Polyplacophora (Polyplacophorans)

Polyplacophorans, or chitons are small to large, primitive marine molluscs. There are 900 to 1,000 extant species of chitons in the class, which was formerly known as Amphineura. These molluscs are also sometimes commonly known as sea cradles or "coat-of-mail shells". They are also sometimes referred to more formally as loricates, polyplacophorans, and rarely as polyplacophores. Chitons have a dorsal shell which is composed of eight separate shell plates or valves. These plates overlap somewhat at the front and back edges, and yet the plates articulate well with one another. Because of this, although the plates provide good protection for impacts from above, they nonetheless permit the chiton to flex upward when needed for locomotion over uneven surfaces, and also the animal can slowly curl up into a ball when it is dislodged from the underlying surface. The shell plates are surrounded by a structure known as a girdle.

http://en.wikipedia.org/wiki/Polyplacophora

Chiton bohemicus		XB103
Chiton		p4897
Eochelodes bergenhayni	Marek (1962), Pl. I, fig. 5	LM69
Eochelodes bergenhayni	Marek (1962), Pl. I, fig. 4	LM67
Eochelodes bergenhayni	Marek (1962), Pl. I, fig. 6	LM70
Eochelodes bergenhayni	Marek (1962), Pl. I, fig. 7	LM71
Eochelodes bergenhayni	Marek (1962), Pl. I, fig. 1	LM66
Eochelodes bergenhayni	Marek (1962), Pl. I, fig. 3	LM68
Polyplacophora Blainville, 1816		JK11998
Polyplacophora Blainville, 1816		JK11999

Virtual museum of the Czech Geological Survey, www.geology.cz, (C) Czech Geological Survey, 2011, v.0.99 [13.12.2011]