Description

Silicified Sponge

Cretaceous

Garraf, Catalonia, Can Casanyas Castellet, Spain

52mm silicified sponge.

Paleontologists consider sponges to be among the oldest groups of modern animals.  It appears that they diverged from their ancestors in Precambrian time because Cambrian-age sponges already bear the same biomineralized skeletal structure as modern forms.  How that skeleton evolved from a more simple form remains a mystery.

Bonus Natural Canvas Helpful Hint: Don’t try to wipe up messes on your counter with a fossil sponge.  It will either damage the counter or the sponge.