Bryozoans are a phylum of mainly marine colonial invertebrates with a rich fossil record. Each colony is composed of a few to many thousands of individual animals (zooids) which filter the water for food using tentacles.
Their calcium carbonate skeletons are a major component of many ancient limestones and the sediments on the present-day sea floor. Despite their abundance we still know little about their taxonomy, evolution, biogeography and palaeoecology.
Research on fossil bryozoans in Museum Victoria is carried out by Dr Rolf Schmidt and includes the following:
Very little has been done to identify the rich Bryozoan fossil fauna of Australia. Most previous studies have focussed on a few deposits near Melbourne, and formations from other areas need to re-evaluated for their Bryozoan faunas. Current research on the South Australian fossil Bryozoa has already yielded interesting taxonomic results.
Australia has a unique present-day marine fauna but this was not always the case. The evolution of bryozoans through geological time can show interesting relationships with other continents, as well as the origination of new taxa. Once the fossil faunas of the southern and western Australian margins have been identified, much better biogeographic and evolutionary analyses can be carried out.
Bryozoan colonies can grow in a wide variety of shapes, from simple encrusting sheets on rocks to large branching 'trees' and even free-living forms. Each growth form may characterise a particular environment, and fossil assemblages are often used to evaluate the environment in which the sediments were deposited.
Last updated 1 May 2008