Archimylacris lived on the warm, swampyforest floors of North America and Europe 300 million years ago, in the Late Carboniferous times. Like modern cockroaches, this insect had a large head shield with long, curved antennae, or feelers, and folded wings. To a modern observer, it would likely appear as a moderate-sized cockroach, with a "tail" (ovipositor) in the female. Presumably, its habits would be cockroach-like, too, scurrying along the undergrowth eating anything edible, possibly falling prey to labyrinthodont amphibians and very early reptiles.
The average length of Archimylacris species was 2–3 cm.[1]
