Dino highlights of 2015

The past year has witnessed some remarkable new discoveries that have provided some amazing advances in our understanding of dinosaur biology and evolution. What follows is a list of the five papers that I found most interesting and/or useful in 2015 (modesty prevents me from including my own papers, of course). There may be some surprises here as, unlike some of my colleagues, I don't always find the latest new species announcements all that interesting - I tend to prefer conceptual papers that have a longer-term impact, rather than those new finds that grab short-term media attention. So, with that in mind, here are my top reads (in no particular order):

1. Chilesaurus diegosuarezi

Reconstructions of Chilesaurus (image from http://www.vocativ.com/culture/science/chilesaurus-new-dinosaur/ courtesy of Gabriel Lío)

Although I'm primarily an ornithischian and sauropodomorph worker, this was -the- stand-out new species of 2015 in my opinion. A truly bizarre herbivorous theropod from the Late Jurassic of Chile, this animal has features of several distantly related dinosaur groups combined into one body. I was lucky enough to see the material before it was named, when visiting Argentina in 2013 and my host, Fernando Novas, teased me by showing me the specimen one bone at time. He showed me teeth and ankle bones that looked like those of a prosauropod, then vertebrae like those of a theropod. After I'd congratulated him on an interesting new fauna, he grinned and revealed that he'd been showing me bones from a single associated skeleton. Fernando and his team happily admit they're not particularly comfortable with Chilesaurus as a basal tetanuran, but regard this as the current best fit for the data that they have. My hunch is that Chilesaurus will eventually occupy a more derived position within Theropoda, but there are a lot of strange, primitive features in the skeleton. It will be interesting to see where Chilesaurus eventually comes to rest in the dinosaur tree.

2. Age of the Chañares Formation

The study of dinosaur origins has been re-invigorated in the past decade by the discovery and re-analysis of many Middle and Late Triassic taxa, as well as the recognition of a whole new clade of dinosaur relatives, the silesaurids. However, understanding the anatomy and relationships of these animals is only part of the story. Most of our knowledge of the earilest relatives of dinosaurs - including lagosuchids and silesaurids - comes from only two places in the world, the Chañares Formation of Argentina and the Manda Beds of Tanzania. Both of these formations have been widely regarded as Middle Triassic in age and this date has been used to constrain the timing of dinosaur origins. However, new work on the age of the Chañares Formation, by Claudia Marsicano and colleagues, used radioisotopic dates derived from tiny zircon crystals within the sediment to check this assumption. The new dates obtained by their team suggest instead that this classic 'Middle' Triassic locality is actually Late Triassic in age and, as a result, that the origin of dinosaurs may have taken place in a geological instant (a few million years), rather than over the more protracted timescale that's currently envisaged. Other teams around the world are now planning similar analyses of the sediments from various Middle and Late Triassic localities to see how good our assumptions over their absolute ages really are.

3. The interrelationships of ornithischian dinosaurs

A major new study by my colleague Clint Boyd has assembled one of the largest ornithischian phylogenies ever attempted. This paper includes a wealth of new character data and represents the first real advance in the area since the earlier efforts of Richard Butler, published back in 2008. Although some individual ornithischian clades have received abundant attention, the overall pattern of ornithischian evolution has been surprisingly neglected. Clint's work offers some new hypotheses on the relationships of major ornithischian lineages that have not been previously proposed (such as the exclusion of parksosaurs from Cerapoda) and also gives an interesting, robust framework for the first rigorous palaeobiogeographic study of ornithischians. Lots to digest here and this paper is likely to be influential for many years to come.

Clint's new phylogeny (Figure 2 in his PeerJ article) - some interesting surprises lurk within.

4. Discovery of dinosaur blood cells

Several research groups around the world have been pushing at the envelope of what's possible regarding fossil preservation. These have included the discoveries of dinosaur muscle fibres, feathers, possible melanosomes (and their implications for dinosaur colour), and even the potential for biomolecular preservation. However, in almost all of these cases (the majority of which are fairly controversial, with more debate among specialists than media coverage suggests) the localities producing these exceptional structures are themselves exceptional - sites known as Konservat Lagerstätte, which have unusual geological characteristics that enable these types of preservation. However, Sergio Bertazzo and Susannah Maidment have provided convincing evidence of microscopic structures (blood cells, collagen fibres) in dinosaur bones from localities where such high-fidelity preservation was previously thought to be impossible. Their work suggests that there may be enormous future potential for studying even poorly preserved dinosaur material in much greater depth than ever imagined previously.

