Pterosaur books to know and love, part 2: The Pterosaurs from Deep Time

Many, many moons ago, the Heroes of Pterosaur.Net were suggested to provide a reading list for people who just can’t get enough of our leathery-winged chums. Longer-term Pterosaur.Net groupies with good memories may recall that our suggested shortlist was, well, very short with only two notable tomes: Peter Wellnhofer’s 1991 Illustrated Encyclopaedia of Pterosaurs and David Unwin’s The Pterosaurs from Deep Time (2005). You were promised reviews of both: we looked at the Encyclopaedia back in January (seriously, where is 2010 going?) and, today, we’re casting our critical eyes over The Pterosaurs from Deep Time. If it sounds like the pterosaur book for you, however, you’re going to have to go Sherlock to find it: it’s been discontinued for a number of years and only loiters now in second-hand stores. However, Mike from Ottawa informed us last time that he found a cheap copy in an online store that only set him back $10, so you may not have to pay through the nose to obtain one. Question is, of course, do you want to own it in the first place?

The best pterosaur book since the last one
Believe it or not, there have only ever been three popular English books on pterosaurs published: Harry Seeley’s Dragons of the Air (1901 – yes, 1901), Wellnhofer’s Encyclopaedia, and the organ under our spotlight today, The Pterosaurs from Deep Time. The former books set a high benchmark for treatment of their subject matter: Seeley’s book is a classic, a slice of pterosaur history that summarises Seeley’s heretical ideas on pterosaur origins, biology and ecology. Seriously diehard pterosaur aficionados will want a copy but, alas, unless you find a lucky copy in a second hand shop, you’ll have to fork out a lot for it (cheapskates like me, though, can download the entire thing, for free, from here). Wellnhofer’s effort, as discussed previously, remains an essential reference tool for anyone with an interest in flying reptiles and has aged with dignity over the last 20 years. In fact, the only thing that Wellnhofer got wrong with his book was his timing: it was published just before the recent pterosaur research bonanza started (fuelled by spiffing new specimens from Brazil and China) and, therefore, doesn’t report the cohesion of ideas that he may have if he wrote it in 2000, say.

So, when Dave Unwin entered this arena with his book in 2005, he wasn’t exactly swamped with competition. With his main contenders being a dusty, ultra-rare historical tome and an excellent but rather old-fashioned encyclopaedia, he could’ve produced a sloppy, poorly-illustrated mess and still stood a chance of writing the best modern pterosaur book. Thankfully for us, The Pterosaurs from Deep Time continues the trend of its predecessors and is an excellent, informative presentation of modern ideas in pterosaur research. Given the prestige of its author, this isn’t a huge surprise: David Unwin is widely recognised as one of the foremost pterosaur experts in the world. Beginning his career with an assessment of the Victorian taxonomic mess that is the Cambridge Greensand pterosaur assemblage, Unwin has since worked on pterosaurs from all over the world and made significant contributions to research on virtually all aspects of their palaeobiology (including [deep breath]: pterosaur phylogeny, several geographical and taxonomic reviews, details of their flight apparatus, pterosaur respiration, reproduction, terrestrial locomotion and, most recently, bringing the world Darwinopterus). Given that his writing style is also extremely breezy and clear, he's surely one of the most suitable pterosaur palaeontologists around to summarise the current status of pterosaur knowledge. Hence, saying Unwin’s book is ‘the best since the last one’ is not only true by default, but also a considerable complement in saying that Deep Time is a worthy follow-on to Wellnhofer’s Encyclopaedia.


The pterosaur story
Although comparisons between Deep Time and the Encyclopaedia are inevitable, they're not entirely fair because the two books have very different formats. The Encyclopaedia is quite schematic in its layout with clearly defined sections and liberal use of detailed, technical diagrams: it feels far more like a textbook than something you would read from cover to cover. Deep Time, by contrast, is far more prosaic, flowing from chapter to chapter in a continuous way that makes it very easy to read in entirety. It begins with an introduction to pterosaurs and the concepts of fossilisation and geological time before moving onto an overview of pterosaur phylogeny (based on Unwin’s 2003 work), their anatomy, locomotion, reproduction and, finally, an attempt to tell the complete tale of pterosaur evolution. The encompassing approach of this latter chapter is very characteristic of Unwin’s work: many of his technical publication feature discussions of the broader implications for whichever topic is under scrutiny, be it eggshells (Unwin and Deeming 2008) or wing membrane distribution and terrestrial locomotion (Unwin 1999). The story presented in the penultimate chapter of Deep Time seeks to tie all the threads from the prior chapters together, explaining how and why pterosaurs took to the skies, the rise and success of pterodactyloids and their eventual extinction. Beyond this lies a wealth of footnotes and references to keep technical pterosaur buffs happy, along with a list of valid pterosaur species. As may be expected, the information was, at the time of writing, entirely up-to-date and we’re given the full benefit of the first 15 pterosaur bonanza years, including pterosaur brain CT scans to the wealth of soft-tissue data revealed by Brazilian and Chinese fossil Lagerstätten. There is, therefore, a wealth of information and interpretation held in Deep Time and, thanks to Unwin’s frequent quips and asides, it’s as enjoyable to read as it is informative.

