Brechin, Ontario, Canada
Size: 5 cm across the top of the calyx.
For many years it has been suspected that Atroporites ottawaensis was the tegmen of a Cleiocrinus rather than a bryozoan as it was first described. However, there has never been any physical evidence to show conclusive proof that it was so. This is the only specimen of that conclusive proof. It is a specimen of a Cleiocrinus calyx with the tegmen attached.