Thursday, January 2, 2014

Still more teeth - on a palate or a mandible

This post covers one more bone recovered that contains teeth. This makes a total of 4 bones with teeth - a jaw fragment with teeth in sockets, a skull, a jaw fragment with a trench where teeth were, and now a long convoluted bone with small teeth in the center.
Originally I thought the bone might be a clavicle of the Ichthyosaur, since we have most of the other shoulder girdle bones. The first side exposed had no indication of the teeth - they were on the rock side (inside) of the bone.

However, the first sign of teeth occurred as we were cutting around the backside of the bone to free it from the rock. We cut it quite deeply so as to not damage anything, since we didn't know what we had. Since the bone was long and thin, the side without rock was coated with latex and mounted in plaster. This provides enough support that even thin and fragile bones can be successfully prepared without breaking them to bits.
Here's the front side after complete removal from the large block and preparation:

 And here's the back side, showing the teeth. 
Here is is zoomed in to the teeth area which is about  4.5 x 1 cm. It probably continued to the right, but the bone is now broken. These teeth sure are cute, but were a real problem to prepare. Most of the teeth crowns are intact, though I did lose one or two of the very small ones during the preparation process. Note that these teeth crowns were broken in life. I don't know if they were mandible teeth, which would have been from the left side, or it they are palate teeth (amphibians have & had teeth sticking down from the hard palate). They look like they are in sockets, multiple rows, so I'm guessing they are from an amphibian and not the Ichthyosaur. But they sure are a different scale - much smaller - from the socketed teeth already prepared.

For your reference I've included pictures of the other jaws and teeth that we have found so far. They are much larger than the teeth on the featured bone above - the teeth in both pictures below are really about the same size.   

 Until next time, this is Greg Carr from OMSI Paleo lab. I hope your holidays were happy and blessed.

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