|Cognate land snail|
informal group Sigmurethra
Amphidromus cognatus is large, with a shell length ranging from 21–33 mm (0.8–1.3 inches) and a diameter of 12–17 mm (0.5–0.7 inches). The ground colour of its shell is yellow, often with a peripheral spiral brown band, a purplish apical suffusion and a light yellow or white lip.
The snail was first described in 1907, from three specimens found at Port Essington on the Cobourg Peninsula before 1850, although it was not found there since. Several sightings were made between 1976 and 1980, at one site on Bathurst Island and three sites at Melville Island.
Amphidromus cognatus is considered Near Threatened by the IUCN (World Conservation Union). The species is not listed on the Australian government's list of threatened fauna, but the Northern Territory government considers it Vulnerable.
- Kessner, V. & Ponder, W.F. (1996). Amphidromus cognatus. 2006 IUCN Red List of Threatened Species. Archived June 27, 2014, at the Wayback Machine. Downloaded on 6 August 2007.
- Laidlaw F. F. & Solem A. (1961). "The land snail genus Amphidromus: a synoptic catalogue". Fieldiana Zoology 41(4): 505-720.
- Threatened Species of the Northern Territory: Cognate Land Snail (Amphidromus cognatus) Archived September 3, 2008, at the Wayback Machine., Government of the Northern Territory.
- Solem A. (1983). "First record of Amphidromus from Australia with anatomical note on several species (Mollusca: Pulmonata: Camaenidae)". Records of the Australian Museum 35(4): 153-166. doi:10.3853/j.0067-1975.35.1983.315, HTM Archived July 6, 2011, at the Wayback Machine., PDF Archived July 6, 2011, at the Wayback Machine..