Calcinea

Calcinea is a subclass of the calcareous sponges (class Calcarea) within the phylum Porifera. Members of Calcinea are marine sponges that produce skeletons made of calcium carbonate, distinguishing them from siliceous sponges. The group includes a diversity of forms, ranging from simple to more complex body plans, and they occur in a variety of marine habitats.

Taxonomy and distinguishing features: Calcinea is one of the two major lineages traditionally recognized within Calcarea, the other being Calcaronea. Calcinea differ from Calcaronea in certain microscopic features of their spicules and patterns of skeleton formation. Across the subclass, spicule types and arrangements serve as key characters for classification, and Calcinea collectively show a range of skeletal organization and body morphology.

Distribution and ecology: Extant Calcinea species are found worldwide in marine environments, from shallow coastal zones to deeper waters. They can form encrusting sheets, forming walls or cushions, or contribute branching and massive structures that contribute to local habitat complexity.

Fossil record and significance: Calcareous sponges, including Calcinea, have a fossil record that extends back to early in the Paleozoic era, providing insight into the early evolution of multicellular animals and the development of marine reef and benthic ecosystems. Calcinea, like other calcareous sponges, contribute to understanding ancient marine biodiversity and skeletal evolution.

Etymology: The name Calcinea derives from Latin roots related to lime or lime-like substances, reflecting their calcium carbonate skeletons. See also: Calcareous sponge, Porifera, Taxonomy.