Dinosaur books

At one time
I wanted to write and illustrate a dinosaur book. I had an idea for one (Fig. 1) and was inspired by the writers and artists of the Dinosaur Renaissance. It took several years…

Figure 1. The cover of Giants, the book that launched my adult interest in dinosaurs, pterosaurs and everything inbetween.

Figure 1. The cover of Giants, the book that launched my adult interest in dinosaurs, pterosaurs and everything inbetween.

Then
I got a contract to do my first book. That begat another and another. The shelf life was no more than one year for any of them. None went to second editions, though several had foreign versions. Reviews were good. Libraries stocked them. Book signings were fun, when there was advanced publicity. Every so often there was a big or small check in the mail. Now Amazon keeps them alive, if just barely. Reviews are still good…

Nowadays
I would not want to write and illustrate another dinosaur book. New discoveries make at least part of the text and part of the depiction of its subjects obsolete, sometimes before shelf life is over. The amount of data needed to be covered is staggering. More pages mean the price the book rises out of the ability to pay for many potential readers. With book publication, there are no ‘do-overs’ or ‘updates.’ What’s done is done. And then there are always the nagging typos. There’s a lot of work involved. And it has to be polished perfect. Editors, working for publishers, have their say. So do collaborators, if any. You have to put your life on hold to get the thing done by deadline. And when it’s done, it sits on a bookstore shelf, just one more Christmas or birthday present vying for the consumer’s eye.

It’s much better to post blogs
and nurture growing websites, like ReptileEvolution.com. These can be updated at will in one’s spare time. There are no paper or printing costs. No ships and trucks to distribute them. No bookstores to deal with. No deadlines. News can be reviewed within a day, while it’s still fresh. Everyone in the world has free access to your work. They can focus in on what they really like and ignore the rest at no cost. And one more thing (quoting Steve Jobs) that books can’t provide: animation. There’s no profit in web publishing, but money was never the front and center issue.

Figure 2. Sample animation you’ll never see in a book. The Vienna specimen of Pterodactylus (wings folded). Animation opens the wings and legs to reveal the true shape of pterosaur wings, stretched between the elbow and wingtip with a short fuselage fillet extending from elbow to mid femur.

Even so
I’m glad I went through that book phase. It had its time and place. The process led me to interact with others of like interest. Some of them are PhDs. Others are fellow artists and writers. Everyone should have a hobby to keep in touch with the world and vice versa.

I was inspired to write this blog post
after seeing parts of Walking with Dinosaurs 3D on YouTube. Click here to see it. So much talent and effort went into this— truly outstanding visuals …but the dialog was horrible, as most others agree. And there are a few new dinosaur books out now, updating older dino books. I wish them all well. Someday, perhaps decades from now, those books will either be considered cherished classics or outdated, ready to be updated. It’s all good.

References
www.DavidPetersStudio.com/books
www.ReptileEvolution.com

Advertisements

A Dinosaur Year 1989 Calendar

This ‘blast from the past’ by request: 
Click here or on image to download all 13 lorez images from my 1989 Dinosaur Year calendar, published by Alfred A. Knopf, New York. Thanks for the request, Leo!

I see two copies are presently available from Amazon.com here.

Click to download PDF of cover + 12 months of 1989 Dinosaur Year Calendar pix by David Peters at 72 dpi. It's over 25 years old and you'll find mistakes here. It was a product of its time.

Click to download PDF of cover + 12 months of 1989 Dinosaur Year Calendar pix by David Peters at 72 dpi. It’s over 25 years old and you’ll find mistakes here. It was a product of its time.

The calendar is over 25 years old
and you’ll find mistakes galore. It was a product of its time and the first time I ever painted dinosaurs in settings.

This followed
the book GIANTS and A Gallery of Dinosaurs, which illustrated dinosaurs on white backgrounds, all to the same scale. Both books are available as pdf files here and as used books at several online sites.

Where are the originals?
Collectors purchased all the originals except for the Brachiosaurus family in a pond (December) because it has a razor knife cut in the sky over the mountain top, inflicted upon opening the package at the publisher. It’s hanging on the wall over my monitor as I type this and I never notice the slit.

But wait! There’s more!
Click here to connect to a FREE build-it-yourself paper Pteranodon model.
And click here to connect to a FREE build-it-yourself paper Thalassomedon model.
All you need is 8.5×11″ bristol (stiff) paper, some glue or tape and a scissors or knife. Have fun, kids!

The Tyrannosaur Chronicles by David Hone

A new book
by Dr. David Hone called The Tyrannosaur Chronicles is now out. He reports here, “Although there is no more famous and recognisable dinosaur than Tyrannosaurus, the public perception of the animal is often greatly at odds with the science. The major image people have of them is the iconic jeep chasing scene in the film Jurassic Park. However, because they are among the best-studied of all dinosaurs, we can say that the tyrannosaurs almost certainly had feathers and may have fought and even ate each other.”

