Filopalpinae, Martens, 2022

Martens, Jochen, 2022, From the Ethiopian Bale Mountains hotspot-Filopalpinae subfam. nov., a new taxon of Laniatorean harvestmen based on external and genital morphology (Arachnida, Opiliones, Assamiidae), Zootaxa 5159 (2), pp. 221-244 : 223-224

Filopalpinae subfam. nov.

Type genus: Filopalpus gen. nov.

Diagnosis: A subfamily of Opiliones in the Suborder Grassatores , family Assamiidae with these characters:

Body: Small-sized (2.3–3.5 mm) and short-legged; males and females similar in size, dorsal side of male and female with a dense cover of pimples or low apophyses, in most species each with a short seta on top (hedgehog-like appearance), prominent forward apophyses on frontal rim of prosoma, on tuber oculorum among smaller apophyses a large one pointing forward and surpassing frontal rim of prosoma, on abdominal free tergites and on coxae of legs heavy prickly armament as well; ventral side less so equipped. Colour of dorsal side of body light brown to dark grey and black with few lighter fields or totally black, ventral side lighter than dorsal side, sometimes with prominent dark and light pattern. The tracheal spiracles are covered by a fine grate. The shape of the dorsal scutum is clearly sexual dimorphic and displays, according to the terminology of Kury & Medrano (2016), the zeta state in males and eta state in females.

Pedipalps: Displaying extreme sexual dimorphism; in males pedipalp thread-like thin and long approaching or surpassing length of 2 nd leg, considerably longer than body length (up to roughly five times), all articles devoid of apophyses, tubercles or large setae; patella nearly as long as femur; tibia and tarsus much shorter and reduced to minute articles of nearly equal length; claw as long or slightly shorter than tarsus. Pedipalp of females much shorter and compact, entire palp always shorter than body length or reaching body length; tibia, tarsus and tarsal claw forming a “grasping hand” with (not in all species) large ventral apophyses on tibia and tarsus, always equipped with few ventral strong setae; claw nearly as long or slightly shorter than tarsus. Male pedipalp 1.9 times ( F. bale sp. nov.), 2.6 times ( F. kakaensis sp. nov.) and 5.1 times ( F. joschmidti sp. nov.) longer than body length.

Legs: All species short-legged, legs of normal size and proportions, no articles enlarged or inflated, cross section of articles round. Scattered low tubercles often with short seta on top on femur, patella, tibia and metatarsus. Single claw in legs I–II, double claw in legs III–IV. Number of tarsomeres of legs I–IV in males and females normally I 4, II 7, III 5, IV 6 with few deviations in the different species; in most cases equal numbers on right and left leg.

Genital morphology: Truncus penis without muscle and tendon system, slender, distally slightly to markedly enlarged with a tube-like glans on dorso-distal side of penis, slightly surpassing distal end of truncus, internal lumen of tube decorated with a dense cover of stings forming an inner cover of minute prickles, resulting in the prickly funnel (“Stacheltrichter” in German nomenclature, Martens 1977), their tips being directed to the distal opening. Stylus not to be seen from unexpanded glans. Glans a longish tube, emerging from dorso-distal enlarged part of truncus, in un-expanded state slightly surpassing distal end of truncus; glans tube ending in a small rounded lamella at ventral side and surpassing it. Ovipositor ( Fig. 24 ) compact, about double its length than diameter at basis, the distal opening flanked by two rounded lobes, with ten long, curved distally thinned out setae, their end slightly bifid.

Relationships: Genital morphology, especially the evertible prickly funnel of glans clearly assigns Filopalpinae subfam. nov. to Assamiidae . Regarding external morphology, there is only the Ethiopian monotypic genus Gulufia Roewer, 1935 which might be a close relative of Filopalpus gen. nov. It is characterized by a large spine in front of the eye mound similar to Filopalpus gen. nov. but lacks the extensive sexual dimorphisms of the species of the latter genus. All characters of other African or Asian Assamiidae are distinctly different from Filopalpinae subfam. nov., i.e. body armament, form and armament of eye mound, pedipalp proportions and equipment with apophyses and tubercles; lack of strong palpal sexual dimorphisms and cover of body with small pimples or pointed apophyses (in most species). Within Assamiidae , Filopalpinae subfam. nov. apparently represent a highly specialized clade with long independent evolution, which is now represented by few species in a remote high-altitude region.

Figures

FIGURES 11–24. Filopalpus joschmidti sp. nov. Male holotype (11–17; 21–23) and female paratype (18–20; 24). 11–12. Penis dorsal and lateral views. 13–15. Glans dorsal, ventral and lateral views. 16–19. Chelicera pro-lateral and retro-lateral views. 20. Pedipalpus retro-lateral view. 21. Pedipalpal femur-patella joint, retro-lateral view male. 22. Pedipalp retro-lateral view. 23. Pedipalpal tibia and tarsus. 24. Ovipositor distal part. Scales: 11–12: 0.3 mm, 13–19: 0.1 mm, 20: 0.5 mm, 21: 0.13 mm, 22: 0.25 mm, 23: 0.5 mm, 24: 0.05 mm.