- RSS Channel Showcase 7459885
- RSS Channel Showcase 3241928
- RSS Channel Showcase 8837963
- RSS Channel Showcase 8673981
Articles on this Page
- 11/28/12--13:56: _Here goes nothing (...
- 11/29/12--07:08: _You've come a long ...
- 12/02/12--03:07: _The Joy of Rex
- 12/05/12--06:47: _Out with the old, i...
- 12/09/12--04:14: _Deconstructing All ...
- 12/20/12--04:03: _Chilly pterosaurs a...
- 01/02/13--04:37: _Pteranodon sternber...
- 01/10/13--03:49: _Skin-deep: the 'One...
- 01/15/13--06:53: _And now... a word f...
- 01/19/13--04:39: _Burrowing dinosaurs...
- 01/25/13--07:00: _Pterosaurs: Natural...
- 02/03/13--08:10: _Overexposure of Ste...
- 02/08/13--05:01: _Ornithocheirus and ...
- 02/21/13--02:46: _The Rise and Fall o...
- 03/04/13--12:10: _"There's something ...
- 03/08/13--07:17: _Putting the 'sin' i...
- 03/12/13--03:19: _Rexperiments in bla...
- 03/21/13--07:53: _Daisy's dragon: the...
- 03/26/13--08:23: _The 'no feathers' J...
- 03/28/13--10:26: _Book news for Easte...
- 11/28/12--13:56: Here goes nothing (redux)
- 11/29/12--07:08: You've come a long way, baby
- Bennett, S. C. 1995. A statistical study of Rhamphorhynchus from the Solnhofen Limestone of Germany: year-classes of a single large species. Journal of Paleontology, 69, 569-580.
- Prondvai, E., Stein, K., Ősi, A. and Sander, M. P. 2012. Life history of Rhamphorhynchus inferred from bone histology and the diversity of pterosaurian growth strategies. PLoS ONE, 7, e31392.
- 12/02/12--03:07: The Joy of Rex
- 12/05/12--06:47: Out with the old, in with the, er... old
- Benton, M. J. 1983. Dinosaur Success in the Triassic: A Noncompetitive Ecological Model. The Quarterly Review of Biology, 58, 29-55.
- Benton, M. J. 1990. The species of Rhynchosaurus, a rhynchosaur (Reptilia, Diapsida) from the Middle Triassic of England. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, 328, 213-306.
- Nesbitt, S. J., Barrett, P. M., Werning, S., Sidor C. A. and Charig, A. J. 2012. The oldest dinosaur? A Middle Triassic dinosauriform from Tanzania. Biology Letters, 9. doi. 10.1098/rsbl.2012.0949
- 12/20/12--04:03: Chilly pterosaurs and rushed festive wishes
- 01/02/13--04:37: Pteranodon sternbergi does the cover of TREE
- Knell, R., Naish, D., Tomkins, J. L. and Hone, D. W. E. 2013. Sexual selection in prehistoric animals: detection and implications. Trends in Ecology & Evolution, 28, 38-47
- Hieronymus, T. L., Witmer, L. M., Tanke, D. H. and Currie, P. J. 2009. The facial integument of centrosaurine ceratopsids: morphological and histological correlates of novel skin structures. Anatomical Record, 292, 1370–1396.
- Mayr, G., Peters, D. S., Plodowski, G. and Vogel, O. 2002. Bristle-like integumentary structures at the tail of the horned dinosaur Psittacosaurus. Naturwissenschaften 89, 361–365.
- Spicer, R. A. and Herman, A. B. 2010. The Late Cretaceous environment of the Arctic: A quantitative reassessment based on plant fossils. Palaeogeography, Palaeoclimatology, Palaeoecology, 295, 423–442.
- Sternberg, C. 1925. Integument of Chasmosaurus belli. The Canadian Field-Naturalist, 39, 108-1 10.
- Zheng, X., You, H., Xu, X. and Dong, Z. 2009. An Early Cretaceous heterodontosaurid dinosaur with filamentous integumentary structures. Nature, 458, 333–336.
- 01/15/13--06:53: And now... a word from our sponsors
- 01/19/13--04:39: Burrowing dinosaurs are also cool. Honest.
- Krumenacker, L. J., Britt, B. Varricchio, D. J., Scheetz, R. and Robison, S. 2011. Idaho's first dinosaur identifiable to genus level, Oryctodromeus sp., from the mid-Cretaceous Wayan Formation, and the geological and paleontological setting. Geological Society of America Abstracts with Programs, Vol. 43, No. 4, p. 16
- Lee, A. H. and Werning, S. 2008. Sexual maturity in growing dinosaurs does not fit reptilian growth models. PNAS, 105, 582–587.
- Varricchio, D. J., Martin, A. J., and Katsura, Y. 2007. First trace and body fossil evidence of a burrowing, denning dinosaur. Proceedings of the Royal Society B, 274, 1361–1368.
- Witton, M. P. and Habib, M. B. 2010. On the size and flight diversity of giant pterosaurs, the use of birds as pterosaur analogues and comments on pterosaur flightlessness. PLoS One, 5, e13982.
- 02/03/13--08:10: Overexposure of Stegosaurus, but in a good way
- Carpenter, K., Sanders, F., McWhinney, L., and Wood, L. 2005. Evidence for predator-prey relationships: Examples for Allosaurus and Stegosaurus. In Carpenter, K. (Ed). The Carnivorous Dinosaurs. Indiana University Press. pp. 325–50.
- Christiansen, N. A., and Tschopp, E. 2010. Exceptional stegosaur integument impressions from the Upper Jurassic Morrison Formation of Wyoming. Swiss Journal of Geosciences, 103, 163-171.
- Maidment, S. C., Norman, D. B., Barrett, P. M., and Upchurch, P. 2008. Systematics and phylogeny of Stegosauria (Dinosauria: Ornithischia). Journal of Systematic Palaeontology, 6, 367-407.
- 02/08/13--05:01: Ornithocheirus and Anhanguera: 4 m wingspans are rubbish
- Martill, D. M. and Unwin, D. M. 2012. The world’s largest toothed pterosaur, NHMUK R481, an incomplete rostrum of Coloborhynchus capito (Seeley, 1870) from the Cambridge Greensand of England. Cretaceous Research.
- Wellnhofer, P. 1987. New crested pterosaurs from the Lower Cretaceous of Brazil. Mitteilungen der Bayerischen Staatsammlung für Paläontologie und Historische Geologie, 27, 175-186.
- Wellnhofer, P. 1991. 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.
- 02/21/13--02:46: The Rise and Fall of Ziggy BigQuetz
- 03/04/13--12:10: "There's something in the mist!"
- Vremir, M., Kellner, A. W., Naish, D., & Dyke, G. J. (2013). A new azhdarchid pterosaur from the Late Cretaceous of the Transylvanian Basin, Romania: implications for azhdarchid diversity and distribution. PloS one, 8, e54268.
- 03/08/13--07:17: Putting the 'sin' in Junggar BaSIN
- Unwin, D. M. 2005. The Pterosaurs from Deep Time. Pi Press, New York, 347 pp.
- Wellnhofer, P. 1991. The Illustrated Encyclopedia of Pterosaurs. Salamander Books Ltd., London. 192 pp.
- Witton, M. P. 2013. Pterosaurs: Natural History, Evolution, Anatomy. Princeton University Press. [In press]
- Young, C. C. 1973. Pterosaurian fauna from Wuerho, Sinkiang. Reports of paleontological expedition to Sinkiang II, Kexue Chubanshe, Nanjing, China, 18-34.
- 03/12/13--03:19: Rexperiments in black and white
- 03/21/13--07:53: Daisy's dragon: the full painting
- Naish, D., Simpson, M. I. & Dyke, G. J. 2013. A new small-bodied azhdarchoid pterosaur from the Lower Cretaceous of England and its implications for pterosaur anatomy, diversity and phylogeny. PLoS ONE 8(3): e58451. doi:10.1371/journal.pone.0058451
- Lü, J., Unwin, D. M., Deeming, C., Jin, X., Liu, Y. and Ji, Q. 2011. An egg-adult association, gender, and reproduction in pterosaurs. Science, 331, 321-324.
- Naish, D., Simpson, M. I. & Dyke, G. J. 2013. A new small-bodied azhdarchoid pterosaur from the Lower Cretaceous of England and its implications for pterosaur anatomy, diversity and phylogeny. PLoS ONE 8(3): e58451. doi:10.1371/journal.pone.0058451
It occurs to me that I don't really have much of an easily updatable, online home at present. My regular internet haunts aren't really suitable for rapid uploading lots of images or interacting with others. My Flickr site is too constrictive on comments and posting, and the Pterosaur.Net blog is a shared site that I don't want to clog with my garbage. Hence, I thought I'd set up a sister blog to my website, where I can post all the images I like, and you can comment all you like, without any hassle*. The objective here is to give myself an outlet for the paintings, ketches, diagrams and other media I've been making for the last few years, but rarely sees the light of day outside of its intended use and occasional posts on Facebook. My plan is to keep this rather straightforward by being word-light and picture-heavy, which should keep the post level up to at least one a week.
