The oldest fossils of Dictyoptera from the Late Carboniferous, referred to as "roachoids" have long ovipositors and did not lay oothecae.

[2] The use of the term Dictyoptera has changed over the years, and while largely out of use for much of the last century, it is becoming more widely used.

[3][4] According to genetic evidence, the closest living relatives of the Dictyoptera are the orders Phasmatodea, Mantophasmatodea, and Grylloblattodea.

[5] Evolutionary relationships based on Eggleton, Beccaloni & Inward 2007 and modified by Evangelista et al. 2019, are shown in the cladogram:[6][7] The cockroach families Anaplectidae, Lamproblattidae, and Tryonicidae are not shown but are placed within the superfamily Blattoidea.

The cockroach families Corydiidae and Ectobiidae were previously known as the Polyphagidae and Blattellidae.