Wikipedia
Tymbochoos
Tymbochoos is an extinct genus of encrusting tentaculitoid tubeworms. Tymbochoos has a laminar tube structure and pseudopuncta similar to the tentaculitoids. It has previously been interpreted as a Palaeozoic polychaete. The worlds oldest build-ups with tube-supported frameworks belong to Tymbochoos sinclairi. They occur in the Ordovician limestones of the Ottawa Valley.