The genus Eurytromma from Sri Lanka: the homology of penial macrosetae in Podoctidae matches the gonyleptoid AE11 pattern (Opiliones: Laniatores: Epedanoidea)

Abstract

A description of the pattern of structure and organization of the penial macrosetae was recently put forward for Gonyleptoidea Sundevall, 1833 and demonstrated to occur also in other families of Grassatores Kury, 2002, such as Assamiidae Sørensen, 1884, Epedanidae Sørensen, 1886 and Pyramidopidae Sharma, Prieto & Giribet, 2011. This set of homology hypotheses is herein called AE11 pattern. In this work, the monotypic Sri Lankan genus Eurytromma Roewer, 1949 of the family Podoctidae Roewer, 1912 (which is currently assigned to the Epedanoidea in the Grassatores) is studied. Male genitalia of Eurytromma are described for the first time and the first attempt is made to reconcile the chaetotaxy of ventral plate of podoctid species with the AE11 pattern. The podoctid genera Hoplodino Roewer, 1915, Strandibalonius Roewer, 1912 and Santobius Roewer, 1949 are also exemplified here; their set of macrosetae is described and the AE11 pattern is demonstrated to occur in all of them. Therefore, AE11 is more phylogenetically widespread in the Grassatores than previously thought. Eurytromma pictulum (Pocock, 1903) from Sri Lanka is redescribed. It is characterized by the presence of a meso-frontal stridulatory saw of denticles on the cheliceral hand and extreme reduction of mesotergal sutures. A further refinement is made on the current terminology system of cheliceral dentition of Podoctidae.