Figure 1. The Tyrannosaur Chronicles by Dr. David Hone is a new book chronicling tyrannosaurs.

Figure 1. The Tyrannosaur Chronicles by Dr. David Hone is a new book chronicling tyrannosaurs.

I have not read the book yet, but I’ll note a possible problem gleaned from quote pulled from a review.

Kirkus Reviews reports: While correctly surmising that tyrannosaurs and other dinosaurs were carnivores, scientists erroneously assumed that they were some kind of previously unknown “giant land reptile.” Subsequent fossil discoveries in polar regions ruled out this possibility since coldblooded reptiles could not survive such extreme cold weather.”

I hope this is a misquote or I’m misreading this. It’s not news that tyrannosaurs and dinosaurs have been and will always be giant land reptiles. They nest in the clade Reptilia, no matter how cold-adapted they might have been. Hone might be going back, back in time to the first English discoveries from 50 years earlier, like Iguanodon and Megalosaurus, the first dinosaurs, which were named terrible lizards, and originally titled, “British Fossil Reptiles.”

And I hate to judge a book by its cover, but…
That small crested dinosaurs in the lower left corner is Guanlong, an ancestor not of tyrannosaurs, but of allosaurs in the large reptile tree. No word yet if Hone included the verified ancestors of tyrannosaurs, Zhenyuanlong, Tianyuraptor and Fukuiraptor.  On that note, GotScience.org evidently quotes Hone when it reports, Early tyrannosaurs had crests used for sexual display and social rank.”

Book and academic publishing is fraught with such risk and danger. Once you print it, you can’t retract or revise it. Sympathetically, I know from experience the things I would have changed about my early papers now, but was less experienced then.

Thankfully
I hear that Hone discusses feathers and such.

Amazon Reviews are universally positive:

  1. Dinosaurs are endlessly fascinating, and the massive, blood-thirsty tyrannosaurs are most popular (and scary) of the lot! Here, renowned dinosaur expert David Hone reveals their story, and how we know what we know about these most amazing of ancient reptiles. — Professor Mike Benton, University of Bristol
  2. Tyrannosaurs are probably the world’s favourite dinosaurs. But what do we really know about this group? David Hone reviews the biology, history, evolution, and behaviour of the tyrant kings – an excellent read, containing the very latest in our understanding of Tyrannosaurus rex and its closest relatives. — Dr Tom Holtz, University of Maryland
  3. Without doubt, the best book on tyrannosaurs I’ve ever read. This is an awesome dinosaur book. — Professor Xu Xing, Chinese Academy of Sciences

Do not be confused with this website:
http://traumador.blogspot.com which earlier featured ‘Traumador the tyrannosaur in the Tyrannosaurus Chronicles’ which can be silly and serious all on the same blog, explained here as:

The Tyrannosaur Chronicles is a blog written by Traumador the Tyrannosaur about his many exploits.Traumador is a tyrannosaurid who hatched from an egg that magically survived the K/Pg Extinction Event and was discovered in Alberta by Craig, an aspiring paleontologist (and the mastermind behind the blog in real life). He eventually gets a job at the Royal Tyrell Museum and things get interesting from there.

From past experience,
such as when Hone attempted to compare the two hypotheses of pterosaur origins by dropping one, or when Hone attempted to show that Dmorphodon had a mandibular fenestra, or when Hone supported the deep chord bat wing model for pterosaur wings, or when Hone flipped the wingtips of Bellubrunnus, we might be wary about what Dr. Hone puts out there. But I don’t think you can go very wrong with tyrannosaurs, the most studied dinosaur. And the reviews speak high praise.

The Dinosaur Heresies NYTimes Book Review from 1986

the_dinosaur_heresies200Now almost 30 years old, here’s something you might like to read (perhaps again?).
This is the NY Times book review of Dr. Robert Bakker’s ‘The Dinosaur Heresies’ from 1986. You can read the complete original here. I went to the prophesies below and marked them with a [+] or a [-] for those supported today or not and for those that are still questionable: [?].

BOOKS OF THE TIMES;
Dinosaur Mysteries
By MICHIKO KAKUTANI
Published: November 8, 1986

THE DINOSAUR HERESIES. New Theories Unlocking the Mystery of the Dinosuars and Their Extinction. By Robert T. Bakker. Illustrated. 481 pages. William Morrow & Company. $19.95.

Mr. [not Dr.?] Bakker has a quirky, free-floating imagination, and in the course of this book – which is generously illustrated with his own charming sketches – he raises many offbeat questions: Were changes in dinosaur eating patterns responsible for the evolution of flowering plants? [+] Did pink pterodactyls exist? [?] What sort of lips did dinosaurs have? [+] Could a human being beat a tyrannosaurus at arm wrestling? [?]

