Taiyutyla caseophila Shear & Crawford, 2019

Shear, William A. & Crawford, Rodney L., 2019, Cave millipedes of the United States. XVI. Two new species from Oregon Caves National Monument, Oregon (Chordeumatida, Conotylidae and Caseyidae), Zootaxa 4674 (5), pp. 571-580 : 572-574

Taiyutyla caseophila Shear & Crawford , new species

Figs. 1–5

Material examined: Type specimens. Male holotype ( UWBM) and 12 male and five female paratypes from Oregon Cave, Oregon Caves National Monument, Josephine Co., Oregon (42.0974º N, -123.4099º W) , collected from pitfall traps set at different in-cave sites from 24 December 1992 to 21 August 1993 by R. Reed and J. Roth ( UWBM). The holotype and several paratypes were collected at station #11 ( Ghost Room ) ; additional paratypes were collected at stations #3 (connecting tunnel), #5 (Imagination Room; 2 male paratypes) and #13 ( Wedding Cake Room ; 4 male paratypes and 2 juveniles).

Diagnosis. Distinct from other Oregon species of Taiyutyla in the shape of the gonopods and in having only the pregonopodal legpair 7 with a modified femur, which is flattened and broadened distally and with a distinctly curved distomesal apophysis ( Figs. 3 , 5 ).

Description. Male paratype. Length, 11 mm, greatest width, 1.0 mm. Subtriangular eyepatch of 21 or 22 distinct but unpigmented ocelli (in preserved specimens, ocelli pigmented in life—see below). Metazonite shoulders weakly developed. Segmental setae about equal in length to half metazonite width. Color (after> 20 years of preservation) pale yellow. Pregonopodal legs enlarged, but pairs one to six usually without femoral modifications (the sixth legs of some males have slightly thickened femora with a small swelling on the mesal side). Legpair seven with femora distally broadened, flattened, with prominent distomesal apophysis ( Figs. 3 , 5 ). Anterior gonopods long, slender, curving posteriorly, abruptly narrowed distally, narrowly acuminate ( Figs. 1, 2 ). Posterior gonopodal coxites stout, broad, with mesal T-shaped branch short. Proximal part of posterior gonopod acuminate, with small basal tooth, distal part complexly fimbriate. Body of posterior gonopod coxite with subterminal fimbriate area, terminating in distal hook-like structure ( Figs. 2 , 4 ). Tenth legpair with coxal glands, eleventh legpair with basal, curved apophyses on prefemora.

Female paratype. Length, 11.4 mm, width 1.1 mm. Nonsexual characters as in male.

Distribution. Known only from the type locality and other locations within Oregon Cave.

Notes. The femoral knobs of the seventh legs bear a mesal group of about 20 small pits. Under high magnification, at least some of these pits have numerous small pores within them ( Fig. 5 ). These pits and pores have not been found on the femoral knobs of any other Taiyutyla species so far described, and a scanning electron microscopy study of several species for a forthcoming monograph on northwestern North American conotylids did not show the pits on any examined species. The pores within the pits are only about 1–2 µm in diameter and so are likely the outlets of unicellular glands, but their function remains unknown.

Specimens were collected throughout the dark zone of the cave (but included sites on the commercial tour route, lighted during tours), during each month from August 1992 to August 1993. In all, over 200 specimens were collected, all but 5 by cheese-baited pitfall traps. The traps, which were baited with spreadable Limburger cheese smeared on the underside of a rock covering the trap, were left in place for periods ranging from 2 to 4 weeks. No specimens were found at the cave entrance or twilight sites. Of the five hand-collected specimens, one was found on the cave wall, one under a half-imbedded rock, and two associated with mammal scats (one next to a moldy Neotoma scat and one apparently feeding on a Peromyscus scat, or its microflora). Observations of freshly collected specimens indicated pale yellowish cuticular pigmentation and black, pigmented ocelli. Epigean species of Taiyutyla are usually well pigmented, tan to brown, and with dark purplish brown cuticular mottling.

Shear (2011) mentioned a conotylid collected in the Marble Mountain Wilderness caves of Siskiyou Co., California, but only females were available for study.

Etymology. The species epithet (Latin) is an adjective meaning “cheese-loving” and refers to the capture of most known specimens in cheese-baited traps.

Figures

FIGURES 1–3. Taiyutyla caseophila, new species. Fig. 1. Anterior and posterior gonopods, anterior view; agp, anterior gonopod; pf9, prefemur of posterior gonopod; s9, sternum of posterior gonopods. Fig. 2. Anterior and posterior gonopods, posterior view; agp, anterior gonopod; cx9, coxite of posterior gonopod; T, limb of T-shaped process. Fig. 3. Left leg 7, anterior view.

FIGURES 4, 5. Taiyutyla caseophila, new species. Fig. 4. Tip of posterior gonopod coxite, posterior view; f, fimbriate region; h, hook-like process; T, limb of T-shaped process. Fig. 5. Pits on femoral knob of leg 7, anterior view.