A stable phylogenomic classification of Travunioidea (Arachnida, Opiliones, Laniatores) based on sequence capture of ultraconserved elements

Molecular phylogenetics has transitioned into the phylogenomic era, with data derived from next-generation sequencing technologies allowing unprecedented phylogenetic resolution in all animal groups, including understudied invertebrate taxa. Within the most diverse harvestmen suborder, Laniatores, most relationships at all taxonomic levels have yet to be explored from a phylogenomics perspective. Travunioidea is an early-diverging lineage of laniatorean harvestmen with a Laurasian distribution, with species distributed in eastern Asia, eastern and western North America, and south-central Europe. This clade has had a challenging taxonomic history, but the current classification consists of ~77 species in three families, the Travuniidae, Paranonychidae, and Nippononychidae. Travunioidea classification has traditionally been based on structure of the tarsal claws of the hind legs. However, it is now clear that tarsal claw structure is a poor taxonomic character due to homoplasy at all taxonomic levels. Here, we utilize DNA sequences derived from capture of ultraconserved elements (UCEs) to reconstruct travunioid relationships. Data matrices consisting of 317-677 loci were used in maximum likelihood, Bayesian, and species tree analyses. Resulting phylogenies recover four consistent and highly supported clades; the phylogenetic position and taxonomic status of the enigmatic genus Yuria is less certain. Based on the resulting phylogenies, a revision of Travunioidea is proposed, now consisting of the Travuniidae, Cladonychiidae, Paranonychidae (Nippononychidae is synonymized), and the new family Cryptomastridae Derkarabetian & Hedin, fam. n., diagnosed here. The phylogenetic utility and diagnostic features of the intestinal complex and male genitalia are discussed in light of phylogenomic results, and the inappropriateness of the tarsal claw in diagnosing higher-level taxa is further corroborated.

World Checklist of Opiliones species (Arachnida). Part 1: Laniatores - Travunioidea and Triaenonychoidea

Comprising more than 6500 species, Opiliones is the third most diverse order of Arachnida, after the megadiverse Acari and Araneae. The database referred here is part 1 of 12 of a project containing an intended worldwide checklist of species and subspecies of Opiliones as Darwin Core archives, and it includes the superfamilies Travunioidea and Triaenonychoidea. These two superfamilies are often treated together under the denomination of Insidiatores. In this Part 1, a total of 571 species and subspecies are listed. Briggsidae and Cladonychiidae are both downgraded to subfamilies of Travuniidae. Peltonychia Roewer, 1935 is an available name and senior synonym of Hadziana Roewer, 1935 and is herein revalidated. Seven genera of Triaenonychidae described by Lawrence between 1931 and 1933 originally failed to comply ICZN rules for availability (Art. 13.3). All of them only became available when Staręga (1992) designated a type species for each. Therefore, the correct authorships of Austromontia Lawrence, 1931, Biacumontia Lawrence, 1931, Graemontia Lawrence, 1931, Larifugella Lawrence, 1933, Mensamontia Lawrence, 1931, Monomontia Lawrence, 1931 and Rostromontia Lawrence, 1931 are all Staręga, 1992. Fumontana Shear, 1977, originally referred only to subfamily Triaenonychinae (as opposed to Soerensenellinae then and not corresponding to present Triaenonychinae), not to any tribe (which in turn correspond to modern subfamilies) is herein included in the subfamily Triaenonychinae. Picunchenops Maury, 1988 originally not included in any tribe of Triaenonychidae, is herein included in the subfamily Triaenonychinae. Trojanella Karaman, 2005, originally ranked as Travunioidea incertae sedis, is herein included in the TravuniidaeTravuniinae. Nunciaovata Roewer, 1915 (synonymized with Triaenonyxcockayni Hogg, 1920 by Forster (1954), but with inverted precedence) is here combined as Nunciacoriaceaovata Roewer, 1915 as correct senior synonym instead of Nunciacoriaceacockayni (Hogg, 1920), which is current in the literature. Neonunciaenderbei (Hogg, 1909) is reaffirmed as the correct spelling for the species, while the deliberate change to Neonunciaenderbyi by Forster (1954) is an incorrect subsequent spelling.

Nitrogen-containing compounds in the scent gland secretions of European cladonychiid harvestmen (Opiliones, Laniatores, Travunioidea)

The exocrine secretions from prominently developed prosomal scent glands in four species of the European laniatorean harvestman genus Holoscotolemon (Laniatores, Travunioidea, Cladonychiidae) were analyzed by gas chromatography - mass spectrometry. Two major alkaloidal compounds were detected: Nicotine accounted for more than 97% of the secretion in Holoscotolemon jaqueti and H. oreophilum, whereas the chemically related nicotinoid alkaloid anabaseine was the major compound in H. lessiniense. In addition, a series of minor nitrogen-containing components was found, namely 3-(1-methyl-2-piperidinyl)-pyridine and anabasine, in H. jaqueti and H. oreophilum, and anabasine together with 2,3'-bipyridyl in H. lessiniense. By contrast, extracts of adult H. unicolor did not show any components. In one juvenile specimen of H. unicolor, however, low amounts of alkyl pyrazines (dimethyl-isobutyl- and dimethyl-isopentylpyrazines) were detected. Nitrogen-containing components previously were found in Sclerobunus robustus (an American travunioid harvestman), so scent gland-derived alkaloids may be widespread or even common in the Travunioidea. Alkaloids have not been reported for other opilionid scent gland secretions outside the Travunioidea, and we hypothesize that they may be the phylogenetically ancestral allomones in the Laniatores, having been reduced and replaced by a phenol- and benzoquinone-rich chemistry in the more derived grassatorean taxa.