Saturday, May 31, 2014

Skull Preparation progress

Now that we have the skull block off the main block we are proceeding to take the other bones and invertebrates off the block to reveal the skull. Some of the interior of the skull is being revealed as we go. Two centrums, two small ammonites, a J-shaped limb bone and the Coracoid have been removed so far.

Here we are before we start. Quite a jumbled mass of good stuff jammed up against the inside of the skull.

 Here's the inside of the jaw with the front teeth at the bottom before the J-shaped bone was removed. The two removed centrums are on the side. They will be finished later.
 Here's the front teeth with the matrix partially removed from them. This is the most delicate work I have to do as the teeth are fractured and break apart extremely easy as I work around them. Lots of precision work on this!

 Block looking at the inside of the jaw to the left, the large crack that has distorted the jaw line is becoming quite visible. It may be possible to separate the two pieces, remove the matrix fill, and restore the jaw to it's original curvature. I'll evaluate this when the crack is fully exposed on both sides. Look at the nice sequence of four invertebrates tucked between the jaw and the larger nautiloid. I think they are very pretty and I think I can salvage them as well. They look like marbles, seem to be two small nautiloids and two ammonites.
 Here are some views of the skull as of 5/28, with the J-shaped bone removed from the anterior (front) end of the jaw and the 2 main teeth exposed. The jaw appears to have a bulge of bone with two teeth following it, so it looks to be complete, not broken off!
 Front teeth and jaw line exposed in profile
 Coracoid still in place.
 Now the Coracoid is removed, exposing the actual jaw line. Broken teeth are partially exposed, but it will take very careful work under the microscope to expose them all. Main teeth are exposed on the far right - you are looking down at the pointy ends.
 Here is the enigmatic J-shaped bone. I think it's a Thalattosaur Pelvic girdle bone, but I'm not sure. It still has more cleaning to be done on it, some of what you see is still matrix.
 Here is the Coracoid removed from the skull block. Beautiful bone!The large crack offsetting part of it evidently occurred as the bones reached their final position in the sediments, but before the rock hardened. It's not due to a later cracking of the rock after it hardened. Same condition applied to the large crack across the nose that offset and rotated it a little.
 And here we are as of Thursday May 29th, 2014.

1 comment:

  1. Can't wait to see more of the beasts skull! Keep up the great work.