*For a few weeks, a version of this has been live at my website, but it communicated poorly with social network sites, so I've moved house to Blogger. Anyone who saw the old version of this post may be feeling a sense of deja vu, but new content will follow soon. Honest.
With that in mind, I'll leave this first opening post here. For the unitiated, the picture above is a full colour version of the opening image to a blog post, and now a full length lecture I recently gave at the University of Portsmouth, about speculative interactions between humans and pterosaurs, called 'Our Lives with Pterosaurs'. Just for fun, I've posted the poster used to advertise the talk below, too. I tried to capture some of the characteristic poster design common to Westerns made in the 50s and 60s, what with the wavy title and quotes from a critic (or Mike Taylor) and all. It's up to the viewer to decide whether the guy riding the azhdarchid is going to burst into 'The Deadwood Stage' from Calamity Jane as he soared away.
Anyway, enough nonsense. Were pterosaurs strong enough to carry humans to work throught the skies? Were they big enough to eat people? Head here, and to the follow up post here, to find out.
This image was the first time I largely excluded showing details of the cranial fenestra in my reconstructed animals. They're still visible, but I recall making a very conscious decision to mute their appearance. Nowadays, my illustrations don't show them at all. Those interested in palaeoart will be aware that there is currently a real push against the classic 'shrink-wrapped' appearance of animals in palaeoart, defying generations of artists who have applied minimal amounts of soft-tissue to their reconstructions to show their osteological details (check out Matt Wedel's festive plea for healthy-looking sauropods for an example. From this SV:POW! post). The observation that most skeletal anatomy is hidden behind soft-tissue is the rationale behind this movement, and it may be one of the most significant paradigm shifts to the palaeoart of Mesozoic and Palaeozoic reptiles since palaeontologists of the late 1960s and 1970s told artists to lift their dinosaur tails off the floor. More on this movement another time, perhaps: this is meant to be a word-light blog, after all.
Like most child dinofanciers, I drew buttloads of Tyrannosaurus when I was growing up, a hobby spurned on by the 1993 release of Jurassic Park. Looking back on that movie, Tyrannosaurus was clearly its star and the creature that most effectively demonstrated the transition from the lumbering, lizard-like dinosaurs of Hollywood's Golden Age to the fast, cunning monsters we recognise them as today. The brachiosaur may have evoked awe, but it didn't behave in a dissimilar fashion to other movie sauropods. Velociraptor revealed an unfamiliar and sinister side to the dinosaur cannon, but mot people had no concept of Velociraptor or other dromaeosaurs before then. Tyrannosaurus, though, was already familiar through its out-of-shape, tail-dragging variants being featured in the 1925 The Lost World, the 1933 King Kongand 1964 Valley of Gwangi*. When the toned, fast and ferocious Jurassic Park version started overturning cars, smashing a small building to matchwood, and almost outrunning a jeep, it was clear that the perception of dinosaurs had received a complete makeover, and that their interpretation as lizard-like creatures had been banished.
*Yes, yes: I know. Gwangi wasn't a straight Tyrannosaurus, but he was half. Harryhausen made Gwangi, as he did his other prehistoric creatures, by compositing his favourite bits of different animals into one model. Gwangi was a mix of Tyrannosaurus and Allosaurus, which Harryhausen termed 'Allo-rex'.
Since 2005, I've drawn considerably fewer Tyrannosaurus, and certainly never painted one. In coming back to Tyrannosaurus after all this time, I made a wholehearted effort to do it justice. All too often, Tyrannosaurus is rendered as a generic theropod with short, two-fingered arms, a large head and massive teeth, but such portrayals miss a lot of remarkable anatomy (above, lateral view of the restored skull and mandible of FMNH PR2081, better known as the Tyrannosaurus called 'Sue', showing the characteristic shapes common to Tyrannosaurus skulls. Image by me, 2008). Tyrannosaurus is the acme of tyrant dinosaur evolution, knocking 'standard' tyrannosaurid anatomy up to 11 to become on the most 'extreme' dinosaurs known. Anatomical quirks include the very wide temporal region of the skull, the abrupt, vertical termination to the muzzle, and the cool shades over the eyes. Their necks probably heavily muscled, judging by the space for neck muscle attachment on the Tyrannosaurus skull, cervical vertebrae and anterior trunk skeleton. The torso shape is unusual too, with their gently arcing ribs forming a thoroughly barrel-chested torso, which would partially obscure the big thigh muscles when viewed from anterior aspect. As with depiction of a coelurosaur nowadays, a decision had to be made about whether to apply a covering of feathers, as is increasingly plausible for theropods of all sizes. I followed the data offered by several scrappy Tyrannosaurus skin impressions showing pebbly scales for much of the body, but also figured that a few large, thickened scales across the face, neck and back wouldn't look out of place. These were animals that habitually tried to bite each others faces off after all, so few bits of toughened hide would not have gone amiss. Oh, and a few feathers can be seen at the end of the tail, because even tough animals have their sensitive sides.
Some time was spent pondering what to have my Tyrannosaurus doing, too. Tyrannosaurus is a seriously busy animal in palaeoartistic renditions. It's always doing something, be it roaring, chasing a hadrosaur, eating a dead Triceratops, roaring, running for no obvious reason, roaring, stalking unseen animals, roaring, making or nurturing babies, roaring, battling other theropods or perhaps roaring (if our depictions of Tyrannosaurus are accurate, the Maastrichtian fauna of North America must've been deafened by the incessant screaming of the local tyrannosaurs, because they always seem to be making noise in our pictures of them!). To avoid these clichés, the Tyrannosaurus here is doing, well, not very much, really. He's just standing around, looking like he's trying to remember why he walked over to that point in the first place, or perhaps wondering where he left his car keys. Point is, it's doing nothing in particular, which seems to be a relative rarity among tyrannosaur palaeoart, but perhaps allows for a little more appreciation of its shape and form. Plus, this is clearly a Tyrannosaurus from the northern extreme of its range, where forests of conifer and deciduous trees were common. I think I may have spent more time on the plants in this image than any other I've drawn, which requires a hat tip towards palaeoart man of the moment John Conway. John's attention to vegetationin his palaeoart has shown up other palaeoartists for all too often using plants as a generic, green backdrop to their work, which I'm entirely guilty of, and need to stop. There does seem to have been a bit of a push against purely green, tropical worlds in Mesozoic palaeoart recently , which joins the 'anti-shrink wrap' palaeoart movement mentioned in the previous post in marking a new age in our depictions of ancient worlds.
Anyway, I've gone on enough for the time being. I think the above painting is one of the more successful bits of artwork I've done, which may be why I'm still going on about it. Still, so much for a word-light approach to blogging.
my book proofs arrive this morning, but my PR image of the oldest known dinosaur, which accompanies the hot-off-the-press paper by Sterling Nesbitt and colleagues, has been making waves on Internet press sites. There's lots of cool things to say about the paper and the image, but time is a little short today, so I'll have to keep my discussion brief.
Starring front and centre in the image Nyasasaurus parringtoni, the 2-3 m long possible dinosaur (or extremely dinosaur-like dinosauriform) from the Middle Triassic Manda Formation of Tanzania. As anyone with an ear to the ground for palaeontology news will know, Nesbitt et al. (2012) have rescued Nyasasaurus from the nomina nuda bin and made a compelling case for it to represent the oldest dinosaur remains yet known, or at least a dinosauriform species that was only a evolutionary stones throw from Dinosauria proper (see Nesbitt et al. 2012 for full details, or one of the many write ups populating the Internet). Unfortunately, Nyasasaurus is known from only a handful of scrappy bones including a few vertebrae and a partial humerus, which doesn't give much to work from for an artist. Paul Barrett and Sterling Nesbitt, the brains behind this image, suggested that another ancient dinosaur, Eoraptor, should be the primary reference, but with a some influence from early sauropodomorphs. The result is an admittedly slightly speculative animal, but one that hopefully captures the generalised anatomy that may have been common to the first dinosaurs and their immediate ancestors. The question of integument, a crucial consideration for any modern image of a Mesozoic dinosaur, was addressed fairly quickly: "...definitely no feathers!" It's funny to think that palaeontologists now have to defend the choice not to cover their dinosaurs in feathers or other fancy integuments, but I don't disagree with the decision here. Feathers are spreading down towards the base of Dinosauria at a rapid rate, but direct evidence is still some distance from the root of the tree. Of course, the occurrence of fuzz in pterosaurs, which some authors have already controversially interpreted as representing early types of feather, does create the potential for fuzzy integuments in all ornithodirans, but we're still waiting for smoking gun evidence of this. Elaborate restorations of prehistoric animals are definitely in fashion at the moment, but we do need to keep perspective on what the fossil record tells us. In the absence of fuzz, I chose the wrinkly, dappled scales of a perente monitor as the inspiration for the Nyasasaurus skin.
