Most shellers at one time or the other have picked up shark teeth.  Last
year I was at a fossil show in Illinois and found a shark tooth book by
Gerard Case,in it was a flyer of teeth for sale from 1967.

Carcharodon megalodon    $5.00       Carcharocles meg.
Carcharodon angustidens  $5.00       "           ang
Isurus hastalis          $1.00       Mako
Notorhynchus primigenius $2.00       Cow shark
Hemipristis serra        $0.50       Snaggletooth shark
Carcharias taurus        $0.50       Sand tiger
Shark vertebral discs    $0.50

This must have been in the good old days.
                           wolfman