Amastigogonus elephas, Mesibov, Robert, 2017

Mesibov, Robert, 2017, Iulomorphid millipedes (Diplopoda, Spirostreptida, Iulomorphidae) of Tasmania, Australia, ZooKeys 652, pp. 1-36 : 7-9

Amastigogonus elephas sp. n. Fig. 6B

Holotype.

Male, Mt Elephant, Tas, -41.6338 148.2421 ± 25 m, 420 m a.s.l., 13 May 2016, R. Mesibov, QVM 23:54519.

Paratypes.

3 males, 3 females, details as for holotype, QVM 23:54520; 1 male, same locality but -41.6244 148.2425 ± 250 m [label "FP 034 910" (= 55G 603400 5391000, AGD66)], 19 January 2002, R. Mesibov and T. Moule, QVM 23:54369.

Other material.

6 males from 5 unique localities; details in Suppl. material 1.

Diagnosis.

Like Amastigogonus verreauxii in having a telopodite with a subquadrate extension of the posterobasal margin and a posteriorly curving pseudoflagellum; distinguished from Amastigogonus verreauxii in the pseudoflagellum having a small, tooth-like, distally directed extension basal to the posterobasally directed tip.

Description.

Mature males observed with (47+3) rings, 3.2 mm midbody diameter to (69+0) rings, 3.6 mm. Cardo not deeper posteriorly. Leg 7 (only) with elongated coxa. Prefemoral pad ca 1/2 femur length. Striae on posterior metazonites reaching ca 3/4 of ozopore height.

Coxite process on anterior gonopod (Fig. 6B) with small portion of posterodistal margin extended as rounded tab (Fig. 6B; t), sharply folded over laterally; process nearly reaching level of telopodite apex. Telopodite with posterobasal surface produced posteriorly as subquadrate flange (Fig. 6B; fl) and with single row of prominent setae on posterior side of medial thickening. Pseudoflagellum with small rounded swelling adjoining base posteromedially; arising at 1/3-1/2 telopodite height, ca 2/3 width of telopodite at base, slightly curving posteriorly, slightly expanded posteriorly at 1/3-1/2 pseudoflagellum height, apically with small, rounded, distally directed, tooth-like extension, the prostatic groove opening on posterobasally directed pseudoflagellum tip.

Distribution.

Eucalypt forest at the eastern end of the Fingal Valley on the Tasmanian East Coast (Fig. 7C), to at least 700 m elevation. The small range of this species is home to other locally endemic invertebrates, including the millipede Tasmaniosoma nicolaus Mesibov, 2015 and the onychophoran Tasmanipatus anophthalmus Ruhberg, Mesibov, Briscoe & Tait, 1991. Amastigogonus elephas sp. n. may be parapatric with Amastigogonus danpicola sp. n. in the upper St Pauls River catchment.

Name.

Latin elephas , elephant; noun in apposition. For the type locality, Mt Elephant.

Remarks.

The anterior gonopod of Amastigogonus elephas sp. n. (Fig. 6B) is similar to that of Amastigogonus verreauxii (Fig. 8D). The wide disjunction in the species ranges (more than 100 km) and the remarkable consistency of form in the anterior gonopod of Amastigogonus verreauxii (across a linear range extent of ca 400 km) suggests that the two lineages have long been separated.