Early Jurassic Insects from the Newark Supergroup, Northeastern United States
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13 Early Jurassic Insects from the Newark Supergroup, Northeastern United States Phillip Huber, Nicholas G. McDonald, and Paul E. Olsen ossil insects from the Early Jurassic (Hettan- Lower Mesozoic sedimentary rocks and interbedded gian–Sinemurian) of the eastern United States basalts of the Newark Supergroup occupy a series of F comprise a small fauna that contains two elongate half-graben basins extending from South elytra-based genera of beetles, abundant larvae and an Carolina to Nova Scotia that formed in response to adult specimen that may belong to adephagan beetles, the crustal extension and rifting associated with the other larvae of unknown affinities, a blattoid, and sev- breakup of Pangea (figure 13.1). Strata of Jurassic age eral indeterminate specimens composed of isolated are restricted to the northern Newark Supergroup ba- segments and isolated appendages. Beetle elytra in- sins, which include the Culpeper, Gettysburg, Newark, clude the cupedid Liassocupes parvus Zeuner 1962 and Pomperaug, Hartford, Deerfield, and Fundy basins. the Holcoptera giebeli Giebel 1856. Mormolucoides ar- These Lower Jurassic (Hettangian–Sinemurian) sedi- ticulatus Hitchcock 1858 is interpreted as a coleopteran mentary rocks represent a broad suite of nonmarine that includes two morphs distinguished by relative size depositional facies, including prominent cyclic dark- and degree of sclerotization that represent different gray, laminated siltstones and shales that record de- stages of instar development. The blattoid is an isolated position in extensive lacustrine environments (Olsen wing that presently cannot be assigned to a family. 1986; Smoot 1991). The Newark Supergroup contains These specimens were obtained from playa and shal- well-documented palynomorph, megafloral, fish, and low lacustrine deposits of the Hartford, Deerfield, tetrapod records (Cornet 1977; Olsen, Schlische, and and Newark basins of the Newark Supergroup. Except Gore 1989; Cornet and Olsen 1990; McDonald 1992; for a single taxon of an aquatic hemipteran from the Lucas and Huber, chapter 11 in this volume), but most Middle Jurassic (Callovian) Todilto Formation of the of the invertebrate groups (mollusks, ostracodes, bran- southwestern United States, the fauna described in this chiopods, decapods, insects, trace fossils) have not re- chapter constitutes the only record of Jurassic insects ceived rigorous taxonomic analysis. However, studies from North America. of the mollusks (Good, Olsen, and McDonald 1994; Good and Huber 1995) and of Triassic age insects (Fraser et al. 1996; Fraser and Grimaldi, chapter 12 in this volume) are in progress. Early Jurassic Insects from the Newark Supergroup • 207 . The Newark Supergroup and details of the Hartford, Deerfield, and New- ark basins. (A) Location of the Newark Supergroup basins. (B) Generalized geologic map of the Hartford and Deerfield basins. (C) Generalized geologic map of the northern part of the Newark basin; HR, Horse Race, Montague and Gill, Massachusetts; G, outcrops with Mormolucoides (Olsen et al. 1992), Montague, Massachusetts; H, Holyoke Dam, Holyoke, Massachusetts; S, former K-F Quarry, Portland Formation, Suffield, Connecti- cut; C, Cromwell, Connecticut; D, Durham fish locality, Durham, Connecticut; R, Rose- land Quarry, Roseland, New Jersey. The first specimens of Mesozoic insects collected in ward C. Hitchcock, who named them Mormolucoides North America were abundant larvae discovered on articulatus (Hitchcock 1858) and in turn sent examples the banks of the Connecticut River during the 1850s of the larvae to Yale geologist James D. Dana for iden- by Roswell Field, a local farmer and naturalist of Gill, tification. Further collections were made at the site by Massachusetts. Field presented the specimens to Ed- other residents of the area, including Dexter Marsh 208 • Phillip Huber, Nicholas G. McDonald, and Paul E. Olsen and T. M. Stoughton, and by Yale paleontologist O. C. Systematic Paleontology Marsh, who visited the locality in April 1867. S. W. Phylum Arthropoda Loper of Wesleyan University discovered additional ex- Class Insecta amples of these larvae in slightly older beds in south- Order Coleoptera central Connecticut during the late nineteenth century. Suborder Archostemata Kolbe 1908 Renewed paleontological investigation of the Hart- Family cupedidae Lacordaire 1857 ford, Deerfield, and Newark basins has led us to new Genus Liassocupes Zeuner 1962 insect occurrences (figure 13.1) as well as to the redis- covery of the Mormolucoides locality (McDonald and Huber 1995). The most important of our new localities Liassocupes Zeuner 1962:167, pl. 27 (fig. 4) was the now infilled K-F Quarry (Portland Formation) Liassocupes (Zeuner 