5. Phylogeny of the diplodocid sauropods

This paper truly wins the award for effort – a monumental specimen-by-specimen analysis of diplodocoid sauropods that formed part of Emanuel Tschopp's PhD dissertation.  Although this study gained media notoriety for resurrecting the name Brontosaurus (a conclusion that's being hotly debated, but which I have to admit some sympathy for), it's much more important than that. It provides an extensively documented set of new character data for these dinosaurs and is one of only a handful of phylogeny papers that really attempts to document and describe its characters for the reader. In addition, it is the only comprehensive evolutionary study of this bizarrre dinosaur clade and offers many new insights into the evolution of the diplodocoid body plan. This one will be a citation classic for sure.

There were many other insightful and interesting dinosaur papers in 2015, too numerous to mention here, and I look forward to what will surely be another busy year in 2016. Happy New Year everyone!

2015: a year of highs and some pretty deep lows ...

Well, it's been a long time since I've posted here and I thought it was about time that I came out of blogging torpor. The end of the year is approaching rapidly and, like many people, I've been taking stock of the past 12 months - one of my most difficult years professionally (and personally) and one that I will not be sorry to see torn from the calendar. Let's not beat around the bush - 2015 felt like my least productive year, at least in terms of research, in a long time. This was due to a combination of factors - partly work-related and partly life-related - and these summed together to mould  a year that's been frustrating and challenging, though not without it's high points too.

So why was it so bad? Well, most obviously, I had a minor accident that led to my hospitalisation from a ruptured spleen back in May (never great to lie squirming in agony on your office floor before being whisked to hospital by ambulance for internal bleeding of unknown origin). Although the rupture turned out to be minor, and I was only in hospital for a few days, the subsequent complications hit me hard and I had three months of pain and discomfort that literally slowed me down to a crawl and effectively took out the middle part of the year. This coupled with lots of work-related travel and various family-related issues (such as my mother's major heart surgery) also contributed to the stress. Finally, I found myself more in demand than ever before by the public and corporate sides of the NHM meaning that any meaningful space for research time was extremely limited. Sigh. However, there have been some highlights too. Although most of 2015 has felt like running through treacle, at least some of the work I've been involved with has come to fruition and raised a much needed smile.

The year began in full Sophie the Stegosaurus mode - dealing with public events in the wake of the exhibition launch (December 2014) and also starting to progress some of the scientific outputs stemming from the acquisition. The first of these to appear was our study of Sophie's body mass ably led by Charlotte Brassey, my research assistant on the project. Although Charlotte was to leave my lab early in the year following the end of her appointment, a sad loss for the museum, we've continued working on Sophie along with Susie Maidment and the second paper - a monographic treatment of Sophie's postcranial anatomy - also came out during the year, following a huge amount of detailed work on the specimen. Other papers on Sophie (notably jaw mechanics and limb mechanics) are currently in the works and there are still a few more projects that we aim to carry out on the specimen before we're finished. I also wrote the text for a popular science book on Sophie that the NHM should be publishing sometime in 2016 ...

It was also good to see movement on our NERC-funded fossil turtle project with our first paper showing a close link between Cretaceous climate and turtle distribution, thanks to some nice data analysis by my postdoc David Nicholson, with lots of help from my colleagues Patricia Holroyd and Roger Benson. Now the data is all there and the methods worked out there should be a lot more on this to come over the final year of the grant. Several other longish-term projects also came to a close this year, including a major re-description of the skull of Lesothosaurus, led by Laura Porro and done collaboratively with Larry Witmer. A long-standing editorial task ended this year, with the acceptance of all of the papers for the A. S. Woodward Symposium volume, which is now published online and will appear in print in the next few months, a real achievement for all concerned.

Some new big projects kicked off - notably an effort to finish publishing on the Middle Triassic Manda Beds archosaur material from Tanzania held at the NHM, which led to some fun visits by Sterling Nesbitt and Richard Butler. Hopefully we'll be able to tell the world something sensible about both Mandasuchus and Teleocrater before too long.

My PhD students have all had an excellent year and hearing about their research and helping them push forward their own agendas has been good for my sanity. Was great to see two of them - Sam Bennett and David Button - finally become doctors in their own right and to see David move on to a post at the University of Birmingham. The rest of the group continue to make good progress, getting deeper and deeper in their respective areas: Simon Wills using isotopic analyses alongside his studies of taxonomy and sedimentology to understand British Middle Jurassic vertebrates; Amy Waterson building ever more sophisticated niche models for forams and turtles; Matt Baron pushing forward manuscripts on Lesothosaurus and building his basal dinosaur phylogeny; Terri Cleary starting to compile much needed data on fossil squamate diversity; Selina Groh assembling the largest character set for crocs I've ever seen; Paul Varotsis CT-scanning skulls of Dorsetisaurus to really investigate its anatomy; Serjoscha Evers gathering huge amounts of comparative data on the early evolution of sea turtles;  David Ford spotting potential new species among Permo-Triassic diapsids; and Omar Regalado-Fernandez building a massive sauropodomorph character matrix. All of these projects are likely to be heading to publications soon, so I envisage a lot of enjoyable reading crossing my desk in 2016. I've also welcomed another new student to the fold this year - Richard Fallon - who'll be doing something outside my comfort zone, but really neat - addressing the impact of early dinosaur discoveries on the popular consciousness of Victorian Britain.

