Four and Counting!

Things have gotten weird in the last couple of weeks. Jerry Dodson is starting to work on another big block, Block 1, where we have identified two skull parts exposed on the surface. They won't be full skulls, of course, since they are broken where the block broke. So here is Jerry's current project. We've run out of table space so it's on a wheeled hydraulic lift table.

I don't know if these holes in the bones are semi-circular canals for ear balance, but they certainly could be.

Here's the block after a large section came off. There are skull bones at the upper end and lower end of the removed block.

I continue to work on good 'ol block 2 which I've been slaving away for two+ years.  I started chasing a small bone cluster on the surface of the break plane between block 1 and block 2 - hah!

I know the bone to the right is part of a centrum. The one in the middle was interesting, and I thought the small bone to the upper right was part of a rib - wrong! There actually were  four bones on this cluster - 2 centrums and two others. The 'others' are the interesting ones. So here I have cut away around the outside of the ones somewhat, digging my normal trench to remove them. They actually went quite deep and when I tried to knock them off....

 This is what happened! The end of the entire block broke off, exposing a beautiful Nautiloid!  It's really quite big.

And it's a species we haven't seen before. The sutures look like a nautiloid, but the sides of the animal don't have the typical indented whorls. Instead, they resemble some of the more globular ammonites. It is a lower priority (and shells are difficult to prepare) but it's still going to be interesting. A new species, perhaps?

So here's the cluster of bones. I think one is a section of mandible while the other one is a thin part of a skull, maybe around the orbit. Full identification will have to wait until they are fully prepped. 

Last of all, when the block broke off it exposed yet another bone clustered with the ones I originally started with. However, preparing this bone revealed a wonderful surprise - it's ANOTHER BRAINCASE!!!! This makes 4 total now - so we have at least four animals!!!!

And to be even more interesting it's about 30% LARGER than the largest one we had (which was the previous largest one) - so we have a growth sequence of four individuals all different sizes! It will take another 3-4 weeks to get this one out as most of it is still in the main block buried deeply. However it's really worth pursuing. 

 Here it is back on the block, with the other full braincase for comparison.

Like I said, it's been a crazy couple of weeks. 

Sincerely, Greg Carr

Chasing out more Skull Fragments and an unexpected Bonus

Since the last post we have been actively taking off the large blocks three pieces of what look like more skull fragments. Since they are still embedded we don't know how large they are, but we have hopes.

Two of the fragments are located on block 1, which we haven't done much work on. Almost all the work over the last two years have been on block 2. I've had to reduce the hour I spend actively scribing due to tendonitus. So I started by pulling out block 1 and removing the plaster. It is as big as block 2 and shares a common cleavage plane so it should be just as productive. Lo and Behold after cleaning we find two skull fragments showing on the surface. Jerry has been given the opportunity to dig them out. Here is a closeup of one of them. There appears to be some large holes in the bones right in the center of this picture. These may be semi-circular canals, though they are much too large to fit in the brain case bone where you'd expect them. We have another scrap with holes like this showing. It will be great to compare the two.

Here's an overview of the block 1 with the part shown above directly in the middle and another skull fragment above it (shown to the left as the picture is turned).

Here is a closeup of possible skull fragments on block 2 / block 1 cleavage plane. Some of this may be centrums, but part is definitely more skull fragments.

Here is block 2 after the end was knocked off to access the skull fragments better. To the right you can see a wonderful invertebrate shell. The sutures look like a nautiloid, but the overall shape is that of a spherical ammonite. We'll just have to see what is is after removal.

 Here is a closeup of the shell. It is really big - over 3 inches across - and will be complete! The lip of the opening is visible, so we have the entire shell.

 Last of all, I have made an archival cradle for the large left side skull roof fragment. I followed the same steps as making the full skull cradle. First, prepare an oversized plywood bottom to be the base.

 Next, wrap the bone in aluminum foil to keep it clan, and apply a layer of clay about 1/8 inch thick tomimic the future foam padding.

Then make up plaster re-enforced with chopped glass, and embed the bone clay-side down into the plaster. You have to work fast as the plaster sets in about 6-10 minutes!

 Last, after the plaster sets remove the clay and aluminum foil and add the padding. Good for a hundred years!

