MORPHOLOGICAL DIFFERENTIATION OF AVICULARIA AND THE PROLIFERATION OF SPECIES IN MID-CRETACEOUS WILBERTOPORA CHEETHAM, 1954 (BRYOZOA: CHEILOSTOMATA)

摘要

Discovery of avicularium-like polymorphs in Wilbertopora mutabilis Cheetham, 1954 has provided not only a new opportunity for revising the genus Wilbertopora Cheetham, 1954, but also a more detailed basis for documenting the series of morphological changes by which avicularia differentiated from ordinary feeding zooids in what appears to be the first occurrence of these characteristic cheilostome bryozoan structures in the fossil record.