We’re treated to glossy, full-colour illustrations for much of the book and, while the sources of many images will be known to those familiar with other pterosaur literature, most diagrams and drawings are well-executed and tie in nicely with the text. The excellent photographs, many of which are of previously unpublished details of well-known specimens or entirely new finds, are worthy of mention as are the superb pterosaur paintings by Todd Marshall that are dotted throughout the book (see image, above, of a Marshall Quetzalcoatlus, along with the Sordes on the book cover at the top of this post). I have a soft-spot for Marshall’s work: his animals and environments look refreshingly imperfect, a bit like they’ve been left outside in the wind and rain for some time. Plus, his style is one of the most striking and recognisable among the modern crop of palaeoartists. His punky, scruffy pterosaurs are no exception, and the depth he gives to his environments creates the impression of a broader world beyond the confines of the canvas. Happily, his pterosaur anatomy and postures aren’t too bad either, making his images a handy source of modern pterosaur restorations.

But…
So it’s praise, praise, praise, for Deep Time, then, but it’s not all good. For one thing, while most of the figures are absolutely spiffing, a few are a bit shaky with ugly, blocky lines, flat colours and poorly-defined details. This never becomes so much of a problem that you cannot see what the figure represents and there are only a handful of instances in the entire book, but the difference in quality between some illustrations is marked. The largest issue I have with Deep Time, however, is that sometimes the reader is given the impression that we know more about pterosaurs than we actually do. Take, for instance, Unwin’s arguments that a lack of pterosaur footprints prior to the mid-Jurassic is indicative of poor terrestrial abilities in non-pterodactyloid pterosaurs: is the record of pterosaur footprints really that complete that we can conclude this? I mean, how many trackways do we have of arboreal protosaurs or small, lithe dinosauriforms? Does that mean that they were clumsy, sluggish terrestrial animals, too? Though I can partially see Unwin's point on this one, I'm skeptical of using negative evidence in such a way, particularly with groups like pterosaurs with particularly patchy fossil records. Likewise, the suggestion that lonchodectids were Cretaceous pterosaur generalists seems a little bit of a stretch given that virtually no-one knows what they were really like and their record is very limited indeed.


On a similar note, the digital modelling of pterosaur terrestrial locomotion – the ‘Roborhamphus’ and ‘Robodactylus’ models crafted and worked on with Don Henderson (see Don's animation above, stolen from here) – is presented as accepted fact when, if I’m not mistaken, this work has only been published in a few abstracts (Unwin and Henderson 1999; Henderson and Unwin 1999) and not actually peer reviewed (please correct me if I’m wrong, though). Given that these models are somewhat at odds with other interpretations of pterosaur anatomy (e.g. laterally projecting hindlimbs in the Rhamphorhynchus model [contra. Padian 1983; Bennett 1997] and inflexible wrists in the pterodactyloid variant [contra. Bennett 2001; Wilkinson 2008; plus lots of pterosaur specimens with articulated, flexed wrists orientating depressing the wing metacarpal at least 40 degrees from the radius/ulna]), it may have been nice if a few more caveats about this work had been put in somewhere. Happily, this section of the book is unusual in not citing other, alternative interpretations and, in most instances, alternative hypotheses are mentioned and discussed.

Still, nothing’s perfect
These are relatively minor quibbles when the overall quality of the book is considered, though, and issues like those mentioned above are too rare top be major failings. In sum, then, even if you already own Wellnhofer’s Encyclopaedia, Deep Time is an essential purpose for the more up-to-date information it contains and, if you’re new to pterosaurs, it’s hard to imagine a better introduction. The fact that I've recommended this book to so many students and other pterosaurphiles is further testament to its quality and, frankly, it leaves a hard act to follow for the next guy in line writing a popular pterosaur book. Wait a second...