At least part of the rationale behind the dabbled, camouflaged tones of the centre animal came from its likely place in its Middle Triassic ecosystem. Nyasasaurus and other dinosauriforms were minor faunal components of a world dominated by other types of reptile (Nesbitt et al. 2012), so they may have done well to remain largely remain inconspicuous for much of the time. The rhynchosaur Stenaulorhynchus (see image detail above, showing the rhynchosaurs in all their inelegant glory) seems to have been a particularly common animal in the Manda Formation, with dozens of individuals being found compared to the one occurrence of Nyasasaurus. We wanted to feature this ecological relationship in the image, showing a lonely early dinosaur in a landscape controlled by other animals. Rather than simply including a bunch of Stenaulorhynchus in the distance however, we thought it would be cool to have the Nyasasaurus following a trail of destructive rhynchosaur foraging. Rhynchosaurs are noted for their adaptations for scratch digging with their hindlimbs, which may have been used to unearth roots, tubers or other food (Benton 1983, 1990) . In this image, several shallow excavations have been made by a troop of Stenaulorhynchus in their quest for food, which the Nyasasaurus is picking over to nab exhumed invertebrates and nutritious plant matter left behind. I must admit that the charisma of Stenaulorhynchus almost stole the show for me when drawing the image: I didn't realise how cool digging, buck-toothed reptopigs were, and I think the depiction of them digging is a first for palaeoart generally.
Finally, a quick word on the environment. Say 'Triassic climate' to most folks and their thoughts will travel to arid, barren landscapes, but this is only true for the latter half of the Triassic. The Early and Middle Triassic (which account for only the first 40 % of Triassic time) were rather wetter and, presumably, lusher than we usually imagine them (e.g. Benton 1983). In keeping with this trend, the Manda Formation palaeoenvironment was a fairly mesic, temperate setting that was likely a lot greener than the Triassic scenes we're used to. And that will have to do for now. So much for a 'brief' post. Again.
controversial painting of a carrion-eating, bristly Styracosaurus. From 2007.)
The All Yesterdays project seems to be the result of looking into this deep abyss of lost palaeontological data. But rather than staying safe at the edge, Conway et al. have dived in, exploring the virtually infinite possibilities of ancient animal reconstructions, critiquing the rationale and methodologies of palaeoart and questioning its very purpose. The results are novel, highly creative, insightful and thought provoking, and should be given serious thought by anyone interested in the palaeobiology and depiction of extinct animals. In short, All Yesterdays argues that modern palaeoart fails one of the only tests we can apply to it, that many depictions of extinct animals compare poorly against the morphological and behavioural diversity of modern species. Specifically, modern palaeoart is too conservative, frequently depicting set behavioural patterns for some species (e.g. the Tenontosaurus vs. Deinonychus meme) and 'shrink wrapping' skin over the skeletomuscular system without any consideration of other soft-tissues. All Yesterdays argues that this can be rectified, in part, through bold transference of modern animal anatomy and behaviour to extinct species, which fills the gulfs of missing data and creates more plausible concepts of life in the past than by following the current, perhaps overly conservative palaeoart methods. The word 'concept' is important here, as this is all we can hope to realistically hope to achieve in palaeoart. For all our efforts, our reconstructions will probably never depict these animals exactly as they were in life, and we just have to live with that. Science will hone and refine our concepts to more closely resemble what was once reality, but most of the details we need to exactly reconstruct ancient worlds are unlikely to ever emerge. There will always be several plausible ideas for the life appearance of extinct creatures*, and we should focus on exploring these concepts to reproduce believable renditions of animals, not ignoring because of (probably) unobtainable data or because they stray from established ideas.
*Is there more than one way to reconstruct a fossil animal? According to some, no, but others would disagree. I think the answer lies somewhere inbetween. The skeletomuscular system of extinct animals may be reconstructed more-or-less correctly from fossils of some species but, as we'll see below, this is only half of the story.
But we must be careful with this liberation of creativity in a science-based discipline. All Yesterdays calls not for recklessness in palaeoart, but confidence, allowing extinct animals to be diverse and unusual, but still constrained by what is known for their evolutionary history and anatomy. The payoff for this confidence is that the All Yesterdays project often portrays extinct animals in a more convincing and realistic manner than much of the work we're familiar with. For example, John's tripodal Therizinosaurus is just as plausible, scientifically speaking, as a more traditional version, but is 100 times more believable. John's Camarasaurus rolling in mud is just as plausible as the hundreds of illustrations of this animal standing and eating, and Memo's super-stocky Lambeosaurus is entirely consistent with fossils of this species. The results are just as valid as hypotheses of appearance and behaviour - arguably moreso - than the ultra-conservative reconstructions currently dominating palaeoart. Erring on the side of caution is still an error, and some of the entrenched, 'conservative' reconstructions of ancient life are actually harder to substantiate than the seemingly bolder ones.
Elements of what I'll call 'the All Yesterdays philosophy' have been creeping into palaeoart for years, but I think Conway et al. have burst the dam here, highlighting the need for a fresh approach in how we approach the reconstruction of extinct life. So far as I see it, there are four points to consider in the All Yesterdays philosophy that both palaeontologists and palaeoartists need to embrace: when to apply it, the composition of our images, what it means for animal appearance, and its application for extinct animal behaviour.
All Yesterdays is entirely about reconstructing long extinct animals with no ecologically similar modern relatives. We don't need to extrapolate data wildly for relatively recently extinct species with lots of closely related modern relatives, and doing so will probably make our work less accurate. All Yesterdays is a philosophy that need only be applied to species for which soft-tissue data and behavioural aspects are inadequately known or entirely unknown. This includes some of the stranger Cainozoic mammals, reptiles and birds, and essentially everything that lived in the Mesozoic or before.
Composition, or aspect and attitude
What do extinct animals look like when not viewed in direct lateral view? Because the fossil skeletons of many species are laterally compressed, and because lateral views arguably show off more anatomy than other aspects, palaeoartists rarely show animals in anything other than side-on attitudes. 3D skeletal remains allow us to reconstruct animals in multiple aspects however, often with surprising and unfamiliar results. This has not percolated into palaeoart yet however, and if animals are shown in non-lateral aspects, their proportions are often 'generic'. In my view, one of Greg Paul's crowing achievements was revealing the variation in dinosaur width, highlighting the extremely wide ribs of ankylosaurs and pachycepahlosaurs, and the narrowness of many theropods. All Yesterdays encourages us to remember that animals are three-dimensional beings, and can be accurately treated as such in art. (Below: the rarely seen anterior aspect of a famous pterosaur. But which one? Detail of a painting from my book.)
Appearance: the anti-shrink wrapping movement
Arguably the most important aspect of All Yesterdays is our reconsideration of extinct animal appearance. As a response to the inaccurate and often shapeless animals common to palaeoart in the early 20th century, most artists in the Age of Greg Paul employ the celebrated 'Rigorous Anatomical Approach' (RAA) to reconstructing fossil animals, and depict their animals with much of their detailed musculature and skeletal anatomy obvious under the skin (classic example of strict RAA in dinosaur art, Greg Paul's running Daspletosaurus, shown below. Image © Gregory S. Paul, from his website). These ultra-lean, toned animals are often devoid of any obvious extraneous tissues, including fats, loose skin or elaborate integuments. Strict RAA remains the most scientifically sound route to reconstructing an extinct animal, as it rigorously employs available data to render an extinct animal, and minimises speculation. It is also an effective way to demonstrate anatomical distinctions between extinct species and produces dynamic looking creatures, which are undeniably appealing to viewers. The rise in popularity of this technique at the time of the Dinosaur Renaissance is probably not a coincidence.
|© Gregory S. Paul|
Anyone familiar with the history of palaeoart will recognise recurrent memes associated with specific animals. Ornitholestes always chases a bird. Archaeopteryx (which is always blue and green) perches on a branch with its wings outspread, its back always to the viewer. Tyrannosaurusis always roaring. Most prevalent of all is the depiction of prehistoric animals incessantly trying to murder each other. Memes often perpetuate because they reflect a certain trait specific to a certain animal (e.g. sleeping Mei, the use of the 'terrible claw' in Deinonychus), but they quickly became clichéd tropes when over used. All Yesterdays makes a case for showing animals undertaking other essential activities such as preening and bathing, socialising (without engaging in life-or-death intraspecific combat), playing, resting, sleeping, nesting and, well, all the other things that real animals do. Phylogenetic tracing of animal behaviour shows that there is no reason not to depict ancient animals undertaking these activities, but we rarely show them doing anything but fighting and eating. Moreover, All Yesterdays emphasises the behavioural plasticity of modern animals, noting that apparently strict carnivores or herbivores will supplement their diets with meat or plant matter on occasion, that animals can locomote in unexpected ways and are proficient at activities that we would not predict from their skeletons alone (this image being the chief All Yesterdays case study). As with the morphological aspects of reconstruction, this is not a call out for all unabashed craziness in palaeoart, but simply to say that we should be more broad minded about the way we depict the behaviour of extinct species, and that some initially outlandish ideas (like my carrion-eating Styracosaurus) are not as ridiculous as they first appear.
