The document discusses the reconstruction of pterosaur skeletons using light, durable, and recyclable extruded polystyrene (XPS) material, presenting methods for achieving scientific accuracy and detail through research, photography, and sculptural techniques. The process, which varies in production time and requires manual skills, is less toxic than traditional methods, making it suitable for indoor exhibitions. The document also highlights the author's past works exhibited in museums and outlines the advantages of using XPS for creating detailed and lightweight replicas of pterosaur skeletons.

1. Reconstruction of
pterosaur skeletons
using light, cheap and
recyclable material
Helder da Rocha
XXIV CONGRESSO BRASILEIRO
DE PALEONTOLOGIA
Originally presented at
(updated december/2017)

2. Scientific sculptures in XPS
Paleosculpture
Paleoart: paleontological art + references
References are essential to justify decisions: the
skeletons are representations of scientific theories
It's a scientific process
Paleontological research
+ research of materials (test, error, learning)
+ execution

3. Pterosaur reconstructions
Research based on
Photographies (one or more visions)
Drawings & diagrams
Descrip,ons, publications, specialized opinions
Goals
Scien,fic accuracy & high level of detail
Lightness and resistance
Flexibility to be assembled in different positions
Production time (depends on quality, research, details, size)
Skulls: 3-15 days
Full skeletons: 4-12 weeks

4. Helder da Rocha
Paleosculptor since 2012
Only pterosaurs
Only sculpture in XPS
4 full skeletons + 4 different skulls
Works exhibited in museums and congresses
Pterosaurs
Guidraco (skeleton), Anhanguera (skull), Tupandactylus (skull),
Dsungaripterus (skull), Tupuxuara (skeleton), Caupedactylus
(skull), Tapejara (skulls and skeleton), Tropeognathus (skeleton)

5. Guidraco venator (2012)
"frankenstein" model;
not scientifically
accurate

6. Anhanguera
piscator (2012)
Based on publication by
Kellner & Tomida, 2000

7. Tupandactylus
imperator (2013)
Based on specimen from
Museu de Ciências da
Terra (Rio de Janeiro)

8. (teeth still missing)
Dsungaripterus weii (2013)

9. Tupuxuara leonardii (2013)

10. Tupuxuara leonardii
First prize (category sculpture)
in the Paleoart Contest
sponsored by Colecionadores de
Ossos (2012) website/blog
Exhibit in I Simposio de
Dinossauros e Rio Ptero 2013
(International Symposium on
Pterosaurs) & Museu de
Geociências USP (Universidade
de São Paulo)
Mentions in Tetrapod Zoology
blog SciaAm (Darren Naish) and
Pterosaur Heresies (David
Peters)

11. Caupedactylus ybaka
(2013)
Source: Paleodirect website

12. Tapejara
wellnhoferi (2014)
Museu de Dinossauros in Peirópolis, in Brazil
Instituto
Geológico de
Lisboa, in
Portugal

13. Tapejara wellnhoferi (2015)
Very detailed skull
(based on three
specimens and
publications)
Exhibit "O Pterossauro
Imaginário" (2016) and
Museu de Geociências
(USP) (2017)

14. Tropeognathus mesembrinus (2016)
Giant 8 meter wingspan pterosaur (3,5kg) - Museu de São José dos Campos (São Paulo), Brazil
It was installed in
December 2016,
but exhibit has
not opened yet

15. Characteristics of a replica
How is it going to be used?
Indoors or outdoors
Exhibition or manipulation
Quality
Scientific accuracy and level of detail
Resistance
Weight
Durability
Cost of maintenance
What should be considered?

