Mural "Hoods" in the Basal Walls of Cyclostome Bryozoans and their Taxonomic Distribution Mural "Hoods" in the Basal Walls of Cyclostome Bryozoans and their Taxonomic Distribution
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Domed mural "hoods" with distinct, pore-like openings occur on the inner accretionary surface of the basal walls of at least twelve species (representing four suborders) of cyclostome bryozoans. The openings are invariably on the proximal side with respect to skeletal wall growth direction. Mural hoods develop independently of skeletal ultrastructural fabric type, with similar structures occurring in walls representing a wide range of fabric suites. The structures are variable in size and shape, varying in outline from sub-circular or oval to pear-shaped, sometimes with a distinct, tubular extension leading to the opening. Variations in hood size and shape in different species may be potentially useful taxonomically to the genus level, and as hard part characters for phylogenetic analysis. The arrangement and direction of hood openings in the protoecium (primary disc) lend support to ultrastructure-based inferences of centripetal growth of the basal floor of the disc.
- Species Diversity
Species Diversity 2(2), 105-119, 1997
The Japanese Society of Systematic Zoology