Uphill Both Ways
Volume 9 - Boston 1956
Anything that was constructed of plaster of Paris, even one of the hard varieties like Hydrocal which was his preferred one, could be modeled with rasps, saws and chisels. Actual fossilized bone was too hard to model that way so a diamond saw was used. Judging from the size of the vertebrae that Dad is cutting on in this photo -which is from the series of Kronosaurus- I judge it to be a proximal caudal. I’d even hazard a guess that it could be just caudad to the sacral series, based on its size. But without others for comparison it’s hard to say. However, if you compare how large it is to his hands here to how large the vertebrae are in the photo above where he’s standing by the suspended thoracic series, you can see that this one is considerably smaller. Look at one of the photos of the completed animal and locate the three vertebrae just above and behind the pelvis in the direction of the tail. They have no “chevrons” hanging from them, nor are there ribs. This vertebra looks to be one of those though I suspect it’s still too small in which case it would fit further back in the tail. Anyway, he’s cutting something into the centrum -the round center portion- of a vertebrae. To complete your education, he’s holding the vertical spine -the one that you feel as bumps in the center of your own back- which is part of the neural arch, a T-shaped structure that sits on top of the centrum. You can see a hole in the neural arch here. That is where the spinal cord ran in the live critter.
Ah yes, there is another feature of the neural arch in this photo that suggests that the vertebrae is about where I suggest. The post-zygopophysis that is to the right side of dad’s hand extends fairly significantly away from the plane of the spine. This means that this vertebrae mated with the mirror image of