Thursday, October 23, 2014

A new block - perhaps a new Skull?

I've decided to take a break from preparing block 2 where we have found so many good bones (80+ and counting, including the half-skull). There were some visible bones on block 5 that have been intriguing me since we cleaned them off almost 2 years ago. So while Jerry Dodson continues on the main block, I've switched over for a few weeks. So here is the block 5 as-found. There are about 5 visible bones. The one most intriguing is on the upper right side, close to the light in this picture.

 Here is a closeup. It turns out that these are two separate bones, touching each other. The lower bone, with holes in it, is particularly intriguing as we haven't see such holes in the bones before.

So we set to work with the large air scribe and after about 4 hours work knocked off a block containing both these bones from the main block. Another volunteer, Janet K, will be working on a part of the block that also got broken off inadvertently during the process. It has at least 3 bones, with 2 centrums and another  (limb?) in it. After about 15 hours total work we have these two bones shown, above, now prepared. Both appear to be fragments of a skull, basically because they aren't anything else. But they don't appear to be parts of the skull we have already removed, or even parts of another skull of the same species. For one thing, they are full of tunnels (sinus?) that the existing skull doesn't have.

We already know that we have more than one species of animal here since we have more than one type of backbone. Perhaps this is fragments of a skull of the second animal. But what kind of animal? And the block 5 has at least two more bones that are not recognizable showing on the surface. I'll be preparing them next in hopes that they too are skull fragments.

Sincerely, Greg Carr

Monday, October 6, 2014

Newest for the Oldest

The title refers to using one of man's newest technologies - 3D scanning, modeling & printing, to study Oregon's oldest bones - Bernie. We have now kicked off a joint project between the University of Oregon, OMSI and Century High School (Hillsboro, Oregon school district)  to scan Bernie's bones, re-create the missing pieces, and print out a variety of skulls based on the real data.

The scanning, modeling and printing will be done as Senior projects by select students at the high school. This sure beats the old High School Shop classes a lot of us took at our high school!

Century High has a very good laser scanner which is capable of mapping up to 40,000 points per square inch of an object in it's view-field. This is a NextEngine. The object to be scanned is placed on a rotatable turn-table and fixed in place. It has to be located a certain distance from the scanner, with larger objects further away and smaller objects closer. In this photo we have a small section of skull, the left side of the braincase / pineal gland area at the rear of the skull. The scanner itself is the white box in the center of the photo, and the very tricked-out desktop computer required is next to it.

Multiple ribbons of laser light pass slowly from the right side to left side of the specimen and are photographed by cameras in the scanner. Wiggles in the light beam are used to compute the surface displacements of the object. This allows the computer to model the 3D dimensions of the object. 

Here's the scanner more from the front while in action. You can see the laser LEDs to the left and the cameras to the center and right of the face. 

Pictures are taken of the object.

Here's a video of it in action:

The laser scans across the surface of a non-moving object from slightly different angles to map the surface. Then the object is turned a certain number of degrees on the turn-table base. Then the scan is repeated. The scans are then combined to create the 3D model. This 'combining' process takes as long, or longer, than the scanning processes due to the complexity of this object.

Once we have models, we can do marvelous things. We will recreate the missing side of the skull. We will also create the missing mandible (lower jaw bone) based on similar animals. I don't claim it will be exact, only close. We do have the tip of the left side of the mandible to start. The back of the skull is also missing - those three prongs that stick out once all joined together and left two holes as the lower and upper temporal fenestras. Again, we will recreate them as best as possible. By the end of the school year we should have some pretty impressive skulls.

Here are two pictures of the first bone we have scanned. It is probably a palate bone, part of the roof of the animal's mouth. It has some small teeth, which some reptiles do (and did) have. It was scanned and printed out at the correct scale. Pretty good!  We did find out that painted-on labels interfere with the scanning processes due to their white background, so catalog labels will be applied after scanning.

Sorry for you readers, but for the near future you will not be able to make your own copy. We must wait to post files until after the classification paper is published in a year or two. Even then the U of Oregon has final say over distribution, not yours truly, since I don't own the Intellectual Property rights to this specimen. However, this field is rapidly changing and has many unanswered legal questions. Meanwhile, back to work!

Sincerely, Greg Carr