From the Upper Ordovician Ashgillian series Upper Drummuck group Threave formation.
Collected from Lady burn Starfish beds,South Threave ,Girvan ,Ayrshire, Scotland.
This species is a bit of an oddity, they are classed as Monoplacophorans
which has a kind of limpet like appearance, but the the Bellerophon gastropod species is also included in this group making it a very difficult item to classify.
This specimen came to me as part of the John Harty collection,which was collected a long time ago
The Sinuites measures 27mm,and including the matrix is 46mm x 36mm .