Three new species of the spider genus Utivarachna Kishida, 1940 (Araneae, Trachelidae) from China and Vietnam.

Three new species belonging to the kinabaluensis group of the trachelid genus Utivarachna Kishida, 1940 are reported from China and Vietnam: U.linyejieisp. nov. (♂♀), U.tamdaosp. nov. (♂♀), and U.zhengguoisp. nov. (♂♀). Type specimens are deposited in the Institute of Zoology, Chinese Academy of Sciences (IZCAS) in Beijing, China and the Vietnam National Museum of Nature (VNMN) in Hanoi, Vietnam.

Two new genera and five new species of Corinnidae Karsch, 1880 (Arachnida, Araneae) from China and Vietnam.

Six species of the family Corinnidae Karsch, 1880 are described from China and Vietnam. Fengzhengen. nov. is erected to accommodate F.menglasp. nov. (♂♀) from China; Penggen. nov. is erected to accommodate P.birmanicus (Thorell, 1897), comb. nov., P.borneensis (Yamasaki, 2017), comb. nov. and P.taprobanicus (Simon, 1897), comb. nov., transferred from Sphecotypus O. Pickard-Cambridge, 1895. Further new species described include Allomedmassatamdaosp. nov. (♂), Echinaxbaishasp. nov. (♂), Medmassalingshuisp. nov. (♂), and Spinirtashaoguansp. nov. (♂). The male of P.birmanicus is described for the first time.

Baiyuerius gen. nov., a new genus of Coelotinae (Araneae, Agelenidae) spiders from China and Vietnam.

Baiyueriusgen. nov., a new genus of the subfamily Coelotinae F. O. Pickard-Cambridge, 1893 is described, including five new species: B.daxisp. nov. (♀), B.pindongsp. nov. (♂), B.tamdaosp. nov. (♀), B.zhupingsp. nov. (♂) and B.zuojiangsp. nov. (♂♀), from southern China and northern Vietnam. Our molecular phylogenetic analyses support Baiyuerius gen. nov. as monophyletic and as a sister group of the newly established genus Yunguirius Li, Zhao & Li, 2023.

On five new species of the genera Araneus and Hypsosinga (Araneae, Araneidae) from Vietnam.

Five new species of the spider family Araneidae Clerck, 1757 from Vietnam are described: Araneuseugeneisp. nov. (♂♀), A.ethanisp. nov. (♀), A.liamisp. nov. (♂♀), Hypsosingaryanisp. nov. (♂♀), and H.zionisp. nov. (♀). Diagnostic photographs of the habitus and copulatory organs are provided. Types of the new species are deposited in the Institute of Zoology, Chinese Academy of Sciences (IZCAS) in Beijing, China.

Thirteen species of jumping spiders from northern Vietnam (Araneae, Salticidae).

A new genus and thirteen species of jumping spiders from northern Vietnam are reported. Zabkagen. nov. is erected to accommodate two species transferred from Euophrys Blackwall,1841, including the generotype, Z.cooki (Zabka, 1985), comb. nov., and Z.xuyei (Lin & Li, 2020), comb. nov. Twelve new species are described: Chinattuscrewsaesp. nov. (♂♀), C.logunovisp. nov. (♂♀), Eupoamaidinhyenisp. nov. (♂♀), E.maddisonisp. nov. (♂♀), E.ninhbinhsp. nov. (♂), E.zabkaisp. nov. (♂♀), Indopadillacucsp. nov. (♂♀), Synagelidesanisp. nov. (♂♀), S.miisp. nov. (♂♀), S.pengisp. nov. (♀), S.sanchasp. nov. (♂♀), and Yaginumaellahagiangsp. nov. (♂). The unknown male of Zabkacooki is described for the first time. Diagnostic photos of the habitus and copulatory organs are provided.

Phylogenomic Analysis of Ultraconserved Elements Resolves the Evolutionary and Biogeographic History of Segmented Trapdoor Spiders.

