What is the fog?

and bivalve is a type of water soft with double -sided symmetrical shell. Each side of the shell is valve ; Therefore, gastropods such as snails are sometimes called univalves . Common types of fogs include clams, oysters and shells. There are both freshwater and sea fog. In Brachiopod, two halves of the upper and lower body of the animal indicate, while both sides of the shells are left and right half in the fog. In addition, fogs have much more morphological sophistication and diversity than brachiopods. For example, many of them have evolved as a mobile, while all brachiopods are sessile or connected to the substrate.

The brigar will first appear in a fossil record about 520 million years ago, near the end of the period known as Cambrian Exporsion. Brachiopods appear earlier in the Cambrian period and are much more numerous in the paleozoic era than foggy molluscs. After 96% of the Brachiopod generations disappeared during the end-Permian EXTICTION event that meant closingThe paleozoic era, began to dominate the fog. The types of bivories survived the extinction event better than most groups, with only 59% of the genera disappeared.

Impressive survival during the End-Permian Extinction event, as well as their later proliferation and contemporary success, is probably related to their many sophisticated sea life adaptations. Instead of using muscles to open and close their shells, as brachiopods do, fogs use muscles to close the shell, but naturally open when the muscle is released to help liga. This adaptation allows the fogs to save energy. Lack radule, a structure similar to the dental tongue used by other molluscs to eat, and instead are filter feed.

Many types of fogs are mobile, even if they move in different ways. Some are driven by opening and closing, suction and water exclusion. Others have a leg that helps themmove and dig. Many types of silence can plunge into sand or even rock or wood, allowing them to avoid predators. Some of the more mobile varieties become predators themselves.