Gastrocopta mussoni Pilsbry, 1917

Whisson, Corey S. & Koehler, Frank, 2013, Gastrocopta (Mollusca, Gastropoda, Pupillidae) in the Pilbara region of Western Australia, ZooKeys 261, pp. 15-39 : 27-31

4. Gastrocopta mussoni Pilsbry, 1917 Fig. 2 H–J

Gastrocopta larapinta deserti Pilsbry 1917 [in 1916-1918]: 170-171, pl. 30, figs 1-3.

Gastrocopta mussoni Pilsbry 1917 [in 1916-1918]: 167-168, pl. 27, figs 5-6; Solem 1989: 494, figs 211-213, 1991: 249; Pokryszko 1996: 1105-1109, figs 20-21; Stanisic et al. 2010: 102-103.

Australbinula helmsiana Iredale 1939: 8, pl. 1, fig. 2.

Australbinula mussoni Iredale 1937a: 301.

Gastrocopta deserti Solem 1986: 102-103, figs 13-15, 1989: 487-490, figs 48-53, 1991: 249; Slack-Smith 1993: 92.

Type locality.

Calliungal (=Mt Morgan), Queensland.

Material studied.

Western Australia: Angelo River: 23.4331°S, 118.7329°E (WAM S65935). Anketell Point area: 20.6356°S, 117.0398°E (WAM S59990); 20.6719°S, 117.0965°E (WAM S599912); 20.7025°S, 117.0473°E (WAM S80936). Area C: 22.9104°S, 118.9664°E (WAM S60417). Barrow Island: 20.7833°S, 115.4000°E °E (WAM S34384); 20.8649°S, 115.4069°E °E (WAM S34455); 20.6666°S, 115.4667°E (WAM S42879, WAM S60847); 20.7921°S, 115.4573°E (WAM S59636); 20.7858°S, 115.4573°E (WAM S59637); 20.7997°S, 115.4403°E (WAM S59640); 20.7069°S, 115.4194°E (WAM S59642); 20.7866°S, 115.4547°E (WAM S59644, WAM S60413); 20.7938°S, 115.4575°E (WAM S59651); 20.8644°S, 115.3428°E (WAM S59652); 20.8101°S, 115.4270°E (WAM S60410); 20.6666°S, 115.4667°E (WAM S42879, WAM S60847); 20.7977°S, 115.4064°E (WAM S65123, WAM S65126, WAM S65127, WAM S65164); 20.7684°S, 115.4673°E (WAM S65174). Cane River Conservation Park: 22.1694°S, 115.5606°E (WAM S42961); 22.4321°S, 115.2895°E (WAM S42967); 22.2685°S, 115.6470°E (WAM S42974); 22.0975°S, 115.4942°E (WAM S42976); 22.2075°S, 115.5260°E (WAM S42981); 22.1451°S, 115.7249°E (WAM S42987); 22.0298°S, 115.4296°E (WAM S42992); 22.0131°S, 115.6325°E (WAM S42998). Cape Preston area: 20.8435°S, 116.2016°E (WAM S59141). Chichester Ranges: 22.0525°S, 118.9883°E (WAM S60407); 22.0516°S, 118.9884°E (WAM S42711, WAM S42713, WAM S42759); 22.1508°S, 119.0179°E (WAM S42709); 22.0503°S, 118.9934°E (WAM S42717); 23.1164°S, 119.8865°E (WAM S64460). Christmas Creek area: 22.4170°S, 119.8941°E (WAM S65603); 22.4078°S, 119.8767°E (WAM S65605); 22.4061°S, 119.7376°E (WAM S65611). Cloud Break area: 20.3216°S, 119.4418°E (WAM S34460); 22.3210°S, 119.4442°E (WAM S42876, WAM S60403, WAM S80957); 22.3181°S, 119.3788°E (WAM S60267); 22.2935°S, 119.3872°E (WAM S61122); 22.2997°S, 119.3737°E (WAM S61123); 22.2881°S, 119.2360°E (WAM S 65137°S, WAM S65143°S, WAM S65153); 22.3251°S, 119.4458°E (WAM S65139); 22.3527°S, 119.4189°E (WAM S65144); 22.3652°S, 119.3409°E (WAM S65148); 22.3894°S, 119.4380°E (WAM S65155); 22.3985°S, 119.4748°E (WAM S65157); 22.3949 °S, 119.5019°E (WAM S65213). Cy Creek: 22.8183°S, 114.0609°E (WAM S34382). Dolphin Island: 20.4833°S, 116.8500°E (WAM S34385). Du Boulay Creek: 21.1833°S, 116.1833°E (WAM S34568). Finucane Island: 20.2982°S, 118.5572°E (WAM S16108). Fortescue Marsh area: 22.2822°S, 119.1276°E (WAM S42926, WAM S64694, WAM S646523); 22.2938°S, 119.0732°E (WAM S61991); 22.5098°S, 119.1274°E (WAM S61993°S, (WAM S61995); 22.2872°S, 