The preparation of Camptosaurus in now officially complete. I spent about three weeks carefully preparing the ossified tendons in the dorsal (back) region and cleaning up and stripping off the shellac of the rest or the skeleton. The tendons came out beautifully! Note how the tendons begin at the top of the back very small and skinny and run parallel to each other but broaden and weave into a basket-like pattern as they continue down the spine. The right side of the specimen preserved very nicely. The tendons on the left side were also preserved, but because of the way the specimen was crushed in the ground, they did not lay as closely to the vertebrae making preparation much more difficlult. These were easily removed from the specimen in blocks. We decided not to replace the tendons or to prepare them at this time so that they may be preserved and rearticulated for future study.

Camptosaurus dorsal vertebrae 5-16. The top photo is of the right side and the bottom photo is of the left side.

Also note how crushed the specimen was in the matrix, as evidenced by the orientation of the transverse processes. The transverse processes should be sticking out at the same upward angle, but in some areas along the column one process is projecting directly down while the other is projecting upward. This will have to be corrected during reconstruction.

Camptosaurus dorsal vertebra 11, anterior view.

Camptosaurus will now be stored safely away until the team is ready to begin restoration.

As I remove more and more rock from the spine, I am puzzled. When the CT scan was being performed, I saw that tendons were missing on parts of the spine. This, I incorrectly assumed, was where there was a lot of loss at a large fracture in the rock. It wasn't that portion I was seeing.

On the left side of the spine, I only find ossified tendons halfway up the back. On the right hand side the tendons appear approximately 10 cm (4 inches) from the neck. The body was distorted obliquely, so that the torso looks like it was rolled and smeared, stretching out one side of the spine. This post burial distortion probably happened when there was a great deal of pressure on the rock and fossil from the weight of the rock above it. Thus the distortion does not explain or is not connected to the lack of tendons.

This picture is looking straight down on the top of the spine. The line of the spine is horizontal. There are stringy-looking tendons in the top half, but none below, which should show a mirror image of the top.

The same situation here, only farther down the spine:

Closer to the hips the tendons finally appear on the left, or in the bottom half of the picture, but they are very far away from the bones of the spine. What is going on (or went on, rather)?

I have mentioned the ossified tendons parallel to the dinosaur's spine several times in my log. Finally I got to see all of them, though I have not removed any more rock around them. How is that possible? A CT scan!

Thanks to the University of Pittsburgh Medical Center, we were able to scan the spine and pelvis of the Camptosaurus. Now I will not have to feel guilty about removing the tendons as I take the vertebrae apart, for we have a permanent digital record of them.

I drove the beast's parts to the hospital and we wheeled them into the scanning room. It's not every day that a hospital gets to scan a dinosaur, so there was a film crew to capture the event. The radiology tech asked me which way the dinosaur was lying on the scanning bed. I ended up with an image in my head of a dinosaur sleeping in the scanner. Too weird. But paleontologists usually think of these old fossils as the living breathing creatures they once were. It takes a certain amount of imagination to be a good paleontologist.

The scanner we got to use was very powerful and fast. Scanning both the pelvis and the spine took very little time. It was just minutes instead of hours, as they told me it would have taken on their older scanners. To penetrate the surrounding rock they had to dose up the dinosaur with a great deal of radiation. In fact, they said they used much more than they would ever use on a person. I found it kind of ironic because some dinosaur bones, including the ones like these from Dinosaur National Monument, have naturally concentrated uranium ions in the fossil material, making them ever so slightly radioactive even before we dig them up. With the scan, we were just enhancing their natural state.

Below are pictures of the "patient" in the scanner at Presbyterian University Hospital:

Here they lined up the patient with the center of the scanner's "doughnut" by using red laser markers.

Not your typical hospital patient.

And the results for first the pelvis, then the spine:

I was very happy to see the dinosaur through and through like this. I learned a lot about the condition of the specimen within the rock, as well as the placement of the tendons along the spine. Ah, the miracles of technology!

"Houston, we have a sacral rib"

Finally, I have found the first left sacral rib (part of the backbone that attaches it to the hip bone). It is very far down in the matrix relative to the ilium hip bone. It seems that after death but before burial the ilium was moved, sliding upward parallel to the body axis. Perhaps the body had started to rot some and started to fall apart just a bit.

In the following pictures I am contrasting the position of the right and left sacral rib ends against the ilia. The rib ends are outlined in pink, and the ilia edges are outlined in blue.

