Glomerula (= Calcisabella) piloseta Perkins, 1991, Recent, Australia, polished longitudinal section of the tube, treated with 1% acetic acid for 2 min.

 

The tube wall in Recent Glomerula  piloseta is composed of subparallel lamellae of aragonitic irregular spherulitic prisms in the inner layer, and spherulites in the outer layer. Calcified lamellae are separated by organic films of different thickness. Tube ultrastructure of Jurassic and Cretaceous Glomerula is simialr to that of Recent Calcisabella supporting synonymy of these genera proposed by Jäger (2004).

 

References

Jäger, M. 2004. Serpulidae und Spirorbidae (Polychaeta sedentaria) aus Campan und Maastricht von Norddeutschland, den Niederlanden, Belgien und angrenzenden Gebieten. Geologisches Jahrbuch, A157, 121-249.

Perkins, T. H.1991. Calcisabella piloseta, a new genus and species of Sabellinae (Polychaeta: Sabellidae). Bulletin of Marine Science, 48, 261-267.