Galathowenia, KIRKEGAARD, 1959

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 : 240-241

GENUS GALATHOWENIA KIRKEGAARD, 1959 ,

EMENDED

Galathowenia Kirkegaard, 1959 ; Fauchald, 1977; Blake, 1984, 2000.

Clymenia Ørsted, 1844 [not Münster (Ammonoidea)].

Psammocollus Grube, 1866 .

Emended diagnosis: Head cylindrical, anteriorly truncated, terminal mouth extending midventrally as an elongated slit and with ventral pharyngeal organ. Breakage groove between first and second chaetiger. Oesophageal commissure Y-shaped. First three segments generally uniramous, with capillaries on notopodia. Following segments biramous, notopodia with capillary chaetae only and neuropodial uncini with two teeth generally obliquely arranged.

Type species: Galathowenia africana Kirkegaard, 1959 , by original designation.

Remarks: The presence of a breakage groove between the first and second chaetiger has been identified in several species of the genus ( Blake, 1984; Parapar, 2001, 2003a), including the type material of the type species (as drawn by Kirkegaard, 1959 and studied by J. P.), as a line of autotomy. Although it has not been described in several other Galathowenia species it could have been overlooked and represents a potential synapomorphy for the genus ( Fig. 1B ). Other main features characterizing Galathowenia are the presence of a cylindrical head with a truncated anterior end, an attribute shared with Owenia but differing from this genus in lacking a tentacular crown, and the presence of a ventral slit with prominent lateral lips. An exception to this head shape, with the ventral slit not well developed, is G. australis ( Grube, 1866) , which has been shown here not to belong to this group ( Fig. 1C, D ), contrary to earlier studies ( Parapar, 2003b).

Figures

Figure 1. A, strict consensus of 185 most parsimonious cladograms with equal weighting for species of Oweniidae with jackknife support values> 50 below nodes. B, first most parsimonious tree (tree length: 86 steps, consistency index: 0.56; retention index: 0.76); solid circles represent unique transformations and open circles multiple transformations. C, strict consensus of seven most parsimonious trees with implied weighting (k, concavity constant = 3–4). D, most parsimonious tree with implied weighting (k = 20). The generic names used in this figure correspond to the classification of the species previous to the present study.