Mr. Bakker, the adjunct curator at the University Museum in Boulder, Colo., has published many papers in the field of vertebrate paleontology, and his book stands as an informative layman’s introduction to the wonderful world of dinosaurs while at the same time making an impassioned case for his own – sometimes heretical – views on their endurance and extinction. ”I’d be disappointed,” he writes, ”if this book didn’t make some people angry”; and given the often fiercely polarized world of vertebrate paleontology, he’s unlikely to be let down.

As Mr. Bakker sees it, dinosaurs have been given a bad rap over the years as ”failures in the evolutionary test of time” – portrayed as small-brained, cold-blooded sluggards who couldn’t ”cope with competition from the smaller, smarter, livelier mammals.” Such portraits, he suggests, are unfair as well as scientifically inaccurate: in the first place, dinosaurs dominated history for 130 million years [+] – a remarkably long period of time that attests to a decided ability to survive (the human species, in contrast, has only been around for 100,000 years). And while Mr. Bakker acknowledges that dinosaurs were probably not brilliant thinkers [+], he makes a persuasive argument for their physiological adaptability and their prodigious energy [+] – he even speculates that tyrannosaurus could gallop about at speeds approaching 45 miles an hour.  [-] 

Much of ”The Dinosaur Heresies,” in fact, revolves around the question of whether the animals were cold-blooded (and more closely related to reptiles) or, as Mr. Bakker contends, warm-blooded (and more closely related to mammals and birds) [+]. While he occasionally stops to summarize opposing viewpoints, he is less interested in presenting an objective overview of the field than in mustering evidence to support his own theories.

He argues that gizzards and large digestive tracts in [some] dinosaurs would have compensated for their weak teeth [+], enabling them to eat high quantities of land plants, necessary to support a high metabolic rate. He argues that birds and pterodactyls – both of which would have had to evolve high-pressure hearts and lungs before flight could have been achieved  [+] – descended from dinosaurs  [+] [-], and that it’s not unlikely that these ancestor dinosaurs were already equipped for high metabolism [+]. He argues that the dinosaurs’ ”adaptations for sex and intimidation” – horns, head-butting armor and all manner of bony frills -suggest that they led active, aggressive lives, uncharacteristic of lethargic, cold-blooded animals  [+]. He argues that the growth rate of dinosaurs more closely resembles that of mammals than reptiles [+]. And, finally, he argues that dinosaurs’ porous bone tissue indicates the sort of high blood-flow rate usually associated with warm-blooded creatures [?].

On the question of the dinosaurs’ demise, Mr. Bakker sides with those paleontologists who discount new theories of mass extinction caused by some sort of cosmic catastrophe – he cites evidence suggesting the extinctions occurred not during a single ”doomsday” period but over tens of thousands of years [+] [-] [?]. In his view, the development of new sorts of dinosaurs and other animals, combined with changes in the physical and genetic environment, gradually led to their doom [+] [-].

On a side note:
I liked Dr. Bakker’s quote about making some people angry with his novel ideas based on overlooked data.

On another side note:
like our antiquated notions about dinosaurs from over 30 years ago, pterosaurs today have been given a bad rap. They are still portrayed as ungainly quadrupeds, bound by membranes that tied their legs together and tied their wings to their ankles (along with a long list of other false paradigms). The data deniers, unfortunately, are still out there, thinking that if they just turn a blind eye toward certain data and hypotheses they will go away.

As everyone knows,
this blog, Pterosaur Heresies, was intended to approach data with the same verve and testing of false traditions that Dr. Bakker demonstrated.

 

 

Scathing book review – Pterosaurs (Witton 2013) – finger mistakes

Earlier here and elsewhere in this blog we looked at the various mistakes and oversights promoted by Mark Witton (2013) in his new book, “Pterosaurs.” Today we’ll look at the configuration of the three free fingers and the many problems with Witton’s proposed configuration (Fig. 1).

Figure 1. Here Witton promotes the idea that pterosaur metacarpals were pressed back to back with the palmar side anterior, the pteroid articulating with the preaxial carpal and the elbow overextended.

Figure 1. Here Witton (2013) promotes the idea that pterosaur metacarpals were pressed back to back with their palmar sides anterior, the pteroid articulating with the preaxial carpal and the elbow overextended. None of these are supported by fossil evidence. 

Witton (2013) promotes the traditional idea that the dorsal surfaces of the three free fingers were appressed to the anterior surface (the former dorsal surface) of the axially rotated metacarpal 4. This means the free fingers would be oriented palmar side anterior during flight (Fig. 1) and extended palmar side ventro-posterior during terrestrial locomotion. Such a configuration  allows no room for the extensor tendons, especially the big one for the wing finger (Fig. 2). Moreover, posterior fingers do not match known pterosaur hand ichnites.

