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.

Sunday, May 18, 2014

The beheading of Bernie!!

We have finally done it. The sub-block containing the skull, other bones and two nautiloids has been successfully removed from the main block. Now we can prepare the skull by  removing the other bones & fossils carefully under the microscope or magnifying visor as needed. I'm hoping that it will be complete by Christmas. Of course, I said that last year too.

The skull (or rather half-skull as it's split down the midline) first appeared in August 2013. It took several months to recognize what it was. But it has taken until now to remove enough rock to break it off. Many bones were in the way. Some were removed entirely, some had to remain connected to the block as they are tucked up into the ventral side (underside) of the skull or were touching items that touched the skull. In all, we took out 1/2 skull, 3 centrums, 1 clear limb bone, 1 Coracoid, 1 fin from a neural arch, 2 unknown bones, 2 Nautiloids and only broke 1 rib (Bernie's, not human)

The skull block was undermined enough that numerous holes passed completely under the fossils.

Then my daughter Gloria had the honor of breaking it off the block by simply prying it off with a large screwdriver. Jerry Dodson had his hands on it as it was removed, and cradled it like his first newborn. My wife Peggy was there as a spectator. Then we passed it around, ooh'd and aah'd, and finally went off to celebrate with a late lunch.

Sincerely, Greg Carr