References

• Bennet, S. C. 1997. The arboreal leaping theory of the origin of pterosaur flight. Historical Biology, 12, 265-290.
• Bennett, S. C. 2001. The osteology and functional morphology of the Late Cretaceous pterosaur Pteranodon. Palaeontographica Abteilung A, 260, 1-153.
• Henderson, D. and Unwin, D. M. 1999. Mathematical and computational model of a walking pterosaur. Journal of Vertebrate Paleontology, 19, 50A.
• Padian, K. 1983. A functional analysis of flying and walking in pterosaurs. Palaeobiology, 9, 218-239.
• Seeley, H. G. 1901. Dragons of the air. Meuthuen and Co., London, United Kingdom, 239 pp.
• Unwin, D. M. 1999. Pterosaurs: back to the traditional model? Trends in Ecology and Evolution, 14, 263-268.
• Unwin, D. M. 2003. On the phylogeny and evolutionary history of pterosaurs. In: Buffetaut, E. and Mazin, J. M. (eds.) Evolution and Palaeobiology of Pterosaurs, Geological Society Special Publication, 217, 139-190.
• Unwin, D. M. 2005. The Pterosaurs from Deep Time. Pi Press, New York, 347 pp.
• Unwin, D. M. and Deeming, D.C. 2008. Pterosaur eggshell structure and its implications for pterosaur reproductive biology. Zitteliana, B28, 199-207.
• Unwin, D. M. and Henderson, D. 1999. Testing the terrestrial ability of pterosaurs with computer-based methods. Journal of Vertebrate Paleonotology, 19, 81A.
• Wellnhofer, P. 1991. The Illustrated Encyclopedia of Pterosaurs. Salamander Books Ltd., London. 192 pp.
• Wilkinson, M. T. 2008. Three dimensional geometry of a pterosaur wing skeleton, and its implications for aerial and terrestrial locomotion. Zoological Journal of Linnaean Society, 154, 27-69.

Pterosaur books to know and love, part 1: The Illustrated Encyclopedia of Pterosaurs

Your local bookshop is probably full of more popular books on dinosaurs than you would ever want to own. There’s the ‘spotters guide’ type, more encyclopaedic efforts, swish-looking coffee table tomes and even handy pocket-sized variants that ensure wherever you’re are, whatever you're doing, you can always find out if it was Ankylosaurus or Euoplocephalus that had the coolest dermal scutes. Of course, if you want to expand your knowledge of fossil forms beyond terrible lizards, you rapidly find that there’s a very short list of books to own. What popular books are there on marine reptiles, stem-mammals, basal archosaurs or the hundreds of other fossil tetrapods you may want to know about? Heck, what about fossil fish or even invertebrates, the forms that really make up the bulk of the fossil record? It’s no secret that there’re virtually no popular texts about these critters at all: despite the fact that they’re just as interesting as dinosaurs, publishers ignore them and push out the same rehashed texts on Tyrannosaurus and his chums again and again.

Dinosaur domination of bookshelves has meant that even extraordinary, spectacular fossil animals with a heavy palaeocult following – such as pterosaurs – are rarely given page space to shine. One of the first E-mails Pterosaur.net received was a suggestion from reader Bob Meek that we compile a list of recommended pterosaur books and, while it’s an excellent idea, I’m afraid the list of books we could recommend is very short. This isn't because we're snobbish and lazy (well, not entirely), but more reflective of the scant number of accessible pterosaur books. In fact, I can only think of two books that are really essential items for casual pterosaurophile bookshelves: the classic 1991 Illustrated Encyclopedia of Pterosaurs by Peter Wellnhofer and David Unwin’s more recent The Pterosaurs from Deep Time (2005). Both are out of print and will require both sleuthing of online second-hand booksellers and probably a fair amount of cash to purchase, but, as I'll try to explain across my next two posts, there are plenty of reasons why budding pterosaur nerds should bother.

The Godfather of pterosaur books, by the Godfather of pterosaurs

We begin, then, with Wellnhofer’s 1991 encyclopaedia (cover shown above, stolen from here). You may be wondering why I’m recommending that you track down a volume that was written almost two decades ago, saw it’s last print run at the turn of the millennium and, in many respects, reports virtually no discoveries from the Golden Age of pterosaur research we’re now enjoying. Circa 1991, there was practically no consensus on pterosaur terrestrial locomotion, most of Azhdarchoidea was unheard of, the Araripe and Jehol Groups were only just beginning to yield pterosaur remains and modern methods of phylogenetic analysis were still being born. It's a valid question, then, to ask why you should bother buying a book that misses out so much new and exciting information. The answer is a wholehearted 'yes', and here's why.

