Silicified Sponge

Cretaceous

Garraf, Catalonia, Can Casanyas Castellet, Spain

62mm silicified sponge cluster.

Sponges are a truly ancient group of animals.  During the Cambrian, they already had the same biomineralized skeleton they have today.  Their ancestors go back somewhere in the Precambrian.  The Cretaceous is like last Thursday to them.