feather duster with 2 crowns...common?

[beaniebeagle]

my feather duster now have 2 crowns.

is this common????

 

[LeslieH]

What kind is it? Can you post a pic? The branchial crowns are made up of 2 half circles. In some species the half circles are simple and appear to make up one single whorl. In others the half circles add radiolar filaments as they grow and the bases elongate to become long stalks; these appears to be 2 separate whorls as in Christmas Tree Worms or Coco Worms.