Hello everyone, I'm new to the forum and I am hoping to get a little bit of help with identification of sea shells. These are shells I find in Orkney. This one in the middle has me completely stuck. There is a lower photo of the other side of the shell. The beach I found this on has areas where there is erosion so I wondered if it might be a fossil shell but I find lots of the little things on the right which look a bit like it and they don't look like fossils. Does anyone know? It is fan shaped and grey with a wavy top edge. Thank you in advance for your time.
I have added a third photo showing a small grey shell I did find in the eroding bit of land at the beach along with more of these little white things I find in the sand.