OWENIIDAE RIOJA, 1917

Capa, Maria, Parapar, Julio & Hutchings, Pat, 2012, Phylogeny of Oweniidae (Polychaeta) based on morphological data and taxonomic revision of Australian fauna, Zoological Journal of the Linnean Society 166 (2), pp. 236-278 : 240

FAMILY OWENIIDAE RIOJA, 1917 , EMENDED

Ammocharidea Kinberg, 1866. Ammocharidae Malmgren, 1867 .

Oweniidae Rioja, 1917 ; Fauchald, 1977; Nilsen &

Holthe, 1985; Blake, 2000.

Emended diagnosis: Body cylindrical. Prostomium and peristomium fused forming the head. Nuchal organs absent. Mouth terminal or shifted ventrally. Segments of unequal length present. Anterior region with one to three short, contiguous or not, uniramous segments, following segments biramous. Notopodial chaetae emerging from body wall, capillaries with characteristic structure of the cortex, resembling small imbricate scales and, on occasions, smooth acicular chaetae. Neuropodia as low tori with irregular rows of bidentate uncini. Parapodial branchiae or cirri absent. Tube as a thin secreted layer encrusted with foreign objects. Distinct mitraria larvae. Intraepidermal nerve cord present.

Remarks: Previous diagnoses or descriptions of the family (e.g. Rioja, 1917; Fauchald, 1977; Nilsen & Holthe, 1985; Blake, 2000) did not include some of the features that were revealed as synapomorphies after our analyses and therefore these features have been incorporated in the emended diagnosis of the family. Nevertheless, the definition of Oweniidae consists of a unique combination of homoplastic characters. The presence of the collar or anterior head appendages (tentacular crown, palps, and lobes) and the shape of the pygidium have been excluded from the diagnosis because of high variation within the group. According to the present study, the family is composed of four genera: Owenia , Myriochele , Galathowenia , and Myriowenia , with about 55 species (Villalobos- Guerrero, 2009).