Nuculidae

Acila cobboldiae

The nut shells ( Nuculidae ) are a family of the superfamily Nuculoidea within the order of Nuculoida. They are considered the most ancient ( living fossil ) shells, and Nucula is their most well-known genus.

Characteristics

The family includes the Nußmuscheln quite small, only about one centimeter species. The housing is often truncated behind gets thereby a triangular shape. The sphincters are both identical thickness, the nut shells have no Sipho and no byssus gland. The wide -area walk reminiscent of the creeping of some snails.

Way of life

The Nußmuscheln live largely buried in soft sediment. The gills, simple Fiederkiemen, no importance is in food intake; the walnut shells do not filter their food, but they gather with their labial palps ( = " tentacle -like appendages of the mouth " ) a. It is typical detritus.

Genus

The genus Nucula is the fossil record since the Devon and contributes to the understanding of the nature of the other mollusc shells, as Nucula embodies an ancient shell type. Even if none of the recent Nucula species has a fossil record, they can still be described as " living fossils ". The oldest representatives of Nußmuscheln are already represented in the Lower Ordovician.

System

Some important genera:

• Acila
• Nucula
• Nuculoma
• Nuculopsis
• Palaeonucula