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

Scientific classification e
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]