Tetraspaannidae
Tetraspaannidae is a taxonomic family of extinct marine invertebrates belonging to the phylum Porifera, commonly known as sponges. These sponges are characterized by their spicules, which are microscopic skeletal elements. The spicules in Tetraspaannidae are typically tetraxial, meaning they have four axes, and often exhibit a complex morphology. The family is primarily known from fossil evidence, with remains found in various geological formations dating back to the Mesozoic Era.
The name Tetraspaannidae derives from the Greek word "tetra" meaning four, referring to the tetraxial nature