16. Sculptural processes
Additive
Process of adding material (ex: ceramics, metal)
Subtractive
Process of removing material (ex: rock)
Cast (ex: part + rubber cast + resin)
High-cost one-time casting, many low-cost copies
Digital: 3D scans or 3D modeling + 3D printing
High-cost one-time 3D modeling, many low-cost copies

17. Paleosculpture in XPS
Very light, durable, resistant, for indoor exhibits
Can be built for extra robustness, for handling (heavier)
Easy to sculpt details, allows for precision of measurements
(easier in large models)
Durable, does not retain humidity, does not crack or shrink
Relatively resistant, flexible; resistance and flexibility may be
increased with acrylic and epoxy layers
Additive and subtractive sculpture + mixed techniques
"Drawing" in 3D: replica by comparison (no casts)

18. Cons
Learning curve requires manual skills
Handmade process
Each part has to be built from scratch every time
Parts need to be copied (by comparing) without casts
Material resistance is relative
Sufficient for installations and simple handling
Not sufficient for outdoor use and "resistance test" handling
Adequate for indoor use

19. Techniques
Plaster, resin, fiberglass
Ideal for casts
Wax and electrotyping
Wood, paper and card
Also recyclable; safer
construction process
Rock (subtractive sculpture),
metal (aditive), etc.
Digital 3D sculpture + 3D printing
in metal, resin, PVC ...
Mixed techniques
Kai-Xiang Xhong
Philippe Pasqua
Chicago O´Hare
by Field Museum (fiber-glass)
(recycled
cardboard)
(chrome)
Jeffrie Parker
(3D printer)
Other

20. Modeling and sculpture with XPS
Additive (modeling using thin sheets) and subtractive
(sculpted with a box cutter and fire on thick blocks)
Copy by comparison (doesn't use casts)
Preferably hollow
Much lighter (only contains air)
For objects with a lot of internal space (large vertebrae) an
internal structure can be created

21. Material
XPS : eXtruded PolyStyrene
Easy to model, squish, fold
Easy to cut (with a box cutter)
It's not the same thing as
"common foam" (EPS:
expanded polystyrene)
Hard to cut with a box cutter
Fragile (hard to work with thin
sheets, hollow parts, etc.)

22. Light and resistant
Tension-resistant
Compression reduces fragility and
softens material which allows
squishing, folding and modeling.
Thin sheets allow modeling of hollow bones
Tapejara skull: 90g
Complete skeleton: 300 - 350g
Tupuxuara skull: 250g
Complete skeleton: 950g

23. Cheap
A 120cm x 60cm x 2.5cm insulation block ~5 USD
Not very dense, thicker, used for adding details
Where to find it: hardware shops e trash
A 42cm x 60cm x 0.2-0.5cm thin sheet ~3,50 USD
Several densities, thin, for modeling, texture, etc.
Where to find it: Art shops, food trays, trash
Recycled: 0 USD

24. Recyclable
Can be found in trash
Foam food trays and boxes
Thermo-acoustic insulation
It's (usually) not a biodegradable material and it's
fabricated in large-scale for temporary use
Recycling XPS for the construction of durable
scientific replicas is ecologically correct

25. Relatively safe process
Low toxicity (for use with fire)
Non-toxic for use and modeling without heating
Heating for softening and texture (without burning) releases CO2
and water vapor; burning releases less toxic gases than wood
Breathing the dust (released by sanding XPS) is most toxic
Less toxic than plaster, polyester resin or fiber glass processes
Low flammability
XPS contains flame retardants: it does not propagate fire
Precautions
Always work in a ventilated environment when working with fire
Use a mask for sanding (+ use water)

26. Applications
Ultra-light skeletons
Easy to transport and install: can be
suspended with nylon cables and paper clips
Ideal for temporary installations and events
Low cost of installation and insurance

27. Other materials used
Acrylic paste (acrylic polymer emulsion
soluble in water)
Foam glue, epoxy, paints, natural stains
(ashes, rust, coffee), etc.
Optional: protective epoxy layer

28. Working with XPS
Folding e squishing
Melting, adding texture, modeling with fire
Tupandactylus imperator
Tupuxuara leonardii