The segmented trapdoor spiders (Liphistiidae) are the sole surviving family of the suborder Mesothelae, which forms the sister lineage to all other living spiders. Liphistiids have retained a number of plesiomorphic traits and their present-day distribution is limited to East and Southeast Asia. Studying this group has the potential to shed light on the deep evolutionary history of spiders, but the phylogeny and divergence times of the family have not been resolved with confidence. We performed phylogenomic and molecular dating analyses of 2765 ultraconserved element loci from 185 liphistiid taxa. Our analyses show that the crown group of Liphistiidae appeared in the mid-Cretaceous at 102 Ma (95% credibility interval 92-113 Ma), but it was not until the Neogene that much of the diversification within the family occurred in mainland Southeast and East Asia. This diversification was coincident with tectonic events such as the extension of the East Asian continental margin, as well as geological upheavals in Indochina induced by the collision between India and Asia. Our study highlights the important role of major tectonic events in shaping the evolutionary history, present-day diversity, and geographical distribution of mesothele and liphistiid spiders. [biogeography; concatenation; Liphistiidae; molecular dating; summary coalescent; UCEs.].

Five new species of the spider genus Khorata Huber, 2005 (Araneae: Pholcidae) from Vietnam.

Five new species of the genus Khorata Huber, 2005 are reported from Vietnam: Khorata bachma Yao Li sp. nov. (Thua Thien-Hue), K. cucphuong Yao Li sp. nov. (Ninh Binh), K. vinhphuc Yao Li sp. nov. (Vinh Phuc), K. palace Yao Li sp. nov. (Ninh Binh) and K. quangbinh Yao Li sp. nov. (Quang Binh). Type material is deposited in the Institute of Zoology, Chinese Academy of Sciences (IZCAS) in Beijing, China.

The genus Vietbocap Lourenço & Pham, 2010 in the Thien Duong cave, Vietnam: A possible case of subterranean speciation in scorpions (Scorpiones: Pseudochactidae).

Two new species of scorpion belonging to the family Pseudochactidae and to the genus Vietbocap are described based on specimens collected in the Thien Duong cave, which belongs to the Vom cave system, in the Phong Nha-Ke Bang National Park, Quang Binh Province, Vietnam. The previously described species from this cave, Vietbocap thienduongensis Lourenço & Pham, 2012 was collected in the initial section of the cave (1500 to 1800m from the cave entrance) and proved to be a true troglobitic element. The diagnosis of this species, only known from males, is completed based on females collected at 750m from the cave entrance. The two new species described here were collected respectively at 3000 and 5000m from the cave entrance and are also true troglobitic elements, very similar to V. thienduongensis, but showing some clear morphological differences. This observed situation suggests a possible case of speciation within the cave system, the first one ever reported for scorpions. The population found at 5000m from the entrance of the cave is a total new record of distance from a cave entrance for scorpions.

Trapdoor spiders of the genus Cyclocosmia Ausserer, 1871 from China and Vietnam (Araneae, Ctenizidae).

A species of the genus Cyclocosmia Ausserer, 1871 collected from Guizhou Province, China is diagnosed and described as new to science: Cyclocosmia liui Xu, Xu & Li, sp. n. (♀). New records of Cyclocosmia latusicosta Zhu, Zhang & Zhang, 2006 (♀) from China (Yunnan Province) and Vietnam (Vinh Phuc Province, Ninh Binh Province), and Cyclocosmia ricketti (Pocock, 1901) collected from Jiangxi Province, China are also reported in this study.

Diversity and endemicity in the scorpion fauna of Vietnam. A preliminary synopsis.

A faunistic inventory is proposed for the known Vietnamese scorpion species. The aim of this contribution is to bring an up-to-date checklist of all known species in Vietnam, prior to a more detailed study of the Vietnamese fauna to be performed by one of the authors (T.-H.T.) in the context of the preparation of a doctoral degree. Final taxonomic decisions should be taken at the end of the doctoral dissertation.

A remarkable new species of Alloscorpiops Vachon, 1980 from a cave in Vietnam (Scorpiones, Euscorpiidae, Scorpiopinae).

Among the genera of the subfamily Scorpiopinae Kraepelin, 1905 Alloscorpiops remains rather discrete. Only recently new species were added to this genus, increasing its number from two to five. Therefore, species of Alloscorpiops remain rare. One remarkable new species, Alloscorpiopstroglodytes sp. n., is described on the basis of a single male specimen collected inside a cave from Song Thanh Nature Reserve, Cha Vanh Commune, Nam Giang District in Vietnam. The new species presents most features exhibited by scorpions of the genus Alloscorpiops, but it is characterized by reduced size, slender body and elongated pedipalps. This new scorpion taxon represents the third species of Scorpiopinae discovered in a cave system, and may be another endemic element in the fauna of Vietnam.

