Archimedes 'is an extinct bryozoan that had a central 'screw' structure to support the colony.
Often the branches and the tubes secreted by the zooids are not preserved, since they are very delicate, so all that remains is the more robust central support.
The individual zooids had a flat, table-like shape.
Archimedes is most commonly found in fine-
grained sediments laid down in calmer- areas of the sea, such as sheltered
bays.
New colonies formed by branching off a parent colony before growing a new screw.
In some instances, thousands of colonies
can be traced back to a single parent branch.