Monthly Archives: March 2013

Tupuxuara: thoracic vertebrae and the notarium, part I


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.


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


After that, I separated the vertebrae.


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 w cerv

Testing the connection to the rest of the spine:


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


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.


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.


Now I can test the connection of the whole notarium.




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.


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.


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.


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


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



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.




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.


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).


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:


And this is the back:


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



A view from above:


And from the sides:


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


Here is a dorsal view:


And a side view:


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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.


Then I assembled it:


And did the same for all the other cervical vertebrae.


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.


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).


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


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.)


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.


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).


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


Here is a view from underneath.


And from the sides:


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.


Here is a view from the sides.


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.



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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.


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:


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.


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


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.


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.


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


This is the 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


Finished Tupuxuara with new mandible

allside1 allside2


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Pterosaur #5: Tupuxuara leonardii


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.


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.


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.


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


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.


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:


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.


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):


The 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.


This is a side view of the rear palate:


And a view from the top:


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


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).


Sides, top, bottom views


Other views

Here is the skull with the mandible attached and 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)


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

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.


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).


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


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.


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.


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.



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


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Tupuxuara: the mandible, some trimming and molding

While I worked on the head I also joined the halves (ramus) of the mandible together and molded it a bit whenever I had to wait for drying glue. Now I made these two foam strips which will be pasted on the insides to give each side a three-dimensional form.

mandible 1

This is the mandible attached to the skull.


I also did some shaping with a lighter which changed the texture and made the insides slightly convex by melting. My source photos only show the mandible sideways, in connection with the skull (not the best lighting). I have no idea what it looks like inside the ramus, nor from below or above. I infer the shape from the photos I have of the skull, but I am also taking from pictures of other models available in Google image searches. So there is some guesswork here. The mandible body seems a bit too short. I think it is. But it’s easier to add later than to remove.


I trimmed the edges of the palate bones and added some more foam to make the connections look organic. I also used a diagram from this article. Here is a view of the head showing some of those details.


It seems almost done in less than two days! But, of course, there are a lot of little details which might take me a day or two. Here are some pictures of the Tupuxuara so far: top, bottom and side views:

above under

day 2 palate

It looks finished from those angles, but If you inspect it closely from other angles you will see some holes, patches, hollow bones. I also have to improve the structure doubling the width of the foam in some parts. The back of the head still needs a lot of work so it resembles better the fossil image. That’s the work for tomorrow.

2013-03-09 03.01.38


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Tupuxuara: adding a palate

The photos I am using as a source include a high resolution image of the palate (below the skull) and occipital (behind and below), so I will have the opportunity to make a much more detailed skull this time.

First I placed the palate photos in the same scale as the side view of the skull in the computer. The right half of the palate of the holotype I am using as a source is damaged, so I duplicated and flipped vertically the other half of the image of the palate to make it symmetrical. Then I transfered the palate drawing to a sheet of foam.

palate 1

I added all the details I could find in the fossil. It’s great to have high resolution photos taken with different lighting, since some three-dimensional details are only visible because of the shadows.

I cut out the palate and trimmed the edges a bit.

palate 2

Then I folded the back (occipital) and creased everything in the shape of the skull so it could fit in place.

palate 4

The palate is convex near the ridges and towards the tip, and concave towards the throat. After some folding and creasing I obtained this effect (this is a view of the palate from the inside).

palate 3

After that, I attached it to the skull. I had to cut a bit along the line that separates the palate part from the occipital part (near the mandible joint), so I could mold it better.

palate 5

I made some small cuts in other places as well.



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Starting pterosaur #5: Tupuxuara leonardii

I should be making the bodies of the other skulls, but yesterday I received some high-resolution photographs of a very-well preserved fossil and promoted Tupuxuara (planned as pterosaur #7) to #5.

I started with a sheet of XPS foam. It’s 0.5 mm thick and 1.00 by 1.20 m. I cut a portion of it (1.10 x 0.45) to draw one half of the skull:

2013-03-06 22.01.11

I am not authorized to publish the photos of the fossil here, but you can see the one I used on my computer screen. It’s from the  Iwaki Coal and Fossil Museum, in Japan. There is a replica in London, and several photos and diagrams in books and the Web. Usually I use diagrams which are drawn from the fossils, but this time I decided to use the picture of a real fossil.

This is the moment I identified the Tupuxuara skull in the foam 🙂 Now I can begin “excavating”!

2013-03-06 22.45.46

After cutting out one half I use it as a guide to cut out the other half using the rest of the sheet of foam. There is still a lot of foam left for the details.

2013-03-07 01.26.16

Then I start folding and molding. If you want to see how I do this, read this post on the Tupandactylus model. I also trimmed the edges near the tip of the beak and mandible.

2013-03-06 23.30.06

These are the folded and slightly molded halves before pasting together.

2013-03-07 01.27.35

Next step is to paste the halves together.

2013-03-07 01.28.44

Then I carved out a bit of the crest. This is the final result after about an hour and a half of work.

2013-03-07 01.21.31 2013-03-07 01.15.58

Today I will work on the insides of the skull and try to mold the orbits. It will be a lot easier since I have detailed high resolution photos of everything. I might be able to finish this model in three days.


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