Transactions of the Kansas Vol. 112, no. 3/4 Academy of Science p. 211-214 (2009)

A from Stewart Valley, Nevada (Raphidioptera: )

Michael S. Engel Division of Entomology (Paleoentomology), Natural History Museum, and Department of Ecology & Evolutionary Biology, 1501 Crestline Drive – Suite 140, University of Kansas, Lawrence, Kansas 66049-2811 ([email protected])

The first fossil snakefly from the Neogene of (mid-Miocene of Nevada) is described and figured. Agulla mineralensis Engel, new species, is represented by an isolated hind wing and is more similar to modern Nearctic in venation than to most Old World species in contrast to some of the Paleogene species which seem to represent a different faunal composition.

Keywords: Miocene, Neuropterida, Nevada, Raphidioptera, snakefly, , Tertiary

Introduction I provide a brief account of this new find and provide some commentary on the possible While snakeflies (Raphidioptera) today are one affinities of this new species. of the least diverse lineages of holometabolous , during the geological past the order Systematic Paleontology was apparently much more diverse. During the Mesozoic a diversity of raphidiopteran lineages Family Raphidiidae Latreille is known to have existed and snakeflies were Subfamily Raphidiinae Latreille found in environments dramatically different Genus Agulla Navás from the ecological norms of their modern Agulla mineralensis, new species counterparts (Grimaldi and Engel, 2005). (Fig. 1) While such a diversity of fossil forms is well known, Tertiary snakeflies from North Diagnosis ― The fossil can be distinguished America are, like the modern species, not from other North American fossil raphidiids common (except for one Eocene species which by the more elongate pterostigma (typically is relatively abundant at one site: Engel, in 2–4.5 times longer than wide in most Tertiary prep.). Hitherto now, 13 fossil species have species except Raphidia mortua Rohwer and R. been documented from North America (one funerata Engel where the pterostigma is 7 and undescribed: Table 1), eleven of which are 6.5 times longer than wide, respectively), Sc from the Tertiary and all of those are restricted terminating well proximal to pterostigmal base, to the Paleogene. the more highly branched apical terminus of R (beyond the pterostigma), the larger number Recently it was brought to my attention that a of radial cells, the more elongate shape of the single snakefly had been recovered from the radial cells, and the longer stem of M. mid-Miocene paper shales of Stewart Valley, Nevada. This site is rich in fossil insects, Description ― Hind wing (determined as although few have been described or studied in hind wing by distinct separation of M and Cu detail (Engel et al., 2009). The Stewart Valley stems in proximal portion of wing and the snakefly represents the first definitive Neogene linear nature of the stem of A): Total length record of Raphidioptera for North America (as preserved) 10.9 mm, maximum width (as and is therefore of some significance. Herein preserved) 3.8 mm; wing apparently hyaline, 212 Engel

Fig. 1. Agulla mineralensis Engel, new species (CAS #539). Preserved wing length 10.9 mm, maximum width 3.8 mm. pterostigma slightly infumate by comparison 2mp-mp proximad forking in anterior branch to remainder of wing; preserved portion of of MP, separated from fork by slightly less than costal space about twice width of subcostal crossvein length. space; Sc terminating on anterior margin well before pterostigma (distance from termination Holotype ― Hind wing; #539, USA: Nevada, to pterostigmal base nearly two-thirds of Mineral County, Stewart Valley, Pacific Union pterostigma length); pterostigma elongate, Site, UTMG [Universal Transverse Mercator about 6.25 times longer than wide (length Grid]: Zone 11, 418.130 E x 4270.090 N, measured along anterior margin of wing); 38°34’38’’ N x 117°56’23’’ W, BLM Site #26- pterostigma bordering about two-thirds of 30-09-335, middle Miocene, Late Barstovian adjacent radial cell; r-rs+ma confluent with [ca. 14–14.5 Ma] paper shales; deposited in rs+ma-mp, the latter of which is only minutely the Department of Entomology, California distad 1mp-mp; 1r-rs meeting anterior branch Academy of Sciences, San Francisco, of Rs shortly after first Rs-Rs fork after Rs-Ma California. separation; 2r-rs just beyond pterostigma apex; R with three superior branches forming beyond Etymology ― The specific epithet is based on pterostigma and before termination near the county from which the fossil originates, wing apex; 2r-rs slightly distad 1rs-rs, itself Mineral County, Nevada. slightly distad 1rs-ma, 1rs-ma slightly more distad ma-mp; Rs with two primary branches, Comments ― Agulla mineralensis differs anterior branch apically twigging to three from other Tertiary raphidiids in that the stem apical branches; stem of Rs one-third length of of M is much longer before the separation into MA stem; stem of M less than one-half length MA and MP, whereas this condition is reversed of M stem; stem of MP shorter than MA stem; in most species where the hind wing is known M forming two apical twigs apical to rs-ma; such as R. creedei Carpenter (cf. Carpenter, first MP cell shorter than second MP cell, 1936: fig. 12). In addition, the pterostigma first more about two-thirds length of second; is more elongate, resembling in this respect Transactions of the Kansas Academy of Science 112(3/4), 2009 213

