A fourth species of rock crawler (Notoptera: Mantophasmatodea: Mantophasmatidae) is described and figured from an individual preserved in middle Eocene (Lutetian) Baltic amber. Adicophasma grylloblattoides Arillo and Engel, new species, is distinguished from its close relative, A. spinosum Engel and Grimaldi (reinstated), by the reduced pedicel, absence of spines on the maxillae, absence of mesofemoral spination, and proportions of the thoracic segments. The fossil shares with A. spinosum the presence of profemoral spination (confirmed by a new photograph of the holotype) and absence of the dorsal profemoral carina, characters that differentiate Adicophasma from the monotypic Raptophasma; it shares with all Baltic amber Notoptera the absence of the setal fan on the arolium. As noted by previous authors, the former order Mantophasmatodea is related to modern Grylloblattodea, whereas Mesozoic and Paleozoic grylloblattodeans represent a stem group to both. As such, Grylloblattodea and Mantophasmatodea are considered suborders of a single order, Notoptera Crampton (sensu novum), following the recommendation of Engel and Grimaldi (2004). The names for three rock crawlers are emended in order that the specific epithet may match the gender of the generic name: A. spinosum, Mantophasma zephyrum Zompro et al., and Tanzaniophasma subsolanum (Zompro et al.) (nomina emendata). Raptophasmatinae and Ensiferophasmatidae are new synonyms of Mantophasmatidae, while Tanzaniophasmatidae and Austrophasmatidae are newly demoted in rank to a subfamily and tribe of Mantophasmatidae, respectively. A hierarchical classification of Polyneoptera is appended.