It has sand-filled tubes, although these may not have been sand-filled in life. It has a shield-like shape, with one end different from the other, and bilateral symmetry, and although it has been suggested that it possesses glide reflection symmetry, such suggestions are based upon a taphonomic effect deforming some specimens.
It has tubes filled with sand, though these might not have contained sand in its original state. It has a shield-like form, with one end distinct from the other and exhibiting bilateral symmetry. Although it is believed to possess glide reflection symmetry due to taphonomic deformation affecting some specimens, such claims are based on specimen distortion.