Firstly, it's hard to think of an author who would be more suited to write a pterosaur encyclopaedia than Peter Wellnhofer. For those who don't know, Wellnhofer is the chap who virtually single-handedly resurrected pterosaur research with his landmark monographs on Solnhofen and Santana Formation pterosaurs (Wellnhofer 1970, 1975, 1985, 1991b), pterosaur handbook (the pterosaur researcher’s equivalent of a car owners manual; Wellnhofer 1978) and much else besides. In essence, Wellnhofer created the landscape on which modern pterosaur researchers would begin to work and, having watched that landscape begin to blossom throughout the 80s, it seems only fitting that Wellnhofer should be the man to summarise work on pterosaurs up to that point. What’s more, Wellnhofer’s thoroughness, comprehensive knowledge and accessible writing style – the same attributes that make his technical work so useful decades after their publication – are all evident throughout the book. The prestige of the author alone, then, tells you that The Illustrated Encyclopedia of Pterosaurs won't be garbage.


Wellnhofer’s encyclopedia was originally published as the sister volume to David Norman’s 1988 Illustrated Encyclopedia of Dinosaurs and the two would eventually be bound together in 2000. While both books devote their first chapters as introductions to their respective groups (discussing their ancestry, anatomy, role in popular culture and a history of their research), the pterosaur encyclopedia does not take a phylogenetic approach to reviewing genera like the dinosaur volume, instead progressing through geological time to introduce pterosaur taxa in their relevant stratigraphic positions. Wellnhofer does make comments about possible pterosaur relationships in his text (they’re quite archaic: Dimorphodon is suggested to be the direct evolutionary ancestor of Anuroganthus, for instance) but they have no relation to the structure the book. Most pterosaur genera known in the early 90s are mentioned and, by discussing and illustrating the majority of these with specimen photographs and life restorations (such as the adjacent John Sibbick illustration of Solnhofen pterosaurs found on p. 86-87, and lifted wholesale from here), this section makes up the meat of the book. The end chapters overview thoughts on pterosaur lifestyles, locomotion, extinction, reconstruction and key museums to visit to see pterosaur remains. As an overview of pterosaurs, then, it’s a pretty comprehensive piece of work and, to my knowledge, there’s not been a volume of similar scope published since.

Imagery is almost always given precedence over text with plenty of large, colour pterosaur paintings and sketches by John Sibbick, pterosaur restorations and technical drawings by the author, buckets of photographs and schematic diagrams of pterosaur anatomy adorning every page. The reliance on imagery gives the impression that the book is more suited to pterosaur enthusiasts or even children than researchers, but complementing the imagery is text loaded with citations of technical pterosaur literature. Granted, the citations are only listed once on context specific pages and finding a particular reference can be awkward but, seeing as some parts of the book stand out as the best available synopses of given topics (the chapter summarising the history of pterosaur research is worth pointing to here), these citations make the Illustrated Encyclopedia of Pterosaurs an incredibly useful research aid. Equally, some of the specimen images are the best – and occasionally the only - published photographs available of certain material (like the non-Quetzalcoatlus Javelina Formation azhdarchid, for instance [p. 144]*) and, to my knowledge, no resource published since has offered so many useful pterosaur images in a single volume.

*This rarely discussed specimen, TMM 42489-2, is actually really intriguing: represented only by a fragmentary rostrum and mandible (but still 80 cm long despite its incompleteness), Wellnhofer’s book mistakenly refers it to Quetzalcoatlus but, as demonstrated by Kellner and Langston (1996), it clearly belongs to another taxon. It’s since been called a ‘tupuxuarid’ (Kellner 2004, Martill and Naish 2006) but more recently referred to Azhdarchidae (Lű et al. 2008; Witton 2009). Whatever it is, it’s clearly distinct from Quetzalcoatlus and shows that another large, and apparently snub-nosed, pterosaur was present in the Javelina Formation. I reckon it should form the subject of a blogpost sometime, in fact.