A new age in palaeoart?
Taken together, these points can be summarised in
It will be interesting to see how much of a shift All Yesterdays generates in attitudes to palaeoart. It's probably very clear by now that I'm a convert, but will others pick up on this, too? The rosy reviews of the All Yesterdays book suggest so, but what actual effect will this project have? I do not think the results will be as obvious as the popularisation of RAA in the 1970s and 80s, but I am optimistic that All Yesterdays marks a 'formalisation' of the anti-shrink wrapping movement, and need for depicting more complex compositions and behaviours. I look forward to seeing its results. Darren suggested at the All Yesterday's book launch that modern palaeoartists are currently working in the 'Age of Gregory S. Paul', with most of us following Paul's methods of strict RAA reconstruction to greater or lesser extent. Looking at the celebratory response to the All Yesterdays project across the internet, I wonder if the Age of Gregory S. Paul is about to end, and palaeoart will enter the 'Dynasty of All Yesterdays'?
Exciting news: thanks to Rob Knell, Dave Hone, Joe Tomkins and Darren Naish, my old image of a male Pteranodon sternbergi and his harem has made the cover of the latest edition of TREE! This is the first time my artwork has featured so prominently on the front page of a journal or magazine, so it's certainly given 2013 an excellent start from my perspective. As may be expected, the illustration accompanies the recent Knell et al. (2013) review of sexual selection in prehistoric animals found in this edition of the journal (which, while I'm in trumpet blowing mode, features another image of mine, showing sexual dimorphism in Darwinopterus). Access to the paper seems unrestricted at the time of writing at least, so be sure to check it out, and thanks to the authors for asking me to be part of their work!
That will do for now: very busy putting the last few hours into a long-term project that will no doubt be of interest to some readers here. Check back for news soon. Happy New Year all!
|The snowy, chilly plains of Maastrichtian Alaska, where Pachyrhinosaurus perotorum roamed. But were they scaly like other ceratopsids, or covered in protofeathers, as shown here?|
The painting in question shows a family of the Alaskan centrosaurine Pachyrhinosaurus perotorum, a species notable for its existence in rather chilly, latest Cretaceous climates at palaeolatitudes of 80-90°. It differs from other pictures of this species by having its Muskox Quotient upped by 500%, replacing the scaly hides of more traditional Pachyrhinosaurus reconstructions with a blanket of fuzz analogous to the fuzzy, unkempt feathers of modern ratites. Fuzzy polar dinosaurs are not unusual in palaeoart nowadays and they result in animals that look immediately more at home in icy, subfreezing climates than their scaly brethren. This image, however, directly contradicts what most folks will say we know about horned dinosaur integument. Some comments on Facebook have already wheeled this argument out: known ceratopsian integuments were predominately scaly, so the concept of a shaggy pachyrhinosaur is nonsense, right? Well, I'm going to argue here that it's not, or at least not a concept that is easily dismissed. Before we go any further, it's worth stressing that I'm not presenting this image as the new 'standard' for Pachyrhinosaurus perotorum: I don't know of any new evidence that confirms the shaggy hides shown here, be it soft-tissue remains of ceratopsids or a new interpretation of dinosaur evolution that suggests super-fuzzy ornithischians were common. Nor, for that matter, do I have the heads up on research indicating that latest Cretaceous Alaskan palaeoclimates were much lower than expected. Instead, across four points, I'm going to argue that, based on what we know of dinosaur evolution, the responses of modern animals to their environments, and - importantly - the vast gulf of unknown data regarding dinosaur appearance, that this concept is as plausible as our scaly variants and, in some respects, may be more plausible. On the way, I'm going to suggest that, as with some other considerations in palaeoart, we may be too conservative when it comes to depicting animal integuments, because we focus too much on their evolutionary relationships without considering their likely adaptations to habitats and lifestyles. Hmm... this is all starting to sound very All Yesterdays, isn't it? That's not a coincidence.
1) Ornithischians were fuzzy, and some were probably fuzzier than others.
First up, the least controversial pin in this case. Thanks to Tianyulong and the early ceratopsian Psittacosaurus, we know that ornithischians were covered in more than just scales, the former being covered in filamentous structures akin to early feathers and the latter possessing long quills (Mayr et al. 2002; Zheng et al. 2009) Accordingly, it's now fairly fashionable, and by no means unreasonable, to restore even large ceratopsids with at least a smattering of quills across their bodies like those seen on Psittacosaurus, reflecting a relict integument from an earlier phase of their evolutionary history. It naturally follows that we should expect some taxa to have been more densely adorned with filaments and quills than others, just as fur and feathers are of variable densities in modern species. Accordingly, while a shaggy pachyrhinosaur is certainly at the 'extreme' end of our predictions for an ornithischian integument, it does not directly contradict anything we know regarding dinosaur evolution. Ceratopsids probably had the appropriate genetic blueprints to produce a shaggy animal, so long as the right conditions promoted its expression. There is a question of how appropriate it is to cover a ceratopsid in shaggy integumentary structures however, in light of preserved skin impressions of other ceratopsids. How likely is it that any horned dinosaurs were fuzzy?
|Fossil integument of Chasmosaurus belli. From Sternberg 1925.|
Skin impressions and the remains of other integumentary structures are Holy Grails to palaeoartists, and we use them extensively in restoring extinct animals. Through phylogenetic bracketing, or use of their basic phylogenetic proxy when less data is available, we stretch these remains over entire clades so that the known integument of one species becomes the norm for an entire group - what I'll call 'One Skin Fits All' approach. Thus, because we have scaly skin impressions for three ceratopsids - Centrosaurus, Triceratops and Chasmosaurus (see image, above, of the latter. From Sternberg 1925), it's assumed that scales were common to the entire clade. There's nothing necessarily wrong with this assessment and, one may argue, it's the most parsimonious way to interpret this data. A stick in the mud, however, is that another dataset, the diversity of integuments in modern animals, suggests that integuments can vary wildly within groups, and that we could be vastly underestimating the integumentary variation in extinct animals.
Consider the different varieties of fluff, fur, feathers, hair, bristles and other fuzzes in a group of modern animals and then think how a future palaeoartist would reconstruct all varieties of that group if they only had access to only one or two examples of integument. Perhaps all reconstructions of bovids would have woolly coats like those of sheep, or, conversely, the sparse, almost naked skin like a water buffalo? We may deck all primates out in the long capes of colobus monkeys, all pigs with boar-like fur, or cover every inch of birds with feathers. We know such approaches are wrong because these groups demonstrably show variation in the distribution, length and structure of their varying integuments, and yet we maintain a One Skin Fits All' approach to fossil clades. We can't even play the 'extremely close relationship card' in this game as the likes of woolly mammoths, and the fuzzy Sumatran and woolly rhinos, show vastly different integuments to their closest, naked relatives.
One could counter this point by arguing that the relative abundance of scaly remains in certain dinosaur lineages suggest that most, if not all members of that clan were scaly. Perhaps, but we should consider both the sample sizes here and the taphonomic window through which fossils are passed to the modern day. We have, at best, skin impressions from a handful of species compared to the group diversity, so statistical support for the 'One Skin Fits All' approach is low. Moreover, which types of skin are more likely to be preserved? Taphonomic observations on modern animals suggest that fur and feathers are easily removed from carcasses by biological or physical processes, so their preservation potential in ancient animals is low outside of fossil Lagerstätten. Is it a coincidence that the only skin impressions we find outside of Lagerstätten are scaly, leathery hides? I don't have the answer to that question, but it's worth chewing over.
With all this in mind, I wonder if applying the fossil integuments of one species to all its relatives, even close ones, is a questionable practise. I'm not saying that skin impressions are useless and that we should pay them no attention, but we should remember that they only highlight possibilities and perhaps some degree of probability for integumentary structures in a related species. They may well also have no bearing whatsoever on the appearance of their relatives. We're dealing with a great amount of unknown data when reconstructing ancient integuments, and we know how complex this issue is through modern species. When applying this thought to horned dinosaurs, we can say that the scaly skin impressions we have for a few species demonstrate that some bore scales, but we cannot rule out the possibility that others were covered in entirely different structures, like the quills and fuzz that seem deeply rooted in dinosaur ancestry. It does seem likely that many centrosaurines heads, including Pachyrhinosaurus, bore heavily keratinised scales and pads (Hieronymus et al. 2009), but, of course, this doesn't tell us much about the rest of the body. The majority of skin in Pachyrhinosaurus could be scaly, fuzzy, or anywhere inbetween. Without skin impressions to directly tell us the integument of specific species, there's no way to be sure. We need to be careful that we do not afflict ourselves with palaeoartistic phyloblindness here, by only considering these animals as denizens of cladograms and evolutionary hypotheses. Phylogenies may tell us what is possible for integument reconstructions, but other factors may help us decide is more probable.