29. Starting point: a 3D "sketch"

30. Texture and color
Heating XPS changes texture
Coarse (microcraters)
Allows for adherence of acrylic
base (paste used to prepare oil
canvases)
Acrylic base dissolves in water
It becomes lighter with time
(evaporation)
Pigments mixed to acrylic base
(paint, natural stains):
ashes, rust, coffee

31. + protection
Liquid epoxi + matte varnish
It's optionall!
Pros:
increases material resistance
Cons:
loss of detail and reflective effect

32. Examples
1. Construction of
Tupuxuara leonardii
2. Construction of
Tapejara wellnhoferi
(Download the complete presentations and read detailed
descriptions of each process at imaginosaurus.wordpress.com)

33. Research: Tupuxuara
Photos of IMCF 1502 (IWAKI, JP): Everything except pelvis, carpals,
tarsals, fingers, dorsal vertebrae and pre-pubis
Other sources: publications and specialized opinions
Details are limited by precision of photos
This is an excerpt from the presentation: Making of Tupuxuara leonardii
See more in http://www.slideshare.net/helderdarocha/the-imaginary-pterosaur-makingof-tupuxuara-leonardii

34. Source: ICMF 1502 (Iwaki, JP)
Resolution of skull
details is limited
since the fossil is not
fully prepared
Will use other
sources & infer
appearance as
closely as possible

35. Material: 5mm XPS foam board
1.0 x 1.2 m

36. Transfer to
foam board

37. Cut out

38. Paste together & let dry
I call this a 3D sketch

39. Stained with coffee

40. Palate
External 3D details based on photos of the Iwaki specimen
Internal 3D details based on articles (Pinheiro & Schultz 2012)

41. Height (without mandible): 34 cm
Height (with mandible): 36 cm
Width: 12.5 cm
Length : 103 cm
Weight: 250 g
Time to produce: 5 days
Further improvements may include
• Fixes (in case better sources are provided)
• Resistance (layers of epoxi – which will also triple the weight)

42. Assemble
Hollow vertebra

43. Compare

44. Compare to source

45. Thoracic vertebrae w fused ribs

46. Notarium

47. Studying the
sources

48. Distal & proximal syncarpals

50. Bone ends

51. Ulna: roll

52. Research:
Tapejara
1. SMNK PAL 1137 Tapejara wellnhoferi (Germany)
2. AMNH 24440 Tapejara wellnhoferi (USA)
3. IMCF 1061 Tapejara wellnhoferi (Japan)
4. MN 6595-V Tapejara wellnhoferi (holotype)
+ 8 sources
osseous labyrinth is well defined, leaving a deep depression
on the endocast around the floccular lobes. The preserva-
tion of a small portion of the lateral semicircular canal
suggests that this structure would have completely sur-
rounded the flocculus.
Quadrate
The right quadrate is complete but lies unfused to the other
elements of the skull. The bone is formed by two branches,
orientated dorsoventrally and mediolaterally, and con-
nected by a thin diagonal laminae of bone to give the
element an L-shaped appearance in its posterior aspect
(Fig. 2; plate 3). The dorsoventrally directed branch is 2.4
times the length of the horizontal branch; the dorsal ter-
mination of the former being smooth and well rounded in
posterior view and preserving an oval shaped cross section.
The ventrolateral margin of the bone forms the articular
facet for the mandible where a pronounced sulcus runs in
an anteromedial direction. A left quadrate of a comparable
size to that described above is also present in the concretion
but the vertical branch is broken only just dorsal to its base.
Mandible
The mandible is edentulous and preserves a short sym-
physis only 44 mm in length, formed by the completely
co-ossified contralateral rami. The dorsal face of the
symphysis is transversely concave and is directed antero-
ventrally at an angle of 18°, starting at a point 45 mm
posterior of the rostral tip (Fig. 2; plate 4B). The ventral
margin is almost straight but forms a sagittal crest reaching
its maximum depth at the symphysis. In its dorsal aspect
the bone appears as an elongate triangle, three times as
long as it is wide (Fig. 2; plate 4) while the posterior
section containing the articular facet is missing.
Cervical vertebrae
Four procoelous vertebra, identified as elements of the
cervical series, are observed in various states of preserva-
tion (Fig. 4). Two of these are attributed to the middle
cervical column (Fig. 4f–o) while a third is identified as the
7th cervical. The remaining element represents the isolated
axis (Fig. 4a–e).
Fig. 4 Cervical elements of Tapejara wellnhoferi, SMNK PAL 1137,
where: A–E axis in lateral (A), anterior (B), posterior (C), dorsal
(D) and ventral view (E); F–J cervical vertebra in lateral (F), anterior
(G), posterior (H), dorsal (I) and ventral view (J); K–O, cervical
vertebra in lateral (K), anterior (L), posterior (M), dorsal (N) and
ventral view (O); P–T, 7th cervical vertebra in lateral (P), anterior
(Q), posterior (R), dorsal (S) and ventral view (T). f foramen, nc
neural canal, ns neural spine, pe postexapophysis, pre preexapoph-
ysis, pz postzygapophysis, prz prezygapophysis, vc vertebral condyle
K. Eck et al.
This is part of the
presentation: Making of
Tapejara wellnhoferi
See more at http://www.slideshare.net/helderdarocha/the-imaginary-pterosaur-making-of-tapejara-wellnhoferi

