Phylum Brachiopoda

Classification -

1.Brachiopods are exlusively marine, benthic, sessile, solitary, attached to substratum, and achored with stalk .

2.The stalk like part called as Pedicle which protrudes through an opening called as foramen.

3.Brachiopods are also called as lamp shell.

1.Brachiopods are unequivalved each valve is bilaterally symmetrical.

2.Two types of brachiopods based on hinge line -

a) If hinge line is straight then the shell is called as strophic brachiopod.

b)If himge line is curved then the shell is called as astrophic brachiopod.

3.Commisure plane is horizontal.

4.Plane of symmetry and commisure plane are perpendicular to each other.

5.Ventral valve is always lager than dorsal valve.

6.ventral vslve is called as Pedicle valve and dorsal valve is called brachial valve.

7Pedicle valve is convex in nature.

1.Biconvex- Both the prdicle valve and brachial valve are convex.

2.Concavo-convex- Brachial valve is concave and pedicle valve is convex.

3.Convexo-concave- Brachial valve is concave and pedicle valve is convex.

4.Convexo-plane-Brachial valve is convex and pedicle valve is nearly flat.

5.Plano-covex- Brachial valve is flat and pedicle valve is convex.

6.Dorsi-Biconvex- Both valve are convex but brachial valve is more convex and large in nature.

7.Ventri-Biconvex- Both valves are convex but pedicle valve is more convex and large in nature.