119.0301°E (WAM S646401, WAM S646556); 22.1322°S, 119.1983°E (WAM S64684); 22.2924°S, 119.0279°E (WAM S64687). East Hamersley Range: 22.8586°S, 119.6728°E (WAM S42921); 22.6335°S, 119.3289°E (WAM S64470). Hope Downs: 23.1474°S, 119.5191°E (WAM S42662); 23.1030°S, 119.2917°E (WAM S59548, WAM S59554); 23.0925°S, 119.2058°E (WAM S59551); 23.0878°S, 119.1609°E (WAM S59552). Jinayri area: 22.9219°S, 119.2036°E (WAM S42929); 23.0530°S, 119.2701°E (WAM S59239, WAM S592412, WAM S59244); 23.0129°S, 119.2371°E (WAM S59240, WAM S59243); 22.9058°S, 119.2000°E (WAM S59576, WAM S59596); 22.9275°S, 119.1275°E (WAM S59585); 22.9169°S, 119.2128°E (WAM S59587); 22.9219°S, 119.2036°E (WAM S59591); 23.0504°S, 119.2731°E (WAM S60406). Kalgan Pool area: 23.1877°S, 119.6965°E (WAM S439823). Kangeenarina Gorge area: 22.1186°S, 117.9427°E (WAM S61763); 21.8489°S, 117.3837°E (WAM S81210). Karratha area: 20.7166°S, 116.8500°E (WAM S60412); 21.4036°S, 116.9392°E (WAM S81217). SE of Karratha: 21.0698°S, 116.9702°E (WAM S81241, WAM S81246); 21.0300°S, 116.9997°E (WAM S81252, WAM S81271); 20.9853°S, 116.8811°E (WAM S81268). Lake Macleod: 24.3544°S, 113.5098°E (WAM S65120). Marillana Station: 22.5840°S, 119.3114°E (WAM S84075); 22.5663°S, 119.2308°E (WAM S34473); 22.5497°S, 119.2147°E (WAM S34476); 22.5851°S, 119.3142°E (WAM S34478). 22.5739°S, 119.2562°E (WAM S34634, WAM S80940); 22.5538°S, 119.2283°E (WAM S34635); 22.6260°S, 119.2834°E (WAM S34639); 22.5625°S, 119.2311°E (WAM S80907); 22.1269°S, 119.2123°E (WAM S80910); 22.5625°S, 119.2311°E (WAM S80913); 22.4080°S, 119.0067°E (WAM S80916); 22.6376°S, 119.3744°E (WAM S80917); 22.4285°S, 119.2043°E (WAM S81437); 22.3182°S, 119.1175°E (WAM S81442); 22.4295°S, 119.1923°E (WAM S81444). Meentheena Outcamp: 21.2671°S, 120.4570°E (WAM S58055); 21.2815°S, 120.4511°E (WAM S58099); 21.2816°S, 120.4508°E (WAM S58098). Millstream National Park: 21.6000°S, 117.1000°E (WAM S42838, WAM S42931, WAM S61043); 21.5833°S, 117.0833°E (WAM S42839, WAM S60943); 21.5833°S, 117.0667°E (WAM S60946); 21.4255°S, 117.0535°E (WAM S81212); 21.1781°S, 117.0461°E (WAM S81250); 21.2039°S, 117.0440°E (WAM S81301, WAM S81296). Mount Brockman area: 22.4815°S, 117.2384°E (WAM S83561). Mt Farquhar area: 22.4815°S, 116.8108°E (WAM S83563). Muiron Island: 21.6666°S, 114.3333°E (WAM S34383). Murray Hills: 22.1147°S, 118.5221°E (WAM S59996). ~60km NW of Newman: 23.0530°S, 119.2701°E (WAM S60235, WAM S60266, WAM S60405); 23.0878°S, 119.1609°E (WAM S59549); 23.0504°S, 119.2731°E (WAM S60404, WAM S60411); 22.9632°S, 119.2276°E (WAM S42928, WAM S60233). ~112km NNE of Newman: 22.3621°S, 119.9691°E (WAM S65650); 22.3132°S, 119.8599°E (WAM S 65672); 22.3871°S, 119.9664°E (WAM S 65694). ~110km N of Newman: 22.2954°S, 119.8109°E (WAM S65638); 22.3132°S, 119.8599°E (WAM S65672); 22.2972°S, 119.8633°E (WAM S65683). ~70km S of Newman: 23.7270°S, 119.7242°E (WAM S58073). North Star: 21.2523°S, 118.8334°E (WAM S65699); 21.1971°S, 118.8286°E (WAM S65706, WAM S65710); 21.2681°S, 118.9682°E (WAM S65713); 21.2104°S, 118.8769°E (WAM S65718); 21.2104°S, 118.8769°E (WAM S65719); 21.2319°S, 118.8263°E (WAM S65728). Nullagine area: 21.8221°S, 120.3409°E (WAM S61802). Orebody 35°E (ca. 8km W of Newman): 23.4108°S, 119.5715°E (WAM S64733); 23.3837°S, 