53. Scaling
Replica is 25% larger
than reference size of
young individual
53

54. Bone construction
Fully documented at
http://imaginosaurus.wordpress.com/2013/08/28/imaginary-pterosaur-7-finished/
54

55. SMNK PAL 1137 limestone slab
Approximate reconstruction (using bones of one pterosaur)
55

56. Neurocranium version 1
replica of SMNK PAL 1137
http://imaginosaurus.wordpress.com/2013/07/06/unfinished-tapejara-skull/
56

57. Cervical vertebrae
Sources: 4 specimens (SMNK, IMCF
Tapejara and Tupuxuara, AMNH)
57

58. Cervical vertebrae
http://imaginosaurus.wordpress.com/2013/07/15/tapejara-cervical-vertebrae/
58

59. Fingers
http://imaginosaurus.wordpress.com/2013/08/01/tapejaras-hands-and-feet/
59

60. Pectoral girdle
http://imaginosaurus.wordpress.com/2013/08/19/tapejara-pectoral-girdle/
60

61. Feet
http://imaginosaurus.wordpress.com/2013/08/01/tapejaras-hands-and-feet/
61

62. Conclusions
Pterosaur reconstructions using XPS are an alternative to
traditional techniques
Material is cheap, light, recyclable and easy to obtain
The process is less toxic than traditional methods
The replicas are relatively resistant and detailed: adequate
for indoor use
The process is handmade: it doesn't produce "copies": the
work has to be repeated for each reconstruction even if it is
identical: it doesn't use casts - each part needs to be re-created
by comparing to an original or photos.

63. Workshop
During the 24th. Brazilian Congress of Paleontology
using the techniques described in this presentation
12 hours (3 days) - 15 participants
XPS replicas made by the
students during the workshop

64. References
Pterosaur reconstructions (Helder da Rocha)
The Imaginary Pterosaur: http://imaginosaurus.wordpress.com
It's a blog, and should be read backwards. The posts detail the full
construction process of 7 with references to palaeontologic research and
materials used.
The Imaginary Pterosaur: Making of Tupuxuara leonardii. March 2013.
http://www.slideshare.net/helderdarocha/the-imaginary-pterosaur-makingof-tupuxuara-leonardii
The Imaginary Pterosaur: Making of Tapejara wellnhoferi. August 2014.
http://www.slideshare.net/helderdarocha/the-imaginary-pterosaur-making-of-tapejara-
wellnhoferi
Paleontological references (publications, sources, etc.), specific to each
project are included in the presentations above.

65. helder.darocha@gmail.com
+55 11 992 910 567
Thank you!