Millions of tiny juvenile cockle shells have been washed ashore at Swansea Bay in August this year (2018). At least, that is what I think they are. I may be wrong because I have never seen such small cockle shells before. Most were under 1 centimetre in length, many less than 5 mm. It may be a common occurrence since most young invertebrates do not survive from each generation. Also, lots of them were coloured or had intricate zig-zag patterns which I have never observed before. Perhaps they are something else?