Glabrocingulum pustulum, Yoo, 1994

Yoo, E. K., 1994, Early Carboniferous Gastropoda from the Tamworth Belt, New South Wales, Australia, Records of the Australian Museum 46 (1), pp. 63-120 : 76

Glabrocingulum pustulum n.sp.

PI. 7 figs 1-4

Description. Shell small, trochiform, with 5 whorls, narrowly phaneromphalous. Protoconch simple, smooth, round. Teleoconch conical, whorl profile round in early whorls becoming rather flat in later whorls with deep suture, about 3Y2 whorls with broadly subangular periphery; ornamentation of sharp spiral lirae bearing nodes where crossed by prosocline collabral threads; ornamentation below selenizone is weaker. Selenizone narrow and flat to just above periphery, ornamented with curved lunulae, present from third whorl. Aperture with inner lip straight, thickened, slightly extended towards umbilicus, outer lip with gentle labral sinus culminating in a small notch.

Types. Holotype ( F78397 ), 1 figured paratype ( F78398 ) and 10 paratypes ( F78392 ).

Type locality. Approximately 250 m west of Babbinboon Lane, in Swains Gully, 15 km south-west of Somerton, NSW (Locality 25).

Stratigraphic position. In bioclastic limestone, 130 m above the base of the Namoi Formation.

Additional material. 8 specimens from Oxley Highway (Locality 22-2), 2 from north-east of 'Rangari' (Locality 15), 2 from 'Marohn' (Locality 28), and 2 from Glenbawn (Localities 30 and 31).

Geographic distribution. 'Rangari' to Glenbawn.

Geological age. Middle to late Tournaisian.

Etymology. Referring to the nodes covering the shell surface.

Remarks. This species differs from G. obesum Y00 in having a conical shell with a narrower umbilicus, and a different pattern of the selenizone ornamentation. Glabrocingulum sp. has a low spired shell with round and inflated whorl profile, while G. pustulum n.sp. has rather flat whorl profile with subangular periphery.