Traditionally the annelids have been divided into two major groups, the polychaetes and clitellates. In turn the clitellates were divided into oligochaetes, which include earthworms, and hirudinomorphs, whose best-known members are leeches. For many years there was no clear arrangement of the approximately 80 polychaete families into higher-level groups. In 1997 Greg Rouse and Kristian Fauchald attempted a "first heuristic step in terms of bringing polychaete systematics to an acceptable level of rigour", based on anatomical structures, and divided polychaetes into:
Traditionally the annelids have been divided into two major groups , the polychaetes and clitellates . In turn the clitellates were divided into oligochaetes , which include earthworms , and hirudinomorphs , whose best - known members are leeches . For many years there was no clear arrangement of the approximately 80 polychaete families into higher - level groups . In 1997 Greg Rouse and Kristian Fauchald attempted a " first heuristic step in terms of bringing polychaete systematics to an acceptable level of rigour " , based on anatomical structures , and divided polychaetes into :
When did Greg Rouse begin trying to categorize polychaetes?
When did Greg Rouse begin trying to categorize polychaetes ?
1997
1997