Some shells deserve to tell you exactly how old the mollusc inside had actually been alive, for example. Typical cockles are few of the ideal shells to see this top top - so these room pictured here.
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While cockles have ridges to run from their narrowest point, to your widest, it is sometimes also possible to see indented currently running throughout the width of the shell (and these are replicated exactly on each half of the shell).
The theory is that each line across represents one farming season, rather prefer the expansion rings that tree trunks.
READ MORE:How to identify shells
The two deep lines across the shell over indicate the the cockle live throughtwo birthdays however dies before the third.
Rings may be a far better indication of period than the size of the shell, as the above photo shows. A bigger covering does no neceassarily typical that the molusc lived a much longer life.
While the shells above are an extremely different sizes, the expansion ring says that they are both about the same period - somewhere in between one and also two years old. Perhaps the larger shell ~ above the right lived in an area where much more food was available enabling that to grow bigger.
To be scientificallyaccurate, the best way to period a shell would it is in to saw with itto gain a overcome section and also look at the internal growth rings.This is, however, a an extremely tricky operation requiring professional equipment.
The 2 shells listed below show less clear development rings together do plenty of shells. In part shells, the rings get worn away in the water, for example.
More about cockles and also other bi-valve shells
Have a look in ~ our galleries that beach finds above.
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