historically, the name blattaria has been used largely interchangeably with the name blattodea. blattodea refers to a larger group that includes fossil groups related to roaches, but not true cockroaches themselves. these earliest cockroach-like fossils ("blattopterans" or "roachids") are from the carboniferous period between 354–295 million years ago. however, these fossils differ from modern cockroaches in having long ovipositors and are the ancestors of mantis as well as modern cockroaches. the first fossils of modern cockroaches with internal ovipositors appear in the lower cretaceous.