The new species is described and illustrated from a male collected in the Restinga de Marambaia, Rio de Janeiro, Brazil (holotype) and two other male paratypes from the Goiás State, Brazil. Micrathyria pseudhypodidyma sp.nov. belongs to the "didyma group" and the closest species seems to be Micrathyria hypodidyma Calvert, 1906, from which it can be easily distinguished by presenting the first abdominal sternite smooth, whereas in M. hypodidyma the sternite has an indented plate. An illustrated key to identify the species with occurrence in the Rio de Janeiro State and comments about them are presented.
Insecta; Anisoptera; taxonomy