Color profile: Disabled Composite Default screen 100 The milliped genus Oriulus Chamberlin (Julida: Parajulidae) Rowland M. Shelley Abstract: The milliped genus Oriulus Chamberlin is composed of one anatomically uniform species for which venustus Wood, 1864, is the oldest available name. The species has the greatest distribution of any known North American dip- lopod, covering three-fourths of the continental United States and adjacent southern Canada. The following binomials are placed in synonymy under O. venustus, all constituting new synonymies: Parajulus rugosus Bollman; O. medianus, O. delus, O. eutypus, O. notus, and O. georgicolens, all authored by Chamberlin; O. grayi Causey; and O. grandiceps Loomis. A neotype is designated for Iulus venustus from West Frankfort, Franklin County, Illinois. Résumé : Chez les millipèdes, le genre Oriulus Chamberlin contient une seule espèce, d’anatomie uniforme, pour laquelle le nom venustus Wood, 1864 est le plus ancien. Parmi les diplopodes nord-américains, c’est l’espèce qui a la répartition la plus étendue, recouvrant les trois-quarts des États-Unis et toute la partie adjacente du sud du Canada. Les binômes suivants deviennent de nouveaux synonymes d’O. venustus: Parajulus rugosus Bollman; O. medianus, O. delus, O. eutypus, O. notus et O. georgicolens, toutes de Chamberlin; O. grayi Causey et O. grandiceps Loomis. Un néotype est désigné pour représenter Iulus venustus; il provient de West Frankfort, comté de Franklin, Illinois. [Traduit par la Rédaction] 109 Introduction Shelley At the generic level, the distribution of Oriulus, while striking, does not warrant superlatives. Other Nearctic diplopod This contribution is the fourth in a series of papers on rep- genera have substantial if not greater distributions, witness resentatives of the Parajulidae, the dominant Nearctic diplo- Polyxenus (Polyxenida: Polyxenidae) (Chamberlin and Hoffman pod family, all to date on genera in the tribe Aniulini (Shelley 1958; Hoffman 1999), Abacion (Callipodida: Abacionidae) 2000a, 2000c, 2000d). The previous works addressed poly- (Shelley 1984), Narceus (Spirobolida: Spirobolidae) (Keeton specific taxa with both localized and widely ranging species; 1960; Hoffman 1999), Cleidogona (Chordeumatida: Cleido- Oriulus Chamberlin differs in having only one species with gonidae) (Shear 1972), and Underwoodia (Chordeumatida: a vast distribution, covering three-fourths of the continental Caseyidae); the latter genus also occurs in Far Eastern Russia United States and the southern periphery of the adjacent (Shelley 1992). At the specific level, however, the range provinces of Canada. I stated (Shelley 1988) that there were must be characterized as immense. Narceus americanus few differences between the nine nominal species of Oriulus (Beauvois) covers much of North America east of the central but deferred making taxonomic changes until the type speci- Plains, extending from southern Quebec and eastern Ne- mens were examined and compared. Having now done this braska to the south Florida Keys and south-central Texas and drawn the gonopods of each, I find that they are virtu- (Keeton 1960; Shelley 1988; Hoffman 1999; plus unpub- ally indistinguishable, leaving no doubt as to their conspec- lished records of the author), but this pales in comparison ific statuses. I have also examined over 800 preserved specimens with the area of Oriulus venustus, which also encompasses in 25 American, Canadian, and British repositories and again the central and western Plains, and extends across the south- found virtually no differences and certainly nothing warrant- ern Rocky Mountains onto the Colorado Plateau. Similarly, ing taxonomic recognition, even at the subspecific level. The Underwoodia iuloides (Harger) is widespread east of the lack of anatomical differentiation in a species covering such Rocky Mountains, ranging from Labrador, Newfoundland, a vast area is truly astonishing; no other known North Amer- and New York to Saskatchewan, North Dakota, and north- ican species has so great a distribution and is so anatomi- eastern New Mexico (Shelley 1992), but this too is dwarfed cally constant. The oldest available name is venustus Wood, by O. venustus, which extends down the Atlantic seaboard 1864; the original type specimens no longer exist, so I desig- into the southeastern states and spreads westward into south- nate a neotype from the locality suggested by N.B. Causey (in central Montana and the “Four Corners” area of the south- Chamberlin and Hoffman 1958). west. In the northern Plains and southern Rocky Mountains, O. venustus seems rather common, to the point that it may be the dominant diplopod, but it occurs sporadically in the Received 1 May 2001. Accepted 29 October 2001. Published southeast, as