The "They ain't no sech a thing as a rare shell. We jest ain't a-found 'em"
idea is evidently an old one. In the 18th century, sech luminaries as Cuvier
and Jefferson believed that mammoths and ammonites could not possibly be
extinct. (Jefferson told explorers Lewis and Clark to be on the lookout for
mastodons.) They reasoned that if God created a species, then creation would
be incomplete without it and therefore it must still exist somewhere. But
common sense comes to the same conclusion, doesn't it? Of course, common
sense is not enough to understand vistas of millions of years... Like seeing
the Grand Canyon for the first time...

Andrew K. Rindsberg
Geological Survey of Alabama