1962) Whalley 1985:66–167, in Suffield, Connecticut (LeTourneau and McDonald figs. 63–66 1985). Collecting efforts at this site from 1986 to 1992 Liassocupes (Zeuner 1962) Olsen 1995:169, fig. 7c yielded approximately 80 beetle elytra, a single blattoid wing, and several fragmentary abdominal segments Liassocupes (Zeuner 1962) Huber and McDonald and appendage elements of uncertain affinities. What 1996:49 we believe to be Roswell Field’s Mormolucoides beds Type species: Liassocupes parvus Zeuner 1962. were found in October 1991, and subsequent efforts Diagnosis (amended from Zeuner 1962): Cupedid yielded approximately 5,000 larvae, several elytra, and with rounded pronotum and elytra that possess a an adult beetle. Other larvae were discovered in 1996 punctate sculpture arranged in 8 to 12 rows defined by in Portland Formation outcrops below the Holyoke longitudinal veins. Dam in South Hadley, Massachusetts, and in the Distribution: Early Jurassic: Flatstones, Black Ven, Shuttle Meadow Formation at Durham, Connecticut Charmouth, Dorsetshire, United Kingdom (Sinemu- (probably Loper’s locality mentioned in Lull 1915, rian: obtusem zone); “Member A,” Towaco Formation, 1953). During the course of excavations for fossil fish Roseland Quarry, Essex County, New Jersey (Hettan- and dinosaur tracks at the Roseland Quarry in the gian). Newark basin (Towaco Formation), a single elytron was collected that represents the only North American Liassocupes parvus record of a Jurassic age cupedid beetle (Olsen 1995; Huber and McDonald 1996). The combined assem- Holotype: BMNH In64008, lower Lias, Dorsetshire, blages from the Hartford, Deerfield, and Newark ba- United Kingdom. sins, excepting a single species of aquatic Hemiptera Referred material: YPM 35964. from the Todilto Formation of New Mexico (Kirkland, Diagnosis: Elytra sculptured by 10 rows of longitudinal ם Denison, and Evans 1995), comprise the only Jurassic veins that segregate cells numbering 40 in each ver- insect fauna yet documented from North America. A tical row. Length: 3–7 mm. preliminary description of this fauna is provided in the rest of this chapter. Discussion Specimens discussed in this chapter are in the Brit- Liassocupes is an archostematan first established by ish Museum of Natural History (BMHN; London), Zeuner (1962), on the basis of elytral morphology, to Nicholas G. McDonald collection at the Westminster contain a single species, L. parvus. The holotype and School (NGM; Simsbury, Connecticut), Shepard and referred materials are part of the Jackson (BMNH) in- Hitchcock Ichnology Collections at the Pratt Museum sect collection obtained from the Black Ven at Char- of Natural History of Amherst College (PMNH; Am- mouth, Dorsetshire. At the time of Zeuner’s descrip- herst, Massachusetts), Virginia Museum of Natural tion, the holotype (BMNH In64008) was the only History (VMNH; Martinsville, Virginia), Wesleyan known specimen. Whalley (1985) described an addi- University, Department of Earth and Environmental tional specimen (BMNH In49210), an isolated elytron Sciences collections (WU; Middletown, Connecticut), that he referred to this species based on the character- and Yale Peabody Museum of Natural History (YPM; istic sculpture. The holotype of Liassocupes parvus is a New Haven, Connecticut). nearly complete (though poorly preserved) beetle in Early Jurassic Insects from the Newark Supergroup • 209 dorsal aspect that displays paired elytra missing their Liassocupes parvus and the other Dorset specimen, posterior margins. As Whalley noted, the head and YPM 35964 has a rounded posterior termination but thorax are detached from the elytra and rotated at a possesses a slightly flattened costal margin. The spec- slight angle, but they lack distinguishing characters imen is identical in all other respects to Liassocupes other than the rounded pronotum. The elytra display parvus, to which it is referred. cells that are ordered into 10 vertical rows segregated by primary and secondary venation. The other speci- Suborder ?Polyphaga Emery 1886 men (BMNH In49210), a complete elytron 4.8 mm in Family incertae sedis length with a rounded posterior end, indicates that Genus Holcoptera Handlirsch 1906–1908 each row contains approximately 40 spots. Whalley (1985) described two additional species (Harpalideous Carabidae) Brodie 1845:101, 124, and provisionally placed them in this genus. Liasso- pl. 6 (fig. 28) cupes maculatus is based on six specimens (holotype Harpalus Giebel 1856:63 BMNH In49577) and differs from L. parvus by a greater length of elytra (up to 12.2 mm) that bear 12 Holcoptera Handlirsch 1906–1908:453, pl. 41 vertical rows of cells and lack intermediate, raised sub- (fig. 64) costal striae. The elytra display flattened costal margins Holcoelytrum Handlirsch 1906–1908:453, pl. 41 and posteriorly terminate in a pointed apex. Liasso-