Nannaria ambulatrix, Means & Hennen & Marek, 2021

Means, Jackson C., Hennen, Derek A. & Marek, Paul E., 2021, A revision of the minor species group in the millipede genus Nannaria Chamberlin, 1918 (Diplopoda, Polydesmida, Xystodesmidae), ZooKeys 1030, pp. 1-180 : 1

Nannaria ambulatrix sp. nov. Figs 88 , 89 Vernacular name: "The Big Walker Twisted-Claw Millipede"

Material examined.

Holotype: United States - Virginia • ♂; Smyth County, west slope of Big Walker Mtn., VA-16; 36.9112°N, - 81.5317°W; elev. 1054 m; 9 Sept. 2014, J. Means leg.; hand collected; VTEC MPE00178 .

Paratypes: United States - Virginia • 1 ♀; same data as for holotype; VTEC, MPE00174 • 2 ♂; same data as for holotype; VTEC MPE00166 , 167 • 2 ♂ and 1 ♀; same data as for holotype; VMNH, MPE00169 , 179, 180.

Other material.

United States - Virginia • 1 ♂ Washington County, Mendota, steep hillside beside intersection of CR 614 and CR 620, near Holston River ; 36.7146°N, - 82.2806°W; elev. 381 m; 12 Feb. 2018; hand collected J. Means, D. Hennen, P. Marek leg.; VTEC MPE03789 • 1 ♂ ; Washington County, Mendota, Anderson Rd. ; 36.7219°N, - 82.2771°W; elev. 464 m; 11 Feb. 2017; J. Means, D. Hennen, V. Wong leg.; hand collected; VTEC MPE02286 • 1 ♂ Washington County, Mendota , VA-620, ca.1 road km NE jct w/VA-614; 36.7192°N, - 82.2775°W; elev. 287 m; 12 Feb. 2018; J. Means, D. Hennen, P. Marek leg.; hand collected; VTEC MPE04240 • 3 ♀ ; same collection data as for preceding; VTEC MPE03797 , 3799, 4270 • 5 ♂♂ ; same collection data as for preceding; VTEC MPE03794 , 3800-3803 • 2 ♀♀ ; Washington County, Mendota, Fugate Gap ; 36.7285°N, - 82.3026°W; elev. 609 m; 12 Feb. 2018; hand collected; J. Means, D. Hennen, P. Marek leg.; VTEC MPE03795 , 3804 • 1 ♂ Washington County, DF site off VA. 620, 1 km E of Mendota ; 36.7108°N, - 82.2904°W; 11 June 1998; VMNH Survey leg.; VMNH NAN0137 • 1 ♂ ; Washington County, DF site off VA. 620, ca. 2 mi NE of Mendota ; 36.7313°N, - 82.2760°W; 8 Aug.-2 Dec. 1997; VMNH Survey leg.; VMNH NAN0307 • 1 ♂ ; Washington County, Abram's Fall , ca. 2 mi SW of Benhams, end of VA. 614; 36.6580°N, - 82.2439°W; 15 June 1960; R. Hoffman leg.; VMNH NAN0308 • 1 ♂ ; Smyth County, Hungry Mother State Park, inside Hemlock Haven conference center; 36.8914°N, - 81.5249°W; 5 Aug. 2009; J. Beard leg.; VMNH NAN0124 • 1 ♂ ; Smyth County, Big Walker Mountain, ca. 3 mi west of Hungry Mother State Park on VA. 16, west slope; 36.9104°N, - 81.5333°W; 9 Sept. 1956; R. Hoffman leg.; VMNH NAN0310. For detailed collection data see Suppl. material 7 .

Diagnosis.

Adult males of Nannaria ambulatrix sp. nov. are distinct from other Nannaria and the co-occurring N. aenigma , based on the following combination of characters: Gonopods. Gonopodal acropodite very slightly curving medially before apex, nearly straight (Fig. 88 ). Distal zone short, directed dorsomedially, with large, triangular lateral flange (Fig. 88A , red arrow), not simple as in N. terricola , or serpentine as in N. aenigma . Telopodite basal zone large, subequal to length of acropodite, not ca. 1/2 length as in N. terricola , or ca. 1/6 length as in N. aenigma . Telopodite basal zone straight, without lateral bulge as in N. terricola . Prefemur with medially curving prefemoral process, not acicular, straight as in N. terricola and N. aenigma . Prefemoral process arising dorsomedially from small, sharp, prefemoral spine (Fig. 88A , red triangle), not arising from prefemur or with spine reduced to a shelf-like ridge as in N. terricola . Color. Tergites with either white/light yellow or orange paranotal spots (Fig. 89 ). Gray to black background. Dorsum of collum smooth with either white/light yellow or orange margin, depending on color morph.

Measurements.

♂ holotype (VTEC, MPE00178): BL = 28.0, CW = 4.3, IW = 2.2, ISW = 1.0, B11W = 5.0, B11H = 3.4; ♀ paratype (VTEC, MPE00174): BL = 32.3, CW = 4.3, IW = 2.5, ISW = 0.9, B11W = 5.6, B11H = 3.7.

Variation.

Specimens of Nannaria ambulatrix sp. nov. collected from the top of Clinch Mountain (36.7285°N, - 82.3026°W, Elev. 845 m) were noticeably smaller than those collected from other localities, suggesting a possible adaptation in the higher elevation population to a drier and/or less suitable habitat. This is the only instance of a stark difference in size between populations of the same species that we have observed in Nannaria .

Distribution.

Known only from southwestern Virginia (Russell, Smyth and Washington counties; Suppl. material 7; Fig. 126 ). The distribution of N. ambulatrix sp. nov. follows the Brumley and Little Brushy Mountain ranges. Distribution area: 488 km2; status: MRE.

Ecology.

Nannaria ambulatrix sp. nov. individuals were collected from mesic broadleaf deciduous forests, often in groups occupying 1-2 m2 patches, suggesting that the species is distributed in a highly aggregated manner.

Etymology.

This species is named for its type locality (Big Walker Mountain), and was informally proposed by R.L. Hoffman. The specific name is a noun in apposition derived from the Latin ambulo, to walk, and trix, 'a female doer of an action.'

Type locality.

United States, Virginia, Smyth County, west slope of Big Walker Mtn., VA-16, 36.9112°N, - 81.5317°W.

Figures

Figure 88. Nannaria ambulatrix sp. nov. holotype ♂ left gonopod (MPE 00178) A anterior view; red arrow indicates large, triangular lateral flange; red triangle indicates prefemoral process arising dorsomedially from prefemoral spine B medial view C posterior view. Scale bar: 0.5 mm.

Figure 89. Nannaria ambulatrix sp. nov. coloration A non-type ♀ (VTEC, MPE 03795) white / tan paranota B paratype ♂ (VTEC, MPE 00167) orange paranota. Scale bars: 4.0 mm.

Figure 126. Distribution map of Nannaria minor species group collection localities in the central Appalachians.