BRODIOPTERA STRICKLANI N. SP. (MEGASECOPTERA: BRODIOPTERIDAE), A NEW FOSSIL INSECT FROM THE UPPER MANNING CANYON SHALE FORMATION, UTAH (LOWERMOST NAMURIAN B)

The insect described in this report was collected from the upper- most units of the time-transgressive unit-the Manning Canyon Shale Formation, in central Utah. This formation of Late Missis- sippian to Early Pennsylvanian (Namurian A and B) age consists predominately, of shales with interbedded limestones, orthoquartz- ites and some siltstones. A flora has been described from the upper portion of this formation at and near the collecting site for this insect. The flora from the upper Manning Canyon Shale, as presently defined, contains 43 genera and 103 species (Tidwell, 1967; Tidwell et aI., 1974; Webster et aI., 1984). Thus, it represents the most diversified flora of Carboniferous age presently known in western North America. Plant fossils from this formation consist of fern or fern-like foliage, lycopods, species with calamitean affinities, various seed types, cordaitean taxa and several forms related to microsporangiate structures. These plants indicate that the area was a swampy, moist lowland with perpetual summer-like conditions (Tidwell, 1975). The Manning Canyon Shale is the oldest horizon reported to be insect-bearing in western North America (Durden, 1984). The age of the uppermost Manning Canyon Shale Formation remains uncer- tain. Many paleontologists and geologists consider the formation to be entirely Mississippian (Upper Namurian A: Bissell, 1959; Gordon and Duncan, 1970; and Webster et al., 1984). Others (Chamberlain and Clark, 1973; Sando, 1985) place the base of the formation in Upper Mississippian and the upper portion in the Lower Pennsyl- vanian (Namurian B and C). The majority of the fossil plants from the upper shales of this formation are encountered only in the Penn-

