Monthly Archives: March 2013

Tupuxuara: thoracic vertebrae and the notarium, part I

lab

I have six photos of the notarium: the six thoracic vertebrae fused together at the pterosaur’s back. I have no photos of the individual vertebrae, and since I want to have as much detail as possible I used other photos of other notariums and thoracic vertebrae as a reference. I also inferred vertebral shape by looking at the last cervical vertebrae of the Tupuxuara.

I started carving the notarium in one piece.

notarium_start

Then I started adding details on the sides with strips of foam.

flaps

After that, I separated the vertebrae.

split

The specimen I am using as a reference has no ribs on the last two thoracic vertebrae, but that doesn’t mean it did not actually have ribs. I might add them later. The photo that shows the notarium seen from behind reveals details of the last vertebra. So I worked on these two first.

last two

Then I started working on vertebrae three and four.

three and four

Here are some pictures of the unfinished notarium without any ribs.

testing

testing w cerv

Testing the connection to the rest of the spine:

testing_neck

And checking what it will look like when connected to the rest of the pterosaur.

testing_skull

It’s easier to add details to vertebrae 3 and 4 with the ribs in place. I made them hollow, using two halves of foam, and using smaller bits of foam to fill the gaps, add detail and strengthen its base. I then connected the notarium together to compare with the photos.

with four

Here are the last four thoracic vertebrae of the notarium seen from the back. I still need to fix some details.

four

Now I started working on the first and second vertebrae. This is part of vertebra no. 2.

number two

And here vertebra no. 2 with a bit more detail.

two

Now I can test the connection of the whole notarium.

bottom_ribs

side_ribs

top_ribs

The shape still does not match the photo. I have to do some twisting, cutting and reshaping before finishing. In the next post I will show the complete notarium.

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Tupuxuara: the chest

Tupuxuara’s chest is protected by a big solid flat bone called the sternum, or stern. The stern will connect to the vertebrae through the scapula-coracoid bone and the ribs. Since it is practically flat, I started out drawing one of the sides on a 5mm sheet of XPS foam.

foam

It is flat, but slightly rounded. It has a deep cavity on the inside near the front, and the tip is slightly rounded. I had to infer all this from the shadows of the fossil, since I only have a photo of each side. There are no side, front or back views. But I looked at some models and other pterosaurs and I think it’s a reasonable stern. So I twisted and folded the foam into shape, and glued some layers to keep everything in place.

pasting

When dry, I used a lighter to burn the foam a bit, add texture and smooth the edges. I think I did it too much, since the stern is slightly smaller than it should be. But I can fix that later. This is a view of the inside.

after_fire_2

And this is a view from the outside of the stern.

after_fire_1

I finished it with a layer of acrylic resin (modelling paste), some sandpaper and later, when dry, stained with coffee. Here is the result.

stern_outside

stern_inside

Those are the views I can compare to the pictures of the fossil. These are the views I did not have of the fossil, so I had to infer. I hope they are not too different from the real bone.

stern_side

stern_front

stern_back

As usual, I can always change something. I probably will review all these bones when I connect them. The stern will connect to the coracoid and ribs, so I might change something when I test the connections.

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Tupuxuara: two more cervicals

I decided to carve the two shorter cervicals from a solid block of foam. These are the last two cervicals. The ones which connect to the thoracic vertebrae (notarium). I tried to make one of them hollow but it got too complicated, so I gave up and cut out a block of XPS foam for each one.

foam

And then I carved them in the shape of the vertebrae. I later added some details with strips of foam, filled in the gaps and shaped with fire. Here they are in dorsal view compared to the sixth cervical vertebra (cervical #5, after atlas/axis).

after_fire

I tried to fit the vertebrae together. Based on how well they connected, I made some adjustments, cut some parts, added some foam. When finished, I covered each one with a layer of acrylic resin (modelling paste) and when dry, stained them with coffee. Here are some pictures of the final result.

This is the front:

front

And this is the back:

back

The two last cervicals seen from below, separated and connected:

connect

connect_bottom

A view from above:

connect_top

And from the sides:

connect_side

These pictures show the last three cervical vertebrae connected. This is a view from below:

connect_w_side_bottom

Here is a dorsal view:

connect_w_5_top

And a side view:

connect_w_5_side

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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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Tupuxuara: fixing the jaw

new mandible

My last post was about the finished Tupuxuara. It was finished, since I did my best with what I had: great fossil pictures. But I only had one side view of the lower jaw. So I was able to make the mandible look like the one in the picture but had to imagine what it would look like from above, below and inside. I used the upper jaw and palate as a starting point, but I was wrong. Shortly after I finished the skull I received the photos of the mandible: it doesn’t match the format of the upper jaw as I thought it did. It is wider on the sides and narrower at the back. The sides are almost parallel from the middle to the back. The mandible body is much larger. There are also many other small details I left out.

