Rowlandesmus dentogonopus Shear & Marek, 2021

Shear, William A. & Marek, Paul E., 2021, Three new genera and eighteen new species of miniature polydesmid millipedes from the northwestern United States (Diplopoda, Polydesmida, Polydesmidae), Zootaxa 4975 (1), pp. 81-126 : 113

Rowlandesmus dentogonopus Shear & Marek , n. sp.

Figs 91–95 , 132

Type. male holotype from 2 mi north of Melrose , Douglas Co., Oregon, 43.2084°, -123.4612°, 400 ft asl, collected 7 February 1972 by E. M. Benedict. The holotype is mounted on SEM stubs WS33-3 and WS33-4, deposited in CAS .

Diagnosis. The gonopod has a hood-like structure with numerous acute teeth overhanging the bent terminal zone. The "kink" in the gonopod is basal to the division of the terminal zone and the pulvillus is more distal than in the preceding species.

Etymology. The species epithet is an adjective referring to the teeth on the gonopod.

Description. Male holotype. Length about 5.5 mm, greatest width 0.62 mm. Head ( Fig. 91 ) densely setose, cuticle alveolate. Collum with anterior marginal row of 20 setae ( Fig. 91 ). Anterior metazonites with three rows of setae, transitioning to four rows about ring 5, setal tubercles becoming almost obsolete on midbody to posterior rings ( Fig. 95 ). Alveolate cuticle absent from metazonite posterior to collum. Epiproct ( Fig. 92 ) swollen, short, slightly decurved, with some slight alveolate cuticle. Anterior legs crassate, tarsi with sphaerotrichomes. Gonopod ( Figs 93, 94 , 132 ) with moderately inflated prefemorite. Acropodite short, robust, basally swollen. Pulvillus (p, Fig. 93 ) distal, just below deflexed part of terminal zone, pulvillar process absent. Terminal zone bifurcate. Longer distal process (x, Fig. 93 ) broad at base, then curved, narrowed, bent posteriorly at acute angle; shorter basal process (y, Fig. 93 ) distal to “kink (k, Fig. 93 )”. Bent portion of terminal zone overhung by hood-like structure bearing numerous teeth, teeth larger on margin. Females unknown.

Distribution. Known only from the type locality.

Figures

FIGURES 91–95. Rowlandesmus dentogonopus, n. gen., n. sp. 91. Head and anterior rings, dorsal view. 92. Pygidium, lateral view. 93. Right gonopod, mesal view. 94. Left gonopod, lateral view. 95. Midbody ring, dorsal view. SEM stub WS33-4. Abbreviations: k, “kink” in gonopod, p, pulvillus; x, y, processes of terminal zone.

FIGURES 127–132. Drawings of gonopods of polydesmid species. 127. Tip of gonopod of Retrorsioides castellum, n. sp., mesal view. 128. Right gonopod of Retrorsioides linnensis, n. sp., lateral view. 129. Left gonopod of Retrorsioides kittitas, n. sp., lateral view. 130. Right gonopod of Retrorsioides bannerti, n. sp., lateral view. 131. Right gonopod of Rowlandesmus millicoma, n. sp., mesal view. 132. Right gonopod of Rowlandesmus dentogonopus, n. sp., lateral view. Abbreviations: adp, anteriorly directed process; p, pulvillus; pf, prefemorite; pp, pulvillar process; tz, terminal zone.