Wikipedia
Cambroclave
Cambroclaves are a group of enigmatic, phosphatized, hollow spine-shaped sclerites, known from their geographically widespread Early to Middle Cambrian fossils. They were probably originally aragonitic. They are lobate with long spines protruding centrally; these spines are in some cases (e.g. Zhijinites) pillar-like, constituted of a bundle rods (originally aragonite?) with an Ionic-like appearance. It has been suggested that they represent the spicules of an ecdysozoan worm.