Blattoid

This result, however, is much younger than some “roachoid” fossils and clearly invalidates the hypothesis suggesting that winged “blattoids” would date back to the Devonian.

However, a subgroup analysis (by order) indicated that the DGC facilitated gaseous exchange in dipterans (0.43 ± 0.34; estimate ± 95% CI; p = 0.01), but not in blattoids (p = 0.89) or orthopterans (p = 0.57) (Figure 5a).

This age is congruent with the presence of “blattoid” ootheca in the Late Carboniferous, suggesting that Dictyoptera with reduced ovipositors were already present at that time, coexisting with “roachoids” with long external ovipositors.

Within the animal kingdom, complex brains and high intelligence have evolved several to many times independently, e.g. among ecdysozoans in some groups of insects (e.g. blattoid, dipteran, hymenopteran taxa), among lophotrochozoans in octopodid molluscs, among vertebrates in teleosts (e.g. cichlids), corvid and psittacid birds, and cetaceans, elephants and primates.

The most parsimonious scenario of the origin of this pattern would be an ancient duplication of the ancestral FAD-A1 and subsequent conservation of its paralogous copy during diversification of blattoid cockroaches and termites.