PROC. ENTOMOL. SOC. WASH. 109(4), 2007, pp. 880-885 EUGNAMPTUS PROTERUS, N. SP. (COLEOPTERA: CURCULIONOIDEA: RHYNCHITIDAE), A TOOTH-NOSED SNOUT BEETLE IN MEXICAN AMBER George Poinar, Jr. and Alex E. Brown (GP) Department of Zoology, Oregon State University, Corvallis, OR 97331, U.S.A. (e-mail:
[email protected]); (AEB) 629 Euclid Avenue, Berkeley, CA 94708, U.S.A. Abstract. — a new species of tooth-nosed snout beetle, Eugnamptus proterus Poinar and Brown (Coleoptera: Curculionoidea: Rhynchitidae) is described from Mexican amber. Distinguishing characters include 1) the next to last strial row joins the last strial row near the middle of the elytra, 2) the presence of a median longitudinal ridge on the rostrum, 3) long, slender, erect dark setae on the frons, 4) a narrow, cylindrical prothorax and extended "neck" region and 5) unusually broad claw appendages. Based on the available literature, the closest described extant species is the Japanese E. awifrons Roel. A brief survey of fossil rhynchitids is presented. Key Words: Eugnamptus proterus, Rhynchitidae, Curculionoidea, Mexican amber The tooth-nosed snout beetles (Rhynch-itidae), often considered a subfamily of the leaf-roller weevils (Attelabidae), are a primitive group that Zimmerman (1994) assigned to his "convenience" Division Orthoceri based on their non-geniculate, straight antennae. There are over 1,000 described species in 49 genera, and while the range is cosmopolitan, most taxa are restricted to the warmer portions of the globe (Zimmerman 1994; Kuschel 1995; Thompson 1992; Voss 1941). The present study describes a represen-tative of this group in Mexican amber. Materials and Methods The specimen was obtained from an amber mine in the Simojovel area of Chiapas, Mexico. Locations of the Chia-pas mines and a synopsis of Mexican amber are presented in Poinar (1992). Amber from this region was produced by Hymenaea mexicana (Fabaceae) (Poinar and Brown 2002) and occurs in lignitic beds among sequences of primarily marine calcareous sandstones and silt. The amber is associated with Balumtun Sandstone of the early Miocene and the La Quinta formation of the Late Oligocene with radiometric ages from 22.5 to 26 million -years (Berggren and Van Couvering 1974). Since the amber is secondarily deposited in these marine formations, it is somewhat older than the above dates. The piece of amber containing the fossil is 1 1 mm long, 5 mm wide and 4 mm deep. The body length measure-ment was a direct line from the tip of the elytra to the anterior border of the eyes (excluding the rostrum). Body width was taken at the widest part of the elytra, head length was measured as the portion of the head bordered by the eyes, head width at the widest point between the eyes, frons width was the head width at
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