Looking for cavities in Mosasaur teeth.

[The QCC]

In keeping with the Micro-paleontology theme I sliced up a few Mosasaaur teeth and made thin section slides. Hoping to find something resembling a cavity.
There are cavities, but not the dental type. The reason my dentist said "No sugar".
All of the teeth were hollowed out at the root end and filled with a soft/loose grainy mixture.

A web presentation may be viewed here.
Photo1 shows a sampling of the Mosasaur teeth I received from  Rocks and Gems Canada.  The teeth are cracked and broken as I requested a grab bag of fossils from the cutting floor.
The Mosasaur teeth are much softer than I expected and the slicing, grinding and polishing went quite quickly.

 

Photo 2 is the tooth I selected for making thin section.

 

 

Photo 3 shows the sandy fill and photo 4 is through a 10x stereo microscope. The microscope view shows a wide variety of colurs that deserve closer attention.

 

Photo 4. Many colours of the fill.

 

 

Photo 5 is the cross section view at 5x with crossed polars.

 

 

My search for cavities narrowed down to what look like root channels in the tooth. This is pure speculation and dreaming.
My stereo microscope has a .8x to 4x optical range so photo 6  at 20x, photo 7 at 100x were taken through the Labomed LB-592 polarizing microscope with the traditional turret mounted objectives.

 

 

 

 

Some of the outer surfaces of the teeth looked to be constructed of two or more layers.
Photo 8 is the tooth I peeled back a bit to reveal the layers in photo 9.

 

 

Photo 9. What appear to be layers in the tooth enamel

 

Photo 10 is a closeup at 10x.

 

[aplomado]

Oh, fantistic!  Wonderful pictures and a great idea!

[-AnThOnY-]

This count? I've always joked about the circle at the base of this tooth being a cavity.

[The QCC]

In my opinion as a not-dentist it looks like a cavity to me.

[Carcharodontosaurus]

Sorry to revive a long dead thread, but I've become very interested in fossil microscopy (despite not having my own microscope) and I'm thinking of buying some mosasaur teeth soon, with one tooth specifically destined to be sliced and have the internal structure looked at under the microscope. What type of equipment is used for slicing, grinding and polishing these teeth? I've seen normal grinders and they look like they could destroy the entire tooth if not used properly.

[The QCC]

Mosasaur  teeth are not overly large in my experience can be sliced with a fine hacksaw for cross sections.
The primary tool is a flat lap disk grinder with six diamond disks with grits ranging from 100 to 1500 plus one or two polishing disks.

I use a Hi-Tech Diamond All-U-Need flat lap  grinder. Flat lap grinder

 

[pachy-pleuro-whatnot-odon]

While the following article pertains to ichthyosaur teeth and plenty of articles have since been published describing similar studies on mosasaur teeth, you might find Scheyer and Moser, 2011 an interesting read, as it clearly illustrates their findings and what to keep an eye out for when undertaking a project like this yourself...

 

Love the cross-sectional images, by the way

Edited May 7, 2022 by pachy-pleuro-whatnot-odon