Other specimens appear to be more complete and to represent sessile, radially symmetrical hollow bag-like organisms with a soft skin armored with star-shaped calcareous sclerites from which radiate sharp spines.

[5] Chancelloriids probably lived on muddy sea-floors, as their sclerites increase in size from the bottom to the top, and all had thickenings at the bases, which are regarded as anchors;[5] they are often preserved in attachment to other organisms or shelly debris.

[10] Butterfield and Nicholas (1996) argued that they were closely related to sponges on the grounds that the detailed structure of chancellorid sclerites is similar to that of fibers of spongin, a collagen protein, in modern keratose (horny) demosponges such as Darwinella.

[11] However Janussen, Steiner and Zhu (2002) opposed this view, arguing that: spongin does not appear in all Porifera, but may be a defining feature of the demosponges; the silica-based spines of demosponges are secreted by specialist sclerocyte cells that surround them, while mineralized chancellorid sclerites were hollow and filled with soft tissues connected to the rest of the animal by restricted openings in the bases of the sclerites; chancellorid sclerites were probably made of aragonite, which is not found in demosponges, and the only sponges that use aragonite are the sclerosponges, whose soft bodies cover hard, often massive skeletons made of either aragonite or calcite, another form of calcium carbonate; sponges have loosely bound-together skins called pinacoderms, which are only one cell thick, while the skins of chancellorids were much thicker and shows signs of connective structures called belt desmosomes.

In their opinion the presence of belt desmosomes made chancellorids members of the Epitheliazoa, the next higher taxon above the Porifera, to which sponges belong.

The hollow "coelosclerites" of halkieriids and chancelloriids resemble each other at all levels: both have a thin external organic layer, and an internal "pulp cavity" that is connected to the rest of the body by a narrow channel; the walls of both are made of the same material, aragonite; the arrangement of the aragonite fibers in each is the same, running mainly from base to tip but with each being closer to the surface at the end nearest the tip.

Porter thought it extremely improbable that totally unrelated organisms could have developed such similar sclerites independently, but the huge difference in the structures of their bodies makes it hard to see how they could be closely related.