So then I had to decide beween making a new one or fixing the one I have. Since the existing incorrect mandible is already in the correct size, and similar (at least when viewed from the sides) to the correct one, I decided to fix it.

I still don’t have authorization to post the pictures of the fossil here to compare the results, but you can see them in my computer screen.

So here is the plan. I matched the photos in scale to the previous ones I used before, and drew a guide on paper.

the_plan

From that guide I cut out a piece of foam to start filling in the gap which was too large, and to help reshape the jaw:

filling_the_gap_1

First I glued the tip in place so I could mold the arms of the mandible twisting them slightly outward and downward, shaping it like the picture.

filling 2

After that, I scraped the acrylic resin to expose the foam and make gluing more efficient.

filling 3

And held everything in place until it was dry. Now the shape of the mandible already resembles the correct one.

filling 4

I reinforced the insides since I was twisting the foam a lot and then I worked on the other side, which has some ridges (which I could see from the side view) and a concave center (which I could not see from the side view).

other side 1 other side 2

After these changes the mandible had the correct shape, but the sides were no longer vertical but flatly slanted outwards. I added some foam on the top sides of the outer arms of the jaw to compensate this.

top_finishing

Then I did some finishing with fire. This is the result.

finishing

I also had some photos showing the insides of the mandible arms. Just one angle though, and not very detailed, but enough to add see two small cavities on either side which I added to my model.

details

When everything was dry I finished it with fire, covered it with a layer of acrylic resin and let it dry overnight. The next day I stained it with coffee.

coffee

And that’s it. Now Tupuxuara has the right jaw. Below are some photos of the finished mandible and of the skull with the mandible attached.

Top, bottom and side views

This is the bottom

bottom

This is the top

top

And these are the sides.

side1 side2

Here are some views in different angles.

angle side angle top

And a close-up showing the mandible body

close up

Tupuxuara with mandible attached

Here are some photos showing the mandible attached to the skull.

attached front side attached side attached_under_1 attached_under

rear

Finished Tupuxuara with new mandible

allside1 allside2

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Pterosaur #5: Tupuxuara leonardii

0_on_the_piano

It’s finished! There you have a giant pterosaur head 35 piano keys long.

Below is the skull after applying a layer of acrylic resin (modeling paste), and later stained with coffee. I used no paint this time. Only natural stains. The resin is slightly yellowish, almost white. The coffee gave it a natural color and dark shadows filled the smaller cavities increasing the contrast of the texture.

1_after_coffee

This time I decided to use the least resin and gauze as possible. I used it a lot with the Tupandactylus. As a result, Tupuxuara weighs almost half of Tupandactylus. It is also much thinner and it’s crest is translucid against sunlight.

above_back

Using less resin also preserved the natural texture of the burned foam, which somewhat resembles the petrified skin, with the veins and arteries that appear in some well preserved Tupuxuara fossils.

back_crest_w_mand

To make it I used the following material:

  • One 1.0 x 1.2 m sheet of XPS foam board, 5mm thick (I used all of it)
  • Some pieces of a 3 mm XPS foam board (of a different brand)
  • Less than 100g of PVA (polyvinyl acetate) glue (adhesive for foam)
  • Less than 100 ml of modeling paste (acrylic resin)
  • Epoxi resin (very little – for reinforcing the beak tip and jaw articulation)
  • Coffee powder (for stains)

These are the final dimensions and weight of this model:

  • Mandible height: 4.8 cm
  • Mandible maximum width: 12 cm
  • Mandible length: 80 cm
  • Height of the skull (without mandible): 34 cm
  • Height of the skull (with mandible): 36 cm
  • Maximum width of the skull: 12.5 cm
  • Length of the skull: 103 cm
  • Weight: 290 g

Sources

I practically used only one image source: photos of the fossil preserved at the Iwaki Museum in Japan. Unfortunately I don’t have permission to post them here. It would be interesting to compare the results. For the mandible, which I didn’t have enough information, I compared photos of a Tupuxuara replicas and fossils available from Google image searches.

From this article: Pinheiro & Schultz 2012, I obtained additional information about the palate.

Mandible

My source for the mandible was a single side view. I had to look at pictures from other models of Tupuxuara which showed very little detail. As usual, I work with what I have, and imagine the rest. Based on that data I made the mandible below:

mandible

This mandible is incorrect. The closed area should be bigger and the shape is different. I had already suspected the sides (mandible ramus) were proportionally too long (considering other pterosaurs), and as soon as I started to write this post I finally received some photos of the actual mandible in many different angles. It is different: the closed area (mandible body) is some 10-12 cm longer and it has a different shape. This week I will discover how I can fix it.