119.6478°E (WAM S64748); 23.3712°S, 119.6127°E (WAM S64749); 23.3819°S, 119.6133°E (WAM S64751); 23.3970°S, 119.6138°E (WAM S64752). West of Pannawonica: 21.7000°S, 116.1667°E (WAM S42805); 21.8063°S, 116.0774°E (WAM S60268); 21.7202°S, 116.0705°E (WAM S60414, WAM S61034); 21.6298°S, 116.0206°E (WAM S60415). Point Quobba, near lighthouse: 24.4797°S, 113.4178°E (FMNH 201611); Phils` Creek area: 22.7320°S, 119.1836°E (WAM S 42878, WAM S 59372); 22.7316°S, 119.1931°E (WAM S 59371, WAM S59375, WAM S59383); 22.7351°S, 119.1856°E (WAM S59373); 22.7384°S, 119.1916°E (WAM S59377); 22.7412°S, 119.1959°E (WAM S59378); 22.7448°S, 119.1927°E (WAM S59379); 22.7412°S, 119.1959°E (WAM S59380); 22.7366°S, 119.1811°E (WAM S59381); 22.7316°S, 119.1798°E (WAM S59382). ~40km S of Port Hedland: 20.6095°S, 118.6661°E (WAM S81404). NNE of Rocklea Homestead: 22.8101°S, 117.4734°E (WAM S80990). Roy Hill Station: 22.6642°S, 119.9458°E (WAM S34588); 22.4943°S, 119.9217°E (WAM S42828, WAM SS60376); 22.4396°S, 119.9453°E (WAM S42837); 22.4898°S, 119.8951°E (WAM S42875, WAM S60234); 22.5383°S, 119.9424°E (WAM S42927); 22.7058°S, 119.7082°E (WAM S60393); 22.6347°S, 119.9698°E (WAM S60394); 22.8174°S, 119.9473°E (WAM S60395, WAM S60399); 22.5771°S, 120.0247°E (WAM S60421, WAM S60866); 22.4793°S, 119.9421°E (WAM S60427); 22.5039°S, 120.0210°E (WAM S60864); 22.5566°S, 119.9700°E (WAM S60865); 22.7489°S, 119.9221°E (WAM S61067); 22.7195°S, 119.9395°E (WAM S61068, WAM S61071); 22.6365°S, 119.9639°E (WAM S61070); 22.6431°S, 119.9642°E (WAM S61074, WAM S61076); 22.5050°S, 119.9042°E (WAM S64448); 22.5843°S, 120.0172°E (WAM S64453).Running Waters (east of Nullagine): 21.6819°S, 121.1254°E (WAM S58050); 21.6815°S, 121.1270°E (WAM S58059). W end of Telfer Road: 21.3290°S, 121.1390°E (WAM S58044). NW of Tom Price: 22.3734°S, 117.4631°E (WAM S34566); 22.1350°S, 117.4728°E (WAM S65775); 22.1519°S, 117.5428°E (WAM S65781); 22.2997°S, 117.6378°E (WAM S65787); 22.3855°S, 117.4667°E (WAM S65788). Weeli Wolli Creek: 22.6166°S, 119.4000°E (WAM S60231). Near Wodgina Mine: 21.1831°S, 118.6569°E (WAM S34567, WAM S65843, WAM S65869); 21.2871°S, 118.8671°E (WAM S64618); 21.1789°S, 118.6463°E (WAM S65841, WAM S65855); 21.1737°S, 118.6503°E (WAM S65844); 21.2383°S, 118.6519°E (WAM S65903). Wonmunna: 23.1436°S, 119.0064°E (WAM S65977, WAM S81002, WAM S81026); 23.1355°S, 119.0384°E (WAM S65983); 23.1596°S, 118.9703°E (WAM S65979); 23.1632°S, 118.9770°E (WAM S65985); 23.1615°S, 119.0020°E (WAM S 65990); 23.1201°S, 119.0484°E (WAM S65993); 23.1287°S, 119.0904°E (WAM S 65996); 23.1283°S, 119.0736°E (WAM S65998); 23.1268°S, 119.0673°E (WAM S81032); 23.1309°S, 119.0689°E (WAM S81036, WAM S81167); 23.1428°S, 119.0099°E (WAM S81053); 23.1355°S, 119.0384°E (WAM S81081); 23.1169°S, 119.0396°E (WAM S81099); 23.1255°S, 119.0797°E (WAM S81094); 23.1216°S, 119.0498°E (WAM S81096, WAM S81171); 23.1393°S, 119.0182°E (WAM S81104); 23.1210°S, 119.0632°E (WAM S81109); 23.1356°S, 119.0463°E (WAM S 81110, WAM S81127); 23.1185°S, 119.0649°E (WAM S81114); 23.1255°S, 119.0797°E (WAM S81116); 23.1201°S, 119.0484°E (WAM S81119); 23.1331°S, 119.0154°E (WAM S81170); 23.1216°S, 119.0498°E (WAM S81178); 23.1220°S, 119.0611°E (WAM S81180). Yandi Mine: 22.8200°S, 119.2500°E (WAM S61774).

