Age: Jurassic.
Location: South Europe.
Calcareous sponge.
The limestones are a class of the phylum Porifera. They are the only
sponges whose mineral skeleton is composed of spicules of crystallized calcium
carbonate in the form of calcite or aragonite. They are believed to be the most
primitive group of sponges.
Measures: 5 cm x 3,5 cm