The shell is strongly curved in an open hook shape and nearly circular in cross section. The posterior part is made up of numerous closely spaced chambers, while the long-living chamber makes up the anterior part of the shell.
Habitat: Experiments suggest that the animal lived head-down in the water, probably near the bottom of the sea. It was able to swim and adjust its bouyancy.
Remark: The specimen featured is an internal mold, from which the original shell has been completely lost.
© 1992 Cyril Walker, David Ward