3) Phylogeny is far from the only factor controlling integument, and can be readily overruled
It's funny to think that, for all the time we spend looking at the phylogenies of extinct animals, we're often missing much about the raw power that drove their evolution: adaptation. This is probably because we're lacking so much anatomical detail in their fossils that their responses to even broad environmental changes are largely undetectable, so understanding why they change through time is not always as certain as how. Nevertheless, we can be sure that different environments drove modification to the anatomy of extinct lineages on small and large scales, and integuments were likely to be one of the most affected tissues. Animal integuments are critical interfaces between body and environment, and have to be appropriately adapted for given habitats. This is a readily observable phenomenon in modern animals, because their integuments reflect all sorts of environmental factors including sun exposure, temperature, local vegetation types, water availability, parasite prevalence, and their local predators. Presumably, this is why such variation in integument exists in even closely related species. But we frequently reconstruct fossil species as if they all live in the same place. Sedimentological and isotope data reveals that closely related ancient species sometimes lived in starkly contrasting settings, but because we frequently take the 'One Skin Fits All' approach, our animals look very similar, irrespective of the requirements of their habitats.
|Hot Fuzz: a reference to the condensing breath of the animal, the controversial concept depicted here, or just an excuse for a bad pun? Whatever: it's an excuse to link to this clip from Hot Fuzz: Best. Granny. Kick. Ever.|
Bringing this back to our fuzzy pachyrhinosaurs, we again have to question the how applicable the currently available ceratopsid skin impressions are to this Alaskan species. The scaly hides of Chasmosaurus, Centrosaurus and Triceratops represent animals living in more southerly regions than Pachyrhinosaurus,which were at least temperate to subtropical in climate. The former two taxa also lived somewhat before Pachyrhinosaurus, when global temperatures were, on average, a little warmer. These sub-arctic coastal plains encountered by Pachyrhinosaurus perotorum, by contrast, were much cooler, and sometimes genuinely cold. Accordingly, the selection pressures on integument may have been very different for P. perotorum compared to these warm-climate ceratopsids, and we have to wonder how suitable the skin impressions of Chasmosaurus et al. are for reconstructions of Pachyrhinosaurus. We wouldn't, after all, expect the integument of a yak to resemble that of a African buffalo, or consider the fur of a lithe gazelle a suitable model for mountain goat fur. With this philosophy in mind, the question of shaggy pachyrhinosaurs shifts focus from arguments about the cladograms and the skin impressions of their relatives, and on to whether or not Late Cretaceous Alaska was cold enough to promote the development of an extreme integument adaptation in a large dinosaur species.
4) Late Cretaceous Alaska: a struggle for any tourist board
Although nowhere near as bleak as our modern Alaska, the dinosaur faunas inhabiting the northern reaches of latest Cretaceous Alaska would have experienced fairly grim weather for much of the time, perhaps akin to that experienced by modern animals living on the northwest coast of Canada or the more depressing parts of Scotland. In a recent review based on palaeobotanical data from the Cretaceous Arctic, Spicer and Herman (2010) suggested that uppermost Cretaceous Alaska experienced mean average temperatures around 6°C, with summer months attaining a comfortable 14.5°C, but winter months dropping to an average of -2°C. The Pachyrhinosaurus perotorum-bearing Prince Creek Formation may have been a little cooler than other parts of the Late Cretaceous arctic circle, with a mean average temperature between 2.5-5°C. Winter lasts a long time at 80-90° latitude, with 5 of darkness bracketed by 2 months of twilight. A permanent cloud cap over the Late Cretaceous Arctic (detected by the oversize nature of the fossil plant leaves from Cretaceous Alaskan localities) acted as a atmospheric blanket for the region, prohibiting temperatures from plummeting below freezing low for long period. The lowest temperatures - perhaps -10°C - may not have lasted more than a few weeks. Evidence for deep freezes is absent however, with neither the sedimentological or palaeobotanical record indicating nothing more severe than week-long frosts and light freezes. Despite this, rain and snow were probably common, with relative humidity averaging about 80% and even the driest months of the year experiencing over 180 mm of rain. The collective three wettest months, by contrast, collected almost 800 mm. (To put this in perspective, rain-soaked England has an average annual rainfall of 854 mm, according to the UK Met Office [via Wikipedia]). Such a climate was capable of supporting a rich array of plantlife, and evergreen taiga-like forests were common, as were swamps, rivers and other bodies of water. Such conditions seem fairly common right the way through Late Cretaceous Alaska, with conditions a full 8° south of the Prince Creek Formation seeming similarly cold and wet. I should add that this consideration of ancient Alaska isn't particularly controversial, the palaeobotanical data mentioned here matching palaeoclimate models based on isotope records, animal distribution and sedimentology.
So the Prince Creek palaeoenviroment wasn't exactly an ideal holiday spot, but was it 'extreme' enough to promote the evolution of an fuzzy coat in a 1.5-2 tonne dinosaur species? Given the dense furs we see in large mammals found in similar climates, I think it's certainly a possibility. It would certainly be far weirder if polar dinosaurs of the Late Cretaceous didn't respond to their climate somehow, and a thick coat of protofeathers is one possible adaptation to their cool, wet habitat. A layer of insulating fat would be another (cue an image of some tubby pachyrhinosaurs). Of course, the picture may be different if these animals hibernated or migrated in and out of Alaska annually, enjoying the brief mild period before heading south to escape the winter. The latter is perhaps the most widely discussed concept, but direct evidence for such migrations in Alaskan dinosaurs is as sparse as evidence for their fluffy integuments or fat layers. In the concept proposed here, the protofeather coat may have acted as an insulator against the cold, prevented wind, rain and snow from hitting the naked skin of the animal, or both. The latter function would benefit from the coat being thick and fluffy, but this may not have lead to overheating even in a big animal like Pachyrhinosaurus: the ragged, loose coats of hot-climate adapted ratites appear similarly thick and massive without overheating their owners. Perhaps the concept of shaggy coats in these Alaskan dinosaurs doesn't seem so as implausible as it may first appear, then.
To bring this more-mammoth-than-intended essay to a close, then, I again stress that I'm not saying 'this is what Pachyrhinosaurus looked like!', but attempting to present it as a product of both its phylogenetic history, its environment and habits, and not simply reconstructed via a cladogram. I think there's a lot of scope for these sorts of palaeoartistic renditions, even it does mean more reliance on the 'informed speculation' principle of All Yesterdays. Of course, this whole argument flows back to the core idea behind the All Yesterdays movement: the conservative, 'One Skin Fits All' approach to integument reconstruction is just as likely to be wrong as our more speculative concepts, but at least the use of informed speculation lines the reconstruction up with our knowledge of modern animal diversity.
Most importantly, the markwitton.com|storeTM designers want to know what you want. The new store, while hot and sensuous, is still in its early stages, and needs more merchandise. But like all good lovers, we want to give you what you desire most. If you think a piece of artwork from markwitton.com, its sister blog, or archived Flickr gallery would look good on a sexy, sensuous t-shirt, tea towl, coaster set or another piece of merchandise, you need to contact us at firstname.lastname@example.org to let us know, and we'll make it just for you*. Genuine requests only please: asking for an item is not an obligation to buy, but please don't request items if you have no intention to purchase them should their design please you.
*And then leave it for sale for anyone else who may like it. But it's you, our special you, that we're thinking of with each sale.
Finally, a brief word on prices. As with any on-demand product, the basic costs for items from the markwitton.com|store are higher than anyone might like, but rest assured that only minimal royalties are being taken: no more than 10% of item cost in the vast majority of cases. Customers outside of the USATM should also bear in mind that the markwitton.com|storeTM ships from the Zazzle warehouse in California, so adjust expectations for postage costs and delivery times accordingly.
Now stop reading this and get shopping, you crazy, sexyTM readersTM you.
I figured that the internet would be awash with palaeoart of Oryctodromeus cubicularis, the small, Blackleaf Formation hypsilophodontid famous for living in family groups within burrows of their own creation (Varricchio et al. 2007). A quick Google image search, thought I, would reveal dozens of images of Oryctodromeus sitting in dens, digging, hanging out in family groups and all that sort of stuff. I was even expecting to make some sharp comments about minor clichés and tropes in the way Oryctodromeus was depicted. Turns out, however, that there aren't many pictures of this dinosaur at all. On reflection, I guess I Oryctodromeus doesn't meet the three Big Criteria for Palaeoartistic Attention: a) it doesn't really have anything to do with bird evolution; b) it doesn't bear any fancy teeth, claws or spikes and c) it wasn't very big. But I still think this is crazy. It was found in a fickin' burrow of its own making. Palaeonerds, artistic and otherwise, spend hours speculating about what sort of interesting behaviour dinosaurs may have got up to, and then one with incontrovertible interesting behaviour is discovered and... we - myself included - don't do much with it, really. Even the PR associated with its discovery favoured a straightforward illustration of an Oryctodromeus head rather than something more exciting, like a depiction of one digging a hole or drowning in its burrow. How odd.
