PaleoLab

Project: Camptosaurus

More Camptosaurus Logs: Spring 2005 | Winter 2005

Click on any thumbnail for a larger image in a new window

July 27, 2006 01:41 PM
posted by Lauren Stevens

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.


campto dorsal vert prepped.jpg
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.

campto 003.jpg
Camptosaurus dorsal vertebra 11, anterior view.


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

January 15, 2006 07:15 PM
posted by Yvonne Wilson

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.

1-14-06 Campto left lack of tendons.jpg

The same situation here, only farther down the spine:

1-14-06 Campto left lack of tendons 2.jpg

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)?

1-14-06 Campto left posterior tendons.jpg

December 16, 2005 05:53 PM
posted by Yvonne Wilson

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:

12-15-05 Campto scan direct posterior.jpg


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

12-15-05 Campto scan lateral with lasersight.jpg


Not your typical hospital patient.

12-15-05 Campto scan pelvis L lateral.jpg


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

12-15-05 Campto scan monitor pelvis.jpg

12-15-05 Campto scan monitor spine 2.jpg


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!

December 04, 2005 12:54 PM
posted by Yvonne Wilson

"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:

12-3-05 Campto R sacral rib remeasure edited.jpg


The left side, which has been moved:

12-3-05 Campto L sacral rib remeasure edited.jpg


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.

December 02, 2005 06:44 PM
posted by Yvonne Wilson

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.

12-2-05 Campto ilium cracks.jpg

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:

12-2-05 Campto R sacral ribs no flash.jpg


And the left:

11-30-05 Campto L ilium no ribs or tendons yet.jpg


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

November 30, 2005 06:26 PM
posted by Yvonne Wilson

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.

11-16-05 Campto tendons near neural spine.jpg

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.

11-30-05 Campto caudals no tendons.jpg


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.

November 09, 2005 02:53 PM
posted by Yvonne Wilson

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:

8-01-05 Camptosaurus ant 1.JPG

11-07-05 Campto ribs removed (5).jpg

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.

11-08-05 Campto ribs separate (2).jpg

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:

11-07-05 Campto left tendons close up.jpg


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.

11-08-05 Campto hip block (2).jpg


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.

10-00-05 Campto humerus stripping close up.jpg


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.)


8-15-05 Campto L manus pre-prep 2.jpg


11-08-05 Campto left manus articulated.jpg


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

July 09, 2005 10:57 AM
posted by Yvonne Wilson

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:

7-09-05 Camptosaurus removing R post rib dorsolat.jpg


and once it has been taken out:

7-09-05 Camptosaurus removed R post rib .jpg


On to the next ones...

July 09, 2005 10:57 AM
posted by Yvonne Wilson

I have been out of town for a few weeks, 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:

7-09-05 Camptosaurus removing R post rib dorsolat.jpg


and once it has been taken out:

7-09-05 Camptosaurus removed R post rib .jpg


On to the next ones...

June 05, 2005 06:34 PM
posted by Yvonne Wilson

Scribe, scribe, scribe. I have been isolated with the fossil in sensory-depriving mask, goggles, bandana, earplugs and earphones. One ends up in a "zone" where the fossil becomes the only thing in the world with you. In this mode I have unearthed most of the ribs.

6-05-05 Camptosaurus R ribs lat 2.JPG


These were not terribly difficult to work on, but I have saved the toughest part of the ribs for last. Each rib has what they call a "head," which is the part that attaches to the vertebra. Getting tools between the bones is quite difficult. In order to get the right angle, I sometimes have to bend at the waist and work with my head upside down. No, I did not take a picture of this undignified posture. I have also learned to work pretty well with my left hand.
Here is a picture of a few rib heads (like the long bone on the left) and the transverse (sideways-sticking) processes (part) of the vertebrae (one looks like a button in the center of the picture). My tools have to fit between the long bones and the button-shaped ones.

6-05-05 Camptosaurus rib head artic.JPG


So the whole beast looks like a side of beef these days:

6-05-05 Camptosaurus ribs verts scap ant.JPG

The ribs are the horizontal brown stripes. The ossified tendons are the vertical strings on the right. The scapula, or shoulder blade, is the large vertical bone in the center. Between the bones you can see the tan sand in plastic bags which I packed around the bones oh so long ago. The bright white jagged stripe is a fracture in which the collectors had poured plaster.

After I free the ribs from the spinal column, my plan is to roll the jacket so that I can attack the vertebrae from the opposide side.

May 21, 2005 01:17 PM
posted by Yvonne Wilson

As I work along the spinal column, I am finding things that are both lovely and awful at the same time -- ossified tendons. These are mineralized tendons that helped stiffen the backbone and support the tail of the dinosaur. They are frequently found in ornithopod dinosaurs (ornithopods include dinosaurs such as Iguanodon, Hadrosaurus, and my Camptosaurus).

Stay tuned. I am consulting with other preparators to see if I can save these slender tendons.

5-20-05 Camptosaurus verts close up 2.JPG


And on the icky side of things, I have run into what might be a layer of shellac slopped into a crack. I can't quite be sure what it is. I know it is not bone. It is unlike any of the matrix in this jacket. It is the same color as the bone, but it is featureless. Bone has a "grain" to it, like wood does. There is some bone sticking through some points in this layer, so I think it might have been gooped over along with the bone.

5-13-05 Camptosaurus schellac layer close up.JPG

May 05, 2005 10:16 AM
posted by Yvonne Wilson

I have spent the week moving rock. That is, using the airscribe to scratch away, bit by bit, this very hard sandstone. One by one the tips of the vertebrae are showing up. When I come across one, I circle it with a magic marker to make sure I don't scribe over the bone. Call it idiot proofing, or call it being careful. But it also makes it easier for you to see where the bone is. At the upper right the spinal column is diving and twisting into the rock, so I have not yet found the next vertebra.

5-5-05 Camptosaurus verts showing up.JPG


You can see these string out from the vertebrae that I have already found.

5-5-05 Camptosaurus verts showing up and exposed.JPG

More Camptosaurus Logs: Spring 2005 | Winter 2005

 

Return to Preparator's Journals

 

spacer spacer spacer spacer