Tag Archives: atlas/axis

Tapejara cervical vertebrae

with neck 1

I got a bit behind schedule this week with some other projects but I was able to recover half of the time this weekend and get the cervicals done. Now Tapejara has a neck, as shown in the picture above.

I started gathering all the data I had which included cervicals from 4 different specimens. The SMNK specimen is smaller than the others. I used the IMCF specimen as a reference, double checked by comparing the size of the cervical vertebra in the AMNH specimen. I also used Tupuxuara vertebrae (from IMCF 1052) scaled to the same size as the Tapejara because of its better resolution and because it has a complete collection. But the IMCF, SMNK and AMNH vertebrae are all proportionally a bit longer and narrower than the Tupuxuara vertebrae, so I made considered that as well. Here I placed all of them in scale.

research_no_IMCF

I started with some prototyping and made hollow cervicals (as I did before with Tupuxuara). This time I used 2mm XPS foam (instead of the 5mm foam I used in Tupuxuara) since the Tapejara vertebrae are less than half the size of Tupuxuara vertebrae.

prototype 1 prototype 2

After assembling, gluing, shaping, adding texture and molding with a lighter, we have a prototyped vertebra.

prototype 3

From those prototypes, I cut out the foam in this pattern for vertebrae 1, 2 and 4 (3 and 5 have a slightly different shape, a bit taller and shorter).

final prototype

Here are the five vertebrae, after assembly and shaping with a lighter.

cervical rod

After finishing all 8 (or 9 if the fused Axis/Atlas are considered 2), I made a spinal cavity in each one, and crossed it with a wooden skewer. Here is the Tapejara with a stiff neck.

stiff neck

As I did with Tupuxuara, I used a rubber tube (4mm diameter) as a spinal cord.

medulla

Here are the Axis/Atlas and seven other cervical vertebrae connected with the tubular medulla.

cervicals connected

The last two vertebrae are slightly shorter.

last cervicals

The neck is assembled connecting the vertebrae. It retains some flexibility (less to the sides, more up or down).

neck

And finally the Tapejara with the neck in place. It’s still not possible to attach it, since the skull still lacks several posterior bones.

curved neck

Tomorrow Tapejara will have some thoracic dorsal vertebrae.

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Filed under Pterosaur #7: Tapejara

A neck for Tupuxuara

I used six photos of each one of the eight cervical vertebrae as sources, from the same holotype as the skull (stored at the Iwaki Museum in Japan). Each photo shows a view from one side of the vertebra. For each group of six photos, I cut out a “cube”, like this.

cube_cut

Then I assembled it:

cube_assembled

And did the same for all the other cervical vertebrae.

cube_set

I used the cube as a quick guide to help me fabricate the vertebrae. This is a first attempt and I will probably have to redo some vertebrae later, since even with these six views it is still possible to overlook something, lose some detail in the cavities, etc. I will only actually finish the vertebrae when they connect properly. I don’t only expect them to look like vertebrae. I want them to work like vertebrae. Later I will make discs out of silicone rubber and I expect the neck to be able to twist, turn, and to have all the flexibility a neck should have.

But at this point I know nothing. I need something to work on, some prototype. So I start cutting out the sides, the bottom, the front and back parts out of foam. After modelling, some parts may not be necessary, and I might have to add foam, fold, twist, burn. But for now I just cut out the views.

flat_foam_set

The best part to attach are the two sides, since they are almost flat at the top. From there, I fold the body of the vertebra, opening its sides until I can attach the bottom or the front/back as support. After folding an cutting there are some places I will need to cover up later.

Here it is after attaching these parts. I think this is cervical no. 5 (not counting the Atlas).

foam_base

After twisting and folding, the foam was not enough to cover the sides. So I will have to close this later:

foam_inside

But those holes are useful for molding. It’s great to have access to the inside. So after the glue dries well (some 6 hours later) I try twisting and folding until I get something like the pictures in the cube. It’s not perfect. This back side, for example, still needs a lot of work since it needs many convex and concave details (I will have to work on these parts after I finish since they are important for connecting the vertebrae.)

foam_compare_back

But the side and top views seem OK.

foam_compare_bottom foam_compare_side foam_compare_top

After that I can start closing the vertebra with some foam, add fire to trim the edges, reshape and give texture, cut and twist if necessary.

closing_holes

I worked on two vertebrae: the atlas/axis (which connects to the skull) and vertebra number 5 (the last of the long cervical vertebrae). I sanded and stained them before I tested the connections (because of that I might have to redo them later).

finished_one

And then I repeated the process with the other four long cervicals. Here they are connected (top view):

cube_and_top

Here is a view from underneath.

bottom_six

And from the sides:

side_six

I only stained vertebra 5 so far. Two more shorter cervicals are missing. I might only have time to work on them in two weeks. And there are still many problems. I have to work on the connections. The pterosaur that uses these vertebrae as they are now has a very stiff neck! I might have to redo some vertebrae. Now that I can test the connections, I finally have feedback about what I need to change.

They aren’t finished, but I tried to connect them to the skull anyway, with the help of some pins and clips.

neck_attached

Here is a view from the sides.

neck_head_close

With its new neck, Tupuxuara can now nod and look ahead (when I improve the connections it will also be able to look back :))

tupu_w_neck_2 tupu_w_neck

I will have to stop working on this model for a week or two. In the meantime, Tupuxuara, now with a neck, will stay floating with the other pterosaur heads. Besides Guidraco, Tupuxuara is the only one of the Imaginary Pterosaurs which has a neck.

hanging_neck

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Filed under Pterosaur #5: Tupuxuara