- This does not have a nervous system
- They are the only sponges that have spicules composed of calcium carbonate
- The spicules don't have hollow axial canals
- The Calcarea first appears at the base of the Lower Cambrian and has been alive until the present day
- The Calcarea has over 100 fossils know to man
- The diversity of the sponges today is greatest in the tropics, just like most marine groups
- They are found in shallow waters, and at least one species is known from a depth of 4,000 meters
- The fossil record of the Calcarea indicates that it has always been living near the shallow water settings
- They are the only sponges that have spicules composed of calcium carbonate
- The spicules don't have hollow axial canals
- The Calcarea first appears at the base of the Lower Cambrian and has been alive until the present day
- The Calcarea has over 100 fossils know to man
- The diversity of the sponges today is greatest in the tropics, just like most marine groups
- They are found in shallow waters, and at least one species is known from a depth of 4,000 meters
- The fossil record of the Calcarea indicates that it has always been living near the shallow water settings