Tuesday, December 9, 2014

Endings and New Beginnings - Three skulls!

The 'ending' of the title refers to the fact that the skull and eleven associated skull fragments have left OMSI and have gone to the University of Alaska, Fairbanks (UAk) for further scientific study. Professor Pat Druckenmiller and his graduate student Eric Metz have undertaken the task of classifying the skull and determining how it is related to the other species of Thallatosaurs. Although I'm sad at seeing Bernie leave, I know he's gone to a better place. Meanwhile I'll mourn our separation.

Kidding aside, it's been a really great couple of weeks. We have a wonderful revelation of sorts. If you remember, I posted about some unusual bones that I thought were vertebrae of a second type of animal. It turns out I was wrong in a very pleasant way. We've been excavating a third of these strange bones, and this one is not only larger but has  pieces that were broken off the two other bones. It turns out that these three are the brain cases and basioccipitals - that is, the back part of the skulls where the spinal column connects. So we now have proof of not only 3 animals, but three skulls (or at least parts of them)!!!And they all are graduated sizes, consistent with the three humerii of different sizes.
Three Basioccipitals and their Humerus's

How wonderful. This will really help us figure out how the back of the skulls were built. Also, what is interesting is that these basioccipital bones very closely resemble those of a modern Komodo Dragon! The resemblance is clear from the photograph.

Basioccipital put in the reproduced skull of a Komodo Dragon

Top side of the three - this is the lower and rear part of the braincase. 

Three brain cases / Basioccipitals two in hand, one still in the block

Here's the largest brain case / basioccipital, removed from the block but not finished. There's lots of rock left to remove. 
Here is the bone fully prepared:

Here are still more skull fragments that are still in the block:

Here's part of the mandible - note the roots of the teeth on the left side of the bone. I count five. The part broken off has probably been lost as there was no rock outside it. Still, it's not too bad for 230 million years old. 

Here's another skull piece located on a side of the block we haven't excavated yet. Pat Druckenmiller said he thought it was a skull piece, and he was right! Good Call. It's about 15cm long showing on the surface - we'll have to see what is buried in the rock.

Sincerely, Greg Carr

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