Rhaucoides riveti Roewer, 1914

Kury, Adriano B. & Medrano, Miguel, 2023, Once upon a time in America: recognition of the species of Libitioides from USA, with comments on other American Cosmetidae (Opiliones, Laniatores), European Journal of Taxonomy 875 (1), pp. 101-141 : 136

Rhaucoides riveti Roewer, 1914

Rhaucoides Riveti Roewer, 1914: 125 , pl. 13 fig. 3.

Libitioides Riveti Roewer, 1914: 128 , pl. 13 fig. 5. Syn. nov.

Type data

Holotype of Rhaucoides riveti

ECUADOR • ♂; Carchí, Tulcán ; 3002 m alt.; 1901; Paul Rivet leg.; reported as in MNHN, but actually also in SMF.

Paratype of Rhaucoides riveti

ECUADOR • 1 ♂; same collection data as for holotype; SMF RI 477 (examined by photograph).

Syntypes of Libitioides riveti

ECUADOR • 1 ♂; [Carchí], El Pelado; 4151 m alt.; Jan. 1903; MNHN, lost? • 1 juvenile; same collection data as for preceding; Paul Rivet leg.; SMF RI 313 , noted as ♀ on the label (examined by photograph) .

Comments about the type material

Roewer (1914) studied the harvestmen collected by French ethnologist Paul Rivet (1876–1958) in two campaigns in the northern páramos of Ecuador (1901–1903). The material was officially split: one part was to be deposited in the MNHN, Paris and subsamples were taken to the Roewer Collection #1. As it happened, it seems that not all material was duly returned to Paris, but rather deposited in Roewer’s collection, from where it ultimately ended in SMF, because it was not located by occasion of ABK’s visit to Paris in 2017. Roewer mentioned only 1 male for R. riveti , but the type series (SMF RI 477) consists of two males. Maybe because of that indication, SMF curators called one of them “ holotype ” and the other “non-type”. As for L. riveti , the paper mentions “ 1 male, 1 juvenile ”, of which, presumably the male would be in Paris. The juvenile is in SMF (SMF RI 313).

Remarks

Both external and genital morphology are conserved and well delimited in Rhaucoides members and L. riveti matches the genus diagnosis at least in external morphology. Decoloration is common in preserved opilions, and more common as in the ancient material studied by Roewer. Despite that, the juvenile syntype in SMF shows a pattern somewhat similar to R. riveti , a species described by Roewer with material collected by Rivet himself. Here, we propose the synonymy of Libitioides riveti with Rhaucoides riveti based on the morphological similarity and the geographic proximity (both type localities are in mountain tops 20 kilometers apart). Likewise, that decision avoids the creation of a secondary homonymy within Rhaucoides and the necessity of a replacement name.