Systematic review and cladistic analysis of the genus Eusarcus Perty 1833 (Arachnida, Opiliones, Gonyleptidae)
Authors: HARA MARCOS RYOTARO , PINTO-DA-ROCHA RICARDO 
Published: January 2019

Eusarcus Perty 1833 is one of the oldest described genera of Pachylinae, comprising 36 species distributed from northeastern to southern Brazil (including the central west region), northeastern Argentina, eastern Paraguay and Uruguay. The genus is reviewed and a new classification is proposed based on a cladistic analysis. A cladistic analysis was performed with the 34 valid species of Eusarcus and 11 species belonging to certain Gonyleptidae subfamilies. The data matrix has 67 characters: 14 from dorsal scutum and pedipalp, 38 from male legs and 15 from male genitalia. Two equally parsimonious trees were found (L=319; C.I.=0.26, R.I.=0.61). Pygophalangodus gemignanii uruguayensis Ringuelet 1955a and Pygophalangodus gemignanii gemignanii Mello-Leitão 1931b are here elevated to the category of species, and the following new combinations are proposed: E. catharinensis (Mello-Leitão 1927); E. berlae (Mello-Leitão 1932); E. gemignanii (Mello-Leitão 1931b); E. signatus (Roewer 1949); E. sooretamae (Soares & Soares 1946a); E. uruguayensis (Ringuelet 1955a). The following generic synonymies are proposed: Eusarcus Perty 1833 (type species E. armatus Perty 1833) = Metagraphinotus Mello-Leitão 1927 (type species M. catharinensis Mello-Leitão 1927), Pareusarcus Roewer 1929 (type species P. corniculatus Roewer 1929), Pygophalangodus Mello-Leitão 1931b (type species P. gemignanii gemignanii Mello-Leitão 1931b) and Antetriceras Roewer 1949 (type species A. signatus Roewer 1949). The following specific synonymies are proposed: Eusarcus hastatus Sørensen 1884 = Pucrolioides argentina Roewer 1913, E. guimaraensi H. Soares 1945, Jacarepaguana pectinifemur Piza 1943, Canestrinia canalsi Mello-Leitão 1931a, and E. maquinensis H. Soares 1966b; E. armatus Perty 1833 = E. curvispinosus Mello-Leitão 1923b, and Enantiocentron montis Mello-Leitão 1936; Eusarcus catharinensis (Mello-Leitão 1927) = E. antoninae Mello-Leitão 1936, E. perpusillus Mello-Leitão 1945, E. tripos Mello-Leitão 1940, and Metagraphinotus trochanterspinosus Soares & Soares 1947b; E. nigrimaculatus Mello-Leitão 1924 = Pareusarcus centromelos Mello-Leitão 1935a, E. furcatus Roewer 1929, Orguesia armata Roewer 1913, and Pareusarcus corniculatus Roewer 1929; E. oxyacanthus Kollar in Koch 1839a = Enantiocentron doriphorus Mello-Leitão 1932, and E. spinimanu Mello-Leitão 1932; E. pusillus Sørensen 1884 = E. vervloeti B. Soares 1944c; E. berlae Mello-Leitão 1932 = Metagraphinotus arlei Mello-Leitão 1935a. Metapucrolia armata (Sørensen 1895) is revalidated, transferred to Eusarcus and considered as a species inquirenda. A new name, Eusarcus metapucrolia is proposed for this species to avoid homonymy with the type species of Eusarcus, E. armatus Perty 1833. Eusarcus aberrans Mello-Leitão 1939a is considered as a species inquirenda. The male of E. teresincola Soares & Soares 1946a is described. Female of the following species are described: E. bifidus Roewer 1929; E. dubius B. Soares 1943b; E. insperatus B. Soares 1944a; E. schubarti Soares & Soares 1946a; E. sooretamae (Soares & Soares 1946a). The following new species are described from Brazil: E. acrophthalmus (type locality: Bahia, Ilhéus, Parataquicé); E. alpinus (Rio de Janeiro, Santa Maria Madalena, Parque Estadual do Desengano); E. caparaoensis (Minas Gerais, Alto Caparaó, Parque Nacional do Caparaó); E. cavernicola (Goiás, São Domingos, Parque Estadual de Terra Ronca, Lapa da Angélica); E. didactylus (Rio de Janeiro, Teresópolis, Parque Nacional Serra dos Órgãos); E. garibaldiae (Santa Catarina, Itajaí); E. geometricus (Rio de Janeiro, Teresópolis, Parque Nacional Serra dos Órgãos); E. manero (Rio de Janeiro, Maricá, Itaipuaçu); E. matogrossensis (Mato Grosso, Chapada dos Guimarães); E. mirabilis (Minas Gerais, Marliéria, Parque Estadual Rio Doce); E. sergipanus (Sergipe, Itabaiana, Parque Nacional de Itabaiana) and E. tripectinatus (Minas Gerais, Rio Preto). The holotype of E. curvispinosus is proposed as the neotype of E. armatus Perty 1833, the type material of which has been lost. Lectotypes for the following species were designated: E. aduncus; E. hastatus; E. oxyacanthus.