The Worms of the Earth
Earthworm Dissection
Going Underground.
Fossil evidence show that earthworm-like creatures have been around for at least half a billion years, surviving the mass extinction about 65 million years ago.
Digging Deeper
~Earthworms can process about 10 pounds of organic material a year.
~Some earthworms can grow as long as 22 inches.
~Earthworms do not have eyes, but can sense light.
~Earthworms have been found 2 miles under the earths surface.
Taxonomy and Ecology
Phylum: Annelida
Class: Oligochaeta
Order: Megadrilacea
Earthworms form the base of many food chains. Earthworms are classified into three main ecophysiological categories: leaf litter- or compost-dwelling worms that are non burrowing, topsoil- or subsoil-dwelling worms that feed on the soil, burrow and cast within soil, and worms that construct permanent deep vertical burrows which they use to visit the surface to obtain plant material for food, such as leaves. Earthworm populations depend on both physical and chemical properties of the soil, such as temperature, moisture, pH, salts, aeration, and texture, as well as available food, and the ability of the species to reproduce and disperse.