Gastrocopta hedleyi Pilsbry, 1917

Whisson, Corey S. & Koehler, Frank, 2013, Gastrocopta (Mollusca, Gastropoda, Pupillidae) in the Pilbara region of Western Australia, ZooKeys 261, pp. 15-39 : 18-21

1. Gastrocopta hedleyi Pilsbry, 1917 Fig. 2B

Gastrocopta hedleyi Pilsbry 1917 [in 1916-1918]: 166-167, pl. 27, figs 1-4; Solem 1991: 250; Pokryszko 1996: 1104, fig. 18; Stanisic 1998: fig. 17.42e; Stanisic et al. 2010: 102-103.

Australbinula hedleyi Iredale 1937a: 301.

Type locality.

Narrabri, New South Wales.

Material studied.

Western Australia: Abydos (64km W of Marblebar): 21.1343°S, 119.1259°E (WAM S64439). Burrup Peninsula: 20.6080°S, 116.7670°E (WAM S60089); 20.6141°S, 116.7548°E (WAM S60226); 20.6066°S, 116.7681°E (WAM S60227); 20.5833°S, 116.8000°E (WAM S60228, WAM S60230, WAM S60349, WAM S61117-21); 20.6102°S, 116.7607°E (WAM S60353); 20.6232°S, 116.7784°E (WAM S60402); 20.6166°S, 116.7833°E (WAM S60475); 20.6119°S, 116.7587°E (WAM S60477); 20.6238°S, 116.7777°E (WAM S60480); 20.6300°S, 116.7800°E (WAM S65167); 20.5858°S, 116.8044°E (WAM S65168). Cloud Break area: 22.2997°S, 119.3737°E (WAM S60416). Hope Downs: 23.0865°S, 119.3184°E (WAM S42661); 23.0379°S, 119.2124°E (WAM S42663); 23.0952°S, 119.2022°E (WAM S59553); 23.1030°S, 119.2917°E (WAM S59555). Kalgan Pool area: 23.1872°S, 119.6958°E (WAM S58079); 23.1877°S, 119.6965°E (WAM S58091). Kangeenarina Gorge: 22.0588°S, 117.8549°E (WAM S60085). Karajini National Park: 22.4782°S, 118.5598°E (WAM S65307); 22.9797°S, 118.5891°E (WAM S65310); 22.8446°S, 118.5403°E (WAM S65314); 22.3714°S, 118.2989°E (WAM S65336). Marillana Station: 22.4285°S, 119.2043°E (WAM S81440). Mount Brockman area: 22.4815°S, 117.2384°E (WAM S83560). Mt Farquhar area: 22.4815°S, 116.8108°E (WAM S83564); 22.4932°S, 116.8679°E (WAM S83586). Nullagine area: 22.3848°S, 119.9696°E (WAM S58093); 22.3210°S, 119.4442°E (WAM S80958). Orebody 35°E(ca. 8km W of Newman): 23.4047°S, 119.6052°E (WAM S64713); 23.3943°S, 119.6316°E (WAM S64715-6, WAM S64718, WAM S64734, WAM S64753); 23.4108°S, 119.5715°E (WAM S64720); 23.3994°S, 119.5843°E (WAM S64722); 23.4045°S, 119.6211°E (WAM S64726); 23.4182°S, 119.5847°E (WAM S64730, WAM S64744); 23.4049°S, 119.6052°E (WAM S64732); 23.4045°S, 119.6247°E (WAM S64735); 23.4049°S, 119.6053°E (WAM S64737, WAM S64747); 23.4003°S, 119.6524°E (WAM S64740); 23.4137°S, 119.5826°E (WAM S64741); 23.4029°S, 119.6021°E (WAM S64742); 23.4003°S, 119.5721°E (WAM S64745); 23.3947°S, 119.5913°E (WAM S64750). ca. 35km E of Paraburdoo: 23.1300°S, 117.8984°E (WAM S41446); 23.1663°S, 117.9484°E (WAM S41447); 23.1670°S, 117.9597°E (WAM S41448). ca. 7.07.5km NW of Tom Price: 22.6500°S, 117.7185°E (WAM S42668); 22.6423°S, 117.7451°E (WAM S42672). Phil’s Creek: 22.7319°S, 119.1940°E (WAM S59376). Sulphur Springs: 21.1475°S, 119.2269°E (WAM S60229). Wonmunna: 23.1216°S, 119.0498°E (WAM S65971); 23.1428°S, 119.0099°E (WAM S65976); 23.1266°S, 119.0470°E (WAM S65992, WAM S81027, WAM S81085); 23.1255°S, 119.0797°E (WAM S80937); 23.1287°S, 119.0904°E (WAM S80938); 23.1393°S, 119.0182°E (WAM S80939); 23.1220°S, 119.0611°E (WAM S80941); 23.1436°S, 119.0064°E (WAM S81001, WAM S81073); 23.1185°S, 119.0649°E (WAM S81004); 23.1592°S, 118.9928°E (WAM S81025, WAM S81062); 23.1632°S, 118.9770°E (WAM S81033, WAM S81054, WAM S81168, WAM S81176); 23.1615°S, 119.0020°E (WAM S81048, WAM S811056); 23.1185°S, 119.0649°E (WAM S81091); 23.1596°S, 118.9703°E (WAM S81052); 23.1283°S, 119.0736°E (WAM S81059); 23.1331°S, 119.0154°E (WAM S81103); 23.1356°S, 119.0463°E (WAM S81120); 23.1546°S, 118.9932°E (WAM S81122); 23.1314°S, 119.0774°E (WAM S81174). ca. 6km W of Wodgina Mine: 21.2383°S, 118.6519°E (WAM S65895); 23.1348°S, 119.0338°E (WAM S81074).

