A paper model of the ‘Discodactylus’ skull

Earlier a flat, but layered Adobe Photoshop plan of the skull of Discodactylus’ was presented (Fig. 1) and nested with the very similar anurognathid pterosaur, Vesperopterylus.

Figure 3. The skull of NJU-57003 reconstructed in animated layers for clarity. This is something the print media just cannot do as well. All elements are similar to those found earlier in other anurognathids.

Figure 1. The skull of NJU-57003 reconstructed in animated layers for clarity. This is something the print media just cannot do as well. All elements are similar to those found earlier in other anurognathids.

Here
a paper, paste and tape model of this plan is presented (Figs. 2, 3), made from a print out of the elements in figure 1.

Figure 1. Paper reconstruction of the Discodactylus skull and mandibles.

Figure 2. Paper reconstruction of the Discodactylus skull and mandibles. Yes, the dentary teeth don’t make sense. They are scattered in situ and this is not corrected here.

The extremely fragile skull
held together from below by slender palatal bones (maxillary palatal rods and hyoids not shown) provides a solution for a flying animal with a wide, rattlesnake-like gape.

Figure 3. Another view of the paper reconstruction of the skull and mandibles of Discodactylus.

Figure 3. Another view of the paper reconstruction of the skull and mandibles of Discodactylus.

Discodactylus megasterna (Yang et al. 2018; Middle-Late Jurassic; NJU-57003) is a complete skeleton of a disc-skull anurognathid with soft tissue related to Vesperopterylus (below). The sternal complex is quite large to match the wider than tall torso. Distinct from other anurognathids, m4.1 does not reach the elbow when folded.

This specimen was featured in a report (Yang et al. 2018) on pterosaur filaments that incorrectly aligned pterosaurs with feathered dinosaurs, rather than their true ancestors, the filamentous fenestrasaurs, Sharovipteryx and Longisquama.

Figure 4. Vesperopterylus skull reconstructed from color data traced in figure 3.

Figure 4. Vesperopterylus skull reconstructed 

Figure 2. Vesperopterylus reconstructed using original drawings which were originally traced from the photo. Manual digit 4.4 is buried beneath other bones and reemerges to give its length. Pedal digit 1 turns laterally due to metacarpal arcing and taphonomic crushing. There is nothing reversed about it. 

Figure 5. Vesperopterylus reconstructed using original drawings which were originally traced from the photo. Manual digit 4.4 is buried beneath other bones and reemerges to give its length. Pedal digit 1 turns laterally due to metacarpal arcing and taphonomic crushing. There is nothing reversed about it.

References
Yang et al. (8 co-authors) 2018. Pterosaur integumentary structures with complex feather-like branching. Nature ecology & evolution.

 

 

Help fix ‘Dracula’ the giant Romanian pterosaur

This comes from a press release with photos,
not an academic paper. Evidently there is a new giant azhdarchid pterosaur named Dracula, known from ‘a majority of bones’, from which the following museum mount was created (Fig. 1).

Figure 1. Dracula the giant azhdarchid pterosaur museum mount. Hopefully it's not too late to fix the problems here.

Figure 1. Dracula the giant azhdarchid pterosaur museum mount. Hopefully it’s not too late to fix the problems here. Most will just take some twisting, some disassembly and reassembly.

Here are the visible problems:

  1. The ridged sternal complex looks like it was created from gastralia. No other sternal complex has such ridges and those from azhdarchids are not big and square.
  2. Fingers 1–3 are located laterally. They should be medially.
  3. The pteroid should anchor on the radiale (not the ulnare), the pre-axial carpal on the medial side of the distal carpal. And the pteroid should always point back to the deltopectoral crest.
  4. In azhdarchids m4.4 is always tiny,
  5. This looks like a dinosaur pterygoid.
  6. Pedal digit 5 should be on the lateral side of the foot.
  7. Twist metacarpal 4 90º laterally so the wing finger extends posterior to the forelimb.

Translated from German:
“In Denkendorf you can now marvel at a bone of “Dracula”, several dozen other bone fragments of the animal are located in Florida, where they are scientifically studied with elaborate technology. A publication on the sensation finding, the researchers have announced for the fall. Until then, “Dracula” remains only the unofficial name of the pterodactyl.”

