Snails from a midden
Below are some pictures of snails from a sample taken from a midden deposit at the site of Cladh Hallan on South Uist in the Outer Hebrides.
At this stage, I am separating the first group I want to look at from the assemblage.
The group I’m looking at belong to the genus Cochlicopa, which is common throughout the British Isles. There may be two species here, Cochlicopa lubrica and C. lubricella.
The exciting part for me is the other species left to look at in the dish though. This sample has not only an unusually high number of shells in it (there is another dish the same size from this sample), but also a lot of different species. In this context, the high number of species is quite likely to reflect a long period of relative ground surface stability. Organic waste in the midden will also have been very attractive to snails, especially the tiny Vertigo species, meaning the midden would have provided a refuge where snail populations can flourish.