The actual orientation and configuration of the three fee fingers is shown below (Fig. 2).

Figure 2. The hand of the most primitive pterosaur with only metacarpal 3 attached to metacarpal 4. This provides room for extensor tendons. It also enables lateral finger extension during terrestrial locomotion and medial grappling during tree clinging. Crushing rotates the unguals anteriorly in this case. The extensor tendon process would bang into digit 2 when fully extended in the Witton model.

Figure 2. The hand of the most primitive pterosaur with only metacarpal 3 attached to metacarpal 4. This provides room for extensor tendons. It also enables lateral finger extension during terrestrial locomotion and medial grappling during tree clinging. Crushing rotates the unguals anteriorly in this case. The extensor tendon process would bang into digit 2 when fully extended in the Witton model.

The actual configuration is supported by evidence.
The present configuration provides room for the extensor tendons and permits the extensor tendon process to move unimpeded whenever fully extended in flight. With the free fingers facing palmar side down, like all other tetrapods, during terrestrial locomotion the fingers would extend laterally, matching ichnites. During tree clinging the fingers would grapple medially rather than, as Witton proposes, opening anteriorly, in a “begging” configuration.

The metacarpal “drawbridge”
The connection between metacarpals 3 and 4 produces a hinge. That’s why the metacarpus sometimes swings up during taphonomy to give the impression of the configuration that Witton proposes, as if the “drawbridge” was raised.

Pterosaur-fingers

Figure 3. Pterosaur wrist and hand images from Witton (2013). Neither demonstrates the palmar side forward configuration. The lower Pteranodon image is in posterior view and the stacking of the metacarpals is therefore anterior, away from the viewer, as in the Peters configuration. The wing finger of the Pteranodon would have been in the Z-axis, toward the viewer, but it was disarticulated during burial. Bennett (1991, 2000) thought metacarpal 4 was axially rotated during taphonomy. Not so. Green = flexor tendons. Red = extensor tendons.

So, where did Witton get his configuration?
From Bennett (2008), and this Santanadactylus specimen (Fig. 4, ignoring, apparently all others).

Santanadactylus hand and fingers

Figure 4. Santanadactylus hand with metacarpals preserved at a 45 degree angle to the anterior face of metacarpal 4. This demonstrates the drawbridge effect in which Bennett elevates metacarpals 1-3, raising the drawbridge. Actually, the drawbridge was down in life. Imagine what would happen to fingers 1-3 when the wing finger was extended! And where were the extensor tendons? Only lowering the drawbridge solves all these problems.

The Santandactylus specimen preserves metacarpals 1-3 raised, like a drawbridge to about 45 degrees, but this is a taphonomic artifact. Bennett’s (2008) configuration further raised the metacarpus to appress against metacarpal 4, palmar side anterior. Peters’s (2002) configuration lowers the metacarpus on its hinge, palmar side down. This provides room for the large extensor tendon and the extensor tendon process of the wing finger when it is fully extended in flight. This also matches all undisturbed pterosaur fossils (Fig. 2).

Added note:
I’m hearing that my notes hear are not swaying the experts. Please see the conversations below and check out this link to pterosaur finger flexion.

References
Bennett SC 2008. Morphological evolution of the forelimb of pterosaurs: myology and function. Pp. 127–141 in E Buffetaut and DWE Hone eds., Flugsaurier: pterosaur papers in honour of Peter Wellnhofer. Zitteliana, B28.
Peters D 2002. A New Model for the Evolution of the Pterosaur Wing – with a twist. – Historical Biology 15: 277–301.
Witton M. 2013. Pterosaurs. Princeton University Press. 291 pages.

Scathing Book Review – Pterosaurs by Mark Witton 2013 – part 2

I finally got the new Witton pterosaur book from Amazon.
Most of the topics you’ll read here have been posted before.

pterosaurs-wittonWith his new book, Pterosaurs, Witton (2013) continues to stick his head in the sand (or wear his professional blinders), avoiding and dismissing the best testable evidence for pterosaur origins, wing shape, take-off, phylogeny, ontogeny, morphology, gender identification and reproduction. (Which is why the Pterosaur Heresies is needed, to right these wrongs). Here’s yet another expert disfiguring pterosaurs big time.

Of  course his artwork is beautiful, flaws and all. And his writing style is friendly, informative and a joy to read, until you come up against bogus information and images. Then you wonder why has the world gone topsy-turvy, where amateurs provide better, more accurate evidence and more parsimonious explanations than professionals do?!

And it’s not just that we disagree.
I am pointing out factual errors here that can be tested by looking at specimens.

Case in point
Earlier we talked about the first few chapters of Pterosaurs in which Witton ignores the four outgroup taxa closest to pterosaurs: Langobardisaurus, Cosesaurus, Sharovipteryx and Longisquama. Witton did produce his version of Sharovipteryx, which explains much of the problem and why he dismissed it. Here it is (Fig.1). See if you can see where Witton pays little heed to accuracy.

