Osvaldo Villarreal Manzanilla

Osvaldo Villarreal Manzanilla
Federal University of Rio de Janeiro | UFRJ · Departamento de Invertebrados

PhD

About

57
Publications
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Citations
Introduction
Osvaldo Villarreal Manzanilla currently works as a associate researcher of Laboratorio de Aracnologia, Museu Nacional -Federal University of Rio de Janeiro and Museo de Zoología Agrícola, UCV Maracay, Venezuela. Their current projects are 'Systematics and taxonomy of the neotropical schizomids (Arachnida: Schizomida)' and 'Systematics of neotropical harvestmen of the superfamily Gonyleptoidea'. He has interest too in arachnids fauna asociated with caves, principally exclusively troglobites.
Additional affiliations
August 2012 - September 2016
Federal University of Rio de Janeiro
Position
  • PhD Student
October 2010 - June 2012
Central University of Venezuela
Position
  • Professor

Publications

Publications (57)
Article
Full-text available
For the first time a hypothesis of homology is proposed for the macrosetae which compose the armature of the distal truncus penis of the Gonyleptoidea. Previous attempts to name them in the literature have not been continued because they started by referring to macrosetae based on their position, which may change widely, and all of them were very n...
Article
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The distinction of genera in Cranaidae (as in many other Gonyleptoidea) is traditionally made on the basis of a combination of armature of scutal areas, tarsomere counts, and some secondary sexual structures (which may vary among males). This historically led to the creation of non-natural groups of species as meaningless genera. Here some nominal...
Article
Full-text available
The homology of three somatic systems in Schizomida is studied yielding the following results: (1) proposal of homology and chaetotaxy of abdominal setae in Surazomus; (2) revision of the cheliceral chaetotaxy in Schizomida, with suggestion of new homology scheme between Hubbardiidae and Protoschizomidae, description of a new group of setae in Hubb...
Article
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The Cranaidae genus Phalangodus Gervais, 1842 is revisited and its species are diagnosed. An identification key for the males of Phalangodus is provided. Four Colombian species are described as new: Phalangodus briareos sp. nov. from a cave in Zapatoca, Santander department, P. cottus sp. nov. from Villavicencio, Meta department, P. gyes sp. nov. f...
Article
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We present a comprehensive revision of the pholcid spider collection of M.A. González- Sponga, who between 1998 and 2011 described 22 new genera and 51 new species of Pholcidae from Venezuela. In addition, we treat the pholcid material collected during three expeditions to Venezuela conducted between 2002 and 2020. Of González-Sponga’s pholcid taxa...
Article
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Fortia, gen. nov., a new genus of Stygnidae with two new Colombian species, is diagnosed and described. Two possibly sympatric species Fortia jedi, sp. nov., and Fortia sith, sp. nov. (both from the Sierra Nevada de Santa Marta, Magdalena, Colombia), are described and illustrated. Relationships of the new genus are discussed.
Article
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The holotype of Avima leucobunus Roewer 1949, type-species of Avima, is studied, and its genital morphology is described for the first time. The Avima albiornata species group is here proposed to include three species, i.e. Avima albidecorata (Šilhavý, 1979), A. albiornata (Goodnight et Goodnight, 1947) and A. intermedia (Goodnight et Goodnight, 19...
Article
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Twelve taxonomic acts are proposed in Gonyleptoidea. In Agoristenidae, 2 specific synonymies are proposed in Avima Roewer and Ocoita González-Sponga. Medellinia bordoni Soares and Avram syn. nov. is transferred from Holocranaus Roewer (Cranaidae) to Manaosbiidae attr. nov. and considered a junior subjective synonym of Rhopalocranaus bordoni Šilhavý...
Article
Some taxonomic changes are made in Amazonian Stygnidae, based on reinterpretation of generic boundaries: (1) the hitherto monotypic genus Jime Pinto-da-Rocha & Tourinho, 2012 is newly recorded from Venezuela: Jime praecursor spec. nov. (Tobogán de la Selva, Amazonas state) is described and a new generic diagnosis is provided. The genital chaetotaxy...
