Muenster (1842), who first recorded the holotype specimen of Muensterella, noted its egg-shaped anatomy and apparent lack of swimming fins.

Fuchs et al. (2003) suggested it possessed marginal fins, as a slight ridge along the sides of its body, when seen under oblique light, can be easily seen.

[1] In two specimens, MC-21 and MC-51, these three-dimensional structures are continuously 100 μm thick, and the gaps between the fibres are of a near-identical size.

In MC-51, almost all of the mantle musculature is preserved, covering the outer surface of the gladius and extending along its length from the posterior end up to the head region.

These muscles appear to have been attached directly to the surface of the lateral sides of the gladius, and run forward up to the location of the funnel.