Figure 2. This is what scientists call complete fantasy and total disregard for data. Upper images from Witton 2013, in which he simply made up the proportions of the pedal elements for Sharovipteryx. No wonder he didn't see the phylogenetic connection to pterosaurs! Below, the actual proportions traced from an 8x10 transparency taken after personal examination of the fossil. Like pterosaurs, cosesaurs, langobardisaurs,  Tanystropheus and Huehuecuetzpalli, Sharovipteryx had a short metatarsal 5 and an elongated p5.1. It's a key trait for this clade. Don't tell me pterosaurs just appeared out of nowhere. Here's the evidence of kinship.

Figure 2. This is what scientists call complete fantasy and total disregard for data. Upper images from Witton 2013, in which he simply made up the proportions of the pedal elements for Sharovipteryx. Lower image from yours truly after examining the specimen firsthand. No wonder he didn’t see the phylogenetic connection to pterosaurs! Like pterosaurs, cosesaurs, langobardisaurs, Tanystropheus and Huehuecuetzpalli, Sharovipteryx had a short metatarsal 5 and an elongated p5.1. It’s a key trait for this clade. Don’t tell me pterosaurs just appeared out of nowhere. Here’s the evidence of kinship.

I rolled my eyes so far back that I actually saw my brain.
Witton (2013) disfigured Sharovipteryx by completely imagining the proportions of the pedal elements. There’s not even a feeble attempt at accuracy here. And because Witton put his blinders on he completely missed the unique morphological similarities in the pes shared by Sharovipteryx and pterosaurs. This is why I earlier stated that Witton was ill-prepared to write a book on pterosaurs. This is not about ‘not knowing’ the correct data. This is about ‘not wanting to know’ the correct data, which has been around for forty years.

If you are of the opinion
that my work (Fig. 1) is flawed, check out the original paper, Sharov (1971), who made the same tracing.

And if you’re friends with Mark
Yes, he’s a great guy and tries hard, but he fkd up here. Don’t run to his defense. There is no defense for this. Earlier Witton slammed ReptileEvolution.com in general. Here, as elsewhere, I’m being surgically precise with my critique. I’m simply trying to lift the blinders off those who profess to be experts in pterosaurs. If you’re an expert, act like it. Be professional. Test ideas and observations. Don’t just follow tradition, especially when you profess to not know the answer. And for Pete’s sake, don’t make up things out of your imagination.

Note that,
even in his figure of Sharovipteryx, Witton ignores several other key traits shared with pterosaurs to the exclusion of basal archosaurs: 1) Elongated and retracted naris (long premaxilla); 2) Large orbit, or is that the antorbital fenestra?; 3) Short torso (knee can reach the shoulder); 4) Elongated ilium (capturing more than four sacrals); 5) Attenuated caudals with chevrons parallel and appressed to centra; 6) Tibia longer than femur: 7) Fibula attenuated and 8) the big one, uropatagia (soft tissue trailing the hind limbs (Witton invents most of the soft tissue in front of the femur. See Fig 3.)). Evidently Witton eschews hard evidence and phylogenetic analysis. I find it answers many, many problems.

Figure 2. Sharovipteryx mirabilis in various views. No pycnofibers added yet. Click to learn more.

Figure 3. Sharovipteryx mirabilis in various views. Trailing membrane on the hand is guesswork based on phylogenetic bracketing. Note, there is a soft tissue flap in front of the femur, but it does not connect to the torso, which, in reality is circular in dorsal view with wide flat ribs. And yes, Sharovipteryx has prepubes, a pterosaurian trait inherited from Cosesaurus.

Simply having an elongated pedal digit 5 puts Sharovipteryx and pterosaurs outside of virtually all archosauriforms (they have vestiges) and squarely in kinship with tritosaur lizards, like Huehuecuetzpalli, which shares some of the traits listed above.

Witton doesn’t like pterosaurs as highly derived lizards
Witton (2013, p. 17) reports, “There seems little similarity between the skulls of pterosaurs and the highly modified, mobile skulls of squamates, or any similarity between the trunk and limb skeletons of each group.” This is, of course, bogus data (imprecise to untrue) to draw you off. Pterosaurs are not related to squamates (Iguania and Scleroglossa), but to a third, more basal lepidosaur clade, the Tritosauria, that did not have a mobile skull and did not fuse the ankle bones. Again, putting his blinders on, and following in the footsteps of Dr. David Unwin, Witton does not introduce his readers to the following lepidosaurs: Huehuecuetzpalli, Macrocnemus, Cosesaurus and Longisquama, all of which demonstrate a gradually increasing list of pterosaur traits as detailed here.