With that in mind, here's a set of Oryctodromeus to help their much needed PR campaign. Rather than showing an Oryctodromeus burrow in section, as is common to the few depictions of this animal that exist, I wanted to draw them as we may see them in life, hanging out at their burrow entrance in a Lower Cretaceous woodland. The burrowing adaptations of the animals, which are clear and obvious across much of the Oryctodromeus skeleton, are not really discernible here, save for their broad, shovelling snouts which I've adorned with thickened scales to resist shovelling abrasion. This is deliberate, however. Much of the burrowing anatomy of Oryctodromeus reflects relatively minor changes to the hypsilophodontid bauplan and they probably didn't look radically different from other hypsilophodontids with their skin and (possibly) fuzz obscuring their skeletons. In addition to their reinforced snouts, we may have noticed that Oryctodromeus had slightly bulkier forelimb anatomy compared to other hypsilophodontids, as these seem to have been their digging limbs (instead of the hindlimbs, as with the rhynchosaurs we met here). Their hindquarters may also have been a little chunkier, as they seem reinforced to provide a stable digging platform. Otherwise, they probably looked much like other members of their clan. Indeed, the overall similarity of Oryctodromeus to other hypsilophodontids suggested to Varricchio et al. (2007) that burrowing behaviours may not be unique to this member of the group.
Much was made of the assemblage of bones found within the Blackleaf Oryctodromeus burrow. The incomplete skeletons, presumably reflecting animals that died within a burrow shortly before or during a flood, represent two juvenile and one adult individual, and additional discoveries of this species (sadly, not in burrows) hint at even larger Oryctodromeus communities of mixed maturity (Krumenacker et al. 2011). I wanted to bring this out in the painting, so have drawn an entire family, with two adults and two juveniles perched atop the head of one parent (did dinosaurs carry their children? Perhaps, seeing as many reptiles and mammals ferry their offspring about when they're especially small). I realised that I'd accidentally made the adults rather different in size rather late in painting the image, but I decided to run with this mistake rather than correct it. First thoughts may be that this could be written off as sexual dimorphism, but I thought it may be better explained though another means: teenage mothers. The early development of reproductive bone histologies in dinosaurs suggests that they, like reptiles, became sexually mature well before they reached their maximum size (generally, no later than halfway to their maximum proportions - Lee and Werning 2008) so it doesn't seem unlikely that some dinosaur couples would be rather mismatched in terms of size if young and old formed breeding partnerships.
|Details of an Oryctodromeus burrow; from Varricchio et al. 2007|
Finally, and on a related note: it seems I've fallen victim to a most foul palaeoart clichés: A Volcano! Behind Dinosaurs!!1! Volcanoes and dinosaurs seem to walk hand-in-hand in some circles, and the dinosaur imagery I was familiar with in my childhood always seemed to have a volcano bubbling away in the background. It seems that the association of angry mountains and dinosaurs is more of a 'popular' notion than a real palaeoart meme however, presumably because most people with genuine interests in palaeontology and geology know that Mesozoic landscapes were not perpetually exploding. I suppose the popular link between volcanoes and dinosaurs stems from ideas that non-avian dinosaur extinction was likely influenced by the extensive volcanism of the Deccan Traps. Or maybe it's because dinosaur fossils are intertwined with geology, of which volcanoes are the flagship popular topic. Or maybe it's simply pandering to the Lava Adds Awesome and Climatic Volcano Backdrop tropes. Whatever the reason for their prevalence in popular palaeoart, the inclusion of a volcano alongside Oryctodromeus is fairly sound: the Blackleaf Oryctodromeus burrow was made in a landscape that was occasionally inundated by volcanic detritus and tuffaceous sediments, blown in from volcanism occurring to the south west in contemporary Idaho. I'm not sure whether the types of volcano shown here - a classic 'cone' volcano - is appropriate, but the temptation to draw a big mountain belching smoke behind some dinosaurs was too much to resist.
Oh, and finally finally, a big thanks to all the people who've stopped by here thus far before I go. This blog is not even two months old, and I've already been visited over 5,500 times. It's very encouraging and flattering to have this taking off so quickly, so thanks for all the visits, comments and linking that must be happening to make this a minor success already.
For the moment at least, you can order the book for an extremely reasonable £19.46 at Amazon.co.uk but, even at its most expensive, you won't have to pay more than £24.95 ($35.00 for US buyers). For that tiny sum, you'll get a large, snazzy hardback tome featuring over 200 illustrations, 152 colour illustrations of which are in colour, almost 300 pages and something like 110,000 words, referencing over 500 peer-reviewed articles, of pterosaur goodness (further details). Alas, there's still a little waiting to be done before the book reaches your hands. Pterosaurs will finally be published at the end of June, with preorders being delivered on June 23rd of this year. I'm giving serious thought to having some sort of book launch around that time with talks and, possibly, a book signing.
|A perfectly cromulent image of Nyctosaurus, cover star. Click to embiggen.|
And finally, my PR agent won't let me go without mentioning that, if you're planning on being an über Pterosaurs fanboy, there's a whole bunch of merchandise featuring this image over at my Zazzle store, which you can buy now to wear and drink from when the book arrives. People will probably think this makes you sad or something, but they'll be wrong.
tyrannosaurs and ceratopsids, have been drawn to death by generations of palaeoartists eager to capture their freakishly weird anatomy, but they don't seem to be quite the mainstay of dinosaur pop culture that they used to be. I could be wrong, but it seems that other dinosaur taxa, primarily feathery, near-birdy things, have take a share of the stegosaur limelight. Perhaps stegosaurs, and particularly Stegosaurus, are just a so familiar now that we've become a bit blasé about them. I know I certainly have, so I've not sketched or painted one in years. It was only in revisiting them for this piece that it struck me how freakin' weird stegosaurs are, even in this world of therizinosaurs, mononykosaurs and four-winged microraptors. The front of their bodies clearly belong to relatively small or medium-sized animals, but evolution thought it would be fun to bolt them hindquarters borrowed from an large elephant or small sauropod. Supporting the dainty head and neck is a set of seemingly well-engineered but overly-short forelimbs, which force their spinal columns into high, curving arches to span the height discrepancy between each limb set. And then there's the osteoderms, shaped into broad plates or spikes, which sit along their backs and may turn the distal end of the tail into a morning star. Stegosaurs make feathery maniraptorans look positively boring.
For this painting, I wanted to show a stegosaur - specifically the Upper Jurassic Morrison Formation species Stegosaurus stenops - with some real character, looking like it had lived a hard life in an unforgiving climate and surrounded by extreme and frequently dangerous animals. For this reason, I chose a rarely depicted, more or less head on aspect for the painting, thus bringing its tiny head to the fore, allowing us to see its face without forgetting that the body behind it was large and powerful. I imagine that standing next to a big stegosaurs should be like standing next to any big, unfamiliar animal. It may not eat you, but the feeling that we're a small, inferior species, and that the 6 tonne animal next to us has absolute right of way, will never disappear. There also seemed to be a lot that could be done with its appearance. Stegosaurus was a large enough animal that they were probably fairly long-lived, and would accumulate decades of wear-and-tear on their hides. Thus, I depicted his very imperfect skin with an extremely washed-out but high contrast colour scheme, in efforts to enhance his battered appearance. Fossil evidence also came into play with creating a history for this animal, as we have good evidence that stegosaur osteoderms were occasionally subject to extreme damage in life, perhaps because they were bitten by predators or, in the case of their defensive tail spines, winged into the side of assailants with enough force to break their tips (Carpenter et al. 2005). With this in mind, my stegosaur has a number of broken plates along its back, this animal having seen off its fair share of aggressors. At one point, he was also going to be depicted drooling long strands of spittle through heat-stress, but the effect wasn't quite in keeping with his posture, so I took a napkin to his beak and tidied him up (see detail, below).
