Probably different species.
Lamp shells found washed up on the beach. The whole critter is 2 shells together, one wider and a different shape to the other.
Found on the beach. Obviously from two different individuals. In this area, regularly seen attached to shallow subtidal rocks.
Many of these found washed up on the beach.
Photo scanned from 35mm slide.
red/orange (the one named here) and black brachipods frequent on these beaches; this we colloquially know as 'Grandma's toenails'.
Black brachiopod frequent here
Brachiopods, phylum Brachiopoda, are marine animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection. Two major groups are recognized, articulate and inarticulate. Articulate brachiopods have toothed hinges and simple opening and closing muscles, while inarticulate brachiopods have untoothed hinges and a more complex system...