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

Abstract

The genus Eulibitia was described by Roewer including three species from Colombia and Ecuador: Eulibitia maculata Roewer, 1912, E. annulipes Roewer, 1912 and E. sexpunctata Roewer, 1914. Herein, the genus is revisited and only the type species, Eulibitia maculata Roewer, 1912 is maintained from the previous configuration. Eulibitia sexpunctata is transferred to Ambatoiella Mello- Leitão, 1943 and E. annulipes is considered as Cosmetinae incertae sedis. Acromares lateralis Goodnight & Goodnight, 1943 and Paramessa castanea (Sørensen, 1932) are here considered junior subjective synonyms of Messatana scalaris (Sørensen, 1932) and Eulibitia maculata, respectively. Brachylibitia Mello-Leitão, 1941, currently a junior synonym of Platymessa, is regarded as a synonym of Eulibitia. Platymessa Mello-Leitão, 1941, with two species, and the monotypic genera Messatana Strand, 1942 and Paramessa Mello-Leitão, 1933, are synonymized with Eulibitia Roewer, 1912, yielding the following new combinations: Eulibitia ectroxantha (for Brachylibitia ectroxantha Mello-Leitão, 1941), E. h-inscriptum (for Platymessa h-inscripta Mello-Leitão, 1941) and E. scalaris (for Libitia (Messa) scalaris Sørensen, 1932). Eulibitia is re-diagnosed and five new species are described: E. castor sp. nov., E. pollux sp. nov., E. clytemnestra sp. nov., E. leda sp. nov. and E. helena sp. nov. A key to the nine Eulibitia species is presented; the morphology of Eulibitia is compared with that of Libitia, Libitiella and Ambatoiella.

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

“…Barros 2014, Medrano andKury 2017) and A. bilineatus is not the exception. The 2 yellow longitudinal blots of the DS exhibit variation between specimens, always beginning at the ozopores level but sometimes ending at the area III level (from Barinas) or reaching the posterior border of DS and fusing to the posterior blot (from Táchira) (Fig.…”

“…In fact, the wide altitude range of A. bilineatus seems not to be uncommon between harvestmen. Medrano and Kury (2017: fig. 33) showed that the cosmetid Eulibitia scalaris (Sørensen in Henriksen, 1932) is distributed in 3 different ecoregions in Colombia, encompassing altitude ranges between 1584 to 3000 m a.s.l.…”

Giving attention to the oldies: redescription of Meterginus basalis (Arachnida: Opiliones: Cosmetidae) with some notes on the genitalia

“…In harvestmen it has been drawn and described in a lot of publications, but only lately used as a source of information for identification keys (Townsend et al, 2010) and phylogenetic studies (Kury & Villarreal, 2015). For Cosmetidae, the penis morphology has been explored more widely in the last decade (e.g., García and Kury [2017] for Rhaucus Simon, 1879;Kury and Barros [2014] for Taito; Medrano and Kury [2017] for Eulibitia Roewer, 1912). Here, we provide SEM images of the Meterginus basalis penis for the first time ( Fig.…”

“…About the genus. Cosmetid genera are not well defined and/or delimited because of the problematic characters proposed by different authors (Goodnight & Goodnight, Mello-Leitão & Roewer), leading to systematic difficulties in the taxonomy and internal relationships of the family (García & Kury, 2017;Medrano & Kury, 2017). García and Kury (2017), in the revision of the Andean genus Rhaucus Simon, 1879 stated that: (...) "To remedy this adverse situation and secure a grasp on the diversity in this family, and to achieve a natural composition of their genera, smaller building blocks are needed" (...).…”

“…The morphological terminology follows Kury and Medrano (2016) for dorsal scutum terms, and Kury and Villarreal (2015) and Medrano and Kury (2017) for macrosetae 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, IOD = interocular distance, MS = macrosetae of penis, Pa = patella, Ti = tibia, VP = ventral plate.…”