions), which diversified mostly during the Mesozoic, but paraphyly of Epiocheirata, with a sister group relationship of Feaelloidea to Iocheirata, with Chthonioidea as their sister group. These three main lineages were established during the mid-to-late Paleozoic. Our phylogenetic scheme is consistent with the prior hypothesis that the lack of venom in Pseudoscorpiones is plesiomorphic and not a synapomorphy of Epiocheirata. Based on the results of this study, a new classification is proposed for Pseudoscorpiones including the following new nomenclatural and taxonomic acts: the new suborders Palaeosphyronida Harvey and Atoposphyronida Harvey for Dracochelidae and Feaelloidea, respectively; the newly recognized superfamily Garypinoidea for Garypinidae and Larcidae; the revised rank for Lechytiidae and Tridenchthoniidae, which are regarded as subfamilies of Chthoniidae; the revised rank for Tridenchthoniini and Verrucadithini which are regarded as tribes of Tridenchthoniinae; and the elevation of Hesperolpiinae as a distinct family, Hesperolpiidae.
