Annelids

Extant Spirorbis sp. reconstruction, modified from several sources.

Annelids are worms, which are seldom preserved as fossils because of the lack of hard body parts. A type of polychaete worm is known from the Essex fauna. Spirorbis is an example of a polychaete that secreted a tube out of calcium carbonate, which is what we find at Mazon Creek. (link to fossil image roll01 spirorbis)

Find our more about Annelids from the Berkeley site's Introduction to the Polychaeta and Introduction to the Annelida.