Calcarea (Calcispongea; phylum Porifera) A class of sponge, ranging from Cambrian to Recent, in which the skeleton is made entirely of calcareous spicules which are commonly of a tuning-fork shape. The sponges are sometimes associated with reefs in the Jurassic, or they may form widespread sponge beds.
More From encyclopedia.com
Heterodonta , Heterodonta (phylum Mollusca, class Bivalvia) A subclass of bivalves which have heterodont dentition consisting of a hinge plate with distinct cardin… Shape , shape / shāp/ • n. 1. the external form or appearance characteristic of someone or something; the outline of an area or figure: she liked the shape o… Form , FORM From the Latin forma, a term signifying figure or shape or "that which is seen" (Gr. ε[symbol omitted]δος) and having many derived meanings, suc… Glass Sponges , Hexactinellida (Hyalospongea; phylum Porifera) A group of sponges that first appeared in the Cambrian. They are of normal sponge shape and have skele… Demosponges , Demospongiae (Demospongea; phylum Porifera) A class of sponges which occur in both marine and freshwater environments. They have a leucon body struct… Monoplacophorans , Monoplacophora (phylum Mollusca) A class of primitive, almost bilaterally symmetrical, univalved molluscs, whose limpet-shaped shell of calcium carbo…
About this article
All Sources -
Updated About encyclopedia.com content Print Topic