UPDATE: I fixed the mandible. There is a new post about it.

Inside the head

This is the imaginary part of this Tupuxuara model. I didn’t find any fossil pictures that showed the details inside the skull, so I inferred it from the external structures, bird skulls, other pterosaurs and some imagination.

in_head

There is a concave rounded cavity (only partially visible in this picture) for each eyeball, as in the previous skulls. The picture below shows the eye cavities (seen from below, through the apertures in the back of the head):

inside

The palate

occipital_palate

The palate was always an almost imaginary part in all my previous models. This is the first time I use fossil data to model it from. The photographs were very detailed and I did some additional research to infer how to place the bones in space.

This is a view from the bottom of the skull, showing the palate.

full_palate_under

This is a side view of the rear palate:

palate_side

And a view from the top:

palate_top

Here is a close-up of the rear palate showing layers of palate bones.

palate_maze

Occipital view

Like the palate, there are few pictures of pterosaur skulls that show the back of the head. Since I had photos in good resolution I tried to make it as detailed as possible; It wasn’t as easy as the palate though: the head was not completely hollowed out and it wasn’t photographed in many angles, which made it harder to discover the three-dimensional shape of the bones (I rely on shadows and reflections).

occipital

Sides, top, bottom views

sides
top_skull
under

Other views

Here is the skull with the mandible attached and open.

side_open

And, to finish this post, Tupuxuara on the piano showing the opposite side (and revealing that it is actually 60 piano keys long! (if you count the black keys as well)

piano_other_side

And now Delacroix’s Young Orphan in the Cemetery (obviously a falsification) is surrounded by five floating skeletons:

pterosaur_family
Jeune Orpheline au Cimetière de Ptérosaures (Delacroix falsification and hanging sculptures by Helder da Rocha.)

How to make a Tupuxuara skull out of foam

Do you want to know how I made it? These are all the posts documenting the making of this model, in order:

  1. March 7: Starting pterosaur #5: Tupuxuara leonardii
  2. March 8: Tupuxuara: adding a palate
  3. March 8: Tupuxuara: the mandible, some trimming and molding
  4. March 9: Tupuxuara: details, details
  5. March 10: Pterosaur #5: Tupuxuara leonardii (this post)
  6. March 12: Tupuxuara: Fixing the jaw

(Of course, if you want your own Tupuxuara skull and don’t want to make one, you can always hire me to make one for you 🙂 )

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Tupuxuara: details, details

I could consider the skull finished. It’s light (about 100 grams) and it took me less than two full days. That makes it the cheapest of the five pterosaurs so far. But this time I have very good fossil images so I will invest time into making it as detailed as possible.

Today I worked on improving the structure of the skull, filling gaps, giving volume to flat layers, molding and shaping. I also worked on the texture of the crest to make it look a bit like veins. I marked inset lines by pressing the foam and formed outset lines by pasting some thin strips of foam along the crest. Then I slightly melted the foam with a lighter, letting it burn away some of the width of the crest while giving it a realistic look. I also pasted extra foam to the edges of orbits and lacrimal cavities so I could mold them better.

details_behind

This is the a side view of the skull. You can see the mandible joint has a different colour. That’s because I coated it with epoxi resin (it needs to have a stronger surface in order to offer stable support to the mandible).

details_side

This is the other side of the skull showing the temporal aperture.

details_1

There is still a lot of work to be done in the back of the head (occipital bone). I started adding some strips of foam to model bones and cavities according to the fossil images.

back_foambottom_foam

Then I added a bunch of minor details by pressing, cutting, burning. I tried to shape it so it resembles the fossil image as much as possible. Of course there are many limitations. My sources are still just photos. I don’t have access to any 3D models (not even digital ones). That means I may be deceived by some stain that looks like a shadow or miss the information given by some shadow that I overlook as a stain. I have two photos of the occipital area in two very similar angles. The lighting is reasonable, but could be better.

details_back_palate details_back

This is what it looks like on the inside. I have no photos of the head from the inside, so I based my speculation on the effect the outer structure (which I know from photos) would cause on the inside and from what I infer from other animals: round concave cases for the eyeballs, for example. This is the imaginary part of this pterosaur.

details_inside

So here are some photos os the Tupuxuara so far. Except for the mandible and the details inside the skull, all the rest is based on photographs of an actual fossil.

side_transparentside_view_2top_foam

tweezers

Tomorrow I will finish it with a coating of acrylic resin, sand it a bit and add some stains.

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