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Seashell or known as a sea
shell, or just call it simply as a shell, a common
name for a hard, protective outer layer that was
created by a sea creature, a marine organism. The
shell is part of the body of a marine organism. In
most cases a shell is an exoskeleton, usually that
of a creatures without a backbone, an invertebrate.
Seashells are most often found on sandy beaches, see
articles for finding
seashells.
The word seashell is most often
used to mean the shells of marine mollusks. It can
however also be used to mean the shells of a wide
variety of other marine organism from various
different phyla. For helpful introductory Seashells
articles, see marine invertebrates and marine
biology.
As well as marine mollusks,
many other kinds of sea creatures have exoskeletons
or even internal shells which sometimes, after
death, wash up on the beach. These shells include
remains from species in other invertebrate phyla,
such as the moulted shells or exuviae of crabs and
lobsters, horseshoe crab shells, the shells of
barnacles, the tests (endoskeletons) of sea urchins,
brachiopod shells, sand dollars and seastars, and
the shells of marine annelid worms in the family
Serpulidae, which create calcareous tubes cemented
onto other surfaces.
Seashells have been
admired, studied and used by humans for
crafts,
decorations, bangles, and many different purposes
throughout history and pre-history. |
