Bifurcatella angulata, Shear & Richart & Wong, 2020

Shear, William A., Richart, Casey H. & Wong, Victoria L., 2020, The millipede family Conotylidae in northwestern North America, with a complete bibliography of the family (Diplopoda, Chordeumatida, Heterochordeumatidea, Conotyloidea), Zootaxa 4753 (1), pp. 1-78 : 58

Bifurcatella angulata , new species

Figs. 212, 213 , 216, 217

Types: Male holotype, male and female paratypes from WASHINGTON: Grays Harbor Co., FS-2153 5.3 mi N of Kelley Road, Canyon River basin, elev. 160 m., 47.3035°N, - 123.5081°W, collected 12 December 2004, by W. Leonard .

Diagnosis: The mesal branches of the anterior gonopods are about half the length of the lateral branches, which are curved at the tips and with a subterminal tooth. The mesal side of the posterior gonopod coxites is developed into a large, serrate flange ( Fig. 217 ) lying parallel to the tip of the pseudoflagellar branch. The pseudoflagellar branch is evenly curved from its base but midway makes a sharp angle before tapering to a thin tip. No other species has this combination of characters.

Etymology: The species name refers to the sharp, angular bend in the pseudoflagellar branch of the posterior gonopod coxite.

Description: Male paratype: Length, 9.5 mm. Twenty ocelli in triangular group. Metazonites with moderately well-developed shoulders, segmental setae curved, acute. Color pale tan marked darker purplish brown. Legpairs one and two reduced, three through six enlarged, seventh near size of postgonopodal legs; fifth femora conspicuously swollen, with long, distomesal knob. Anterior gonopods ( Figs. 212 , 216 ) long, narrow, mesal branch half length of lateral, cylindrical, blunt, slightly clavate, anterior branch slender, curved at tip, with subterminal tooth. Posterior gonopod coxite ( Fig. 213 , 217 ) with pseudoflagellar branch evenly curved from base, reflexed at acute angle, tapering to finely pointed tip, lying alongside serrate lamella on mesal side. Fimbriate branch relatively large. Main branch of coxite with two hooked terminal processes, subterminal tooth large, broad. Tenth coxae, eleventh prefemora as usual.

Female 9.0 mm long, nonsexual characters as in male.

Distribution: WASHINGTON: Grays Harbor Co., Middle Satsop Road 2 mi N of Brady near Satsop River, elev. 25 m., 47.0245°N, - 123.5196°W, under maple leaves, 3 January 2003, W. Leonard et al., mm ff. Lewis Co., Iron Creek Campground, FS-25 9.6 mi S of Randle, Gifford Pinchot National Forest, elev. 340 m., 46.4289°N, - 121.9868°W, 21 December 2003, W. Leonard, C. Richart, m.

Notes: molecular phylogenetics and integrative taxonomy of other poorly dispersing arthropods only known from the Southern Cascades and the Olympic Peninsula have found that these regions support populations that are independently evolving species (e.g., Richart and Hedin 2013). Thus, we recommend that future research evaluate our B. angulata hypothesis with molecular data.

Figures

FIGS. 208–213. Bifurcatella spp. Figs. 208, 209. Bifurcatella olympiana. Fig. 208. Right anterior gonopod, posterior view. Fig. 209. Left posterior gonopod coxite, posterior view. Figs. 210, 211. Bifurcatella hoh. Fig. 210. Right anterior gonopod, posterior view. Fig. 211. Left posterior gonopod coxite, posterior view. Figs. 212, 213. Bifurcatella angulata. Fig. 212, Anterior gonopods, posterior view. Fig. 213. Left posterior gonopod coxite, posterior view.

FIGS. 214–217. Bifurcatella spp. Figs. 214, 215. Bifurcatella hoh. Fig. 214. Anterior gonopods, posterior view. Fig. 215. Right posterior gonopod coxite, posterior view. Figs. 216, 217. Bifurcatella angulata. Fig. 216. Anterior gonopods, posterior view. Fig. 217. Right posterior gonopod coxite, posterior view.