Article
Based on the most recently published morphological cladistic analysis of the family Agoristenidae, the taxonomic position of an undescribed harvestman species was evaluated. According to the results of an updated phylogenetic analysis, the description of a new monotypic genus is proposed to accommodate this new species. The diagnostic characters of...
Article
Full-text available
The family Orsolobidae Cooke, 1965, is newly recorded for Uruguay, with the first record of Losdolobus nelsoni Pompozzi, 2015, a recently described species that is endemic to the Buenos Aires Province, Argentina, and herein recorded in the Rocha and Montevideo departments. The biogeographic implications of this record are commented on and some data...
Article
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A new species of Leptostygnus Mello–Leitão, 1940, Leptostygnus yarigui sp. nov. from Colombia (Santander department) is described and illustrated. Photographs of Leptostygnus leptochirus Mello-Leitão, 1940 (type species of the genus) and L. marchantiarum (González-Sponga, 1987), a map with geographical distribution and a key to the species of the g...
Article
The penial and tarsal morphology of Protimesius is studied and morphological data support the revalidation of Obidosus with the subsequent new combinations (20 species) and restored combinations (two species). Emended diagnoses are proposed for both genera, and two cave-dwelling new species of Protimesius are described and illustrated: P. lucifer s...
Article
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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...
Article
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We herein propose the transfer of Metaphareus punctatus Roewer, 1913, to the genus Eutimesius Roewer, 1913 (Heterostygninae) based on the genital morphology of the species and morphology of tarsi III and IV, resulting in the new combination Eutimesius punctatus (Roewer, 1913), comb. nov. New geographical records for E. albicinctus (Roewer, 1915) ar...
Poster
En años recientes, la sistemática del orden Schizomida ha experimentado importantes avances, y las primeras hipótesis filogenéticas han sido desarrolladas entre algunos neotropicales de Hubbardiidae, pese a ello una definición genérica definitiva es aún lejana. En las Grandes Antillas existe un alto grado de endemismo genérico, pese a ello en los ú...
Article
Two new species of short-tailed whip-scorpions (schizomids), Calima embera sp. nov., and Calima nutabe sp. nov. are described based upon collected material from the Natural Park Planes de San Rafael, Risaralda department, and the Natural Reserve El Romeral, Antioquia department, Colombia, increasing the number of known species for the genus to four...
Article
Full-text available
The Rowlandius dumitrescoae species group is reviewed and rediagnosed, and its composition is revised. The group now includes R. cousinensis, R. decui, R. dumitrescoae, R. insignis, R. linsduarte, R. monensis, R. peckorum, R. potiguar, R. sul, R. ubajara, and R. pedrosoi sp. n. A new species is described from a cave in northeast Brazil (Santa Quité...
Article
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Pseudonemesia tabiskey sp. nov. is described from an Andean Forestin Trujillo, Venezuela. The new species is the third for the genus and differs from the other two species by the presence of one short andapically rounded modified seta on the retrolateral distal portion of the male tibia I and clavate setae on the dorsal and lateral sides ofabdomen...
Article
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The monotypic genus Temucus Roewer, 1943, originally placed in Pachylinae (Gonyleptidae) is transferred to the Cranainae (Cranaidae) and synonymized with Phalangodus Gervais, 1842, therefore Phalangodus palpiconus (Roewer, 1943) comb. nov. is proposed. The synonymy is based on the following features: (i) the outline of dorsal scutum type alpha; (ii...
Article
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A new species belonging to the schizomid genus Piaroa Villarreal, Giupponi and Tourinho, 2008 is described from northwestern Venezuela. A complementary description of Piaroa guipongai Villarreal and Garcia, 2012 is provided including SEM pictures of relevant structures of both sexes. A key for males of Piaroa and Colombiazomus Armas and Delgado-San...
Article
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A new genus, Calima, and two new species, C. bremensis and C. valenciorum, of Hubbardiidae are here described,respectively from Bremen Forest, Filandia, Quindio department and Andinapolis, Trujillo, Valle del Cauca department,both localities located in the Colombian Andes. A comprehensive map of the South American species with a four-segmented fema...
