How old are earthworms as a species?

Earthworms are all soft tissue which doesn't lend itself well to fossilization. It seems likely that the first worms evolved after the Cambrian explosion. The earliest known fossil from the phylum Annelida is thought to be 518 million years old. read more

Earthworms were once found only in Europe, but they now thrive across the North American and Asian continents as well. While it may seem that one worm is as good as another for fishing and gardening, the term "earthworm" actually describes thousands of unique species that fill various ecological roles. read more

Several common earthworm species are mostly parthenogenetic, meaning that growth and development of embryos happens without fertilization. Among lumbricid earthworms, parthenogenesis arose from sexual relatives many times. Parthenogenesis in some Aporrectodea trapezoides lineages arose 6.4 to 1.1 million years ago from sexual ancestors. read more