North Island Explorer: Guide to North Vancouver Island









































Transverse Lampshell


Photo 1: A Transverse Lampshell stuck to a rock.



Transverse Lampshell: Terebratalia transversa


Lampshells belong to a group called Brachiopods that at first glance resemble bivalves. However, they are unrelated and the similarity is an example of convergent evolution. Lampshells are a very old organism and flourished in past eras, much more than bivalves of today. Although, both bivalves and lampshells have two shells, the similarity stops there. Bivalve valves tend to be symmetrical mirror images of each other. With lamphells, the two shells are different and the symmetry is perpindicular to the shell opening.





Photo 2: Transverse Lampshell Peduncle

Though attached to a rock for life by its peduncle, or stalk, the transverse Lamphell can orientate itself 'smile' up or 'smile' down.



 More Cnidarians of Vancouver Island and the Pacific Northwest