Archimylacris (meaning "primitive Mylacris", in reference to another species of Carboniferous cockroach)^{[clarification needed]} is an extinct genus of cockroach-like blattopterans, a group of insects ancestral to cockroaches, mantids, and termites.

Archimylacris Temporal range: Carboniferous, Westphalian-Stephanian PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	†Blattoptera
Family:	†Archimylacridae
Subfamily:	†Archimylacrinae
Genus:	†Archimylacris Scudder, 1868
Type species
Archimylacris acadica Scudder, 1868
Other species
Archimylacris atrebatica Pruvost, 1919 Archimylacris belgica Handlirsch, 1904 Archimylacris bertrandi Pruvost, 1919 Archimylacris bucheti Pruvost, 1912 Archimylacris calopteryx Handlirsch, 1906 Archimylacris eggintoni Bolton, 1921 Archimylacris johnsoni Woodward, 1887 Archimylacris lerichei Pruvost, 1919 Archimylacris lubnensis Kušta, 1883 Archimylacris oberstebrinki Schmidt, 1962 Archimylacris parallelum Scudder, 1879 Archimylacris? paucinervis Scudder, 1890 Archimylacris regularis Bolton, 1934 Archimylacris scalaris Bolton, 1930 Archimylacris schmidti Boersma, 1969 Archimylacris simoni Pruvost, 1919 Archimylacris straeleni Pruvost, 1930 Archimylacris venusta Lesquereux, 1860

Archimylacris lived on the warm, swampy forest 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]