Another Month, More Skull Parts

We have been focusing on bones that appear to be skull parts since they tell us so much about new animals, and are generally very descriptive and unique. We know from having three brain cases that we have parts of three skulls in this first block we are excavating. We now have as well three specimens of the left side of the skull roof that include the pineal gland. I believe these are found in the parietal and frontal bones.

Here is the latest bone - the anterior part (front part) is toward the left with the midline running along the top of the piece. This piece has a very delicate part left on the rear-projecting spur on the lower left in this picture. I believe it is the supratemporal and the squamosal. These are missing from the other two pieces.

Here are a couple of closeups of the posterior projection of the spur. The fin is only about 1 mm thick and (of course) it was difficult to prepare. 

This one shows the interior of the braincase and the pineal gland as well. 

Here is the one before that. I can't seem to find it totally prepared in this same position, so here it is with the anterior end (front end) pointing up. The pineal is the notch on the right side, the brain case in the lower projection on the right. 

 And here is the third one. It is the most broken piece, but the pineal and some of the midline suture rugosity is evident upon inspection.

When we get these all together we will compare sizes. It is my impression that the largest piece is actually from the largest skull, but it awaits accurate dimensioning. Two of these fragments are already in Alaska so I can't do it right now. I have begun scanning parts with two new students at Century High School. After all the skull bones that are here in Oregon are scanned they will be sent to the U of Alaska, Fairbanks, to join the rest of the skull parts. 

Sincerely, Greg Carr 

Plugging Away on lots of Skull Pieces

We now know that the block containing Bernie (and Ernie, Bernice, Bernard...) has at least three specimens of the same species of Thalattosaur. We have three brain cases of different sizes and three humerii of different sizes. So we've been focusing on removing identified skull fragments from the block as fast as possible. However, it is slow as explained below.

First of all, we have a complete brain case, now fully prepared. This is one reason it's been a while since the last post. This bone alone took 4 weeks (3 days per week) to remove from the main block and totally prepare. On the other hand, it's reeeealy nice, and the first one ever found with 3-D preservation. I am waiting to get it 3D scanned before I send it to Pat Druckenmiller at the U of Alaska. You can see all the little holes where the nerves exited the bone out into the body.

  I'm not sure what is up with the Occipital Condyle - normally these are round and solid, or arc-shaped surrounding the hole where the spinal cord exits. In our case, we appear to have two holes where the spinal cord(s) come out, one directly in the center of the round condyle and one above it.

 The next skull bone we have it a partial mandible. This appears to be the right side of the mandible, complementing the left side found many months ago. Here is the bottom:

 Here is the top, broken off where the bone stuck out of the concretion it was in. There are roots of 6 teeth at the right side of this view, though they are clearest under the microscope.

 And here it is from the cheek side (outside). It is furrowed and rugose, just like the skull is in that area.

 Here is the lingual side (inside next to tongue):

 And here it the mandible fragment prepared in June 2013 from the left tip of the mandible. Somehow these fit together, though it doesn't look like it was a mechanically strong joint.

 Here is the second-largest skull fragment found to to-date. It is about 6 inches ( 16 cm) long. I can't yet place where it is in the skull, but there appears to be numerous projections on both ends. It will be several weeks before it is removed from the block, and several more then that before it's fully prepared. I can't even tell if it's the left side of the skull we already have, or part of a second skull. It is definitely a skull fragment, I'm sure of that.

Here is yet another fragment in a block removed from the side of the block to allow access to take off the above fragment. It is only about 3 inches (7 cm) long, and busted all around. It will take a couple more days work. 

Last of all, here is a shot of two of our other volunteers, Jerry and Janet. Jerry is talking to a visitor to the lab. Janet is learning how to use the Paleotool #5 under the microscope, something she never had to do while preparing Triceratops bones. Good Luck Janet!

Endings and New Beginnings - Three skulls!

The 'ending' of the title refers to the fact that the skull and eleven associated skull fragments have left OMSI and have gone to the University of Alaska, Fairbanks (UAk) for further scientific study. Professor Pat Druckenmiller and his graduate student Eric Metz have undertaken the task of classifying the skull and determining how it is related to the other species of Thallatosaurs. Although I'm sad at seeing Bernie leave, I know he's gone to a better place. Meanwhile I'll mourn our separation.

