Classification:
They are classified as Protosomia which branch off to coelomates. Annelids are a large invertebrate phylum. Annelids have three body regions, and the majority of the body is comprised of repeated units called segments. Diversity: There are 22,000 living annelid species. They are all different types of worms. The three major groups of annelids are Polychaeta, Oligochaeta (earthworms etc.) and Hirudinea (leeches). Life History: Since annelids are are soft-bodied, finding fossils are very rare. The best-preserved and oldest specimens come from Cambrian Lagerstätten such as the Burgess Shale of Canada, and the Middle Cambrian strata. Putative Annelid ichnofossils are known from the Ediacara Hills of Australia and the White Sea Regions of Russia. Annelids are also abundant amongst the Pennsylvanian-age. Ecological Roles: The most significant things annelids do ecologically is renew and and rework sediment and soil. they live in the soil and sediment, so are constantly working and renewing soil. They also create oxygen for us by renewing the soil which gives nutrients to plants and flowers which gives us oxygen. Human Impacts: We could affect annelids by using all marine annelids for fishing. Another reason we could affect them is if we take away all their soil because then they will have nothing to live in or renew. Work Cited: http://www.ucmp.berkeley.edu/annelida/annelida.html http://www.ucmp.berkeley.edu/annelida/annelidalh.html http://tolweb.org/Annelida |