This catalog contains exceptional teeth from one of very difficult to locate Ptychodus sharks - Ptychodus anonymus, Ptychodus polygyrus, Ptychodus whipplei, etc. which are Hybodotid sharks. These teeth were found in the Smoky Hill Member, Niobrara Chalk Fm. of Gove County and other Kansas locations which was part of the great inland sea area of North America during the Cretaceous (70-90 million years ago). These are beautiful, well preserved teeth. These teeth are high quality - extra nice condition and preservation.