Maybe it is all based on just the one cervical and some shards. We’ll find out later.

Some links below,
courtesy of Ben Creisler on the Dinosaur Mailing List.

http://www.donaukurier.de/nachrichten/panorama/Denkendorf-DKmobil-Dracula-in-Denkendorf;art154670,3721531

https://www.n-tv.de/wissen/Museum-stellt-Riesensaurier-Dracula-aus-article20350242.html

Full scale models from the vault

Back in the day
when I was writing and illustrating dinosaur books (1988~1992) I also built a few full scale models that I intended to use as subjects for paintings and museum displays. Here are most of them. Other models include the pterosaur skeletons you can see here.

Figure 1. Brachiosaurus skull, carved out of wood. Full scale.

Figure 1. Brachiosaurus skull, carved out of wood. Full scale.

At this point in my life
(1990s) the work (paintings / illustrations) was considered ‘acceptable.’ Even my papers were ‘acceptable.’ Unfortunately, when I started applying phylogenetic analysis to taxa and discovering new and overlooked relationships (published at ReptileEvolution.com, ) my work and manuscripts were no longer considered ‘acceptable,’ despite the fact that early discoveries made here are being re-discovered and validated years later by PhDs.

FIgure 2. Camarasaurus baby model. Full scale.

FIgure 2. Camarasaurus baby model. Full scale.

This Dimorphodon
(Fig. 3) was among the first of the models, based on Kevin Padian’s 1983 running illustrations.

Figure 3. Dimorphodon skull with dog hair for pycnofibers.

Figure 3. Dimorphodon skull with dog hair for pycnofibers.

Not sure why I produced this plesiosaur
because it took up a bunch of garage space and only entertained the mailman. Ultimately it was purchased by the AMNH, but never put on display. Where it is now is anyone’s guess.

Figure 4. Plesiosaur model. Full scale.

Figure 4. Plesiosaur model. Full scale. See figure 5 for the face.

Much of this plesiosaur
was fashioned at the late Bob Cassilly studios, who was a famous St. Louis sculptor and founder of The City Museum. Bob contacted me after seeing my book, Giants, because he had been commissioned to produce some of the giant marine animals pictured therein. Through that friendship in the 1990s, I was able to study specimens, including Sharovipteryx and Longisquama, from the traveling Russian Dinosaur Exposition that came to the City Museum for their first stop.

Figure 5. Plesiosaur model head detail. Full scale. Teeth are tree thorns.

Figure 5. Plesiosaur model head detail. Full scale. Teeth are tree thorns.

Among the smaller full scale models
is this sparrow-sized Pterodactylus in a bipedal pose (Fig. 6), ready to take flight.

FIgure 6. Pterodactylus scolopaciceps (n21) model. Full scale.

FIgure 6. Pterodactylus scolopaciceps (n21) model. Full scale. Later I learned that this genus was plantigrade (flat-footed), when quadrupedal. This one is about to take flight from a bipedal configuration. Digitigrady at this instance would have given Pterodactylus a bit more power in its initial leap during take-off.

And based on the evolution book

From the Beginning, these three (Fig. 7) are fleshed out steps in the evolution of tetrapods, cynodonts, mammals and man. Ichthyostega is a bit out of date now.

Figure 7. Ichthyostega, Osteolepis and Thrinaxodon, all more or less ancestral to humans. Full scale.

Figure 7. Ichthyostega, Osteolepis and Thrinaxodon, all more or less ancestral to humans. Full scale.

References
Padian K 1983. Osteology and functional morphology of Dimorphodon macronyx (Buckland) (Pterosauria: Rhamphorhynchoidea) based on new material in the Yale Peabody Museum, Postilla, 189: 1-44.

They’re out there somewhere!

Back in the ’90s, 
I built several full scale prehistoric reptile models out of wood, wire, foam, glass (eyes) and what have you. Two of them are shown here (Fig. 1).

Figure 1. Baby Camarasaurus and featherless Deinonychus models built by David Peters in the 1990s.

Figure 1. Baby Camarasaurus and featherless Deinonychus models built by David Peters in the 1990s.