Article
Full-text available
Licornus tama sp. nov. is described from Táchira State in Venezuelan Andes. This is the first record of real Gonyleptidae from this country, although in the past some Venezuelan species, currently placed in other families, have been assigned to Gonyleptidae. The genus Licornus Roewer, 1932 had hitherto two species, both endemic to Ecuador. Male gen...
Article
Full-text available
Licornus tama sp. nov. is described from Táchira State in Venezuelan Andes. This is the first record of real Gonyleptidaefrom this country, although in the past some Venezuelan species, currently placed in other families, have been assigned toGonyleptidae. The genus Licornus Roewer, 1932 had hitherto two species, both endemic to Ecuador. Male genit...
Article
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: Piaroa guipongai sp. nov. is described based on specimens found in a secondary forest in the department of Tolima, Colombia, representing the third species of Piaroa Villarreal, Giupponi & Tourinho, 2008, and the fi rst from this country. It shares with P. virichaj Villarreal, Giupponi & Tourinho, 2008 the shape and size of the male fl agellum an...
Article
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Two cases of paternal care are described for species of the genus Stenostygnellus (Stygnidae), S. flavolimbatus Roewer 1913 and S. aff. flavolimbatus, both from Venezuela. Males of both species guard multiple clutches containing a large number of eggs, which are laid under rotting logs (S. flavolimbatus) or in the base of palm petioles (S. aff. fla...
Article
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Santinezia albilineata Roewer, 1923 is revalidated from the synonymy of Santinezia curvipes (Roewer, 1916). Both species, which inhabit the central northern costal mountain range in Venezuela, are illustrated and compared. Santinezia albilineata can be differentiated easily from S. curvipes, by the following characters of the males: development and...
Article
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The daily activity rhythm of the harvestman Rhaucus cf. vulneratus Simon, 1879 was characterized, in order to determine the possible regulator mechanisms of this rhythm. We recorded the daily activity of adult males and females of this species under three lighting treatments: constant light, natural photoperiod and constant darkness. We compared th...
Article
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Zomus bagnallii (Jackson, 1908) is recorded for the first time from Samoa. One female and one immature were studied, the taxonomic characters were illustrated, and a complementary description was pre-sented. This is the first record of any nominal species of the order Schizomida for this country and a new habitat is recorded for this species.
Article
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Se describen tres especies nuevas de esquizómidos de Costa Rica que pertenecen al género Surazomus Reddell & Cokendolpher, 1995: una de la Estación Biológica La Selva, provincia Heredia; las otras dos, de la Estación Biológica Las Cruces, Coto Brus, provincia Puntarenas. Con estos nuevos aportes, se elevan a 16 los miembros del género y a nueve las...
Article
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A new species of the genus Mastigoproctus Pocock, 1894 is described from Falcon state in northwestern Venezuela. This is the third Mastigoproctus species recorded for this country, the northernmost record of the genus in South America and the first record of the order for Falcon state. Una nueva especie del género Mastigoproctus Pocock, 1894 es de...
Article
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A new species of Stygnidae is described from the state of Bahia, Brazil. Protimesius bahiensis sp. nov. can be distinguished from the remaining species of the genus by the combination of: male femur IV unarmed and cylindrical; male patella IV with a row of large dorsal acute tubercles, increasing in size distally and male tibia IV with one meso- di...
Article
A new species of Stygnidae is described from the state of Bahia, Brazil. Protimesius bahiensis sp. nov. can be distinguished from the remaining species of the genus by the combination of: male femur IV unarmed and cylindrical; male patella IV with a row of large dorsal acute tubercles, increasing in size distally and male tibia IV with one mesodist...
Article
Full-text available
Manzanilla, Osvaldo Villarreal, Kury, Adriano Brilhante (2009): A new generic homonym in the Agoristenidae (Arachnida: Opiliones). Zootaxa 2045: 65-68
Article
Full-text available
Our attention was recently called to one generic nomen in Arachnida Opiliones which is a junior homonym, hitherto undetected (see Kury 2003). Below, a replacement nomen is provided to comply with the rules of the International Code of Zoological Nomenclature (ICZN, 1999).
