Preparation was, however, remarkably similar to working on the centrum. A painstakingly slow process removing matrix piece by piece, almost particle by particle, was followed. Only occasionally did I have the luxury of being able to mechanically remove one or two stubborn spots of matrix with no fear of damage to the specimen.
Although the bone was well mineralised and robust, the surface of the bone could be easily chipped in places if you were not careful. This was especially apparent when cleaning out all the nooks and crannies that were formed during fossilisation as extreme pressures distorted the bone and the cracks that resulted filled with matrix and slowly widened. Every pore of the bone had clay or other matrix in situ and this was prised out speck by speck. These areas were consolidated with Butvar B76 as I went along.
The neural canal itself was the longest job of all. The vertebra had been distorted so that the neural canal was not only compressed mediolaterally but also angled between 5° and 10° rostrocaudally, and this made cleaning out the canal particularly awkward. Removing the bulk matrix from the canal did not pose any particular problems but the finer preparation did, as I struggled to work in a tight enclosed canal with both magnification and light impaired.
Eventually, though, the canal was virtually clear of matrix and I was surprised at how big it was and how deep it ended up, as it plummeted ventrally into the centrum. The rest of the processes were more or less straightforward with only one or two areas of stubborn resistance. Once the prep had been finished, the specimen was gently cleaned and a final coating of consolidant finished the job.
To be honest, there are bound to be a few specks of matrix in situ, especially in the neural canal and I’m sure that I could probably keep on prepping the bone but I am happy that the vast majority of it is fully prepared and that the specimen is complete.
There are many projects still in the pipeline just now and I am particularly keen to start work on an impressive hadrosaur dentary but, the immediate plan is to start work on some associated plesiosaur material that I’ve already alluded to in earlier posts beginning with the stunning humerus pictured below.
As can be seen, this particular bone is virtually complete and is broken in two pieces but the join is excellent suggesting that the fracture has only occurred recently. Preparation would appear to be straightforward although both the proximal and distal ends are somewhat encrusted with shell debris and detritus.
The bone, again, is heavily mineralised and dense and the join will need to be exceptionally strong. To support the bone will require a small purpose built cradle which will needed to be constructed for the task and this will also serve the dual purpose of providing the permanent storage case for the specimen when it is finished.
After the humerus there will be a lot of the other bones from the same forelimb to work on including the radius, ulna, and a host of other associated bones. These too are all well preserved and there appear to be no obvious complications. I will detail these bones as I go along and post periodic updates.
|The pliosaur vertebra - as found|