Bryozoans of the order Melicerititida: Morphological features and position of the order in the taxonomic structure of the class Stenolaemata

Resumo

Morphological features of a distinctive group of Post-Paleozoic bryozoans belonging to the order Melicerititida (Stenolaemata) are discussed. They include funnel-shaped zooecia, facettes, semicircular zooecial apertures with a straight proximal edge, calcified opercula, and various types of vicarious eleozooecia, which resemble avicularia of cheilostome bryozoans. These morphological structures are unique within the class Stenolaemata. They not only differentiate these bryozoans both morphologically and evolutionarily from Cyclostomata, in which some authors place them, but also from all the other orders of this class.