(fam.: Ampeliscidae, size: up to 30mm, depth: 50-550m)
A. richardsoni lives, sometimes in large populations, on sandy bottoms of the Weddell Sea.
It builds a bivalve shell-like cell made of sediment grains conglomerated by gland secretion, wherein it settles upside down. The species is a suspensivore, feeding mainly on plankton.