states like North Carolina and Virginia have on the NRC Research Press Web site at http://cjz.nrc.ca on been heavily investigated and produced only a handful of 7 February 2002. samples. With only one anatomically uniform species, this R.M. Shelley. Research Laboratory, North Carolina State revision of Oriulus becomes primarily a report of locality re- Museum of Natural Sciences, 4301 Reedy Creek Road, cords. Abbreviations of sources of preserved study material Raleigh, NC 27607, U.S.A. (e-mail: [email protected]). are as follows: Can. J. Zool. 80: 100–109 (2002) DOI: 10.1139/Z01-205 © 2002 NRC Canada J:\cjz\cjz80\cjz-01\Z01-205.vp Wednesday, January 30, 2002 11:50:12 AM Color profile: Disabled Composite Default screen Shelley 101 AMNH American Museum of Natural History, New York, Diagnosis New York, U.S.A. A genus of moderate-sized Aniulini, ca. 19–26 mm long ANSP Academy of Natural Sciences of Philadelphia, and 1.5–2.5 mm wide, with 48–54 segments in adults. Ster- Pennsylvania, U.S.A. num of segment 8 greatly enlarged, extending dorsad well BMNH The Natural History Museum, London, U.K. into body cavity with enlarged medial lobe extending anteriad CMN Canadian Museum of Nature, Ottawa, Ontario, and overlapping most of segment 7, widely separating gonopod Canada pairs of latter segment. Anterior gonopod coxae flat or slightly CMNH Carnegie Museum of Natural History, Pittsburgh, elevated in midline, without syncoxal lobes; lateral syncoxal Pennsylvania, U.S.A. process expanded into broad leaflike structure, margin smooth or slightly angular. Posterior gonopod with moderately long, CNC Centre for Lands and Biological Resources upright prefemoral process, extending for ca. 2/3 of length Research, Agriculture and Agri-Food Canada, of telopodite; latter a doubly curved, somewhat sigmoid struc- Ottawa, Ontario, Canada ture without accessory branches. Cyphopods with gynaspis DC Natural Science Division, Dixie College, St. George, very broad and lobed, extending strongly dorsad between Utah, U.S.A. valves, not extending appreciably ventrad. FMNH Field Museum of Natural History, Chicago, Illinois, U.S.A. FSCA Florida State Collection of Arthropods, Gainesville, Distribution Florida, U.S.A. Covering around three-fourths of the continental United States and adjacent southern Canada, extending from south- INHS Illinois Natural History Survey, Champaign, Illinois, ern Quebec and central Alberta in the north to southern Lou- U.S.A. isiana and central New Mexico in the south; east–west the JAB Private collection of J.A. Beatty, Carbondale, Illinois, area extends from Massachusetts and the Outer Banks of U.S.A. North Carolina to the Colorado Plateau and Wasatch Moun- MCZ Museum of Comparative Zoology, Harvard tains of Utah, the Rocky Mountains of Idaho, Montana, and University, Cambridge, Massachusetts, U.S.A. Wyoming, and the western Plains of Alberta (Fig. 7). MPM Milwaukee Public Museum, Milwaukee, Wisconsin, U.S.A. Species MTSU Biology Department, Montana State University, One. Bozeman, Montana, U.S.A. NCSM North Carolina State Museum of Natural Sciences, Raleigh, North Carolina, U.S.A. Relationships NDSU Entomology Department, North Dakota State While four genus-group taxa have been revised, taxo- University, Fargo, North Dakota, U.S.A. nomic investigations of the Aniulini are still in progress, so NMNH National Museum of Natural History, Smithsonian affinities among tribal genera have not been fully resolved. Institution, Washington, D.C., U.S.A. Nevertheless, I believe that Oriulus is most closely related to Aniulus Chamberlin because of gonopodal similarities and PMA Provincial Museum of Alberta, Edmonton, Alberta, the shared enlargement of the sternum of segment 8 and its Canada medial lobe, which extends anteriad between at least part of ROM Royal Ontario Museum, Toronto, Ontario, Canada the gonopods and over part of segment 7, although the struc- RSM Royal Saskatchewan Museum ture is larger and extends farther anteriad in Oriulus.Onthe TMM Texas Memorial Museum, Austin, Texas, U.S.A. posterior gonopods, the prefemoral process and telopodite UL Biology Department, University of Louisville, are close together or overlapping basally in both genera, and Louisville, Kentucky, U.S.A. the general curvatures of the telopodites are similar, being UNM Biology Department, University of New Mexico, somewhat sigmoidal and passing through more than one ver- Albuquerque, New Mexico, U.S.A. tical plane in Oriulus as opposed to co-planar in Aniulus. UVT Zoology Department, University of Vermont, Burlington, Vermont, U.S.A. Oriulus venustus (Wood, 1864) UWY Department of Plant, Soil, and Insect Sciences, Figs. 1–7 University of Wyoming, Laramie, Wyoming, U.S.A. Iulus venustus Wood, 1864: 10–11; 1865: 196–197, VMNH Virginia Museum