I also thought it might be fun to play with the scaly depiction of stegosaurs a bit, decking the thagomizer out with a set of long, bright filaments. Excellent skin impressions from Morrison stegosaurs (possibly even from Stegosaurus itself, if the assessment of stegosaur taxonomy by Maidment et al.  is correct) reveal that their bodies were covered, probably mostly, in typically archosaurian pebbly scales (Christiansen and Tschopp 2010). This integument is exactly what we would expect from a large ornithischian in a warm climate. As with many dinosaurs, their scales are of variable size across the body, with long rows of large (20 mm wide) scales stretching across the dorsal regions and smaller scales lining the belly (see image, below). By analogy with modern 'naked' mammals however, I wondered if some scaly dinosaurs would retain small regions of fuzziness from their ancestors for specific functions. The bushy tails, ear tufts and eyelashes of naked mammals are good analogues here. In this case, my stegosaur's thagomizer isn't bristly to swat flies as are the hairy tail tips of mammals, but to advertise its bristling spikes to marauding predators, and make them think twice about attempting an attack. Further analogy can be made here with the striking colours of many poisonous or otherwise well defended animals: camouflage is thrown to the wind in favour of making themselves unmistakeable to predators, letting them know to think twice about attacking them. Additional uses for fuzzy thagomizers may be sociosexual display, dusting hard to reach shelves and corners or, perhaps for defensively tickling they way out of hairy situations (hat tip to Spike Ekins and Simon Clabby for the latter).
|Stegosaur skin impressions, probably from Stegosaurus, from Christiansen and Tschopp (2010). Top, belly scales, bottom, large scale surrounded by smaller, satellite scales. Scale bars represent 20 mm (top) and 10 mm (bottom).|
Right, that's a reasonably concise post for these parts, and will have to do for now: I need to get going with a big palaeoart project that will, coincidentally, also require some consideration of ornithodiran eyelashes. If I'm allowed, there may even be some bits of it being posted here before any of us are too much older.
|Cock of the slight awkward walk: Ornithocheirus. mesembrinus out for a stroll, possibly trying to accentuate it's bottom. Perhaps it works out.|
|Two cowardly Anhanguera santanae, being cowardly.|
Back in 2010, when I was employed in building a series of giant pterosaur models for the University of Portsmouth and Royal Society, I painted the above image of several giant azhdarchids in flight for use on our display boards and advertising work (bonus sauropods can be seen playing in the water below the pterosaurs). The azhdarchids are meant to be a fairly close match for our models, and specifically the giant, 10 m wingspan jobby we suspended between Royal Festival hall and the neighbouring buildings:
|Our 2010 exhibition, with BigQuetz at the topright. Two smaller giants follow behind it, with the giant Bamofo looking on. Pterosaur worker Michael O'Sullivan can be seen in the bottom left.|
|BigQuetz in all its 10 m span glory|
|The BigQuetz body and wing frame, with pterosaur workers for scale (I'm on the left, Dave Martill is on the right)|
Sadly, that very day arrived at the turn of this year, when University of Portsmouth staff found the BiqQuetz head had been smashed in by unknown individuals (sadly, I don't have any photos to show of this). It seemed that the damage was well beyond repair, and the BigQuetz story was brought to a close when the model was chopped up and disposed of. It's a terrific shame that our model should meet such an inauspicious end, and particularly stings because I personally experienced the many hours of work that were poured into its creation, often by volunteers, and know of the craftsmanship that went into its production, particularly on its aluminium frame. Plus, I find it hard to rationalise its demise being caused by anything other than a stupid stunt pulled by bored delinquents, seeing as its location on campus was not conducive to being accidentally damaged by university staff. Some consolation can be found in the fact that our other models have found homes elsewhere, and are hopefully being looked after, but it still seems a tremendous waste. Hey ho. RIP BigQuetz, we hardly knew ye. Or whatever people say about this sort of thing.
One of the most effective movies I've seen in recent years is the 2007 science fiction siege thriller, The Mist, which isn't to be confused with the considerably more forgettable eighties pirate horror outing, The Fog (which has one of the most long-winded and least suspenseful trailers ever). Like all good stories, the plot of The Mist is dead simple, with a mysterious, creature-filled
One of the best things about The Mist is that Frank Darabont, it's director, knew exactly what to do with his monsters, in that he shows as little of them as possible. Instead, most species (and there are many) are glimpsed in silhouette at the far reaches of the
The handling of the creatures in The Mist got me thinking about how bizarre, and perhaps how terrifying, the silhouettes of barely-glimpsed creatures in the Mesozoic may have looked on misty, drizzly days. It's not hard to think of a number of Mesozoic animals that would look downright weird when glimpsed through thick fog, but the outlandish proportions of giant azhdarchid pterosaurs, with their long necks and limbs, oversize heads and small bodies, make them unlikely animals at the best of times and truly strange when only seen in outline. The lightweight frames and long limbs of these animals would probably make them lithe and quick over land, and it's not hard to imagine these enormous carnivores giving many Mesozoic animals the hebbie-jebbies as they stalked silently across Cretaceous landscapes. And not just little animals, either: prey of human dimensions may also have been alarmed by a stealthy, fog-strewn azhdarchid.
With this in mind, I've been slowly adding to the painting above for the last few weeks in a very piecemeal, 5-minute burst fashion. It's a deliberately basic image with a limited colour palate and detail, which came from both a desire to attempt something a bit different with my art and enhance the dreary atmosphere. The intention was to make the pterosaur in the background looming and menacing, all but invisible in the dismal weather save for its treetop-scraping silhouette. The small azhdarchid in the foreground, who's giving its big relative an understandably wide berth, serves to add scale, as does the rotting log in the foreground. The taxa here are not meant to be any azhdarchids in particular, but this scene could take place in several places around the Late Cretaceous world. As pointed out by Matyas Vremir et al. (2013), several azhdarchid-bearing deposits yield azhdarchid species of vastly contrasting size, suggesting giants and diminutive species frequently lived alongside one another (see summary image, below, of cohabiting azhdarchids of distinct size, from Vremir et al. , featuring Ron Blakey's fantastic latest Cretaceous palaeomap (Colorado Plateau Geosystems, Inc.), and my handiwork. The image features a new skull reconstruction of Quetzalcoatlus sp., which offers a sneaky peak into some of the imagery used in my book). The scant record we have of these cohabiting species indicates that at least some bore distinct jaw and skull proportions, suggesting different dietary preferences and habits which would prevent them stepping on each other's ecological toes.
|Some geological units reveal evidence of two or even three sympatric azhdarchid species. Diagram produced by Mark Witton and map used with kind permission of Ron Blakey, Colorado Plateau Geosystems, Inc; from Vremir et al. (2013).|
The reaction to a very detailed commission, development of the minimalist theme of my misty azhdarchid painting and an overindulgence in Prodigy tracks has lead to the above, a monochromatic Dsungaripterus weii striding its way through a Cretaceous swamp in what will become China's Junggar Basin. Some readers may note more than a passing resemblance between the style of this and the artwork of Frank Miller's Sin City graphic novels, and I can't deny their obvious influence on this work. In keeping with their noirish aspects, I wanted this painting to be a little edgy and dark, but not overtly violent or gruesome. I figured a skull-like motif was a good place to start, with the chunky dentition of Dsungaripterus continued across the posterior skull region with a fleshy structure meant to recall a Glasgow smile (fascinating Dsungaripterus fact to share this evening at dinner: the teeth are actually fully overgrown by the jaw bones in adult individuals. Check out the posterior teeth in IVPP 64043-3, a Dsungaripterus skull and mandible described by Young , for an example, below. Image from Witton 2013.) The eye region is also deliberately socket-like. If you think the face of this thing is slightly creepy, I've succeeded.
The nastiness continues with the limp body of a baby pterosaur seen dangling from the Dsungaripterus jaw tips. This chap is loosely based on Nemicolopterus, a small pterosaur from China's Cretaceous Jiufotang Formation that is almost certainly a baby Sinopterus (of course, I'm not the first to say this and won't elaborate more here, but do go into more detail on this issue my book). Dsungaripterids are not normally shown with vertebrate prey, as their edentulous jaw tips and large, blunt posterior teeth are generally seen as evidence for a diet largely comprised of shellfish (e.g. Wellnhofer 1991; Unwin 2005; Witton 2013). I don't disagree with this assessment, and further evidence for shell crushing may stem from the rarely-discussed knobbly palatal ridge found in Dsungaripterus, which projects prominently along its palatal midline at the back of the jaw. To my knowledge, similarly robust and prominent ridges are not present in any other pterosaurs, despite considerable variation in palatal structure across the group, and I wonder if they provided an additional crushing surface within the jaws. But, while their powerful jaws and teeth would undoubtedly make short work of clams and snails gleaned from lakes and ponds, I doubt these powerful pterosaurs would turn their noses up at baby pterosaurs and other small tetrapods if they could catch them. And besides, a little bit of infanticide also seems entirely in keeping with the noir overtones of this image.
As a bonus extra for this post, here's an inverted version of the above painting, shifting the setting from a cloudy night to the middle of the day. I was flicking the colours of the painting constantly when working on it, and couldn't really decide which version I liked most. I think the black version just edges it, but it's a close contest.
And as an additional bonus extra, here's a Warhol-inspired portrait run of our murderous friend, just for fun.
That's it for now, then. I'm off to lament not choosing the dsungaripterid Noripterus as the subject for this post, because of the NOIRipterus jokes I could have made in the title. D'oh.
