Archedota O’Loughlin, 2007

O’Loughlin, P. Mark, 2007, New apodid species from southern Australia (Echinodermata: Holothuroidea: Apodida), Memoirs of Museum Victoria 64, pp. 53-70 : 55

Archedota O’Loughlin gen. nov.

Figure 1

Diagnosis. Taeniogyrid genus with body wall ossicles irregular thick spinous plates with wheel-spoked perforations with complex hubs, and rare chiridotid wheels; lacking sigmoid hooks.

Type species. Archedota lapidea O’Loughlin sp. nov. (below; monotypic)

Distribution. Australia, Victoria, western Bass Strait, 39°S 143°E, 92– 85 m.

Etymology. From the Greek arche (old, beginning), referring to the apparently primitive form of the wheel-spoked perforated plates, with dota from the family name Chiridotidae (feminine).

Remarks. The characters of this new apodid genus Archedota O’Loughlin gen. nov. are in accord with the above diagnoses of suborder, family and subfamily, with the exception of the presence of spinous plates with wheel-spoked perforations. This significant diagnostic character difference supports the erection of new higher taxa (suborder, family, subfamily), but on the basis of having only 2 specimens, and in the absence of molecular genetic data, I am limiting my response to the erection of a new genus only. Archedota lapidea O’Loughlin sp. nov. (below) differs only in ossicle form from the other genera of Chiridotidae . The presence of wheel-spoked single perforations in thick, closely spinous plates is a unique character amongst the chiridotids. Rare chiridotid-type wheels are present amongst the abundant, massed, perforated wheel-spoked plates. Absence of sigmoid hooks is also exceptional within the diagnosis of Taeniogyrinae . I acknowledge that in subjectively describing (etymology) the plate ossicles as “primitive”, and perhaps precursors to wheel ossicles, the form of the plates may in fact indicate a regressive condition or wheel ossicles with secondary developments.