Cipangopaludina japonica River Snail

 This is not a fossil but it could be one day.  Snail shells found in the White River of  Indianapolis, Indiana.  Some how this Asian snail has gotten loose in the river and is multiplying.  I found 6 shells on a 5 meter stretch of river bank.  A naturalist at the Indiana State Museum identified it as maybe a Cipangopaludina japonica.

Two specimens are shown in these images.  The largest is 5.2 cm long, 4.0 cm wide, and 3.8 cm tall.  I wonder if these creatures are edible?

In addition, I found two types of river bivalves and two other types of smaller snails.