Hundreds of snail shells were found in thin layers of earth and stone in the cairn of Newgrange during excavations there in the 1960s.
The spiriform snail shells pictured above were among about 19 different species of land molluscs found in thin layers between much thicker layers of loose cairn stones during the excavation of Newgrange by Professor Michael J. O'Kelly.
It's not thought that the snail shells were collected intentionally by the builders – rather that the most abundant species would be "typical of a rock-rubble fauna".
The theory is that . . . "the habitat provided by the loose stones of the cairn provided, for a snail, all the elements of shelter, shade, moisture, etc. to be found in a wood." (O'Kelly,1982, Appendix F, page 227).
Carol Mason and J.G. Evans of University College Cardiff suggested that the shells of the dead molluscs would have fallen down between gaps in the stones until they "landed" on these narrow "earthy horizons", the thin layers between the stones, where "death assemblages" were formed.
There was a particular abundance of Oxychilus, Discus and Vitrea, "typical of rock-rubble fauna". These species, say Mason and Evans, are carnivores, which is why they are abundant in habitats lacking vegetation.
Whatever way they arrived there, one cannot help noticing the spiriform shapes of the snail shells, and one wonders whether there is a connection with the spirals which are carved so magnificently on some of the most decorated kerbstones at Newgrange - namely K1, K52 and K67, all shown above.
The spiral shape is ubiquitous in the megalithic art of Newgrange. And within the structured layers of the cairn are hundreds of spiral-shaped shells of snails (3,000 were found in four cuttings). Is it possible that the snail shells provided inspiration for the spirals carved in stone?