Distribution.

This species has previously been recorded fromnorthern New South Wales and from scattered localities in northern Queensland (Cape York Peninsula), central Australia (Glen Helen area) and northern Western Australia (King Leopold Ranges) ( Pokryszko 1996). In addition, it is now recorded from the Hamersley Ranges, the Burrup Peninsula and a few isolated sites from approximately 100 km SSE of Port Hedland in the Pilbara region (Figure 3).

Comparative morphology.

Gastrocopta hedleyi shellsare slightly smaller (shorter) than those of other Gastrocopta species (excluding Gastrocopta sp. CW1) recorded from the Pilbara. They typically have (1) a large, usually rounded (sometimes acute) columellar tooth that is drooping at the anterior end (2) a high, strongly convergent upper palatal tooth (3) a long, high, strongly twisted parietoangular tooth that usually comes in close proximity to the upper palatal tooth (4) a prominent infraparietal tooth that is sometimes prolonged as thin ridge on parietal wall (5) often a strong basal tooth (6) very occasionally with a weak interpalatal tooth.

Some Gastrocopta hedleyi shells (particularly more elongate specimens) can be difficult to separate from the ovate form of Gastrocopta mussoni but (1) are smaller (slender) when sympatric (2) have a less rounded body whorl (3) have a more strongly sigmoid lower palatal tooth (4) have a larger upper palatal tooth that is usually strongly convergent with the lower palatal (5) have a longer, more strongly twisted parietoangular tooth (6) have a larger, more rounded columellar tooth that is usually drooping at the anterior end.

The cylindrical form of Gastrocopta mussoni is also very similar to Gastrocopta hedleyi but (1) has a lower, shorter and less twisted parietoangular tooth (usually at 45o angle in apertural view) (2) has a shorter and less sigmoid (usually straight) lower palatal tooth (3) generally lacks an infraparietal tooth (4) has a smaller upper palatal tooth (occasionally slightly convergent with lower palatal) (5) has a more acutely angled, slanted columellar tooth, rarely drooping at the anterior end.

Remarks.

There is considerable variation in the shell size and barrier length of specimens identified as Gastrocopta hedleyi during this study. Many specimens grouped as Gastrocopta hedleyi from the eastern Hamersley Range (eg. Wonmunna, Kalgan Pool) have reduced barriers and often a lower parietoangular tooth (nearing 45o angle in apertural view) but a large series shows a progression to shells that typically possess a large, strongly convergent upper palatal tooth and a strongly twisted parietoangular tooth.

Solem (1989) mentioned that Gastrocopta hedleyi was somewhat similar to Gastrocopta pilbarana , although in that case he was actually referring to the ovate form of Gastrocopta mussoni (see section on Gastrocopta mussoni ).

The abundance and seemingly allopatric nature of Gastrocopta hedleyi on the Burrup Peninsula is intriguing. The large numbers are presumably related to its’ habitat requirement of either Fig tree, Cypress or Brigalow Stands among rocky substrates, and its’ preference for high calcium soils ( Pokryszko 1996). Away from the Burrup Peninsula, the distribution of Gastrocopta hedleyi is somewhat patchy and is probably related to the isolated occurrence of its’ preferred vegetative structures among rocks as well as less alkaline soils.