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.].

Seven new species of the segmented spider genus Liphistius (Mesothelae, Liphistiidae) in Thailand and Myanmar.

Seven new species of the primitive segmented spider genus Liphistius are described and assigned to species groups based on characters of the male palp and vulva plate. The bristowei group includes L.dawei Sivayyapram & Warrit, sp. nov. (♂♀) from southeastern Myanmar, L.choosaki Sivayyapram & Warrit, sp. nov. (♀) from northwestern Thailand, and L.lansak Sivayyapram & Warrit, sp. nov. (♀) from western Thailand; the trang group (Complex A) contains L.kaengkhoi Sivayyapram & Warrit, sp. nov. (♂♀), L.hintung Sivayyapram & Warrit, sp. nov. (♂♀), L.buyphradi Sivayyapram & Warrit, sp. nov. (♂♀), and L.champakpheaw Sivayyapram & Warrit, sp. nov. (♂♀) from central Thailand.

Three new species of the spider genus Liphistius (Araneae, Mesothelae, Liphistiidae) from Thailand.

We diagnose and describe three new species of the primitively segmented spider genus Liphistius from Thailand, based on male palp and female genital morphology: L.hatyai Zhan & Xu, sp. nov. (♂♀), L.keeratikiati Zhan & Xu, sp. nov. (♂♀), and L.inthanon Zhan & Xu, sp. nov. (♂♀). The classification of the three new species of Liphistius is discussed: L.hatyai sp. nov. and L.keeratikiati sp. nov. are assigned to the trang-group, and L.inthanon sp. nov. is placed in the bristowei-group according to male palp and female genital morphology.

Two new species of the Southeast Asian Dwarf tarantula genus Phlogiellus Pocock, 1887 (Theraphosidae, Selenocosmiinae) and a discussion on the taxonomic problem of the genus: Addendum.

Sivayyapram et al. (2020) omitted to note the full type deposition of Phlogiellus daweiensis and Phlogiellus raveni; that is corrected herein.

Records and redescription of a mygalomorph spider genus ignored for over 100 years with a new species: the genus Atmetochilus Simon, 1887 (Araneae, Nemesiidae) in Thailand.

The wishbone spider of genus Atmetochilus Simon, 1887 (Nemesiidae: Bemmerinae) containing six species and is known from Asia. We describe a new Thai species, Atmetochilus songsangchotei sp. nov. Since the holotype of the type species of Atmetochilus, A. fossor, is presumed lost, we describe fresh specimens (ARA-2018-132) and designate one as as neotype; similarly, because a holotype (only syntypes) of Atmetochilus atriceps in NHMUK was not designated, we chose the most intact specimen of the syntypes (NHMUK 1895.9.21.16) and designate it as lectotype. From a photo of the type specimen of Atmetochilus bifidus (sternum) from ZSI, we transfer Atmetochilus bifidus back to Damarchus.

Two new species of the Southeast Asian Dwarf tarantula genus Phlogiellus Pocock, 1887 (Theraphosidae, Selenocosmiinae) and a discussion on the taxonomic problem of the genus.

Phlogiellus is one of the least studied theraphosid genera; there is only one recent revision on the genus. However, the "revision" only provided several taxonomic problems in the genus by giving unclear diagnostic characters of the genus and its species, using third party information in their descriptions and many of their examined specimens of are inaccessible. Here, we discuss the taxonomic problems of the genus, and provide a new genus description and diagnostic characters of Phlogiellus by combining information from previous studies with our examinations. Variation within species of previously diagnostic characters renders them of little value. In addition, two new Phlogiellus species from Myanmar and the Philippines are described and diagnosed here.