The bad bits


Of course, it was be foolish to say that the book hasn’t dated: it has. The last two decades has seen so much pterosaur research published that many ideas familiar to modern readers are noticeably absent from The Illustrated Encyclopedia of Pterosaurs. There’s no sexy images of UV-illuminated pterosaurs, quad-launches, flamboyantly crested forms like Tupuxuara or Tupandactylus, no istiodactylids outside of southern England, no cladograms of pterosaur relationships, precious little on pterosaur trackways and much else besides. Equally, Sibbick’s restorations, though beautifully painted, are rife with anatomical inaccuracies such as pterosaurs demonstrating twiglet-like limbs, hanging, bat-like from tree branches by their feet, a considerably overly muscled tail on the Rhamphorhynchus (see image, above), a duck-billed Istiodactylus, an Anhanguera that is disarticulating its neck vertebrae to grab a fish (see Sibbick Santana Formation pterosaur spread from pages 128 - 129 of Wellnhofer [1991a], above. Swiped from here)... you get the idea. Many of these inaccuracies are classic problems with pterosaur palaeoart but, crucially, most could’ve been avoided if more attention had been paid to pterosaur anatomy. You couldn’t, for instance, fit the pterosaur arm skeleton within the restored forelimbs of Sibbick's pterosaurs, meaning it violates one of the most fundamental requirements of any palaeoart: the restored animal's flesh should fit around it's skeleton, right? The biggest gear grind, though, comes from the text: virtually every pterosaur in the book is suggested to eat fish regardless of skull moprhology, dentition, wing anatomy and everything else. Like, seriously: practically all of them. And the jaw morphology of Dsungaripterus is even favourably compared to that of modern skim-feeders. Sheesh.

But that’s OK

Still, these are minor niggles compared to what is offered in the rest of the book. Simply put, the comprehensiveness and straightforwardness of its approach mean it is the best summary of the first 200 years of pterosaur research out there, full stop. No serious pterosaur enthusiast or researcher should be without a copy and, although out of print for 10 years, you can still find some cheap(ish) copies online. Top buyer’s tip: if you’re not fussed about buying an original 1991 print, the combined Norman/Wellnhofer volume is often cheaper and, aside from the page numbers, presents exactly the same content as the standalone 1991 version. You can then use the money you save buying that to purchase Dave Unwin’s 2005 book, The Pterosaurs from Deep Time, which is what I’ll try to persuade you to read next time.

References

• Kellner, A. W. A. 2004. New information on the Tapejaridae (Pterosauria, Pterodactyloidea) and discussion of the relationships of this clade. Ameghiniana, 41, 521-534.
• Kellner, A. W. A. and Langston, W. Jr. 1996. Cranial remains of Quetzalcoatlus (Pterosauria, Azhdarchidae) from Late Cretaceous sediments of Big Bend National Park. Journal of Vertebrate Paleontology, 16, 222-231.
• Lü, J., Unwin, D. M., Xu, L., and Zhang, X. 2008. A new azhdarchoid pterosaur from the Lower Cretaceous of China and its implications for pterosaur phylogeny and evolution. Naturwissenschaften, 95, 891-897.
• Martill, D. M. and Naish, D. 2006. Cranial crest development in the azhdarchoid pterosaur Tupuxuara, with a review of the genus and tapejarid monophyly. Palaeontology, 49, 925-941.
• Norman, D. 1988. The Illustrated Encyclopedia of Dinosaurs. Salamander Books, London. 208 pp.
• Unwin, D. M. 2005. The Pterosaurs from Deep Time. Pi Press, New York, 347 pp.
• Wellnhofer, P. 1970. Die Pterodactyloidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Bayerische Akademie der Wissenschaften, Mathematisch- Wissenschaftlichen Klasse, Abhandlugen, 141, 1-133.
• Wellnhofer, P. 1975. Die Rhamphorhynchoidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Palaeontographica A, 148, 1-33, 132-186, 149, 1-30.
• Wellnhofer, P. 1978. Handbuch der Paläoherpetologie. Teil 19: Pterosauria. Gustav Fischer Verlag, Stuttgart. 82 pp.
• Wellnhofer, P. 1985. Neue pterosaurier aus der Santana-Formation (Apt) der Chapada do Araripe, Brasilien. Palaeontographica. Abteilung A, 187, 105-182.
• Wellnhofer, P. 1991a. The Illustrated Encyclopedia of Pterosaurs. Salamander Books Ltd., London. 192 pp.
• Wellnhofer, P. 1991b. Weitere pterosaurierfunde aus der Santana-Formation (Apt) der Chapada do Araripe, Brasilien (Translated title: Additional pterosaur remains from the Santana Formation (Aptian) of the Chapada do Araripe, Brazil). Palaeontographica Abt. A, 215. 43-101.
• Witton, M. P. 2008. The Palaeoecology and Diversity of Pterosaurs. Unpublished Ph.D. thesis, University of Portsmouth. 307 pp.