What the shell could this be?..

Welcome back Everyone! I have a quick find to display whilst uploading a pile, please have a look :)

Seems like another fossilised creature of sorts, not sure to be honest.. The small triangular piece was originally inside the stone, but came loose and out in transit.

Many thanks everyone, also please leave comments or plus if you like, (bearing in mind the pluses may not appear), to show support, and stay happy, healthy and loved :)