Lingula (brachiopod)

Lingula sp. on the beach of Ozamis City (Philippines ).

Lingula is a genus of brachiopods ( Brachiopoda ). The animals live in self-dug in the sandy mud tubes on the shores of tropical and subtropical seas. In contrast to other brachiopods they also tolerate brackish water. The sides of the tube are living with a sticky secretion, which isolate the animals from her coat, solidified. In the tubes they can move up and down with the help of her muscular, long stem. Like all brachiopods Lingula feeds as filter feeders.

In Japan, Southeast Asia and the South Seas the muscular stalk the animals of people being eaten.

Features

Lingula is about 20 inches long with stem and has a zweiklappiges concluded loose housing. The two halves are held together only by closing and opening muscles and not secured by lock pits and teeth. Thus, the flaps are mutually strongly movable, movable and can be used for digging. The housing consists of alternating layers of calcium phosphate, and organic material.

A living fossil

Lingula can be fossil already in the Silurian 400 million years ago to prove, making it one of the geologically oldest, still living species and is considered a living fossil. It has survived both the great mass extinction at the Permian - Triassic boundary as well as the better known at the Cretaceous - Tertiary boundary. The fossil remains can be morphologically indistinguishable from the extant. Also from the Ordovician shells are known Lingula -like brachiopods. Here, however, the shell inside and thus the number and location of muscle attachment points is unknown, so that they can not be assigned to the lingula.

Extant species

• Lingula adamsi Dall, 1873
• Lingula anatina Lamarck, 1801
• Lingula parva Smith, 1871
• Lingula reevei Davidson, 1880
• Lingula rostrum ( Shaw, 1798)
• Lingula translucida Dall, 1920
• Lingula tumidula Reeve, 1841