A fresh look at Cosmetus Perty, 1833 (Opiliones: Cosmetidae), with new synonymies and description of two new species from Colombia Author Medrano, Miguel 0000-0002-3215-3592 Departamento de Invertebrados, Museu Nacional / UFRJ, Quinta da Boa Vista, São Cristóvão, 20940 - 040, Rio de Janeiro - RJ, Brazil Grupo de Investigación Biodiversidad del Caribe Colombiano, Departamento de Biología, Universidad del Atlántico, Barranquilla, Colombia & miangelmed @ gmail. com; https: // orcid. org / 0000 - 0002 - 3215 - 3592 miangelmed@gmail.com Author Kury, Adriano B. 0000-0002-8334-6204 Departamento de Invertebrados, Museu Nacional / UFRJ, Quinta da Boa Vista, São Cristóvão, 20940 - 040, Rio de Janeiro - RJ, Brazil Grupo de Investigación Biodiversidad del Caribe Colombiano, Departamento de Biología, Universidad del Atlántico, Barranquilla, Colombia & adrianok @ gmail. com; https: // orcid. org / 0000 - 0002 - 8334 - 6204 adrianok@gmail.com Author Martinez, Leonel 0000-0002-4166-0561 leonelmarbio @ gmail. com; https: // orcid. org / 0000 - 0002 - 4166 - 0561 leonelmarbio@gmail.com text Zootaxa 2021 2021-07-21 5004 3 430 446 journal article 10.11646/zootaxa.5004.3.2 1175-5326 5120713 E5AB5F1C-CA71-48D7-95AE-C982C6825AB1 Cosmetus varius Perty, 1833 Cosmetus varius Perty 1833: 203 . Cosmetus varius —C.L. Koch 1839c: 20; C.L. Koch 1840 a: 109, pl. 248, fig. 586 (misidentification of C. delicatus (Soares & Soares, 1946)) ; Lucas 1840: 458 ; Gervais 1844: 116 (French vernacular “Cosmète varié”); Simon 1879 a: 191; Roewer 1912 d: 101; Roewer 1923: 377, fig. 458; Mello-Leitão 1923c: 114; Roewer 1928a: 609; Mello-Leitão 1932: 60, fig. 25; Kury 2003 a: 41 (cat.). Cosmetus mesacanthus C.L. Koch 1839b: 111 , pl. 249, fig. 587. SYN. NOV. Cosmetus mesacanthus — Simon 1879: 191 ; Roewer 1912 d: 101; Roewer 1923: 377; Mello-Leitão 1923c: 114; Strand 1926: 43; Roewer 1928a: 609; Mello-Leitão 1932: 60; Sørensen in Henriksen 1932a: 315. “ Cosmetus mesacathus ”: C.L. Koch 1839c: 20 . ‡ Incorrect subsequent spelling. “ Cosmetus mesacanthos ”: Mello-Leitão 1933c: 104 . ‡ Incorrect subsequent spelling. Cosmetus pleurostigma Sørensen in Henriksen 1932a: 316. SYN NOV. Cosmetus pleurostigma —Mello-Leitão 1933c: 104; Mello-Leitão 1935b: 115. Cosmetus turritus Sørensen in Henriksen 1932a: 317. SYN. NOV. Cosmetus turritus —Mello-Leitão 1935b: 115. “ Cosmetus tursitus ”: Mello-Leitão 1933c: 104 . ‡ Incorrect subsequent spelling. Type data. C, varius : ( ZSMC , lost), from BRAZIL , without further locality data. C. mesacanthus : ♂ ♀ syntypes ( NHMW , not examined), from BRAZIL , without further locality data. C. pleurostigma : 3 syntypes dried ( ZMB 952 , examined by photograph), BRAZIL , Bahia , Salvador . C. turritus : 2 syntypes ( ZMB , not examined), BRAZIL , Bahia , Salvador . Material examined. BRAZIL , Bahia : 1♂ 1♀ ( MNRJ 7632 ), Elísio Medrado , RPPN Jequitibá. oct 07 2007 . R . Bertani , R . H. Nagahama & C.S. Fukushima leg. ; 1♂ 2♀ ( MNRJ 8539 ), Mata de São João , RPPN Mata de São João. oct 08 2011 . Pérez A. & Huber, B. ; 2 unsexed specimens ( ZMB 951 ), identified as C. mesacanthus by Roewer in 1916 ( Figs 3 A−D) . FIGURE 2A−D. Living specimens of Cosmetus spp . from Atlantic Forest in Brazil. (A − B) C. delicatus from Espírito Santo. (C) C. arietinus , from Espírito Santo. (D) C. varius from Bahia . Photos by Miguel Medrano & Adriano Kury (A–B) and courtesy of Marcos Martinelli (C) and Airton Carvalho (D). Rationale for the synonymies. We recognize here the coarsely granular brown Cosmetus from Eastern Bahia , profusely and variably sprinkled with golden-white dots and wavy reticles as Perty’s C. varius . The color pattern varies from a well-developed complex mask, covering the animal’s entire body and giving it a honeycombed appearance ( Fig 5A ), to a more dissociated pattern ( Figs 2D and 5B ), where the animal is more “bicolor” like the average cosmetid. FIGURE 3A−E. Cosmetus varius from ZMB with labels, from Brazil, Bahia. A−D. C. mesacanthus (ZMB 951) ID by Roewer. E−H. Syntypes of C. pleurostigma (ZMB 952). Courtesy of Anja Friederichs & Jason Dunlop. If we follow the itinerary of Spix & von Martius in their Brazilian Expedition ( Fig. 11C ), it is easy to note that they bypassed Espírito Santo and bisected Bahia ending up in Salvador , which is entirely consistent with our proposed identification of C. varius . Perty (1833: 203) characterized C. varius as follows: “Fuscus, margine undique et punctis numerosis dorsalibus albidis”, which does not match the “redescription” of this species as given by C.L. Koch (1840: 109) . Koch’s description and illustration of C. varius correspond to Cosmetus delicatus instead. However, Koch mentions that his C. mesacanthus is yellow. Roewer (1912) followed Koch blindly. We do not think that either has recognized the true C. varius , which we deem to be the same species as C. mesacanthus . Additionally, Sørensen (1932) described two other species also within the distribution of the herein recognized C. varius ( Fig. 11D ), and these correspond respectively to the honeycombed ( C. turritus ) and bicolored ( C. pleurostigma ) variants depicted in Figs 3 E−H and 4A−B.