Hi, @james-beech – Where did you find this specimen? That can help us narrow in on the other geologic context information. Is that a large drill hole on the top?

Thanks for sharing, Jen

Hi, @james-beech – Is it possible this is Astarte concentrica: https://neogeneatlas.net/species/astarte-concentrica/

Check out the images tab on that link. If you upload another image of the interior of the shell we can work to narrow in on the taxonomy.

Here is a link of the geologic context for the Aurora area:…[Read more]