terebratulida

#953 - Magellania flavescens - Lamp Shell

I literally jumped and yelled when I picked this up on the beach at Leschenault, and realised what it was. Sure, the orange sponge was pretty, but I’d initially thought it was just some bivalve species.

It ain’t. It’s a freakin’ BRACHIOPOD.

I’ve never seen a Brachipod in real life before, except as a fossil - they’re an ancient lineage, unrelated to the molluscs, that have come through mass extinctions since at least the Cambrian, and may have evolved from the Tommotiids of the earliest Cambrian series, 540 million years ago. They have two shells, like bivalves, but the structure and symmetry is completely different, and the internal anatomy even more so. This species, in the Terebratulida has a hole at the rear of the shell, through which the peduncle emerges to attach it to the rocky seafloor. That gives the shell a resemblance to the ancient oil lamps that give them their common name.

Inside the shell brachiopods have a lophophore, a crown of tentacles which filter seawater for food particles. They’re supported on a brachidium - which was still intact in this one!

As you can imagine, I was hugely pleased with this find :)