Most shells come from soft-bodied mollusks. Snails, clams, oysters, and others need the hard protection of their shells. This tough outer covering protects the tasty body hiding inside. Other animals, such as crabs and lobsters, also make a tough outer covering, but here we focus on mollusk shells.
One question we ran across in our research was “Where do shells come from?”.
The most common answer is, Their whorls, curves, and shiny iridescent insides are the remains of animals. Most shells come from soft-bodied mollusks. Snails, clams, oysters, and others need the hard protection of their shells.
One answer is, the currently accepted understanding of how shell forms is that the protein matrix of bone and seashell is secreted out of the cells. These proteins tend to bind calcium ions while guiding and directing calcification. Binding of calcium ions to the protein matrix enhances crystal formation according to precise hierarchical arrangements.
What are the different types of shells?
Common types of shells include seashells, land snail shells, turtle shells or even crab shells. All those animals make their shells in different ways, but my research is all about the sea so today we will focus on seashells. All those seashells you find on the beach were actually once home to small, soft-bodied creatures called molluscs.
Where do seashells come from on the beach?
Most seashells on the beach come from Mollusks, but because there is such a wide variety of different kinds you will find all sorts of shells that a mollusk has left behind. These include: Gastropods – sea snails. These are the most commonly found shells and have a spiral shape.
Strong, healthy seashells are made mostly of calcium carbonate. (So are eggshells!) A mollusk produces calcium carbonate from its mantle, laying down layers of it over its lifetime. Together, those layers form the seashell. You can think of a seashell kind of like your own hair.
Is a seashell a living thing?
You can think of a seashell kind of like your own hair. Your hair grows and is part of you, but it isn’t alive on its own. A living mollusk produces a shell with its body, but the shell itself isn’t alive.
Are there shell middens in the United States?
There are fairly recent shell middens in Australia, within the last couple hundred years anyway, and the most recent shell middens in the United States that I’m aware of date to the late 19th century and early 20th century AD when the shell button industry was in progress along the Mississippi River.
Aboriginal shell middens are distinct concentrations of shell. They contain evidence of past Aboriginal These middens consist primarily of concentrations of discarded shell and bone, botanical remains, ash and charcoal.
What do shell middens look like?
Aboriginal midden material may appear on the ground surface as sparse scatters or concentrations of broken shell, and are often associated with dark, ashy soil including charcoal. Middens can also be visible in eroded or collapsed sections of dunes where they may appear as a dark, ashy band with layers of shell throughout.
We can figure it out. The hole in the middle was where the apple tree stood! The oldest shell middens in the world are about 140,000 years old, from the Middle Stone Age of South Africa, at sites like Blombos Cave.
Middens can also be visible in eroded or collapsed sections of dunes where they may appear as a dark, ashy band with layers of shell throughout. Midden sites can range in size from small shallow discrete scatters to extensive deposits that run along a coastline for hundreds of metres.