Article
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Resumen: Diversos autores han citado la localidad tipo de Surazomus macarenensis (Kraus, 1957) de tres departamentos di-ferentes de Colombia, siendo fijada aquí para el departamento de Meta. Palabras clave: Schizomida, Hubbardiidae, taxonomía, Región Neotropical, Colombia. Precise type-locality of Surazomus macarenensis (Kraus, 1957) (Schizomida: H...
Article
Full-text available
A new species of the genus Rowlandius Reddell & Cokendolpher, 1995 is described from Sierra San Luis, Falcón State, northwestern Venezuela. Rowlandius arduus sp. n. may be characterized by having movable finger of chelicerae with a diminute sub-distal tooth, male with a poorly developed dorsal eminence on abdominal segment XII, and female with two...
Article
Full-text available
We report a case of predation by harvestmen (Prionostemma sp.) on a terrestrial isopod (“Philosciidae”), observed in the San Luis Mountains, Falcón State, Venezuela. Data on habitat and associated fauna are given.
Article
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A new Amazonian genus and species of Schizomida is described from Tobogán de la Selva, Amazonas state in Venezu-ela. Piaroa virichaj n. gen. and n. sp is the seventh species of the order described for Venezuela. Piaroa virichaj gen. and n. sp. is distinguished by having the metapeltidium entire; abdominal segment IX – XII elongated in the male; mal...
Article
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Two cases of depredation of tree frogs (Eleutherodactylus; Flectonotus) by Santinezia curvipes (Opiliones: Cranaidae) are commented upon and illustrated, both coming from rainforest in the central track of the Coastal Range in Venezuela at an altitude of 1100 m.
Article
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A new species of whip spider from Sierra de Perijá, in Zulia State, Venezuela, is described. Phrynus araya sp. n. is characterized by cheliceral morphology, pedipalp spination and the shape of the female gonopods. Comments on the knowledge of the order Amblypygi in Venezuela are made, with emphasis on Zulia State. Some comments on the natural histo...
Article
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Cynorta conspersa (Perty 1833), the type species of Cynorta Koch 1839, is redescribed, based on abundant material from the lower Amazon basin, Brazil. A neotype is designated for this species and the species Cynorta mayi Mello-Leitão 1931 is herein considered a junior subjective synonym. Genital morphology of the species is described for the first...
Article
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Una nueva especie de opilión es descrita para el Parque Nacional San Esteban, en la Cordillera de la Costa, Venezuela. T. vigirima puede ser distinguida de las restantes especies del género por la presencia de una mancha dorsal elipsoidal de color pardo negruzco con bordes irregulares, ocupando parcialmente las áreas II y III, siendo más ancha que...
Article
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Two new species of Stenophareus are described from the Guiana Shield region of Venezuela. S. aonda sp. n. (type-locality: Auyán-tepui, Bolívar) is characterized by ocular and tegumentary depigmentation and by extreme pedipalp and leg elongation, representing the first troglomorph stygnid. S. guerreroi sp. n. (type-locality: Chimantá-tepui, Bolívar)...
Article
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Se cita por primera vez la presencia del vinagrillo Mastigoproctus formidabilis Hirst, 1912 en los estados venezolanos de Trujillo y Mérida, a partir de un macho adulto y una hembra inmadura, respectivamente. Además, por primera vez se describen los genitales de ambos sexos. De esta especie solamente se conoc'ia la serie tipo, recolectada en La Pol...
Article
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Five new species of the harvestmen genus Protimesius Roewer, 1913 are described from Brazil: P. foliadereis n. sp. (type-locality: Juruena, Mato Grosso), P. junina n. sp. (type-locality: Gruta Califórnia, Pau Brasil, Bahia), P. cirio n. sp. (type-locality: Ananindeua, Pará), P. boimbumba n. sp. and P. carnaval n. sp. (type-locality for both: Rio Mo...
