Characteristics Adult Platyneuromus are easily identified by the distinct postocular flanges present on their heads. These plates, just posterior to the eyes are variable in development, in proportion to the size of the specimen. Also, males bear larger flanges than females, so there should be some caution especially in smaller examples in order to not oversee this diagnostic trait. Males and females have short mandibles with discrete dentition, that is, they are monomorphic in mandible shape, although as explained above, there is some sexual dimorphism due to the relative size of the postocular flanges. Forewing length of males ranges from 26-59 mm, and as in Corydalus, intraspecific variation in size may be misleading, however male genitalic characters are distinct for each of the species.
Body color is brownish, sometimes with vittae on head and pronotum.
Wings are clear to semitranslucent, somewhat patterned with darker areas. Photograph copyright 1989 Atilano Contreras-Ramos. Larvae of Chloronia are unpatterned. Pupae of Platyneuromus are easily distinguished because they already have noticeable postocular flanges, which are a diagnostic character for the genus. Natural History Much of what has been said for other Neotropical dobsonflies holds for Platyneuromus.