Family CUPULADRIIDAE Lagaaij, 1952

Museums

Regional Maps

Introduction

The Cupuladriidae was introduced by Lagaaij (1952) for Cupuladria only. Cook (1965a and b) revised the family, including Discoporella and species now assigned to Reussirella (Cook & Chimonides, 1994). The colony form is superficially similar to that of the other 'lunulite' bryozoans of the Families Lunulariidae, Lunulitidae, Selenariidae and Otionellidae.

The family is characterised by its discoidal or cup-shaped (lunulitiform) colonies, which rarely exceed 20 mm in diameter. Each radially budded autozooid has a small, distally placed avicularium with a long, bristle-like mandible. Colonies originate upon a minute substratum, rapidly growing beyond it.

The concave basal surface is formed by radial compartments of extrazooidal coelom which alternate with the autozooid rows overlying them and are enclosed by a basal cuticle. Virtually all calcified walls are interior. The avicularia alternate in asymmetry in each radial series, and the mandibles are slung on paired condyles. Larvae are brooded in ovisacs and have a short free-swimming life (Winston 1988). Colonies are typically indicators of a 'sand fauna'; they live upon or within the upper layers of particulate sediments, supported and stabilised by the more peripheral avicularian mandibles. Normal orientation is with the convex zooidal side uppermost, but colonies can feed in any position. Mandibular action enables them to turn over, move vertically through the sediment and to clear particles from the zooidal surface. The family has an extensive fossil record from the Paleocene onward. Lagaaij (1963) gave a detailed and comprehensive account of the fossil and Recent distribution of species now included in the C. canariensis - complex, and discussed their ecology and palaeoecology.

The genus Cupuladria has autozooids with a simple marginal cryptocyst, and small basal sectors, each of which has one or more pores which are often enlarged to form vertical series of chambers. The only Australian species, C. guineensis (Busk, 1854), does not have enlarged basal chambers. It occurs from the Philippines and East Indies, as well as from Western Australia and Queensland, in shelf waters from 16 to 60 metres. Previous reports from Bass Strait have not been confirmed by subsequent collections, but Cupuladria is known to occur in the Miocene deposits in Victoria.

Diagnosis

Colony free-living, cap-shaped, zooids opening on convex surface, budded radially from triple ancestrular complex encrusting a sand grain. Basal surface of extrazooidal tissue in radial compartments alternating with overlying zooidal rows. Autozooids with narrow marginal cryptocyst, or with a cryptocystal layer perforated by several openings. An avicularium is associated with each autozooid, in a distal position. Avicularian mandibles setiform, pivoting on pair of condyles. Larvae brooded internally; no visible differentiation of brooding zooids.

General References

Busk, G. 1854. Catalogue of Marine Polyzoa in the collection of the British Museum, Part 2. London : Trustees of the British Museum 55-120 pp.

Cook, P.L. 1965. Notes on the Cupuladriidae (Polyzoa, Anasca). Bulletin of the British Museum (Natural History) Zoology 13: 151-187

Cook, P.L. 1965. Polyzoa from West Africa. The Cupuladriidae (Cheilostomata, Anasca). Bulletin of the British Museum (Natural History) Zoology 13: 189-227

Cook, P.L., & Chimonides, P.J. 1994. Notes on the genus Anoteropora (Bryozoa, Cheilostomata). Zoologica Scripta 23: 51-59

Lagaaij, R. 1952. The Pliocene Bryozoa of the Low Countries and their bearing on the marine stratigraphy of the North Sea region. Mededelingen van de Geologische Stichting, (Serie C) 5: 6-233

Lagaaij, R. 1963. Cupuladria canariensis (Busk) - portrait of a bryozoan. Palaeontology 6: 172-217

Winston, J.E. 1988. Life histories of free-living bryozoans. National Geographic Research & Exploration 4: 528-539

History of changes