In the perspective of the general review of the ‘archaeorthopterid’ insects (including Orthoptera and the extinct orders Caloneurodea and Titanoptera), a redescription of Protophasma dumasii Brongniart 1879, type species of the Protophasmatidae Brongniart 1885, is provided. The forewing morphology allows the assignment of this taxon to the Archaeorthoptera, but the hindwing morphology is very similar to that of Blattodea, with some particular features. Protophasma dumasii shares several symplesiomorphies with the Blattodea and Neoptera. Thus, this species is a good candidate to be the absolute out-group for the future phylogenetic analysis of the Archaeorthoptera.