Phylum: Porifera
Sponges
are simple animals that vary in size and shape.
They first appeared during the Precambrian Era and are still living in
our oceans today. Sponges are almost
entirely marine animals which usually attach themselves to firm objects on the
ocean’s floor because they lack the ability to move around. The animals in the Porifera phylum are the
simplest multi-cellular animals. They
lack true tissue and have no nerves, muscles, or glands. There are two layers of cells in a sponge
with a jelly-like material between them.
This jelly-like material holds the spicules which make up the skeleton
of the sponge. Most sponge’s spicules
are not joined, and when they die, the spicules are scattered on the ocean
floor, leaving little evidence of the sponge’s past life. A few, however, have the spicules fused and
form a rigid skeleton. The latter would
be the types collected in the Pennsylvanian Age rocks in Kansas, such as Girtyocoelia
and Amblysiphonella.
When identifying a sponge, look at the end; it simply looks like a tube.
The Porifera phylum is divided into four classes.
Class Demospongea (Precambrian to Recent)
Most living sponges belong to this class. The spicules are made up of spongin, which is a protein material. Common fossilized sponges found in Kansas in this class include Girtyocoelia, Meandrostia, and Amblysiphonella.
When identifying a sponge, look at the end; it simply looks like a tube.
The Porifera phylum is divided into four classes.
Class Demospongea (Precambrian to Recent)
Most living sponges belong to this class. The spicules are made up of spongin, which is a protein material. Common fossilized sponges found in Kansas in this class include Girtyocoelia, Meandrostia, and Amblysiphonella.
Class Hexactinellida (Cambrian to Recent)
Commonly known as the glass sponges. Their spicules are made up of siliceous material and form a rigid framework. Not commonly found in Kansas.
Class Calcarea (Ordovician to Recent)
This class is sometimes called Calcispongea. They represent the most primitive sponges. The spicules are usually made up of calcareous material which is fused together into a rigid framework.
Class Stromatoporidea
This class is thought by some to belong to the Phylum Cnidaria or the Kingdom Monera (blue-green algae). They are included among the sponges today because of their similarity to modern sponges which have calcareous skeletons and siliceous spicules. This class was important reef builders during the Silurian and Devonian Periods. To identify this class of sponges to a genus is nearly impossible and should not be attempted.
Commonly known as the glass sponges. Their spicules are made up of siliceous material and form a rigid framework. Not commonly found in Kansas.
Class Calcarea (Ordovician to Recent)
This class is sometimes called Calcispongea. They represent the most primitive sponges. The spicules are usually made up of calcareous material which is fused together into a rigid framework.
Class Stromatoporidea
This class is thought by some to belong to the Phylum Cnidaria or the Kingdom Monera (blue-green algae). They are included among the sponges today because of their similarity to modern sponges which have calcareous skeletons and siliceous spicules. This class was important reef builders during the Silurian and Devonian Periods. To identify this class of sponges to a genus is nearly impossible and should not be attempted.