Acanthopleura spinosa showing its eight valves and surrounding girdle. Chitons are small to large primitive marine Mollusks in the class Polyplacophora.

Valves, when referring to Chitons, are eight dorsal, articulated shell plates, which are frequently brightly coloured and/or sculptured. Chitons are small to large primitive marine Mollusks in the class Polyplacophora. In Anatomy, the dorsum is the upper side of animals that typically run fly or swim in a horizontal position and the back side of animals (like humans that walk upright These valves contain unique microscopic structures called aesthetes which appear to have both sensory and secretory functions.

Tonicella lineata illustrating the coloration possible in chitons. Tonicella lineata, commonly known as the lined chiton, is a species of Chiton.

The valves are embedded in a fleshy, muscular, flexible girdle which may bear calcareous scales or spicules and is sometimes highly coloured or patterned. Calcareous refers to a Sediment, Sedimentary rock, or Soil type which is formed from or contains a high proportion of Calcium carbonate in the This article is about the skeletal structure See also Spicule (solar physics and Spicule (glass manufacture. The girdle and articulated valves allow the animal to curl up if it becomes detached.

Valves can also refer to the two shells in a bivalve mollusc. Bivalves are Molluscs belonging to the class Bivalvia. They have two-part shells and typically both valves are symmetrical along the hinge line Molluscs are animals belonging to the phylum Mollusca. There are around 250000 extant Species within the phylum with an estimated 70000

References

• [1]