R. mortua and R. funerata, but in these latter share more similarities (perhaps superficially) species there are fewer cells (particularly with modern genera from the Old World fauna radial cells), less apical twigging of the veins, (cf. figures in Aspöck et al., 1991). Until more and (where the hind wing is known), the stem complete material of all Tertiary snakeflies of M is much shorter, with the stems of MA is recovered and the fauna suitably revised and MP elongate before their fusion with it is nearly impossible to determine true Rs or branching, respectively (Carpenter, phylogenetic affinities of these species, but 1936; Engel, 2003). It is difficult to compare it would appear that there was a shift in the snakefly species solely on the basis of hind faunal composition of Raphidioptera around or wing venation owing to variation observable sometime shortly after the Eocene-Oligocene among the modern fauna. Nonetheless, A. transition. Such a shift would correspond mineralensis shares some similarity with with climatic cooling taking place during this modern North American species such as A. era which likely played a significant role in astuta (Banks), A. arnaudi (Aspöck), and A. shaping the modern North American snakefly modesta aphynphte Aspöck owing to the shape fauna. The Stewart Valley paleoenvironment of the pterostigma and the highly branched represented a large lake, formed by the apical terminus of R. None agree in specific anastomosing of several smaller lakes and details (e.g., in A. arnaudi r-rs meets Rs before ponds within the drainage system. During it branches to form the three apical radial cells its maximum extent Stewart Valley Lake was such that the anterior and posterior of these perhaps up to 5 miles wide (East to West) and three cells meet proximally; the pterostigma 10 miles long (North to South) and had fine in all three is proportionally shorter than in material regularly brought in and deposited A. mineralensis), but certainly there are more uniformly, with thin layers of mud forming similarities in wing venation between A. in the depths of the lake (resulting in today’s mineralensis and the modern North American paper shales). The surrounding environment fauna than that of the Paleogene species which was likely well forested and apparently of 21 Engel much higher elevation than that of the current Carpenter, F.M. 1936. Revision of the area today (e.g., Wolfe et al., 1997), both Nearctic Raphidiodea (Recent and fossil). consistent with a relatively modern snakefly Proceedings of the American Academy of species occurring in this habitat. Arts and Sciences 71(2):89–157. Engel, M.S. 2003. A new Eocene-Oligocene Acknowledgements snakefly from Florissant, Colorado (Raphidioptera: Raphidiidae). Transactions I am grateful to W.J. Pulawski for making the of the Kansas Academy of Science 106(3– specimen reported herein available for study, 4):124–128. and to R.J. Beckemeyer and J.E. Jepson for Engel, M.S., Hinojosa-Díaz, I.A. and reviews of the manuscript. Partial support Rasnitsyn, A.P. 2009. A honey bee from the for this work was provided by U.S. National Miocene of Nevada and the biogeography Science Foundation grant DEB-0542909. of Apis (Hymenoptera: Apidae: Apini). This is a contribution of the Division of Proceedings of the California Academy of Entomology, University of Kansas Natural Sciences, Series 4, 60(3):23–38. History Museum. Grimaldi, D. and Engel, M.S. 2005. Evolution of the Insects. Cambridge University Press; Literature Cited Cambridge, UK; xv+755 pp. Wolfe, J.A., Schorn, H.E., Forest, C.E. and Aspöck, H., Aspöck, U. and Rausch, H. Molnar, P. 1997. Paleobotanical evidence 1991. Die Raphidiopteren der Erde: for high altitudes in Nevada during the Eine monographische Darstellung der Miocene. Science 276(5319):1672–1675. Systematik, Taxonomie, Biologie, Ökologie und Chorologie der rezenten Raphidiopteren der Erde, mit einer zusammenfassenden Übersicht der fossilen Raphidiopteren (Insecta: Neuropteroidea). Goecke and Evers; Krefeld, Germany; vol. 1: 730 pp, vol. 2: 550 pp.