Nannaria davidcauseyi Causey, 1950

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 davidcauseyi Causey, 1950 Fig. 34 Vernacular name: "David Causey’s Twisted-Claw Millipede"

Nannaria davidcauseyi Causey, 1950b: 194, figs 3, 4. Hoffman 1999: 366. Marek et al. 2014: 36. Means et al. 2021: S69.

Mimuloria davidcauseyi : Chamberlin and Hoffman 1958: 37. Hennen and Shelley 2015: 10, figs 4-8, 16, 17.

Material examined.

United States - Arkansas • 1 ♀; Newton County, Dismal Hollow ; 35.8506°N, - 93.2701°W; 2 Nov. 2013; pitfall trap; M. Skvarla leg.; NCSM NAN0539 • 2 ♂♂; Newton County, Steel Creek, Buffalo Nt River ; 36.0380°N, - 93.3402°W; 7 Nov. 2013; pitfall trap; M. Skvarla leg.; NCSM NAN0537. For detailed collection data see Suppl. material 7 .

Diagnosis.

Adult males of N. davidcauseyi are distinct from other Nannaria and the nearby N. castanea based on the following combination of characters: Gonopods. Gonopodal acropodite gently curving medially, and distal zone with medial and lateral flanges at 90° angle to solenomere, not with medial flange at 135° angle to solenomere as in N. castanea (Fig. 34A , red arrow). Acropodite with small medial flange near apex, not simple lacking flange as in N. castanea (Fig. 34A , red triangle). Telopodite basal zone height 1/2 length of acropodite. Prefemoral process pronounced, acicular, arising distantly from small blunt prefemoral spine, not from top of projected prefemoral spine as in N. castanea . Color. Hennen and Shelley (2015) described specimens of N. davidcauseyi as having clear paranota with irregular orange spots internally, and orange/pink collum margins.

Measurements.

♂ (VMNH, NAN0537): BL = 23.3, CW = 3.0, IW = 1.5, ISW = 0.6, B11W = 3.8, B11H = 2.2.

Variation.

Causey (1950b: 194) mentions that the male paratype of N. davidcauseyi has variation in the shape of both the prefemoral spine and the "keel at the end of the main blade" referring to the caudally-directed acropodite tip.

Distribution.

Known only from the northwest corner of Arkansas (Arkansas: Johnson and Newton counties, Fig. 129 ). Distribution area: 131 km2; status: MRE.

Ecology.

Causey (1950b) describes the habitat in which she and her husband found N. davidcauseyi as an eastern-facing hillside in an oak-hickory woodland. Two individuals of N. davidcauseyi were collected from Steel Creek Campground in Arkansas by M. Skvarla (NAN0537) who listed oak, hickory, American beech, and eastern red cedar as the primary tree species in the area ( Skvarla et al. 2015).

Etymology.

Causey (1950b) gave no explanation of her choice in name for this species, however it is presumed that this species is named after the author’s husband and its collector, Dr. David Causey.

Type locality.

United States, Arkansas, Newton County, about three miles northwest of Jasper.

Notes.

In the original description Causey (1950b: 194) designates a male holotype and one male and two immature paratypes collected by Dr. David Causey on 25 August 1950. Hennen and Shelley (2015: 10) refer to a female paratype and one immature paratype, which would suggest that Causey’s original identification of the female specimen as an immature was incorrect.

Figures

Figure 34. Nannaria davidcauseyi Causey, 1950 ♂ (VMNH, NAN 0537) left gonopod A anterior view; red triangle indicates small acropodite medial flange, red arrow indicates medial flange at apex B medial view C posterior view. Scale bar: 0.5 mm.

Figure 129. Distribution map of Nannaria minor species group collection localities west of the Appalachians.