In order to further dismiss my work, Witton references Hone and Benton (2007) which has been lauded as one of the worst papers of all time based on the fact that they set up a battle between the fenestrasaurs and archosaurs, then eliminated the fenestrasaurs from consideration and declared archosaurs the winners. They also had typos in their matrix (found by Bennett 2012) which they used to dismiss data. And there were many other problems listed here. I just want to ask Dr. Witton, “Where is the critical thinking?” I know it’s easy to cozy up to your friends’ work and difficult to accept others’, but really, you have to examine the evidence without bias.

Final pertinent note
Witton reports that my work has received little attention due to my “highly controversial techniques used in his analyses and anatomical interpretations.” At least I don’t just make the stuff up (see Fig. 1) !!!!! Dr. Witton, this is really “the pot calling the kettle black.” Please look at the specimen or get precise references next time. It will solve lots of problems and get us back on the right track.

As always, if anyone has better data, I am known to frequently make corrections wherever warranted. Just made a bunch this week.

More later.

References
Bennett SC 2012. 
The phylogenetic position of the Pterosauria within the Archosauromorpha re-examined. Historical Biology. iFirst article, 2012, 1–19.
Peters D 2000. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Peters D 2011. A Catalog of Pterosaur Pedes for Trackmaker Identification. Ichnos 18(2):114-141. http://dx.doi.org/10.1080/10420940.2011.573605
Sharov AG 1971. New flying reptiles from the Mesozoic of Kazakhstan and Kirghizia. – Transactions of the Paleontological Institute, Akademia Nauk, USSR, Moscow, 130: 104–113 [in Russian].

Mark Witton’s “Pterosaurs” – a book review part 1

Dr. Mark Witton is fantastic artist and devotee of pterosaurs. He has a new book called Pterosaurs (with an Amazon.com preview). I’ve ordered the book and will make an in depth report after it arrives. The following is based on the online preview of chapter 1. Witton’s writing style is entertaining and engaging. The book should have popular appeal on that level.

The cover portrays a magnificent crested Nyctosaurus at sunrise or sunset. Gorgeous!

Then things tumble.

Witton’s Table of Contents shows an embryo Pterodaustro with a very short rostrum, unlike any Pterodaustro I’ve ever seen. And I’ve seen the embryo. The rostrum extends nearly the entire length of the egg. An agreement with Laura Codorniú prohibits me from publishing the image until she does, but the reconstruction of the long-beaked embryo Pterodaustro is based on that tracing. As we learned earlier, pterosaurs grew isometrically, resembling their parents on hatching.

Witton’s Rhamphorhynchus image on page 2 portrays the infamous cruro/uropatagium, a membrane spanning the hind limbs and not including the tail. The image also includes the infamous deep chord wing membrane, for which there is no evidence whatsoever as the Sordes situation was falsified. Witton’s two Rhamphs also have much shorter wings than any Rhamphorhynchus I’ve ever seen. One of Witton’s wonders has brought its wrists (carpals) in close to the base of the neck, which is novel, at least, but kills the tension on the extensor tendon that keeps the wing membrane aerodynamic. As in birds, when the elbow flexes, the wing folds. Having the wings fold in flight isn’t bad. Birds do it all the time for a brief low drag rest. At least the feet are properly positioned in Wittons’ illustration.

Page 3 portrays several dozen pterosaurs doing the forelimb leap that is such a travesty and fantasy that I slap my head every time I see it again and again. It has become firmly entrenched. Gadzooks@!# what is the ptero-world coming to?

Page 4 has a fine picture of Pterodactylus antiquus, the first pterosaur known to science, with a big round head crest. Not quite ready to buy into that one quite yet. Some Pterodactylus did have a crest, but not that one.

Page 12 portrays a hypothetic pterosaur ancestor. It looks like Peteinosaurus with a short digit 4 leaping from a branch (using muscular hind limbs). The caption reads, “The fossil record has yet to reveal an “intermediate” between fully formed pterosaurs and possible ancestors, meaning we can only speculate on their anatomy and appearance.” And once again, pterosaur professors are casting a blind eye toward the hard evidence presented in the large reptile tree where dozens of ancestors are lined up. As you’ll recall, ludicrous as it sounds, we can even put turtles up as the closest known sisters to pterosaurs if we delete all the other sisters and candidates from the new Lepidosauromorpha, as demonstrated here. This just proves that pterosaur workers are actively avoiding the issue and the answer. But, I have to say, it’s a beautiful and evocative image that Witton has created, wrong though it may be.

Page 16 portrays three purported pterosaur ancestor/sisters, Sharovipteryx, Euparkeria and Scleromochlus. Witton calls Sharovipteryx an archosauromorph protorosaur, when it is neither. It is a fenestrasaur tritosaur lepidosaur, as we learned earlier. Euparkeria is closest to erythrosuchids, about as far from pterosaurs as one could imagine. Scleromochlus, shown hopping in Witton’s illustration with a dino quadrate leaning the wrong way, is a basal crocodylomorph. Witton strongly leans toward the “pterosaurs are ornithodires” direction despite the tiny hands and lack of pedal digit 5 in Scleromochlus.