Distribution.

This species has previously been recorded from central Australia (the southern part of Northern Territory), with a few records from the mid-west coast and northern Western Australia; northern Northern Territory; northern and north-eastern parts of Queensland and South Australia ( Pokryszko 1996). In addition, it is now recorded from throughout most of the Pilbara region (Figure 5).

Comparative morphology.

Cylindrical and elongate-ovate forms of Gastrocopta mussoni can be mistaken for Gastrocopta larapinta specimens (with a small or absent interpalatal tooth) but (1) are slightly to moderately slender (2) have a higher, usually longer parietoangular tooth (3) have a larger, more strongly slanted and acutely angled columellar tooth, with its posterior edge often forming a prominent wide ridge along the columellar wall (4) quite frequently have an upper palatal tooth that is slightly (occasionally moderately) convergent with the lower palatal (see also earlier section on Gastrocopta larapinta ). Gastrocopta mussoni very occasionally possesses a small interpalatal tooth, usually located close to the upper palatal.

The typical ovate form of Gastrocopta mussoni can be confused with Gastrocopta hedleyi (particularly those with reduced apertural barriers) but (1) are larger (obese) when sympatric (2) have a less sigmoid lower palatal tooth and (3) have a smaller, less convergent upper palatal tooth (see also earlier section on Gastrocopta hedleyi ).

Remarks.

There appears to be two size forms in Gastrocopta mussoni , the larger ovate form and smaller, slender cylindrical form, and in agreement with Pokryszko (1996) both are confirmed as ecological phenotypes from the CO1 and 16S sequences. Based on specimens identified by Pokryszko (1996) and during this study, there is enormous variation in shell shape, shell size and apertural barrier structure between and including these two forms.

The ovate form of Gastrocopta mussoni appears to be most common in the Pilbara. Prior to Pokryszko’s 1996 publication, Gastrocopta pilbarana Solem, 1986 was described from the Shark Bay area with an isolated record from the Chichester Range (north of Roy Hill). This species was synonymised with Gastrocopta margaretae (Cox, 1868) by Pokryszko (1996) although the Chichester Range paratype was not included in that study. This Chichester Range record is actually the ovate form of Gastrocopta mussoni .

Some of those specimens tentatively identified as the elongate-ovate form of Gastrocoptamussoni during this study (Wonmunna; Cy Creek; Cloud Break, Barrow Island) are (1) much larger (obese) than the usual elongate-ovate form (2) have the parietoanangular tooth lower (45o) (3) usually have a supraparietal tooth and (4) quite frequently possess a small interpalatal tooth. These specimens may prove to be the somewhat variable Gastrocoptalarapinta with a small or no interpalatal tooth, but in the absence of a larger series of specimens and more detailed molecular data, we have left them as Gastrocopta mussoni .

The nature of many cylindrical Gastrocopta mussoni identified by Poykrosko (1996) and during this study requires more work. It is probable we have lumped the slender form of Gastrocopta larapinta from Kalgan Pool (no interpalatal tooth) withcylindrical Gastrocopta mussoni .