Lingulida Waagen 1885

Figures illustrating the tubes in which Lingula anatifera lives. The upper figure is a view of the trilobed opening of the tube. The lower figure shows the tube in the sand laid open and the animal exposed. The dotted line indicates the position of the body when retrcted. The darker portion is the tube of sand agglutinated by the secretion of the stalk..

Muscle-scars of Lingula anatina. Inner survace of A, Pedicle-valve or ventral valve. B, Brachial or dorsal valve..

Lingula is often cited as an example of a living fossil, an organism that has hardly changed over geological time.