Sunday, June 10, 2018

New kid on the block - a Sabertooth Salmon!

I haven't posed much about the thalattosaurs lately, as there hasn't been much new to report. The rocks I'm working on at OMSI are pretty barren. A typical rock the size of my head contains one or two bones, almost always ribs, gastralia or centrums. I have found another partial braincase, bringing the total to 7! However, it's been pretty boring. I think I'll be done with all the blocks around the end of the year.

However, fossil preparation continues. One new addition is one of my favorites - a "Saber Tooth Salmon"! These large salmonoids lived about a million years ago, and swam up rivers in the western US (none have been found in Canada or Alaska to-date). They were 8-10 feet long (2-3 meters) and weighed 400 pounds (180Kg). he best remains have come from a gravel quarry near Madras Oregon, the ancestral river bed of the Deschutes river.

A very complete fossil skull and articulated backbones came up on an Ebay auction earlier this year. I was lucky enough to purchase it for the University of Oregon, which has the holotype and two other specimens. This specimen was collected in 1980 by Reuben Holleman, a local fossil collector. He prepared it and kept is safe for almost 38 years before selling it as part of his collection liquidation. I did some more preparation of the skull, removing the majority of the remaining matrix and making archival cradles for both skull parts. This really is the best specimen of this animal in the world - I'll let the pictures speak for themselves!. It is on display at OMSI for the next few years as the U of Oregon has no place to display it. The UO and I are working on dating the site, and OMSI and the OHSU (Oregon Health Science University) will be working on CT scanning/printing to make copies.

Here is the skull in all its glory, about 20 inches (50cm) long - that's a 6 inch (15cm) ruler beside it!

Articulated backbones and a fin

Ribs

Still more ribs

And another set of ribs (well, what do you expect from a 2 meter animal?)


Bones as displayed in a case at OMSI

The two large teeth stick sideways out of the upper jaw - perfect for fighting other fish!

Front ends of the jaws, the original on the left and 3D print on the right

Tuesday, January 16, 2018

Epic printing Jobs - Part 2

One block of fossil bones and shells I plan on leaving as a display piece, as it looks really cool and yet has no unique bones in it. I scanned it recently and intended to print it out. It is a big print - it takes slightly more than 1 full roll of filament, and takes about 5 full days to print! Things went fine for the first 4 days - about 102 hours or printing - then disaster (of sorts) We had a power blip, which reset the printer and the print stopped!

So I figured out roughly where the print stopped and made a small print of the remaining piece. Since I couldn't get it exact, I printed a little more at the interface and will have to physically trim the piece to fit. You may also notice that the print changes from Ivory to White. I thought I had another roll of Ivory when I started - opened the box and it was white! So I had to splice in white on the fly (always fun, but I've figured out how to do it.)

 I don't plan on doing another one.

 The printer has also developed a rather nasty Z-axis wobble. The Z-feed screw spontaneously developed a 0.010 inch (ten-thousandths) bend, and the linear guide bearings are poor enough that they don't keep it straight. I've re-bent the screw to be straight and ordered some new bearings. We'll see if that fixes it.

Sincerely, Greg Carr




 4 days and counting - almost done!

 The (almost) finished product.





Friday, January 5, 2018

Epic 3D Printing jobs - part 1

I haven't had too much new in preparing actual bones lately - ribs, gastralia pieces, centrums and neural arches. All well known stuff, even somewhat boring. No limb, skull or unusual bones at all. Several large blocks have been pretty barren of bones, so they quickly went from 'unprepared' to 'scrap' piles.

What I have been busy with is 3D printing. I decided to print out 3 reference sets of bones - basically all the scanned bones that I have files on. I had never seen all the bones all together, since as soon as they are prepared and scanned I send them off to Alaska for Eric Metz to study. So I decided to make 3 sets - one for OMSI, one for myself, and one for the U of Oregon. Since I have about 150 scanned bones, this makes for a LOT of 3D printing - about 450 individual pieces!

