Acanthodrilidae is an ancient and widely distributed family of earthworm

Earthworm

Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female...

s which has native representatives in Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, New Zealand

New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

, South Africa

South Africa

The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

, South America

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

 and North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

. Interestingly, no native species are known from India

India

India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

 (cf. Octochaetidae) nor Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

. The family possibly shows a pre-Pangaea

Pangaea

Pangaea, Pangæa, or Pangea is hypothesized as a supercontinent that existed during the Paleozoic and Mesozoic eras about 250 million years ago, before the component continents were separated into their current configuration....

n distribution.

Membership requires an 'acanthodriline' arrangement of male pores and holoic nephridia.

Sources

• Blakemore, R.J. (2005). Whither Octochaetidae? – its family status reviewed. In: Advances in Earthworm Taxonomy II. Eds. A.A. & V.V. Pop. Proceedings IOTM2, Cluj University Press. Romania. Pp. 63-84. http://www.oligochaeta.org/ITOM2/IOTM2.htm ; http://bio-eco.eis.ynu.ac.jp/eng/database/earthworm/Octochaetidae5.doc .
• Blakemore, R.J. (2006). Revised Key to Earthworm Families (Ch. 9). In: A Series of Searchable Texts on Earthworm Biodiversity, Ecology and Systematics from Various Regions of the World – 2nd Edition (2006). Eds.: N. Kaneko & M.T. Ito. COE Soil Ecology Research Group, Yokohama National University, Japan. CD-ROM Publication. Website: http://bio-eco.eis.ynu.ac.jp/eng/database/earthworm/.
• Michaelsen, W. (1900). Das Tierreich 10: Vermes, Oligochaeta. Friedländer & Sohn, Berlin. Pp. xxix+575, figs. 1-13. Online here: http://mail2web.com/cgi-bin/redir.asp?lid=0&newsite=http://www.archive.org/details/oligochaeta10mich.
• Stephenson, J. (1930). The Oligochaeta. Clarendon Press, Oxford. Pp. 978.