Polychaete Worms (Bristle Worms)

Considered one of the most diverse assemblages in the fossil record, the marine polychaete worms of Mazon Creek were large, predacious, and free swimming. This contrasts present-day marine polychaetes, which are generally small, sedentary, and deposit- or suspension- feeders. The polychaete body is a cylinder of muscles in segmented units. Chitinous bristles (chaetae) are secreted by the epidermis and adorn the body and extensions of the segments. Today, Polychaetes as a class are robust, with over 10,000 described species, and widespread in every type of ocean habitat. 

1. Mazopherusa prinosi, commonly called the Fan Worm, is considered a colonial animal and rather sluggish. While fan worms rest in their burrows, they extend their fans to create eddies causing detritus to fall into their mouths.