portion of this formation at and near the collecting site for this insect. The flora from the upper Manning Canyon Shale, as presently defined, contains 43 genera and 103 species (Tidwell, 1967;Tidwell et al., 1974;Webster et al., 1984). Thus, it represents the most diversified flora of Carboniferous age presently known in western North America. Plant fossils from this formation consist of fern or fern-like foliage, lycopods, species with calamitean affinities, various seed types, cordaitean taxa and several forms related to microsporangiate structures. These plants indicate that the area was a swampy, moist lowland with perpetual summer-like conditions (Tidwell, 1975).
The Manning Canyon Shale is the oldest horizon reported to be insect-bearing in western North America (Durden, 1984). The age of the uppermost Manning Canyon Shale Formation remains uncertain. Many paleontologists and geologists consider the formation to be entirely Mississippian (Upper Namurian A: Bissell, 1959;Gordon and Duncan, 1970;and Webster et al., 1984). Others (Chamberlain and Clark, 1973;Sando, 1985) place the base of the formation in Upper Mississippian and the upper portion in the Lower Pennsylvanian (Namurian B and C). The majority of the fossil plants from 310 Psyche [Vol. 94 sylvanian, whereas a small number of species are typically Mississippian. Therefore, we consider this upper flora, as well as the insect, to be lowermost Namurian B in age.
The insect specimen described in this paper is a compression fossil consisting of the body, four wings, cerci, legs, and antennae. It is assigned to Brodioptera of the paleopterous order Megasecoptera, which is related to the orders Diaphaneropterodea and Paleodictyoptera. All of these Paleozoic orders had sucking beaks and probably fed by sucking the contents of fructifications and cones of lycopods, cordaiteans, and pteridosperms (Kukalov-Peck, 1983, 1985. Riek and Kukalova-Peck (1984). The order Megasecoptera occurs from Upper Carboniferous to Upper Permian (Brues, Melander, and Carpenter, 1954 DESCRIPTION. Male, length from head to distal portion of genitalia 26 mm; expanse measured between apices of forewings of complete specimen 57 mm; head with vaguely preserved mouthparts; antennae filiform, incomplete right remnant 9 mm in length, left remnant 40 mm; legs poorly preserved, three on left side, two on right; length of each forewing 28 mm, width of each forewing measured at apex of Sc 8 mm; length of right hindwing 25 mm, not flat during preservation, length of left hindwing 28 mm, width of each hindwing 8 mm measured at apex of Sc. Wings as in Figs. 2a-d; Sc joining C near midlength of each wing; R and Rs forking in basal quarter, Rs with four branches; MA and MP forking at 1/3 wing length, MA arching anteriorly near fork with MP to nearly contact Rs; CuA and CuP forking in basal 1/3; anal veins composed of three branches with A3 seen only in right hind wing (Fig. 2d); crossveins few but straight and irregularly placed. Abdomen with faint indication of segmentation; genitalia 4.8 mm in length, composed of lateral claspers and medial gonapophyses, neither claspers nor gonapophyses with annulations; cerci long and filiform more than 54 mm in length.
PRESERVATION. The specimen of B. stricklani consists of a part and counterpart with characters better preserved on one rather than the other of the faces. The specimen is lying ventral side up. In this position, the basal portions of the wings are covered from view with the legs lying over parts of the specimen. Details of the head as well as the thorax including attachments of the legs and wings cannot be observed. The specimen is a compression fossil with concavities and convexities of the wings not apparent. Many of the structures of the specimen are,indicated by hematitic material; however, the legs and DIA6OSS. Brodioptera stricklani is closely related to B. cumberlandensis Copeland 1957. Comparison of the wing of B. cumberlandensis (Carpenter, 1963) reveals that it more closely resembles the forewing of B. stricklani than the hindwing. The two may be separated on the basis of details of forking patterns of the veins. The shorter subcosta of B. stricklani joins the costa at about the midpoint of the wing while that of B. cumberlandensis joins the costa well beyond the midpoint. The radial sector, media, and cubitus all fork more distally in B. stricklani than in B. cumberlandensis. Both the fore and hind wings of B. stricklani have a relatively broader anal region than does B. cumberlandensis. Further, the MA in B. stricklani does not curve forward as sharply as in B. cumberlandensis.
ETYMOLOGY. This species is named in honor of Mr. Dave Stricklan of Provo, Utah, who donated the holotype specimen for this study.
DISCUSSION. The well-spread wings of B. stricklani give supplementary support to the concept that Megasecoptera were unable to fold their wings over the dorsum of the abdomen and, therefore, that Carpenter (1963) was correct in placing Brodioptera in Megasecoptera. Further, the adequately preserved genitalia of this specimen closely resemble those of extant Ephemeroptera (Edmunds, et al., 1976) and should provide valuable information for future phylogenetic and evolutionary studies. It is interesting to note, as did Carpenter (1963), that such apparently apomorphic reduction in venation is present in an insect found so near the age (Namurian) in which the oldest winged insects have been discovered. ADDITIONAL MATERIAL. A second specimen consisting of genitalia and cerci has been collected near the same locality as the holotype. The specimen is considerably smaller than the holotype but has a similar genitalic structure. This specimen consists of both the part and counterpart that reveal the dorsum of the specimen including the dorsal attachment of the cerci to the abdomen. This second specimen is tentatively assigned to B. stricklani and is deposited as figured specimen #3243 in BYU paleontological collection.

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Nelson & Tidwell--Brodioptera 315 ACKNOWLEDGMENTS We thank Dave Stricklan for the generous donation of the holotype specimen as well as Victor Call for the second specimen.
Many thanks are given to Dr. J. Kukalovh-Peck of Carleton University for valuable information and numerous suggestions that greatly improved this paper and to Dr. A. T. Cross of Michigan State University for his assistance with stratigraphic problems. Additional thanks are extended to J. Chandler for help with literature searches and to N. Hebbert for inking the illustrations. SUMMARY A fossil megasecopteran of the family Brodiopteridae, Brodioptera stricklani n. sp., is described. This is the first report of a nearly complete specimen of the family and is the first insect recorded from the transitional Mississippian-Pennsylvanian (Namurian A and B) Manning Canyon Shale Formation of Utah in western North America.