Well, I'm done with that. It took over 3 months with the printer running 12+ hours a day. To get the best quality surface print quality, I found that making the prints very slowly gives the best surface. The specifics of the printing are roughly as follows:

Ivory PLA material. 1.75mm filament
0.3 or 0.4mm nozzel
205 C extruder temperature
80 C heated bed temperature
10 mm per second outer perimeter speed (very slow!)
3mm thick shell
25% fill
So here are the bones laid out on my family room floor. For scale, the planks are 2.25 inches (60mm) wide. Quite an impressive lot. The skull, of course, is both the original and it's mirror image to make a whole.
 So looking at these individually I have 7 ribs. Actually I have prepared a LOT more, but since most of them are short broken pieces I haven't scanned them. Some ribs are thin with a figure 8 cross-section, some are round and tapered.

 Nest to them I have limb bones. Some are quite small. One is stuck in a chambered nautilus. There are about 33.
 Next we have shoulder and pelvic bones. I have about 13.
 These are unknowns. I swear some of them are osteoderms, except that thalattosaurs don't have them! Perhaps the guys in Alaska have identified them by now.
 Next through the center of this picture are the skull & braincase bones. Along with the large half-skull, there are most of the other skull bones like the pteregoid, volmer, postorbital, etc. We may have part of the mandible, but no complete mandible! In total, about 32 bones including 6 brain cases (two not pictured, they are in Alaska before I got them scanned).
 Last of all, backbones. About 50 whole & partials are not pictured as I sent them to Alaska without scanning (who needs 80 backbone scans?). There are 6 centrum+neural arches paired together, 29 separate centrums, 17 separate neural arches , and 3 chevrons. One chevron is so big it may have come from a 30 foot (9m) animal!
Sincerely, Greg Carr

Thursday, November 9, 2017

tiny bones in the rocks

When I was much younger I was lucky enough to see Don Ho in Honolulu in his Waikiki stage show. His favorite song was 'tiny bubbles'
(Tiny bubbles (tiny bubbles)
In the wine (in the wine)
Make me happy (make me happy)
Make me feel fine (make me feel fine)...

When I see tiny things I often think of this song. Anyway, not all the bones I find in these 'Bernie Blocks' are large - some are very tiny. I have recently prepared 3 small bones, which may or may not belong to thalattosaurs. I've blown them up quiet large, as they are each less than one inch long. The top center one may be a worn neural arch, and the left one is definitely a limb bone or digit. The one on the right is a complete mystery - I suspect it may be an amphibian bone of some type. It is very thin, most of it is less than 1 mm thick, so it was 'difficult' to prepare, to say the least. However it's nice that it's finished. Maybe the guys in Alaska can figure out what they are. 
Sincerely, Greg Carr




Thursday, October 19, 2017

Bones, Bones - Lots of Bones

I'm doing a project that is giving me perspective on how much we have accomplished in the past 5 years. I have decided to print out a reference set of all the bones I have prepared so far. In fact, I have decided to print out 3 sets - one for myself, one for OMSI, and one for the University of Oregon's Condon collection. Right now I have scanned about 138 bones, so 3 sets will have 414 bones. In addition, most of these bones are not from the centerline of the animals. So if I print both the original bones and the mirror images, I will have about 700 bones.

I have been printing the bones for about a month out of ivory-colored PLA. It prints well, and I'm enjoying it. So far I have printed 33 sets of 3 bones, about 3 per day. At this rate it will take another 15 weeks or so for the original bones to be printed, so I won't get them all done by Christmas.

Here are the skull bones I have printed so far. This is only about half of the total number of skull or brain-case bones that we have. This really makes me thankful to have so much skull material! This is truly is a treasure.

Here are the other bones I have printed so far. Keep in mind that this is only about 1/4 of what I will eventually end up with. So many Bones!


And here is the workhorse - my printer. 


But wait - there's more! I have  lot of bones that I have not scanned. Most of them are fragmentary or are part of groups that I don't intend to totally prepare. This is because most of the groups contain bones we know well, or are very aesthetic. There are another 160 or so bones or parts of bones in the cabinet at OMSI These too will go to the University of Oregon, along with the bones sent to Alaska. 

