|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Polyplacophora - Multiplacophora
If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.
|M. J. Vendrasco et al. 2004||As for order, but with valves ornamented with low radial ridges and grooves. Marginal spines have a concave upper surface, a porous external layer and two peg-like projections of the underlying shell layer on the proximal end. Valves are ornamented with radiating ridges and faint growth lines. Head valve is suboval in dorsal view, arched, slightly longer than wide and with distinct mucro. The anterior-most lateral valve has a flat, triangular lateral surface and is as long as it is wide. The remaining lateral valves are suboval in dorsal view, highly arched, slightly wider than long and with a distinct apex. The central valves range from squarish in dorsal view (near the head valve) to spinose (near the tail valve). The tail valve has a distinct mucro close to the rounded posterior margin.|