annelids (Annelida). Their living tubes are the elements with the greatest chances of preservation in the
fossil state. Biochemical studies on Recent pogonophores showed that a chitin-protein complex is the
basic structural component of these tubes.
The morphology of tubes is of importance for the taxonomy of Pogonophora. Features such as
length, diameter and ornamentation of the tubes and their differentiation into sections are helpful in
identification of species and genera, whereas they appear insufficient as criteria for families and orders.
Therefore, I consider that all the fossil pogonophores should be treated as forms of incertae ordinis et
familiae. In working on fossil pogonophores one should bear in mind possibility of essential
differences between individual section of a given tube. The situation is addtionally complicated by the
fact that all the fossil tubes hitherto described are known only on the basis of fragments. The case of
the Recent Pogonophora is not dissimilar because the material coming from seas is usually crushed.
Sokolovites pogonophoroides Kozłowski, 1967
Beklemishevites grandis Mierzejewski, 1986