But wait - there's still more! These bones have been taken from only about 2/3 of the find - we still have 1/3 to go! 

So ultimately I predict we will have (138+160)*3/2 = 450 unique bones !

Ribs and Gastralia


Other stuff

Backbones - centrums & neural arches


 Sincerely, Greg Carr

Wednesday, September 27, 2017

Just more backbones - as if we don't have enough of them!

Just a quick note to tell all you folks about more backbones that I've prepared. Sometimes the backbones cluster together - must be something about how the water currents & waves sorted items of similar density and shape together. Anyway, I have been working an a small rock about the size of two fists together. This rock has at least 6 backbones, maybe more. We have both centrums and centrums combined with neural arches. Some are rather unusual in the way the rib attachment knobs on the centrums look. I believe that the rib attachment point (on the centrums) migrates from the top  to the bottom of the centrum side as you go from the front of the rib cage to the back. So if you know enough you can tell where the backbone came from. However, I'll leave that to the guys in Alaska to figure out.

Here's two centrums hooked together. I was able to separate these with a bit of care. The big one on the bottom had a short, robust neural arch that was not blade-shaped in cross-section. Instead it is an oval cross-section, pretty robust.

 Here's a view of the prepared centrums I just sent to Alaska. The top group has 3  centrums as well as a nautilus, perched directly on the end of a centrum. Pretty cool! 


 Here's a centrun+neural arch that has the centrum rib attachment knobs on the side blending into the neural arch on the top. Must have come from the forward part of the rib cage. 
  And here is a rib with the neural arch that has no rib attachment knobs. Perhaps this came from the neck, where there are no ribs?
I still have 2 more backbones to finish preparing from this rock, and maybe more hidden inside it. Anyway, that's all there is for now. 
Sincerely, Greg Carr

Saturday, September 23, 2017

Bartender - yet another illium - small, please, on the rocks

Three items to report: ilium, lots of backbones, and a 3D printing project!

I have prepared yet another ilium - I think that is about 7 in total that we have found. Most all are different sizes from the different animals. The ilium is one of the three types of pelvic bones in reptiles. They are the ilium, ischium and pubis. In mammals these three bones are fused together to form the pelvis, but in reptiles they are separate bones (6 total, 3 per side). These ilia (plural of ilium) look rather like seal scapula, being a thin fan-shaped bone with a thickened knob at the base of the 'fan'.  Here is a picture of the ilium as it was being prepared, compared with a 3D replica of another one prepared a couple of years ago. The current one is much smaller.

Here it is after being prepared and labeled with the UO number.


And here is a top view, showing how thin it really is. Much of this bone is 1 mm thick or less! It makes it really challenging to prepare them, as you can imagine. However, it is finished and safely up in Alaska with about 135 other bones I have prepared.


I have a whole cluster of backbones I'm working on. So far there are 5, one is a triplet in a tight cluster that I probably won't be able to dissect, as they are too nestled together. Like all the other backbones I have ever found, they are not articulated and not sequential, and probably not even from the same animal. Pictures with the next post. 

I have just begun to do a major 3D printing project. I am going to be printing up 3 complete print sets of all the bones I have prepared. One set will be for me, one for OMSI, one for the U of Oregon. (I figure the U of Alaska can print their own as they have a 3D printer.) I have prepared, scanned and labeled about 135 bones as of this posting. Just printing out the bones directly is about 400 pieces. I figure this will take me about 4-5 months to do  them all. Additionally, about 110 of these bones are not backbones, so there is a corresponding mirror image bone on the other side of the animal. If I print out the mirror images as well I'll end up printing about 700 bones! Lots of printer time! I just print one bone at a time. I've never had a lot of luck printing multiple objects at the same time. It seems that something goes wrong with one print which screws up the other ones as well. And it really doesn't take much longer as a 3 object print takes 3 times as long - it is just the setup that takes longer. 

Here's a picture of the printer in operation. It is just about finished printing  out a limb bone that I have been told is a radius. I like the fact that I can change the color of the LED lighting to match my mood! 
Sincerely, Greg Carr