At the time, 
like the the extinct Steve Czerkas and the extant Charlie McGrady, I wanted to be build dinosaurs, not just illustrate them in books. At the time, St. Louis did not have a Science Museum and that’s when (so I was told) you are supposed to get in on the ground floor. Also at the time the late sculptor Bob Cassilly was building squids, pterosaurs, sharks and rays for the St. Louis Zoo based on illustrations in my book Giants. (Bob was instrumental in bringing Sharovipteryx, Longisquama and the other Russian dinosaur exhibit to St. Louis.) Alas, that phase fizzled and the writing of papers followed. Early on you’re driven by enthusiasm and reined in by naiveté. In evolutionary terms, it worked out for that time and place.

Along with
the baby Camarasaurus and adult Deinonychus, I built a plesiosaur, Tanystropheus, fuzzy Dimorphodon, Pterodactylus and the several pterosaur skeletons seen here. The fleshed out sculptures went to the AMNH in NYC. The baby sauropod went to Martin Lockley in Colorado. The skeletons all went to Mike Triebold. Many artists want to see their art hanging in museums. Well, it happened to me, sort of, with those pterosaur skeletons. They’re out there, all over the world. The AMNH ultimately decided to display only skeletons in their renovated prehistoric displays and sold off what they had purchased.

I have no idea
where the various pieces are now or what shape they are in. But it was fun for awhile and the mailman probably told his kids about the address that had dinosaurs under the carport. Now a longer list of illustrated and animated prehistoric reptiles can be found on the Internet here.

The “Imaginary Pterosaur” Artist, Helder da Rocha and his peek into Rio Ptero 2013

Helder da Rocha builds pterosaurs. Lots of them!
And you can read all about them at his blog, The Imaginary Pterosaur at WordPress.com.

Helder da Rocha, sculptor of the Imaginary Pterosaur  and its blog.

Figure 1. Helder da Rocha, a wonderful pterosaur sculptor and blogger.

In his own words
“Helder da Rocha is a nomadic computer scientist, traveller, writer, actor, musician and visual artist who lives (most of the time) in São Paulo, Brazil. Some of his other works can be found in this Flickr gallery or in his personal website. He can be contacted via email (helder dot darocha at gmail dot com) or Facebook.

South America in the Early Cretaceous
The home of many of the most spectacular pterosaurs of all time is Brazil and da Rocha is right where he needs to be to access these wonders of the Early Cretaceous. Brazil was also home for the third pterosaur symposium, Rio Ptero 2013.

Rio Ptero 2013 Exhibitor
Da Rocha was an exhibitor at Rio Ptero 2013 and provided many wonderful photos (Fig. 2) of the symposium at his blogsite. There’s even a YouTube video of the event. Well worth seeing! Here are several of da Rocha’s pterosaur skeleton sculptures, centerpieces for the Rio Pterosaur art show.

Figure 2. Pterosaur bone sculptures by Hector da Rocha as centerpieces for Rio Ptero 2013.

Figure 2. Pterosaur bone sculptures by Helder da Rocha as centerpieces for Rio Ptero 2013.

Da Rocha also exhibited at the First Brazilian Dinosaur Symposium with more images of his work here.

Beginning with Guidraco
Inspired by the skull-only pterosaur Guidraco (Fig. 3), da Rocha set out to imagine the rest of it. Hence the title of his blog. He did pretty well. Here is his first blog post dated March 2012.

Da Rocha takes his readers through the process of building Guidraco and later, other large pterosaurs. Here (fig. 3) is the skull carved from foam at an early stage of construction.

 Guidraco sculpture by Helder da Rocha at an early stage of construction.

Figure 3. Guidraco sculpture by Helder da Rocha at an early stage of construction.

Step-by-step instruction
I applaud da Rocha’s talents and efforts at creating full scale pterosaur skeletons. If you want to learn how he does it, he tells you, step-by-step in his blog.

Minor issues
I can’t agree with the way da Rocha puts a few of the bones together (for instance, he mounted Tupuxuara doing a forelimb leap with medial hands facing posteriorly, and the pteroids should be on the proximal carpals, not emerging from the preaxial carpals, fig. 4). Apparently others also had issues with his pterosaurs poses. Da Rocha reports, “I would like to thank Christopher Bennett, Darren Naish, Nathan Carroll, Ashley Poust, David Unwin and Felipe Pinheiro for pointing out inaccuracies in the assembly, which I was able to fix.” 

