Early Jurassic Insects from the Newark Supergroup, Northeastern United States

F ossil insects from the Early Jurassic (Hettan-gian–Sinemurian) of the eastern United States comprise a small fauna that contains two elytra-based genera of beetles, abundant larvae and an adult specimen that may belong to adephagan beetles, other larvae of unknown affinities, a blattoid, and several indeterminate specimens composed of isolated segments and isolated appendages. Beetle elytra include the cupedid Liassocupes parvus Zeuner 1962 and the Holcoptera giebeli Giebel 1856. Mormolucoides ar-ticulatus Hitchcock 1858 is interpreted as a coleopteran that includes two morphs distinguished by relative size and degree of sclerotization that represent different stages of instar development. The blattoid is an isolated wing that presently cannot be assigned to a family. These specimens were obtained from playa and shallow lacustrine deposits of the Hartford, Deerfield, and Newark basins of the Newark Supergroup. Except for a single taxon of an aquatic hemipteran from the Middle Jurassic (Callovian) Todilto Formation of the southwestern United States, the fauna described in this chapter constitutes the only record of Jurassic insects from North America. Lower Mesozoic sedimentary rocks and interbedded basalts of the Newark Supergroup occupy a series of elongate half-graben basins extending from South Carolina to Nova Scotia that formed in response to the crustal extension and rifting associated with the breakup of Pangea (figure 13.1). Strata of Jurassic age are restricted to the northern Newark Supergroup ba-These Lower Jurassic (Hettangian–Sinemurian) sedi-mentary rocks represent a broad suite of nonmarine depositional facies, including prominent cyclic dark-gray, laminated siltstones and shales that record de-position in extensive lacustrine environments Lucas and Huber, chapter 11 in this volume), but most of the invertebrate groups (mollusks, ostracodes, bran-chiopods, decapods, insects, trace fossils) have not received rigorous taxonomic analysis.