Witton takes aim at my placing pterosaurs within the Squamata as the most unlikely hypothesis currently under consideration. See a recent post on this here. Witton writes, “There seems little similarity between the skulls of pterosaurs and the highly modified, mobile skulls of squamates or any similarity between the trunk and limb skeletons of each group.” Well, frequent readers will know that pterosaurs are tritosaur lepidosaurs, an outgroup clade to the two that make up the Squamata, the Iguania and the Scleroglossa. Pterosaurs are neither of these. Tritosaurs do not have the mobile skulls found in some squamates. They also don’t have the fused tarsals of squamates. They are distinct. Witton has whitewashed the tritosaur fenestrasaur hypothesis with this “red herring,” while virtually ignoring the fenestrasaurs, following in the less than noble footsteps of our colleague Dr. David Hone, whose exploits you can read about here. In chapter one, at least, Witton avoids any discussion of the pteroid and prepubis in Cosesaurus and other fenestrasaurs. Why should he ignore these key and readily observable traits? Dr. Pierre Ellenberger saw them first without recognizing their significance.

Page 17 Witton then discusses the possible protorosaur origins of pterosaurs, pointing to the shared trait of an elongated neck and forgetting the not-so-elongated neck of the basalmost  pterosaur, MPUM6009.  Witton points up the “fact” that protorosaurs lack an antorbital fenestra, but recent finds show that two protorosaurs had such a fenestra by virtue of convergence (really a side issue of little consequence). Witton finishes with protorosaurs by noting the body shapes are not at all pterosaurian, which is true.

Witton invites a closer look at Sharovipteryx and notices similarities to pterosaurs in the hind limbs and their membranes, but notes, “It’s hard to find other features that reliably link this animals with pterosaurs.” He may not have looked at the actual specimen as I have. Evidently he did not notice the ilium was anteriorly elongated, prepubes were present, more than five sacrals were present, the tail was attenuated with parallel chevrons, the bones were hollow, the feet have the same morphology as pterosaurs with a short metatarsal 5 and an elongated and robust p5.1 as obvious and compelling similarities. Once again, the blind eye rules. Witton reports that the Sharovipteryx skull lacks an antorbital fenestra and the foot is unlike that of any pterosaur. Where does he get his information? Certainly not from any sort of direct observation or adherence to the literature. Of course he doesn’t back up any of this with evidence. Witton concludes by noting that gliding with hind limbs is unique, failing to find parallels in Microraptor and the uropatagia of fenestrasaurs including pterosaurs. Sharovipteryx had fore limbs. Witton just doesn’t know or doesn’t show what they look like. But you can see them here.

Page 18 Witton prefers the archosauriform ancestry hypothesis due to the shared features of an antorbital fenestra and reduced bone counts in the fifth pedal digit, perforated lower jaws, and “many other anatomical similarities.” Really? Witton equates an evaporating pedal digit 5 in archosauriforms with the robust element in pterosaurs (and, of course he doesn’t count the ungual on the pterosaur digit). A robust pedal digit 5 is also found in Huehuecuetzpalli and all the tritosaur lepidosaurs that followed (except Macrocnemus and the drepanosaurs). Why doesn’t Witton consider these and put some study into them? The antorbital fenstra of archosauriforms is always (except for proterosuchians) surrounded by a fossa, a trait lacking in any pterosaurs.

Witton also prefers archosaurs as pterosaur sisters, and, in particular, Scleromochlus, despite the tiny hands that were, ironically, used to rule out Sharovipteryx. Evidently Witton prefers to have it both ways, so long as he stays within tradition. Witton lists fusion of the two proximal ankle bones to the shin (which does not occur in pterosaurs), reduction of the fibula (also in tritosaurs), the structure of the foot (actually more like that of tritosaur lizards like Cosesaurus, which retain an elongated pedal digit 5, which archosaurs lack), “several limb and hip proportions” (can Witton get even more vague here?) and the lack of bony scales along the back (then why is he ignoring those on Scleromochlus and Scutellosaurus).

Witton notes the shield-like pelves were different than in dinosaurs, but defends that by saying, “This may not be surprising, however, given, that pterosaur hindlinmbs were, uniquely among ornithodirans, used to support the wing in flight.” Utter rubbish!!! on the face of it and not pertinent to any phylogenetic discussion. You take the traits as they are and you let the computer decide where the taxa belong most parsimoniously. The “why” question or reason is never in play. By the way, similar pelves to pterosaurs can be found in fenestrasaurs, but these are ignored by Witton.

