Animal Phyla/Gnathostomulida

Gnathostomulida Name Meaning: Jaw orifice English Common Name: Jaw worms Major distinguishing characteristics: Approximate number of species described: about 300

Natural History
Jaw worms are all aquatic and marine. They live in the sand and mud in shallow coastal waters.

Taxonomy
There are two recognized orders within the Phylum Gnathostomulida.


 * Filospermoidea
 * Bursovaginoidea

Anatomy
The powerfully jawed mouth is just behind the head end and opens into a blind-ending tube. There is no anus. They have no circulatory or respiratory system.

They are hermaphroditic, with one ovary and two testes.

The Fossil Record
There is no known fossil record.

Quiz

 * /Gnathostomulida Quiz/

References and Further Reading

 * [Gnathostumulida] at Wikipedia
 * Gnathostumulida at Tree of Life
 * Gnathostumulida at Encyclopedia of Life