I have been slowly going through both the Cretaceous micro matrix from the Mesaverde formation and the Permian micro from the Council Grove Group of Kansas. I have found quite a bit of partial shark and ray teeth from the Mesaverde stuff but have not photographed it. So far the Permian mix has been a different story. The fossils are much smaller and there has been little shark material. I am not too upset though as I have only been through about 1/3 of it. The fossils are so small it takes quite a bit of time to go through.
We did have a little success though and I am quite thrilled. We found one tooth that I am sure is a very tiny partial Cladodont tooth. I also found a partial that I believe is a Cladodont tooth but could not even be a tooth. Both of these are roughly 1mm so there are extremely small. I am quite unsure of the species as there are some unpublished descriptions from this formation according to the Oceans of Kansas website.
Anyway, here are the first two Permian micro shark teeth I have found. I will post pictures as I continue the search My apologies for the trippy background. Our microeye at work prodcuces that background on photographs