After last week's moody Dsungaripterus, here's a stylistically similar image with a pair of tyrannosaurs. This was thrown together quickly yesterday following a numbing Powerpoint preparation marathon, so please excuse any inaccuracies. My intention was to make each animal look distinctive despite the monochromatic colour scheme and their morphological similarity, and think it's been fairly successful. It's already been suggested that they need names, so they must look like distinct individuals. Suggestions for names are welcome, but they must be better than 'Speckles'. That shouldn't be hard.
I've been having a whale of a time with this concept and have received a lot of positive feedback from chums and Facebook friends. So much so, in fact, that I'm starting to give serious thought to putting them to use in a more substantial project. Still, no time for that now: best get back to something that will actually pay the bills.
For more tyrannosaur goodness, and some colour, head here.
Sadly, I've been too busy this week to synchronise posting of the image above with the wave of publicity now surrounding Vectidraco daisymorrisae, the new diminutive Isle of Wight azhdarchoid recently described by Darren Naish and colleagues (2013). The story of the Vectidraco discovery by little Daisy Morris is becoming well known thanks to a storm of media interest, so I won't repeat the details here. Instead, I'm showcasing the press release image I drew up for the Vectidraco launch, shown here in its full, uncropped form rather than the smaller version currently doing the rounds in news outlets (below). I should stress, of course, that the animal is only known from a sacrum, so much of what you see here is extrapolated from other azhdarchoids. Because we cannot tell what sort of azhdarchoid Vectidraco is from a pelvis alone, I rendered an animal that attempts to pander to all non-azhdarchid azhdarchoid clades. The obvious influence on its colouration is the European magpie, a deliberate choice to make the animal look convincing to eyes unaccustomed to pterosaurs. Some reconstructions of extinct animals try to play up the more unusual or horrific parts of their anatomy to produce monstrous and grotesque species (sometimes even against overwhelming fossil evidence to the contrary: for shame, Jurassic Park 4 director Colin Trevorrow), but I wanted this one to look like it was a regular animal, one that could even be considered unremarkable if part of our modern fauna. This wasn't an effort to downplay the importance of the discovery of course, but instead an effort to make the reconstruction appear more convincing. I think this is also one of the first pterosaur reconstructions to show iridescent pycnofibres.
The reason for compositing the pterosaur at the top of the full image stems from the use of the painting as a cover image for the upcoming book by Martin Simpson, Daisy and the Isle of Wight Dragon. The book covers the story of Daisy's discovery of the Vectidraco holotype, and is fully illustrated by myself and two other illustrators. I have 9 images in the book, including the following painting of the holotype specimen, NHMUK PV R36621 (below). I'm quite new to painting fossils, rather than fossil animals, but am quite pleased with how this turned out. The book should be available soon from Martin's website and Amazon, and will only set you back £5. Purchasing links will be posted once they are available, perhaps with more of my illustrative contributions. In the meantime, like the Daisy and the Isle of Wight Dragon Facebook page for more immediate updates.
No surprise about what this post will cover: the announcement by Jurassic Park IV director Colin Trevorrow that his new JP instalment will not feature feathered dinosaurs (unlike the new image, above, which features a fully feathered Dromaeosaurus raiding a giant azhdarchid nest). Like many folks in the palaeoblogsphere, my reaction to this hasn't been particularly positive. It seems like an overlooked opportunity to bring the dinosaur-bird themes of the first movie full circle, jars with overwhelming evidence that some JP dinosaur stars were feathered, and misses an terrific chance to affirm modern concepts of dinosaur palaeobiology with a wide audience. The JP franchise would also probably benefit more from featuring feathery species than it will from maintaining its flimsy creature design continuity (see Laelaps for more on this) as the series clearly needs some fresh ideas and content. It hasn't really delivered much else than people being chased by dinosaurs since the one hour mark of the first film, and a certain amount of repetition has set in ("Oh, look, they're running away from a large predatory dinosaur. Oh, look, they're running away from smaller predatory dinosaurs. Oh, look, one dinosaur is fighting another dinosaur. Oh, look, it's a sweeping shot of peaceful dinosaurs", etc.). The introduction of feathers could provide some nuances to the JP story and provide a new edge for its overly familiar creatures. Beyond this, as someone with an interest in science education, I find broader concepts to be upset about as well here. Feathering dinosaurs in JP IV would demonstrate the incremental processes through which science works, highlighting the way in which the dromaeosaurs of the series became progressively more feathered as the dinosaur bird link was cemented by mounting evidence*. There's obvious utility with this movie being a basis for teaching concepts of evolution, too. And yes yes yes, I know this movie isn't being made to educate people, but I genuinely think featuring feathered designs would be of advantage to many.
*Before anyone mentions it, I know the JP franchise didn't leap on the feather bandwagon quick enough, but it's one of the few major areas of common knowledge of dinosaurs, and provides a good focal point for educating laymen or children about these topics.
There's a truckload of things we could talk about concerning the lack of feathers in JP IV, but I don't want to focus on that here. Instead, I want to highlight one point that troubles me with all this discussion and outrage. This whole episode was started by Colin Trevorrow tweeting only two words: "no feathers" (well, three, if you include the '#JP4' bit). As others have noted, that doesn't really tell us much about the plot, the species under discussion or anything else. This has got me wondering how much of the film has actually been set into place yet. To my knowledge, Trevorrow has only been at the helm of JP IV for a couple of weeks, and the movie is still in pre-production. No casting details have been announced, no shooting schedule, no sneak-peaks of the plot. So are Universal Studios, the JP franchise wranglers, playing their cards close to their chest, or is much about the movie may still up in the air? If the latter is true (and it may not be: I'm not claiming any insider knowledge, just that I pay attention to movie news), I'm wondering if the glib 'no feathers' tweet was simply put out there to test the waters. See what the reaction was from JP fanboys and other demographics to see if they should keep their dinosaurs canonical or give them a much needed update. The movie isn't destined for release until June 2014 - perhaps that's enough time to design and implement feathery integuments to their dinosaurs? Note that I don't know much about VFX in movies, so I could be talking out of my bottom on this. That said, movie release dates change all the time, so the projected release may not mean much at this early stage.
If the feathers comment is a cheeky PR exercise for this franchise, it's in good company. Universal Studios have made repeated attempts to reignite interest in the JP franchise over the last few years. We had the core of the franchise, the first movie, back in cinemas in 2011 to coincide with the JP Blu-ray launch. The same film is returning to the big screen again this year, this time in 3D. We saw the first licensed Jurassic Park video game for 8 years in 2011. Concept art for the aborted JP IV dinosaur-man movie was revealed late last year. That in itself seems pretty unusual to me. There must be piles of discarded movie concept art in Hollywood which never sees public eyes, and creature design imagery is typically owned by movie studios. Heck of a coincidence if that just happened to slip onto the internet as rumours of a new JP film are circulating. Even if the latter was coincidental, we've had a lot of JP events in a short space of time, and only one of them coincides with a sensible franchise anniversary (this year's 3D Jurassic Park release, for the 20th anniversary of the original movie). Seems to me that Universal really, really want to remind us that Jurassic Park exists, perhaps because well over a decade has passed since the last chapter of the story. Generating discussion about whether the next instalment should feature feathered dinosaurs is an excellent way to get some free PR for the upcoming movie as well as, possibly, testing reaction to realistically feathered dinosaur species.
Of course, this may all be the wailing, cynical conspiracy theory of a madman. Time will tell, I suppose. In the mean time, I'd best get back to other things.
Daisy and the Isle of Wight Dragon, which I co-illustrated, direct from Amazon for a mere £5. To celebrate, here's an vaguely Easter-themed illustration I contributed to the book, depicting a Vectidraco hatching from a typically soft-shelled pterosaur egg. I'm sure hatchling pterosaurs would be adorable little urchins that we'd feature in innumerable YouTube videos if they were alive today, but perhaps only once they'd dried out from hatching. Like freshly-emergent bird chicks, baby pterosaurs were probably initially covered in goopy, matted integuments and would look pretty skanky (as in the image above, then). For the nerdy among you, I used the hatching body mass regressions detailed in Lü et al. (2011) to work out the likely mass of a Vectidraco hatchling to get an idea of its size and proportions. The reported wingspan estimate for an adult Vectidraco by Naish et al. (2013) is 0.75 m, which translates to a freshly-laid egg mass of 10 g, an egg mass of 16.25 g at the end of the incubation period, and a hatchling mass of 7.25 g. To put that into perspective, Vectidraco hatchlings would have tiny wingspans of 18-19 cm, and would probably neatly fit inside your loosely-closed hand.
The second bit of good news is that Princeton University Press and I have been putting our heads together to plan some launch events for my own book, Pterosaurs (preorders being taken here). They're still at very early stages and we cannot say anything concrete about them yet, but there are plans to bring some leathery-winged goodness to the Internet, and parts of the UK, this July. Further updates as they come in. Enjoy the Easter weekend, all!