The prickly blade mapped: establishing homologies and a chaetotaxy for macrosetae of penis ventral plate in Gonyleptoidea (Arachnida, Opiliones, Laniatores)

Abstract

For the first time a hypothesis of homology is proposed for the macrosetae which compose the armature of the distal truncus penis of the Gonyleptoidea. Previous attempts to name them in the literature have not been continued because they started by referring to macrosetae based on their position, which may change widely, and all of them were very narrow in scope. The present project instead names groups of macrosetae that do not mandatorily refer to their position, thus compensating for their hypothesized secondary position shifts. Using criteria of topology, shape and exclusion, six groups of setae are recognized, A–E, and their topological and phylogenetic distribution is studied and described in all families of Gonyleptoidea and two other related families of Grassatores. A cladistic analysis is performed, providing the following results: (1) the Microsetata are recovered including Metasarcidae/Cosmetidae sister to an expanded Gonyleptidae; (2) the genera Quindina (Cranaidae) and Zygopachylus (Manaosbiidae) are transferred to Nomoclastidae rank nov., hitherto regarded as a subfamily of Stygnidae, now a sister group of the Microsetata; (3) Zamorinae, currently placed in Cranaidae, is the sister group to Nomoclastidae, and it is therefore transferred to this family; (4) an expanded Gonyleptidae is recovered, including Manaosbiidae and Cranaidae, but the independence of these families is also recovered because the Gonyleptidae stricto sensu form a clade; (5) the Ampycinae, in spite of many particularities, are recovered inside Gonyleptidae; (6) the zamorine‐less Cranaidae are recovered as a monophyletic sister group to Gonyleptidae, but not nested inside it. Jabbastygnus gen. nov. is described in Stygnidae along with its type species J. huttorum, from Colombia. © 2015 The Linnean Society of London

Taxonomic revision of the Andean genus Eulibitia Roewer, 1912 (Arachnida, Opiliones, Cosmetidae), with the description of five new species

“…The morphology of the reproductive organs in Gonyleptoidea has been shown to be very valuable in phylogenetic analyses (i.e., Kury & Villarreal 2015;Cruz-López & Francke 2015), and has been well explored in detail for some species (i.e., Bennett & Townsend 2013;Walker & Townsend 2014;Townsend et al 2015). In Cosmetidae, however, the genital morphology is somewhat uniform, if compared with Gonyleptidae for example.…”

“…Descriptions follow for external morphology; DaSilva & Gnaspini (2009) for the dorsal armature; for the outline of the dorsal scutum; Kury & Villarreal (2015) and for the chaetotaxy of macrosetae on the ventral plate of the penis; and Kury (2016b) for terminology of the microsetae. The order of numbers of tarsomeres in tarsus I to IV is from left to right side (figures in parentheses denote number of tarsomeres only in the distitarsi I-II).…”

New records of Acritas bilineatus Sørensen, 1932 (Arachnida, Opiliones, Cosmetidae) in Venezuela

“…Drawings were made using Inkscape 0.91 software. The morphological terminology follows Kury and Medrano (2016) for dorsal scutum terms; Kury and Villarreal (2015) and Medrano and Kury (2016) for macrosetae; and Kury (2016) for microsetae of male genitalia. Morphometric abbreviations are: AL = maximum abdominal scutum length, AW = maximum abdominal scutum width, CL = carapace length, CW = maximum carapace width, DS = Dorsal Scutum, Fe = femur, MS = macrosetae of penis, ms = microsetae of penis, Pa = patella, Ti = tibia, VP = ventral plate.…”

Four new species of Cosmetus from Panama, with comments on the systematics of the genus (Opiliones: Cosmetidae)

“…Nomenclature of genitalic description followed KURY & VILLARREAL (2015). Descriptions of the external morphology of females only contain information on features that differ from the male.…”