Extant primitively segmented spiders have recently diversified from an ancient lineage.

Living fossils are lineages that have retained plesiomorphic traits through long time periods. It is expected that such lineages have both originated and diversified long ago. Such expectations have recently been challenged in some textbook examples of living fossils, notably in extant cycads and coelacanths. Using a phylogenetic approach, we tested the patterns of the origin and diversification of liphistiid spiders, a clade of spiders considered to be living fossils due to their retention of arachnid plesiomorphies and their exclusive grouping in Mesothelae, an ancient clade sister to all modern spiders. Facilitated by original sampling throughout their Asian range, we here provide the phylogenetic framework necessary for reconstructing liphistiid biogeographic history. All phylogenetic analyses support the monophyly of Liphistiidae and of eight genera. As the fossil evidence supports a Carboniferous Euramerican origin of Mesothelae, our dating analyses postulate a long eastward over-land dispersal towards the Asian origin of Liphistiidae during the Palaeogene (39-58 Ma). Contrary to expectations, diversification within extant liphistiid genera is relatively recent, in the Neogene and Late Palaeogene (4-24 Ma). While no over-water dispersal events are needed to explain their evolutionary history, the history of liphistiid spiders has the potential to play prominently in vicariant biogeographic studies.

An interesting new subgenus of Scorpiops Peters, 1861 from North Vietnam (Scorpiones: Euscorpiidae: Scorpiopinae).

Scorpiops (Vietscorpiops) dentidactylus subgen. n. et sp. n., belonging to the family Euscorpiidae Laurie, 1896, is described on the basis of single male collected in Dien Bien Province, Muong Nhe District, Nam Vi Commune, in a limestone formation covered by rainforest, in the extreme North of Vietnam. The new subgenus is characterized by the presence of only two lateral eyes represented by lenses and a strong, peculiar apophysis on the internal face of the chelal movable finger. This new scorpion taxon may represent yet another endemic element in the fauna of Southeast Asia, mainly Vietnam and Laos.

Pholcid spiders (Araneae: Pholcidae) from northern Vietnam, with descriptions of nineteen new species.

Five genera and 26 species belonging to two subfamilies Arteminae Simon, 1893 (one genus and one species) and Pholcinae C.L. Koch, 1850 (four genera and 25 species) are reported from northern Vietnam, including 19 new species of three genera: Belisana babensis sp. nov. (male, female; Bac Kan), B. cheni sp. nov. (male, female; Bac Kan), B. clavata sp. nov. (male; Ha Giang), B. curva sp. nov. (male; Vinh Phuc), B. decora sp. nov. (male, female; Ninh Binh), B. halongensis sp. nov. (male; Quang Ninh), B. phungae sp. nov. (male, female; Bac Kan), B. pisinna sp. nov. (male; Quang Ninh), B. triangula sp. nov. (male; Phu Tho), B. vietnamensis sp. nov. (male, female; Ninh Binh), B. zhengi sp. nov. (male; Vinh Phuc), Khorata dangi sp. nov. (male; Bac Kan), K. huberi sp. nov. (male, female; Bac Kan), K. protumida sp. nov. (male, female; Quang Binh), Pholcus bifidus sp. nov. (male, female; Quang Binh), P. caecus sp. nov. (male, female; Quang Binh), P. hochiminhi sp. nov. (male, female; Quang Ninh), P. phami sp. nov. (male, female; Bac Kan), and P. zhaoi sp. nov. (male; Ninh Binh). One genus Khorata Huber, 2005 and five species Belisana schwendingeri Huber, 2005, B. sepaku Huber, 2005, Khorata digitata Yao & Li, 2010, Leptopholcus podophthalmus (Simon, 1893), and Pholcus bangfai Huber, 2011 are reported from Vietnam for the first time. Additional new records are given for two species Leptopholcus huongson Huber, 2011 and Physocyclus globosus (Taczanowski, 1874). 

One new species of the genus Belisana Thorell, 1898 (Araneae, Pholcidae) from northern Vietnam.

One new species Belisanadenticulata sp. n. (♂) is reported from northern Vietnam based on material collected by fogging the forest canopy. This species resembles Belisanascharffi Huber, 2005, but can be distinguished by relatively long distance between proximal parts of proximo-lateral apophysis and distal apophysis on male chelicerae, by presence of a nearly saddle-shaped prolateral sclerite on procursus, and by different shape of retrolateral membranous flap on procursus. Type specimens are deposited in the Vietnam Academy of Science and Technology in Hanoi.

