Pachyloidellus butleri ( Thorell, 1877 )

Acosta, Luis E. & Guerrero, Elián L., 2021, The missing Eusarcus: generic relocation of Pucrolia minuta, with synonymic notes (Opiliones: Laniatores: Gonyleptidae), Zootaxa 4990 (3), pp. 587-590 : 589

Pachyloidellus butleri ( Thorell, 1877)

Pachylus Butleri Thorell 1877: 207 . urn:lsid:zoobank.org:act:DC19978E-40C9-43E7-8EDF-9273602BBD1F

Sphaleropachylus butleri: Ringuelet 1959: 387 , figs. 29d, 57, Pl. XVI, figs. 3, 4.

Pachyloidellus butleri: Acosta 1993 [synonymy]: 4; Kury 2003: 181 [synonymy].

Pucrolia grandis Mello-Leitão 1930: 213 ; Ringuelet 1959: 374, fig. 53. Female holotype (MACN 4746), from Buenos Aires, examined. urn:lsid:zoobank.org:act:925AD709-18F6-4A44-B08F-2BDFD2EE2996 . Syn. nov.

Pucrolia grandis is the largest member of Pucrolia (“mais do dobro das outras duas especies”, Mello-Leitão 1930: 213), and was diagnosed by a very infrequent feature: the single apophysis on the ocular mound is curved backwards ( Ringuelet 1959: fig. 53a). This species is only known by its holotype, a female from (allegedly) Buenos Aires ( Ringuelet 1959). Mello-Leitão (1930) placed this species in Pucrolia just by using characters based upon the Roewerian system, including: ocularium armed with a single apophysis; dorsal scutum, free tergites and anal operculum unarmed; palpal femur with a sub-apical mesal spine; and tarsal formula 5-6-6-6. Nonetheless, this combination is not exclusive to Pucrolia , as these traits can be observed in females of other taxa, e.g., Pachyloidellus Müller, 1918 and Acanthopachylus Roewer, 1913 . A side-by-side comparison demonstrated that the type of P. grandis is a female Pachyloidellus butleri ( Thorell, 1877) , considering the subtle armature of leg IV, especially the retroapical apophysis ( Ringuelet 1959: fig. 53b-c), and shape and granulation of the dorsal scutum ( Acosta 1993). The only difference is the armature of the ocularium, with P. butleri having a straight apophysis, slightly inclined frontwards, instead of bent backwards as in P. grandis . The curved apophysis seems a striking feature not found in other species of Pucrolia or Eusarcus , but the condition on the holotype is most likely an individual abnormality. Based upon all of the evidence, we propose the new synonymy.

Brazilian species: Pucrolia dubitata and P. pulcherrima show no special resemblance with Eusarcus . Despite being little studied (the former is only known by a single female, and the genital morphology is unknown for both), for the moment they should be referred to as incertae sedis.