Be careful, Helder.
I only know a few of those names. Some of those experts have promoted a raft of falsifiable hypotheses in the past, all documented at PterosaurHeresies.Wordpress.com. The world of pterosaurs is filled with opinions based on evidence and other opinions that ignore the evidence, which is why the PterosaurHeresies blog has been created — to separate one from the other.

Tupuxuara by Helder da Rocha in a controversial forelimb launch pose with medial hands facing posteriorly.

Figure 4. Tupuxuara by Helder da Rocha in a controversial forelimb launch pose with medial hands facing posteriorly.

Helder Da Rocha is a young man with talent,
drive and decades of creative production ahead of him. I see him as a future leader in the world of pterosaurs. His foam sculpture techniques appear to create accurate work that is lighter, cheaper and faster to create than traditional sculpture techniques.

References
Helder da Rocha’s Imaginary pterosaur blogsite

New Pterosaur Sculptures Hit Japan

Dr. Tai Kubo tells me a new pterosaur exhibit will begin soon in Japan featuring many important specimens, including Darwinopterus and several of my pterosaur sculptures purchased over a year ago by Triebold Paleontology with their plastic and fiberglass reproductions destined for this exhibit. These are pictures of the wood/wire/plastic originals.

Model of Jeholopterus, the famous vampire pterosaur.

Figure 1.  Model of Jeholopterus, the famous vampire pterosaur.

Unfortunately the original skull of Jeholopterus was popped off and the bizarre Bennett anurognathid skull was added for the new exhibit. You can see a YouTube video of the Triebold modifications here. We earlier discussed how Bennett mistook a displaced maxilla for a scleral ring and so many other mistakes. The rest of the sculptures, I think are unaltered.

Pterodaustro by David Peters

Figure 2. Pterodaustro sculpture

Pterodaustro.

Quetzalcoatlus sculpture by David Peters

Figure 3. Quetzalcoatlus sculpture

Quetzalcoatlus.

Standing model of Nyctosaurus by David Peters

Figure 4. Standing model of Nyctosaurus

Nyctosaurus UNSM93000

Dorygnathus model by David Peters

Figure 5. Dorygnathus model.

Dorygnathus R156

Rhamphorhynchus model by David Peters

Figure 6. Rhamphorhynchus model

Rhamphorhynchus muensteri  In this model I raised the elbows more than in traditional models, which added curvature to the wing.

Istiodactylus model by David Peters

Figure 7. Istiodactylus model. Gray areas are unknown, but based on sister taxa.

IstiodactylusGray areas are unknown, but based on sister taxa.

Dimorphodon model by David Peters

Figure 8. Dimorphodon model. This one has the bad deep jugal, which I realize now is a displaced surangular.

Dimorphodon. The model pictured here is old and does not represent the latest thinking on the deep jugal, which was promoted here by others, but in reality this represents a displaced surangular, as covered in the same blog. No other pterosaur has such an autapomorphy. No other pterosaur has the purported external mandibular fenestra.

Pteranodon model based on the Triebold specimen by David Peters

Figure 9. Pteranodon model based on the Triebold specimen

Pteranodon NMC41358. One of the most complete Pteranodons ever found. Small crested and small pelvic opening, standard for most Pteranodons. 

Thalassodromeus model by David Peters

Figure 10. Thalassodromeus model

Thalassodromeus only the skull is known.

And finally two others that were sold long ago and are not in the museum exhibit.

 Pterodactylus by David Peters

Figure 11. Pterodactylus. Note the feet are should be plantigrade. I made these before I knew much about matching pterosaur footprints. The one on the left is wood. The one on the right is plastic with hair and rubber wings.

Pterodactylus. Yes, the feet are wrong. They should be plantigrade, but I think these models preceded the 1995 papers that revolutionized thinking on pterosaur tracks and certainly preceded my interest in pterosaur feet.

These models have been online at DavidPetersStudio.com where you can also download pdfs of some of my books from the 1980s.