Family BITECTIPORIDAE MacGillivray, 1895

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Family BITECTIPORIDAE MacGillivray, 1895

Compiler and date details

July 2001 - Dr Philip Bock

Hippoporinidae Brown, D.A. 1952. The Tertiary cheilostomatous Polyzoa of New Zealand. London : Trustees of the British Museum (Natural History) 405 pp.
Bitectiporidae Macgillivray, P.H. 1895. A monograph of the Tertiary Polyzoa of Victoria. Transactions of the Royal Society of Victoria ns 4: 1-166 [106].

Introduction

The family was introduced by MacGillivray (1895) for the Victorian Tertiary genus Bitectipora. Gordon (1994) investigated the type species, B. lineata, and considered that the Bitectiporidae was a senior subjective synonym of the family Hippoporinidae Brown (1952).

The family is characterised by encrusting colonies, autozooids with frontal shields which have marginal septular pores, and usually numerous pseudopores. Orifices have a wide sinus, oral spines are absent. The ovicells are hyperstomial, not closed by the operculum and have large, sometimes irregular pores on the frontal surface. Avicularia are adventitious, suboral or latero-oral, and have a complete bar.

Gordon (1994) included the genera Metroperiella (which may be a synonym of Codonellina), Schizomavella and Schizosmittina in the family; all of which have Recent Australian representatives. The genus Parkermavella was introduced by Gordon & d'Hondt (1997); Hippomonavella and Hippoporina are also represented in Australian faunas.

Bitectipora includes Recent Victorian B. rostrata (MacGillivray), illustrated by Gordon (1984) as Hippoporina, from New Zealand colonies, which were brownish-black. Metroperiella mortoni (Haswell) is almost certainly M. lepralioides. M. mortoni was reported from Queensland (Gordon 1994). A species described as Lepralia bifrons by Hincks (1884) is closely related to Bitectipora, but has not been described since its introduction. In this species the avicularia do not have a complete bar.

Among several species of Schizomavella from Australia, S. inclusa (Thornely) was illustrated from the Great Barrier Reef by Ryland & Hayward (1992) and S. australis from Torres Strait and the Queensland coast by Harmer (1957). The relationships between the Australian species referred to Schizomavella and the European type species is an open question; some of this group are attributable to Parkermavella, including P. punctigera MacGillivray.

Schizosmittina vitrea (MacGillivray) was figured from southern Australia by Bock (1982) as Smittina maplestonei. Colonies encrusted algae. S. maplestonei is also found in the region, but is distinguished by having a narrow, rather than a broad sinus.

Hippomonavella is represented by the species H. formosa, distributed on the southern Australian shelf. In this genus the frontal shield lacks pseudopores.

Several species from southern Australia appear to be referrable to the genus Hippoporina, including H. elegans MacGillivray.

Hayward (1995) assigned the endemic Antarctic genus Kymella to the Hippoporinidae, but it differs considerably from the Bitectiporidae. The colonies are erect and flustrine, the autozooids have only marginal pores, and the ovicells, which are closed by the operculum, have a membranous ectooecium and imperforate entooecium.

Fossils identified as Hippoporina sp. are known from the Late Eocene of the Indian Ocean (Taylor 1993). Australian fossils from the Tertiary of Victoria include the type species of Bitectipora, B. lineata.

Diagnosis

Colony encrusting or erect. Zooids with a lepralioid ascus. Frontal shield evenly pseudoporous with marginal areolae, or the pseudopores few to absent. Zooidal orifice with or without a lyrula. Articulated oral spines present or absent. Adventitious and vicarious avicularia present or lacking. Ovicell with endooecium and ectooecium calcified but unfused, the ectooecium with several relatively large pores.