> Please excuse me.
>
> I rarely post, but this issue sparked some interest.  Occasionally a
> researcher discovers a species which is so unique that it is obvious
> to him
> or her that it is new to science.  What is the minimum number of
> examples
> required to be considered?  I'm unable to find the answer in the
> ICZN.

There are species of shells where only a single specimen was known and
described at the time.

> Second question.  How does one determine if a new species is
> juvenile, if he
> or she does not have a baseline to compare?

I can't help you with chitons.  Many groups of shells can show evidence
of immaturity seen by a thin or fragile edge.    I imagine Cypraea can
give conchologists and malacologists quite a challenge.

When we used to dive the Bay Islands off Honduras, we found typical small
Latirus martini around an inch long (25-30mm).  We started exploring
other areas around Roatan Island and we found a few monster L. martini
which were over two inches.  These shells looked more like Latirus
carniferus when larger.  Someone on that trip thought these monsters were
something else.  I argued, "Suppose I chop the spires off these big ones.
 Now what do I have?".  The other diver then agreed with me.

I hope this helps Ghost Sheller.  I also hope I don't come across an
invisible collector when I am out in the field.

Andrew