Atelomastix grandis, Edward & Harvey, 2010

Edward, Karen L. & Harvey, Mark S., 2010, A review of the Australian millipede genus Atelomastix (Diplopoda: Spirostreptida: Iulomorphidae) 2371, Zootaxa 2371 (1), pp. 1-63 : 22-23

Atelomastix grandis , sp. nov.

Figs. 9, 60, 102, 103.

Type material: AUSTRALIA: Western Australia: holotype male, Mount Le Grand, Le Grand National Park , 33°59’25”S, 122°07’35”E, hand collected in soil, 27 December 2006, M.L. Moir, K.E.C. Brennan ( WAM T 83221 ) . Paratypes: 5 males, 4 females, collected with holotype ( WAM T 78761 ) ; 3 males, 13 females, Mount Le Grand, Le Grand National Park , summit, 33°59’41”S, 122°07’48”E, hand collected under granite rocks, 4 June 2007, M.L. Moir, M.C. Leng ( WAM T80740, T80741 ) ; 1 female collected with holotype ( WAM T 78760 ) .

Etymology: This species is named both for its distribution within Le Grand National Park and the great size of the male gonopods ( grandis, Latin : large, great, noble, etc.).

Diagnosis: Atelomastix grandis , although not the biggest millipede in length or number of segments, has the longest gonopod of all Atelomastix species (total gonopod length= 1.78–1.79 mm). It differs from all other species by several distinct gonopod morphological differences. Sclerite c is relatively straight, broad, indented sub-distally with a broad rounded distal tip. Sclerite b has a pointed narrow distal tip and does not extend to sclerite c. Sclerite a has a short but deep distal hood, entirely exposing an elongate pseudoflagellum.

Description: Male (holotype). Colour: generally chocolate-brown; legs, antennae, mouthparts, and head golden brown; well defined bands between segments; prozonites dark chocolate brown, metazonites brown to lighter brown in preserved specimens.

Body: ca. 48 mm long and ca. 2.9 mm wide at collum. With 54 trunk segments, 97 pairs of legs, last 2 segments without legs.

Head: with ca. 37 ocelli ( Fig. 60), arranged in 5 rows (4: 7: 8: 9: 9).

Gonopods: anterior gonopods ( Figs. 102, 103) heavily sclerotised, 2.5 times longer than broad; sclerite a with swollen base that forms short but deep curved distal hood; upper distal face of sclerite a with 21–22 (n=2) short blunt setae; pseudoflagellum elongate and entirely visible beneath distal hood; sclerite b narrowed and curved subdistally, with short, narrow rounded distal tip, 8–14 (n=2) short setae present on sub-distal edge; basal process of sclerite b rounded, 0.06 times length of main process; sclerite c relatively long and broad, indented sub-distally, with broad rounded distal tip, 7–10 setae (n=2) present near indentation; subbasal setae not visible where sclerites overlap and group of 15 (n=2) short setae sub-basally on sclerite c; posterior gonopods inconspicuous, small, with several small setae on interno-lateral face of each gonopod.

Dimensions (mm): holotype male (paratype male, WAM T78761 ): length ca. 48, width ca. 2.9, L/W=16.6; sclerite a 1.792 / 0.712 (1.784 / 0.680), setae 22 (21); sclerite b 0.680 (0.680), basal process of sclerite b 0.038 (0.045), setae 8 (14); sclerite c 1.360 (1.280), setae 7 (10).

Female. Similar to male, other than sexual characters, and slightly larger.

Distribution and habitat: Atelomastix grandis is only known from under rocks or in soil on granite outcrops and Agonis heath of Mount Le Grand in the Le Grand National Park ( Fig. 9). It occurs in sympatry with A. brennani near the summit of Mount Le Grand and is larger than this species, thus possibly showing evidence of character displacement.