Causeyella dendropus (Loomis)

Shear, William A., 2003, The milliped family Trichopetalidae, Part 1: Introduction and Genera Trigenotyla Causey, Nannopetalum n. gen., and Causeyella n. gen. (Diplopoda: Chordeumatida, Cleidogonoidea), Zootaxa 321, pp. 1-36 : 29

Causeyella dendropus (Loomis)

Fig. 22

Scoterpes dendropus Loomis, 1939:181 –182, fig. 9.

Types: Male holotype from Marvel Cave, Stone Co., Missouri, collected 27 June 1938 by Kenneth Dearolf (MCZ).

Diagnosis: Distinct from the two Arkansas species in having the colpocoxite branch finely fimbriate and the ectal coxite nearly as long as the mesal.

Male from Marvel Cave: Length, 12.5 mm, width, 1.1 mm. Unpigmented, eyeless. Segmental shoulders well developed, paranota­like; segmental setae slightly more than half pleurotergal width. Pregonopodal legs slightly enlarged, no podomeres modified. Gonopods ( Fig. 22 ) with large, bulbous coxae bearing fine, scale­like trichomes on anterior surfaces; coxal setae normal, acute, about 10 on each coxa, 3 basalmost form group slightly separated from others. Mesal coxites rodlike, evenly tapering, not spatulate, longer than ectal coxites. Ectal coxites basally broad in lateral view, with long anterior branch and two short posterior branches appearing as acute teeth. Fimbriate branch large, not extending anteriorly. Colpocoxites lobular, rounded, poorly sclerotized. Ninth legs typical, coxae laterally flattened, with vestigial glands, prefemora fusiform, small distal articles with distinct articulation and spine­like claw. Coxae 10 and 11 with glands, not modified.

Female from Marvel Cave: Total length, 13 mm, width 1.4 mm. Nonsexual characters as in male.

Distribution: Specimens examined (all FSCA): MISSOURI: Barry Co ,, Rockhouse Cave, 7 Sept. 1959, J. Tocklen, male. Stone Co., Marvel Cave, 2 April 1959, T. C. Barr, 6 males, 4 females; Gentry Cave, 3 May 1958, no collector, male, female; Old Spanish Cave, 26 January 1958, T. C. Barr, female. Taney Co.: Tumbling Creek Cave, Ozark Underground Laboratory, 21 June 1969, T. Aley, D. Walley, female. ARKANSAS: Newton Co.: Fitton Cave, 14 December 1963, R. Martin, male; 13 May 2001, G. Greening et al., male. Literature records: MISSOURI: Barry Co.: Buck Ridge Cave, Chimney Rock Cave, Sweet Potato Cave ( Gardner, 1986), Radium Cave (Elliott, 2002). The whereabouts of the specimens on which these records were based is not known, but they are within the range of C. dendropus and no other troglobitic trichopetalids occur in these counties. Sutton (1993) reported the species from Adams Cave #1, Oregon Co., but this is much closer to the range of C. causeyi than it is to that of dendropus . The specimen was immature and found in company with many more individuals of the widespread troglobitic tingupid milliped Tingupa pallida Loomis. McDaniel and Smith (1976) recorded dendropus from Newton and Carroll Cos., Arkansas. I have not seen any specimens from Carroll Co., and aside from the general statement from McDaniel and Smith (1976), no detailed collection data. I was inclined to dismiss the Arkansas records of dendropus as curatorial errors, but the discovery of a second male from Fitton Cave in 2001 seems to prove that dendropus indeed occurs in Arkansas, impinging on the range of the quite distinct younsteadtorum. This is also the only verified record from south of the White River, which theoretically could serve as a barrier between dendropus and youngsteadtorum . More collecting is needed in northwestern Arkansas (Benton, Carroll, Washington and Madison Counties) to delineate the ranges of the two species. Unfortunately 2001 collections of Causeyella from Joyce Cemetary Cave in Benton Co. were all females. The putative records of dendropus (as a Scoterpes ) from southeastern Missouri and from Illinois have already been discussed in the generic account; they probably are in error.

Figures

FIGURES 22 – 26. Causeyella dendropus Loomis, 22, gonopods, anterior view. C. causeyae, n. sp., 23, 24. 23, gonopods, anterior view. 24, male ninth legs, anterior view. C. youngsteadtorum, n. sp., 25, 26. 25, gonopods, anterior view. 26, male ninth legs, anterior view. Scale lines = 0.1 mm (100 µm) for Figs. 22, 23, 25, 0.5 mm (500 µm) for Figs. 24, 26.