At least 4 abalone are present in lower frame (also a cart-rut shell) but I am not sure if they're all blacklip. The lower 1-2 might be greenlip, so if anyone thinks I should specify which one(s) are the subject of this observation I'll do that, or post cropped versions.
3421/2/3 all my shells are dead, beach washed.
perhaps Canarium urceus?
3791/2/3 All my shells were dead, beach washed.