Article
Ethobunus meridionalis (Caporiacco, 1951) (Zalmoxidae) is recorded from Hacienda El Limón, in Distrito Capital and Río del Medio and Playa Grande in Henri Pittier National Park, in Aragua State, Venezuela. In the latter locality at scarce 20 m from the water breaking line in costal zone with high salinity sandy soils. This is the first record to th...
Article
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Se describe una nueva especie de Hansenochrus Reddell & Cokendolpher, 1995, la cual habita en una caverna del Estado Lara en la región noroccidental de Venezuela y es la cuarta especie del mismo conocida para este país. Hansenochrus urbanii sp. nov. representa el primer registro del género para la fauna hipogea venezolana.A new species of Hansenoch...
Article
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Resumen: La segunda especie del género Phareus Simon, 1879 es descrita, con material proveniente de la Cueva del Chim-balo, Gambita, Santander, Colombia. Se diferencia de P. raptator (Gervais, 1844) por la presencia de tres setas ventrodistales en la placa ventral del pene, forma del Stylus, menor ornamentación de los tergitos libres I-III y borde...
Article
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Oreophrynella weiassipuensis sp. nov. is described from Wei-Assipu-tepui on the Guyana-Brazil border. The new species is distinguished from other species of the genus by the presence of well developed post-orbital crests, toe webbing, dorsal skin minutely granular with scattered large tubercles, and reddish brown dorsal and ventral coloration.Descr...
Article
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Paravima acanthoconus sp. nov. is described from eastern range of Parque Nacional El Ávila, north to Guatire, Miranda State, Venezuela. The new species can be distinguished from the other species of the genus by the distinctive form of the spines in the area III.
Article
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Stygnoplus lomion sp. n. is described from the Turimiquire range in Anzoátegui State, in north-eastern Venezuela. S. clavotibialis and S. forcipatus are recorded for the first time from Venezuela, from Peninsula de Paria, in Sucre State and the coastal range, in Aragua State. The penis of the latter species is described and illustrated.
Article
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We present the preliminary faunistic results obtained as collateral activity to the speleological expedition to Wei-Assipu-tepui of the Roraima formation, conducted by members of the Italian and Speleological Venezuelan Speleological societies in July of 2000. We are reporting the presence of new taxa with emphasis in the anurans and harvestmen.
Article
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Trichomycterus spelaeus, new species catfish is described coming from Punto Fijo Cave, located in the Guasare river basin, Sierra de Perijá, northwestern of Venezuela. The new species presents as dis tinctive character that distinguish it of all the known species of the genus Trichomycterus, the absence of eyes. A comparative analysis with the spec...

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Projects (7)
Project
Agoristenidae is a small family of Laniatores (less than 80 species) distributed exclusively in the Neotropics. The real diversity of the group is underestimated, with a lot of new genera/species waiting to be described, and some genera representing a hodgepodge of unrelated species. So, to better understand its diversity and internal relationships, taxonomic descriptions and cladistic analysis should be done.
Project
Venezuela poses a challenge to the study of pholcid spider systematics. It ranks among the most diverse regions in the world, in particular for taxa with largely tropical distributions like Pholcidae. Venezuela was the focus of Manuel Ángel González-Sponga who between 1998 and 2011 created a total of 22 new genera for Venezuelan pholcids. Unfortunately, much of his published work is deeply flawed for various reasons. The main goals of our project are (1) to initiate long-term collaboration on Venezuelan pholcids, (2) to remove the impediment created by González-Sponga’s inadequate descriptions, and (3) to intenstively collect fresh material suitable for molecular work.
Project
Although the family is one of the most studied and there are proposals for phylogenetic relationships, the real diversity of this group in northern South America is much greater than what is known in literature, as evidenced by the review of material from museum and the constant appearance of new species and even genera. Our short-term central goal is to contribute to the knowledge about the morphology and taxonomic diversity of the family, describing new species and solving some taxonomic problems related to this group, and in the medium term, to be able to construct a new hypothesis of phylogenetic relationships based at least on morphology, while their relationships allow us to understand the current pattern of geographical distribution of the family in South America and the Antilles.