Witton writes, “arguments that basal pterosaurs were bipedal and digitigrade may be flawed” because basal ornithodires (aka: Asilisauruswhich bears no resemblance whatsoever to pterosaurs) were quadrupeds. This is far-reaching and totally bogus. I would be ashamed and would expect heavy chastisement having made such a comparison, especially after promoting bipedal Scleromochlus as a potential ancestor. But then Witton tops that bungle of reasoning by saying that Scleromochlus is “suspected of hopping about on plantigrade feet.” More fantasy! Few creatures, other than deer and horses, have feet more obviously digitigrade than Scleromochlus. Witton also ignores the known bipedal pterosaur footprints  (more here, here and more info here).

Page 21 Witton prefers an imagined hypothetical ancestor to a real one, and it glides from trees. Of course, this does nothing to explain the origin of flapping (because no gliders flap, unless they started off as flappers). Witton ascribes the mobility and length of the fifth toe to its use as a stabilizing tool, ignoring the fact that most tritosaurs from Tanystropheus to Sharovipteryx, have such a fifth toe, thus it cannot be developed for flight. Witton reports that the fifth toe, which is lateral, elongates to frame the medial membrane, which should strike you as odd and implausible. In reality the fifth toe is not connected to a membrane, except in Sharovipteryx, and each membrane trails each hind limb. They don’t cross to connect with each other.

Page 22 Witton reports that the hind limbs rotate out sideways to create efficient airfoils, but even that is fraught with error. One: Archosaurs can’t do this with their erect femurs. Two: Basal pterosaurs can’t do this either with their erect femurs. Raising the hind limbs to the horizon happens in later, more derived pterosaurs with a more sprawling femur.

Witton reports that during the evolution of pterosaurs that the fourth finger became so enlarged and unwieldy that it needed to be stowed away when grounded. We can all stow away our fingers by pressing them against our palms, but Witton ignores this. He also ignores the axial rotation of metacarpal 4 so that digit flexion puts digit 4 along the posterior rim of the hand, not the palmar side any longer. Witton reports ungual 4 was missing, since it was no longer necessary. We’ve seen so many several cases of ungual 4 present on pterosaurs that it needs to be considered universal.

Witton adds fibers to wing membranes as they need to be more sophisticated in their unsupported regions, ignoring that Cosesaurus had trailing fibers before it had wing membranes (Ellenberger 1993, Peters 2009).

With regard to flapping, our expert Dr. Witton reports, “At some point, manipulation of these wings in the vertical plane produced flapping, and self-propelled flight was achieved.” Gee, he makes it sound almost as if it was that easy. At ReptileEvolution.com and the PterosaurHeresies blog you learned the exact steps the exact taxa took to achieve flapping prior to the development of wings in pterosaurs, paralleling that same development in birds. So if Witton’s book leaves you unsatisfied and yearning for real answers, come see these websites and blogs.

Witton ascribes the development of flight muscles and bones to the ability of quadrupedal pterosaur ancestors to chiefly employ the forelimbs during leaps. He sort of leaves the larger hips and thighs out of the equation, evidently incapable of creating all the power necessary for a leap and leaving the unused arms in this bipedal model to do something else, like flap as a secondary sexual trait.

Dr. Witton does take the brave leap of including my published works in his reference list, something Dr. Unwin did not do in his less recent pterosaur book.

Let’s face it
If Dr. Witton does not even know what pterosaurs are (which he has acknowledged in his book), he has no business acting as an expert on pterosaurs and writing books about them. Unfortunately this is an acceptable trend continued by Dr. Unwin from Dr. Peter Wellnhofer. In chapter one Witton has already published too many errors. It’s too late in the game to fold ones’ hands and politely tell your readers, “Good question… we really don’t know. It’s one of the mysteries of paleontology.” There’s something called phylogenetic analysis that is guaranteed to give you an answer when you’re looking for an ancestor. However, you’ll have to include at least a few of the right taxa (among the tritosaurs in this case), to get close to the right answer. If you’re looking for the ancestors of pterosaurs, they’re right here in one place.

We’ll look at other Witton chapters in the future. But this one on pterosaur origins really irks me. It’s rather embarrassing that this sort of crap (a complete avoidance of certain data) is still being circulated. But I _do_ love the artwork.

References
Ellenberger P 1993. Cosesaurus aviceps . Vertébré aviforme du Trias Moyen de Catalogne. Étude descriptive et comparative. Mémoire Avec le concours de l’École Pratique des Hautes Etudes. Laboratorie de Paléontologie des Vertébrés. Univ. Sci. Tech. Languedoc, Montpellier (France). Pp. 1-664.
Peters D 2009. A reinterpretation of pteroid articulation in pterosaurs. Journal of Vertebrate Paleontology 29: 1327-1330.
Witton M. 2013. Pterosaurs. Princeton University Press. 291 pages.