Silicified Sponge – Moretiella elegans
Cretaceous
Garraf, Catalonia, Can Casanyas Castellet, Spain.

39mm silicified sponge.

Moretiella is a genus of sea sponge best known from the Early Cretaceous of Europe but also found in Late Cretaceous deposits.

Sponges are a truly ancient group of animals.  Back in the Cambrian they bore the same biomineralized skeletal structure that we see in forms today while every other phylum of the time was still getting its act together.  The origins of that skeleton remain undiscovered somewhere in the depths of the Precambrian.

Vive Bob L’Eponge!