Temporena whartoni is a mid-sized snail — average shell width is 36 mm, shell height 25 mm.Its home — Holbourne Island — is a granite outcrop that was formerly mined for guano. The 34 ha island is now a national park, so the species is presumably doing all right.
Its taxonomy is another matter. It has been shifted around from one genus to another. Originally described as Helix whartoni (in the 1800s, Helix was the catch all genus for large, rounded shells), it was later moved into Temporena, Iredale's (1933) subgenus of Gnarosophia. Then Iredale (1937) elevated Temporena to genus with H. whartoni as type species. Subsequently, it's been shoved into another catch all — Sphaerospira (Smith, 1992). It almost certainly belongs in a different corner from that genus. It shares some conchological and anatomical characteristics with three other species on the adjacent mainland, including the smaller Varohadra macneilli Iredale 1937, which also occurs on granite islands.
So there's a nice little investigation for someone. A bit of DNA analysis, some historical biogeography ... Oh, and Varohadra — another can of taxonomic worms.
References
Cox, J.C. (1871) Descriptions of seven new species of Australian land shells. Proceedings of the Zoological Society of London 1871: 53–55.
Iredale, T. (1933) Systematic notes on Australian land shells. Records of the Australian Museum 19: 37–59.
Iredale, T. (1937) A basic list of the land Mollusca of Australia. Pt II. Australian Zoologist 9: 1–39.
Smith, B.J. (1992). Non-marine Mollusca. In Houston, W.W.K. (ed.) Zoological Catalogue of Australia. Vol. 8. Canberra: Australian Government Publishing Service.
