The Preparation of Riley

The first pieces to be prepared were the segments of the snout, which had broken off of the skull and arrived in a separate jacket. As luck would have it, the snout had had split into a series of almost perfect cross sections. This is the complete snout, with all of the cross sections reassembled. Clearly visible in this picture is the break and misalignment of the upper jaw. It no longer parallels the lower, but instead angles sharply upwards. It may have been broken as the skull sank into the mud when the carcass settled to the bottom.

Fossil preparator Deborah Hartmann is using an air scribe to gently remove rocky build-up from a cross section near the base of the snout.

Because of the way that the snout fractured, we have some interesting cross-section views. The dark color is the bone; the light color is rock, or matrix. Several loose teeth have been found 'floating' in the matrix. The photos are oriented with the lower jaw to the bottom.

In mid-December of 1998, we finally cut into the plaster jacket that covered the main part of the skull. As mentioned above, the snout is no longer attached to the skull.

Here we can see the left side of the skull with its huge orbit, a glimpse of the rear of the skull, and the right side of the skull. The right side of the skull is cracked, possibly due to the effects of a plant root (not visible) which grew through the orbit as the fossil lay in the ground. The diagram in the first picture shows an intact ichthyosaur skull.

The ribs and vertebrae are enveloped in dense layers of calcite, difficult to remove by hand. We emerse the blocks in a solution of 5% acetic acid to dissolve the calcite. If monitored carefully, the acid does not harm the bone. In the third image, lab supervisor Steve Sperber places a block of vertebrae into water to soak after removing it from the acid bath.