Psaironeura jeronimoi (Odonata: Zygoptera: Coenagrionidae) sp. nov. from the Brazilian Amazon rainforest, with a key for species of tenuissima group, and discussion on the significance of the genital ligula to the taxonomy of the group Author Mendoza-Penagos, Cristian Camilo Programa de Pós-graduação em Zoologia - PPGZOOL, Universidade Federal do Pará, Belém, Brazil. & Laboratorio de Ecología e Conservação - LABECO, Universidade Federal do Pará, Instituto de Ciências Biológicas, Rua Augusto Correia, No. 1 Bairro Guamá, CEP 66.075 - 110 Belém, Pará, Brazil. Author Juen, Leandro Laboratorio de Ecología e Conservação - LABECO, Universidade Federal do Pará, Instituto de Ciências Biológicas, Rua Augusto Correia, No. 1 Bairro Guamá, CEP 66.075 - 110 Belém, Pará, Brazil. Author Muzón, Javier Departamento de Ambiente y Turismo, Universidad Nacional de Avellaneda, Universidad Nacional, Avellaneda, Provincia de Buenos Aires, Argentina. Author Vilela, Diogo Silva Laboratório de Biologia Aquática, Departamento de Ciências Biológicas, Faculdade de Ciências e Letras de Assis, Universidade Estadual Paulista, Assis, São Paulo, Brazil. text Zootaxa 2022 2022-10-19 5196 2 291 300 journal article 170604 10.11646/zootaxa.5196.2.9 af1fbc1c-879a-4e53-be33-5fcdac757df3 1175-5326 7224616 8A349E8C-D758-4A95-BF54-978A72C776E4 Keys to males of the tenuissima group (adapted from to Garrison, 2004 ) 1. Tip of cercus in dorsal or posteromedial view branched or bluntly rounded, but without black tooth in the external branch ( Fig. 3 h−i).................................................................................... P. tenuissima . 1’. Tip of cercus in dorsal or posteromedial view branched, with a black tooth in the external branch...................... 2 2. Tip of cercus in dorsal or posteromedial view branched, both external and internal branch with distinct black tooth ( Fig. 3 e−f).......................................................................................... P. bifurcata . 2’. Tip of cercus in dorsal or posteromedial view branched, with external branch armed with distinct black tooth and internal branch with an ante-apical rounded lobe ( Fig. 3 b−c)................................................. P. jeronimoi .