The right side, which is in place:

The left side, which has been moved:

On the right, the distance between the sacral rib and the exterior edge of the ilium is about 2 cm (about 3/4 inch). On the left the ilium has slid up so this distance measures more than 6 cm (about 2 1/2 inches). I will be able to remove the ilium without touching the ribs, in fact. The displacement has made my life easier.

I have been removing more rock from the hip region. There are many cracks, so I am wary of what shape the bones may be in. One crack that worries me is up to 2 cm wide (3/4 inch). It has been filled with purple plaster, but the bone that should be within the area of this crack has not appeared yet.

Like many fossils, this skeleton was distorted somewhat while it was buried in the rock. The pressures at this depth caused the solid rock and fossils within the rock to stretch and twist. The hip block is showing some of this distortion, as well as possible displacements of bone that occurred before burial. On the right side of the pelvis I have uncovered the sacral ribs, the portions of backbones that connect the spinal column to the ilia (hip blades). On the left side, however, I can find nothing but rock. Where are the sacral ribs?!

The right side, with the edge of the hip blade at the top of the picture:

And the left:

All I can do is to go deeper in the rock. Hopefully they will turn up.

Still working on the block with the hips, I have uncovered traces of ossified tendons here and there, but nothing like what is found further up the spine. Those that are appearing now are short and scrappy. Apparently this section of rock was badly broken. I am not sure when this happened, but the first preparators of the specimen poured lots of plaster into the cracks. Here is one tendon that seems to have been within a crack. It is the red line in the middle of the plaster.

This tendon is lying almost on top of the neural spine of the vertebra, the part of the bone that sticks straight up from the spinal column. These I expected to find.

What is not turning up are the intramuscular tendons like those that occurred about halfway up the back. See in the picture below how there are none of these spaghetti-like tendons parallelling the backbone. It is just rock.

So Camptosaurus needed a stiff back, but not so much of a stiff tail. Or the muscles in the back needed more help than those near the base of the tail. Hmm...here is where paleontologists have to imagine how the animal may have moved and stood, based upon the anatomy.

She's ba-aaaack! I have spent the last few months assisting on the Samson Tyrannosaurus rex skull. The Camptosaurus was put on hold. I did, however, sneak in a little work here and there.

So here is where the project stands: from having the full ribcage and shoulder blade on the "side of beef", the specimen is now just a backbone with some short scrappy ribs on one end. Photos for comparison:

Some of the ribs have been distorted badly during the fossilization process. They have come out wavy or curvy, which might cause problems when mounting them.

Otherwise, I have begun to uncover the tendons on the left side of the spine. Again, there is evidence of distortion. They are up to 15 centimeters (about six inches) away from the centra, the main bodies of the vertebrae. On the right the tendons were all found within 5 centimeters (about two inches). I am curious how that distortion will appear when I uncover the left side of the spine.

Here are a couple of the tiny, spaghetti-like ossified tendons from the left side:

Also, I started working on the second fossil jacket that contains the hips and a few attached vertebrae. Apparently the gentlemen that collected this specimen were a conservative lot. Back in 1925 they decided to leave an awful lot of rock around the margins of the bones, "just in case". That rock could have contained other bones, but so far I haven't found anything new.
I have used the heavy chisel-tipped airscribe to plow through half the depth of the jacket, and have just found the first sign of bone.

Here is the jacket that is hip block. It used to be twice as high.

We have volunteers stripping the shellac off the previously exposed bones. Shellac was used back then to help protect the fossils. We have much better chemical consolidants now, so we want to get rid of the shellac. However, old shellac turns chocolate brown and is very difficult to remove. We cannot use paint strippers without doing harm to the fossils, so we use denatured alcohol to soften it. Then it gets carefully scraped or scrubbed off the surface of the bone. Bone, however, is porous and often has an uneven surface. Areas like these just won't scrape clean. Some shellac will remain on the fossils, but we will try to get off as much as we can.

This is the surface of the humerus, or upper arm bone, during the stripping process. It starts out chocolate brown.

And lastly, for the update, I want to show you the left hand. It is remarkably complete, missing the last bone of only one digit. Below are pictures of this hand as it was mounted in 1925 and one possible position of the hand when we remount the dinosaur. (Thanks to Ken Carpenter for the new hand articulation.)

It's good to be back on my favorite project.

I have been out of town for a while, but have started back in on the ribs. I wrestled with the anterior (closest to the head) rib heads for a while, but moved to the posterior ones for a change of pace. They are small and simple, and come off fairly easily. On the right is the second rib up from the hip bone:

and once it has been taken out:

On to the next ones...