Ichthyosaur Preparation Diary #1

BEFORE: The underside is the side
 that I will be preparing from, 
far too much rock
for a small drill to get through.

The first major work that needed doing to the Ichthyosaur was that it needed cutting down to size. The blocks were very thick and very heavy. Plus, I plan on mechanically preparing the bones by going from what looks to be the bottom. This is because the bones are exposed on the top surface, great for spotting them in the field, not so good for their preservation. Some of the vertebrae in the long block are badly worn but going from the other side will reveal them at their best.

The round block was easy enough to split. The stratification was completely parallel to the bedding surface and split like a dream. On the underside, there are another three rather large vertebrae waiting to be revealed.

AFTER: The thickness of the rock has been greatly reduced,
making it easier for the drill to get to the better preserved side
of the bones.

The long block didn't want to play as nicely. The position of some of the bones had created cylindrical structures which split vertically rather than horizontally. Unfortunately, it broke into three pieces, not beyond repair but something that would have been better avoided.

Next step was gluing the off cuts, and now broken pieces back onto the main blocks so that the bones were complete when they are prepared out. Again the round block went back together with little to no fuss. One piece was guided in by a handy belemnite that had broken in two and stuck to either piece of shale. The long block was proving difficult again. The larger of the broken pieces was thicker than the main block and so the other end is being propped up to stop it snapping again. The rest was repaired with no problem, another three vertebrae added to this block with numerous ribs completed.

Block 1 after the repairs. The glued piece at
bottom of the picture is the large broken piece.
The glued slab on the right of the block has
three more vertebrae in it and numerous ribs, it
also completes a number of vertebrae along the
glued line.

Block 2 much more neatly glued and split with
the three large vertebrae revealed in the centre.
There is also potentially a fourth near the
tape measure but we will have to wait and see.

BEFORE: The small odd piece that doesn't fit
anywhere

But there is one piece that just does not fit anywhere. A shame but in this small piece of shale there are two vertebrae, at different angles. One appears to be squashed anterio-ventrally and the other is half complete. But once prepared it'll make a nice display piece.

Although the epoxy glue looks unsightly, I have smeared it onto the side that will be face down when it comes to preparation so this will not be seen.

AFTER: The small odd piece after splitting, this brings
the bone closer to the surface. The first vertebra is
clearly seen in cross section here.

The second vertebra is harder to see, it is in the centre of
the rock in side view, the lip around the centrum is rather
prominent.