Kidding aside, it's been a really great couple of weeks. We have a wonderful revelation of sorts. If you remember, I posted about some unusual bones that I thought were vertebrae of a second type of animal. It turns out I was wrong in a very pleasant way. We've been excavating a third of these strange bones, and this one is not only larger but has  pieces that were broken off the two other bones. It turns out that these three are the brain cases and basioccipitals - that is, the back part of the skulls where the spinal column connects. So we now have proof of not only 3 animals, but three skulls (or at least parts of them)!!!And they all are graduated sizes, consistent with the three humerii of different sizes.

Three Basioccipitals and their Humerus's

How wonderful. This will really help us figure out how the back of the skulls were built. Also, what is interesting is that these basioccipital bones very closely resemble those of a modern Komodo Dragon! The resemblance is clear from the photograph.

Basioccipital put in the reproduced skull of a Komodo Dragon

Top side of the three - this is the lower and rear part of the braincase. 

Three brain cases / Basioccipitals two in hand, one still in the block

Here's the largest brain case / basioccipital, removed from the block but not finished. There's lots of rock left to remove. 

Here is the bone fully prepared:

Here are still more skull fragments that are still in the block:

Here's part of the mandible - note the roots of the teeth on the left side of the bone. I count five. The part broken off has probably been lost as there was no rock outside it. Still, it's not too bad for 230 million years old. 

Here's another skull piece located on a side of the block we haven't excavated yet. Pat Druckenmiller said he thought it was a skull piece, and he was right! Good Call. It's about 15cm long showing on the surface - we'll have to see what is buried in the rock.

Sincerely, Greg Carr

Recreating the full skull with 3D modeling programs

We continue to work on extracting bones from the main block, and getting the identifiable skull bones ready to go to the University of Alaska for proper scientific study. It will be sad to see the skull go away, probably never to return to OMSI. The skull is going to be classified (a formal scientific process) and then it will become the original type specimen for a new species (if not family or genus) of animals. At that point it will be scientifically very valuable. It will go back to the University of Oregon and will be kept in special "Holotype" storage. However, since we have scanned it, we will be able to keep 3d printed copies of it - and more!

 3D models of scanned objects can be modified in any way conceivable, and I have been playing around with the scanned parts of Bernie's skull to re-create a full skull with missing parts. I've been using Rhino software to do it, which is available for a 90 day evaluation period free of charge. It's really good software but I don't think I can justify purchasing a real copy when my 90 day period is up. So I'll just have to work fast, I guess!

Here's some screen captures of the process I've gone through. I have modeled the back art of the skull, currently missing, as an Ichthyosaur skull without temporal fenestras. It is easier that way, and seems to fit the back end projections better. In some ways the resultant skull resembles a cross between Ichthyosaurs and large Amphibians such as Temnospondyls. This may not be real, but until we get more loose bones we don't know for sure what it looked like. If it has temporal fenestras like other Thalattosaurs, the skull and mandible would be even longer than in this recreation.

So here's the process in pictures: Here is four views of the original half-skull scan.

Here it is from the right side

 Now since the skull was broken in half we can create a mirror-image copy. The nose needed to be twisted to remove some distortion so the two halves fit together nicely. Rear view:

 And a top view:

 Now we add in another potential part - the tip of the left mandible.

 So now we add a mandible of a reasonable size and dimensions, and the missing part of the skull. I have not attempted to delineate the multiple bones that these parts would be made from. Nor could I easily make them blend in evenly and smoothly to the existing bones. Something about the way the software treats the imported scans differently from the created objects makes this hard to do.

 Now the new parts are copied in a mirror-image and placed under the jaw line.

 Here are so spheres of about the right size to be eyes, placed in the orbits.

 Now I modify the spheres to incorporate some pupils. It's beginning to look really good!

 Here it is from the front. I think this animal had limited binocular vision with much better vision to the sides. My daughter Gloria says this is typical of birds-of-prey such as eagles and hawks, where the eyes can work both independently and together.

 Here's some fun - open the mouth! Looks like a Japanese monster!

 Imagine this coming after you!

 Last of all, add some teeth. These are roughly copied from one of the existing teeth as to dimensions. They were placed on the upper jaw where the roots of broken-off teeth exist, duplicating positions. The teeth in the lower jaw were placed in-between those of the top jaw. You could argue the angle the teeth make in respect to the jaw bones, but straight vertical works for me.

And here we have a re-created head of the animal!!!
Sincerely, Greg Carr