Cyberdiversity: improving the informatic value of diverse tropical arthropod inventories.

In an era of biodiversity crisis, arthropods have great potential to inform conservation assessment and test hypotheses about community assembly. This is because their relatively narrow geographic distributions and high diversity offer high-resolution data on landscape-scale patterns of biodiversity. However, a major impediment to the more widespread application of arthropod data to a range of scientific and policy questions is the poor state of modern arthropod taxonomy, especially in the tropics. Inventories of spiders and other megadiverse arthropods from tropical forests are dominated by undescribed species. Such studies typically organize their data using morphospecies codes, which make it difficult for data from independent inventories to be compared and combined. To combat this shortcoming, we offer cyberdiversity, an online community-based approach for reconciling results of independent inventory studies where current taxonomic knowledge is incomplete. Participating scientists can upload images and DNA barcode sequences to dedicated databases and submit occurrence data and links to a web site (www.digitalSpiders.org). Taxonomic determinations can be shared with a crowdsourcing comments feature, and researchers can discover specimens of interest available for loan and request aliquots of genomic DNA extract. To demonstrate the value of the cyberdiversity framework, we reconcile data from three rapid structured inventories of spiders conducted in Vietnam with an independent inventory (Doi Inthanon, Thailand) using online image libraries. Species richness and inventory completeness were assessed using non-parametric estimators. Community similarity was evaluated using a novel index based on the Jaccard replacing observed with estimated values to correct for unobserved species. We use a distance-decay framework to demonstrate a rudimentary model of landscape-scale changes in community composition that will become increasingly informative as additional inventories participate. With broader adoption of the cyberdiversity approach, networks of information-sharing taxonomists can more efficiently and effectively address taxonomic impediments while elucidating landscape scale patterns of biodiversity.

A second species of Euscorpiops Vachon from caves in Vietnam (Scorpiones, Euscorpiidae, Scorpiopinae). Cave Euscorpiops scorpion from Vietnam.

Euscorpiops dakrong sp. n., belonging to the family Euscorpiidae Laurie, is described on the basis of one male and one female collected in the Dakrong Nature Reserve cave system, Dakrong District, Quang Tri Province, Vietnam. The new species presents most features exhibited by scorpions of the genus Euscorpiops, but it is characterized by a slender body and elongated pedipalps. This new scorpion taxon represents the second species of Scorpiopinae discovered in a cave system and may be yet another endemic element in the fauna of Vietnam. Some taxonomic propositions on the generic position of Scorpiops oligotrichus Fage, 1933 are also suggested.

The genus Chaerilus Simon, 1877 in Vietnam (Scorpiones; Chaerilidae): a possible case of a vicariant species.

A new species of the genus Chaerilus Simon, 1877 is described from a cave in Dien Bien District, West of Dien Bien Phu city in northern Vietnam. The new species is morphologically similar to other Chaerilus species distributed only in the south of Vietnam and Cambodia and suggests a case of a vicariant species between northern and southern populations in the Southeast Asian peninsula.

First record of a cave species of Euscorpiops Vachon from Viet Nam (Scorpiones, Euscorpiidae, Scorpiopinae).

Euscorpiops cavernicola sp. n., belonging to the family Euscorpiidae Laurie, is described on the basis of two male and two female specimens collected in the Hua Ma cave located in the Quang Khe commune, Ba Be district of Bac Kan province in Viet Nam. The new species presents most features exhibited by scorpions within the genus Euscorpiops, however it may represent the first discovered Scorpiopinae species exhibiting certain adaptations to cave life.

First description of comb-tailed spiders (Araneae: Hahniidae) from Vietnam.

Spider family Hahniidae was firstly recorded from Vietnamin the present paper. In total, three genera and five species were recorded in three national parks of Northern Vietnam: Alistra hamata sp. nov. (male), Hahnia himalayaensis Hu & Zhang, 1990 (male, female), H. rimiformis sp. nov. (male, female), H. zhejiangensis Song & Zheng, 1982 (male, female) and Scotospilus longus sp. nov. (male, female). Morphological illustrations and photos of new species as well as descriptions and copulatory organs' photos of known species are given. The genus Scotospilus and the position of S. longus sp. nov. are discussed.