Diastoporidae Busk, 1859

Gordon, Dennis P. & Taylor, Paul D., 2010, New seamount- and ridge-associated cyclostome Bryozoa from New Zealand, Zootaxa 2533 (1), pp. 43-68 : 46-47

Family Diastoporidae Busk, 1859

Remarks. While Diastoporidae and Plagioeciidae have generally been regarded as synonymous, molecular evidence ( Waeschenbach et al. 2009) suggests that the two families may differ: Plagioecia falls within a major clade that also contains Lichenoporidae and Densiporidae , whereas the other sequenced genera ( Cardioecia , Diplosolen , Entalophoroecia ) traditionally assigned to Plagioeciidae belong to a second major clade that contains Frondipora and Horneridae . The type genus of Diastoporidae is a Jurassic–Cretaceous fossil. However, morphologically it appears closer to Cardioecia and Entalophoroecia than to Plagioecia . Therefore, we provisionally recognise Diastoporidae and Plagioeciidae as distinct families pending a more complete study of cyclostome phylogeny.

Discantenna n. gen.

Type species. Discantenna tumba n. sp., by monotypy.

Etymology. From the resemblance of the elevated discoidal part of the colony to a dish antenna (Latin discus, plate, dish + antenna, antenna).

Diagnosis. Colony with narrow encrusting base, initially forming a linear biserial structure, its distal end developing an erect column that flares outwards at its summit as a bereniciform disk in which zooids are centripetally arranged. Brood chamber simple, transversely oval, densely pseudoporous, not pierced by zooidal peristomes; ooeciostome terminal, cowl-like, concealing ooeciopore.

Remarks. A new monotypic genus is introduced here for the following species. It invites comparison with Penciletta Gray, 1848 (Tubuliporidae) , the type species of which, P. penicillata ( Fabricius, 1780) , has an oligo- to pluriserial encrusting portion with erect peristomes; from this base arise one or more erect capitula, each with an apical disc. The brood chamber in fertile colonies occupies much of this disc, ramifying between the short rows of connate peristomes. Discantenna differs most significantly from Penciletta in the form of the brood chamber, which is more “diastoporiform”, being transversely elongate with a short, cowl-like ooeciostome. The genus Plagioecia Canu, 1918 contains some species with erect branches but these arise from an initial radially encrusting colony and the brood chamber is pierced by zooidal peristomes. Discantenna is not included in the Oncousoeciidae because the brood chamber is transversely elongate and, while not pierced by zooidal peristomes, is crossed by at least one peristome so that the brood chamber appears on either side of it.