An illustrated catalogue of South American species of Omorgus Erichson, 1847 (Coleoptera, Trogidae, Omorginae) including a neotype designation and taxonomical changes Author da Costa-Silva, Vinícius 0000-0002-4556-3793 Department of Zoology & Entomology, University of Pretoria, Private Bag X 20, Hatfield, 0028, South Africa & Laboratório de Scarabaeoidologia, Instituto de Biociências, Universidade Federal de Mato Grosso (UFMT), Cuiabá, Mato Grosso, Brazil Author Strümpher, Werner P. 0000-0002-7047-2666 Ditsong National Museum of Natural History, PO Box 413, Pretoria 0001, South Africa Author Barclay, Maxwell V. L. 0000-0003-4989-2014 Department of Life Sciences, Natural History Museum, London SW 7 5 BD, UK Author Vaz-de-Mello, Fernando Z. 0000-0001-9697-320X Laboratório de Scarabaeoidologia, Instituto de Biociências, Universidade Federal de Mato Grosso (UFMT), Cuiabá, Mato Grosso, Brazil text Contributions to Entomology 2024 2024-07-29 74 1 81 101 journal article 10.3897/contrib.entomol.74.e126799 339AB68C-DCB1-435F-B88E-2C42D0A7B05E Omorgus ( Omorgus ) loxus ( Vaurie, 1955 ) Trox loxus Vaurie, 1955: 58 (original description); Vaurie 1962: 147 (redescription); Ratcliffe 1978: 301 (new distribution records). Trox ( Omorgus ) loxus : Scholtz 1982: 11 (catalogue). Omorgus ( Omorgus ) loxus : Scholtz 1986 a : 361 (phylogenetics); Scholtz 1990: 1416 (redescription), Moragues 2010: 77 (checklist – as “ lauxus ”); Zidek 2013: 12 (checklist); Zidek 2017: 103 (checklist); Hielkema and Hielkema 2019: 11 (checklist of the Guianas); Costa-Silva et al. 2021: 1999 (review of Brazilian species). Omorgus loxus : Deloya 2000: 67 (checklist); Diéguez and Gómez 2004: 94 (checklist); Deloya 2005: 122 (checklist); Gómez 2008: 515 (key for Argentinean species). Type specimen examined. Holotype , by original designation ( MCZH ). See Costa-Silva et al. (2021: 1999) for high-quality images of the type specimen. Type locality : “ El Palmar, 16 k. W. of Tetzonapa ” [ Mexico ]. Geographic distribution. Argentina , Brazil , Colombia , Costa Rica , French Guiana, Mexico , Panama , and Paraguay ( Vaurie 1955 ; Ratcliffe 1978 ; Scholtz 1990 ; Costa-Silva et al. 2021 ). Non-type examined material ( three specimens additionally to Costa-Silva et al. 2021 ). ARGENTINA La Rioja 1 ♀ ; Patquia ; 1933; K. J. Hayward leg.; NHMUK 1 ♀ ; Santiago del Estero , Bords du Rio Salado , D’Icano , Mistol paso; 1909; E. R. Wagner leg.; MNHN . BRAZIL • 1; Matto Grosso (sic!); 1886; P. Germain leg.; MNHN .