One of the bryozoans that formed colonies
in curtain-like curved sheets, Cbasmatopora
(sometimes known as Subreteporai formed
its fronds by branching off the main stems
from the narrow base or 'root' anchored to
the substrate.
Each of the stems or strips is
about six zooecia wide - that is, formed
from six rows of tiny zooid animals in their
box-like containers.
These sets of parallel
rows of tiny containers, known as zooecia,
branched and then joined to form an
enlarging net riddled with a regular pattern
of holes.
More than a dozen species of
Chasmatopora have been identified, most
from Eastern Europe (Estonia, Russia) and
China, with a few from North America.