Miguel Medrano

Federal University of Rio de Janeiro | UFRJ · Departamento de Invertebrados

The American species of Cosmetidae, in spite of being clearly distinguished in the older literature, were mixed-up by Roewer.

A small group of species historically included in the genus Cynorta C.L. Koch, 1839 has been identified and described in this study. Based on a phylogenetic analysis using morphological data, we propose that these species be recognized as a non-monotypic genus, for which the available name Abria Sørensen, 1932 is used. Abria is newly diagnosed and...

Rhaucoides Roewer, 1912 is herein revisited and re-diagnosed based on somatic and genital morphology, including the differences of both expanded and unexpanded glans complex shown for the first time in Cosmetidae. The genus is characterized mainly by abdominal ornamentation, coloration and by having the two basalmost tarsomeres of leg I fused. The...

Eucynorta quadripustulata (Simon, 1879), the type species of the third most diverse genus in Cosmetidae, Eucynorta Roewer, 1912, was described for ‘Colombia’ and after more than a century, a more specific locality was not known. Based on the examination of abundant material from several collections, including the type material, we were able to bett...

The cosmetids are conspicuous harvestmen, remarkably diverse in size, shape and colour. However, the effectiveness of all these morphological traits for diagnosing groups is scarcely explored in the literature. Since the early 20th century, the family Cosmetidae has been divided into two subfamilies, Cosmetinae and Discosomaticinae, and there has b...

Cosmetus Perty, 1833 is the type genus of the most diverse subfamily of Laniatores, Cosmetinae. The genus currently includes 22 valid species with a disconnected distribution, including coastal forests of NE Brazil, dry forests of the Ecuadorian Pacific, Chocó-Darien moist forests and the Venezuelan Andes. The morphology among species in the genus...

The sixth species of Gonyleptellus is described from the mountains of Nova Friburgo in Rio de Janeiro State, south-eastern Brazil. Gonyleptellus camelopardalis sp. nov. more closely resembles G. pustulatus and G. angeloi due to the proapical apophysis curved backwards with a secondary branch, and more specifically the latter because of the reduced...

The old genus Libitia Simon, 1879 of small Andean harvestmen is revisited. The monotypic genus Libitiella Roewer, 1947 is herein considered a junior subjective synonym of Libitia. Accordingly, Libitiella bipunctata (Sørensen, 1932) is restored to the combination Libitia bipunctata. The species Libitia cordata and Libitia bipunctata comb. nov. are r...

The species Brachylibitia ectroxantha was described by Mello-Leitão in 1941 and since then it was never again reported or studied. Its type is certainly lost and his identity was until now a mystery; it is currently considered as species inquirenda and transferred to Eulibitia in a recent revision of the genus. Herein, we designate a neotype and pr...

Usatama gen. nov. is described to include a new species of Kimulidae from Colombia. This is the first record of the family from the country. The new genus presents a weakly armed ocularium, feeble sexual dimorphism, and unique genital structure with three parallel horseshoe-shaped girdles in pars distalis and absence of cochleariform macrosetae.

The genus Neocynorta is here revisited, resulting in the increase of its diversity from three species to 13, maintaining only the type species N. virescens from its former conformation. Two subjective synonyms of Neocynorta are proposed: Forfexia and Szczurekia, transferring their members to Neocynorta (F. marmorata, S. frigida, S. petrae and S. vi...

The generic name Paecilaema C.L. Koch, 1839 is anchored to the nomen dubium Cosmetus u-flavum Perty, 1833, and the fixation of the latter is proposed by designating a neotype. The choice was made on a potential topotype, being a common species in metropolitan Rio de Janeiro city, SE Brazil, which has been described as new five times and is currentl...

The phylogeny of the genus Roquettea Mello-Leitão, 1931 and its position in Discosomaticinae are investigated. The monophyly of an expanded Roquettea is for the first time tested and corroborated. The internal relations of Roquettea are elucidated by means of a morphological maximum parsimony cladistic analysis. Synapomorphies for the genus include...

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 t...

In many Opiliones (notably the Laniatores) the five most anterior opisthosomal tergites are fused with the carapace forming the so called dorsal scutum (DS) (Latreille 1804; Simon 1879; Hadži 1942) with a highly variable shape arising from multiple factors, such as differential development of musculature (especially of coxa IV), internal organs and...

The genus Platymessa was originally described by Mello-Leitão and diagnosed following the Roewerian system. It originally included two species from the Colombian Andes. Subsequently, a third species was described: Platymessa transversalis Roewer, 1963, which is herein transferred to the genus Chusgonobius Roewer, 1952, forming the new combination C...