Lots of travel this year too, with several trips to the USA, including the Tuscon Rock and Mineral Fair (January), SVP Executive Committee Meeting in Bethesda combined with a research trip to Cincinnati (May), and the SVP Annual Meeting (October) - the latter leading to the irritating theft of my laptop thanks to the incompetence of the TSA staff in Dallas. During my stay in Cincinnati, Glenn Storrs and I were able to push forward our work on the new ?Apatosaurus in the CMC, which hopefully we'll finally finish in the new year. An overnight trip to Berlin in late December allowed me to witness the unveiling of Tristan the Tyrannosaurus, which was an interesting night. However, by far the best trip was my three weeks in South Africa working with Jonah Choiniere, his students Kimi, Blair and Casey, and my students Matt and Simon. A week working in the collections on various Lesothosaurus and Massospondlyus related projects was followed by a much-needed fortnight in the field, working on the Early Jurassic exposures of the Upper Elliot Formation in the Free State, following a transect from Clarens to Ladybrand. We found several promising new localities for further work and lots of material - our papers on this will be appearing as soon as the specimens are prepared, though that is some months away yet. At some point I should write up an account of this trip, but that's a post for another time.

Other than Sophie, public outreach duties this year have included significant time working with BBC Radio 4 on two different series (Natural Histories and Natural History Heroes), in which I discussed dinosaurs and the life and times of Baron Nopcsa. Various TV-based dinosaur projects around the launch of Jurassic World also took time, though with fewer obvious effects - one of these didn't make it the screen due to licensing issues (though I had a fun day of playing working with iguanas, ostriches and lions at Chessington World of Adventures to make up for it). It's also likely that many people didn't know that I was heavily involved in helping Dean Lomax with ITV's Dinosaur Britain (I read numerous script drafts, advised on the CGI and was the official advisor), but I don't make it on to the screen as I was due to be filmed on the days I ended up in hospital: luckily Mike Benton and others expertly stood in for me at exceptionally short notice, with thanks to them for doing so. Another major push at public outreach was the completion of a new official NHM dinosaur book, which I co-authored with Darren Naish: Darren did most of the heavy lifting, however, and deserves the lion's share of the credit. This new title should hit the bookshelves in the next couple of months and will boast some new artworks by Bob Nicholls.

So, 2015 was a year of some interesting highs, but not without it's share of unpleasant lows. Here's looking forward to having a more research-friendly 2016 and wishing all of my friends and colleagues all the very best for a successful and happy New Year.






 

Farewell Dippy!

As many of you will have heard, the Natural History Museum (NHM) plans to renovate many of its public galleries over the next few years, starting with a major overhaul of the museum's most heavily used and best-loved space - Hintze Hall (formerly known as the Central Hall). The project is already well underway behind the scenes, with planning meetings, content development work and detailed investigations all underway with the aim of refreshing the content of this cathedral-like space. The NHM announced its intentions to the public early in 2015 and intends to complete the transformation by 2017. An artist's impression of the dramatic new vision was circulated with the press announcement, showing an impressive Blue Whale skeleton suspended from the ceiling, floating in mid-air. However, although the impact of the whale skeleton received a lot of attention following the announcement, more attention was paid to the fate of an object that was absent from the plans. Perhaps the most dramatic aspect of the new vision relates to the removal of one exhibit in particular: the NHM's iconic replica of Diplodocus carnegeii, affectionately known as Dippy. After  more than three decades of greeting visitors to Hintze Hall, Dippy will be moving on to pastures new in 2017.

Dippy was presented to the NHM in 1905 by the Scottish-American philanthropist Andrew Carnegie, following a request from King Edward VII. In its 110 years at the NHM, Dippy has moved around - from an original position in the now defunct marine reptile gallery to its current position in Hintze Hall. It's pose has changed, reflecting changes in our knowledge of Diplodocus, and it is arguably the NHM's best known and most photographed object. So, why does it have to go?*

Personally, I have a strong sentimental attachment to Dippy: after all, it was one of the displays I visited again and again as a child and a teenager and it was definitely one of the objects that nurtured my early interest in palaeontology. Moreover, my first scientific papers were on feeding in Diplodocus and since joining the NHM I have spent many hours talking about the specimen, both to the public, VIPs and on camera, and have written a book on the specimen's history and influence. However, even with of all this in mind, it may surprise many to know that I am not against the proposed change to Hintze Hall – and this is a personal view, not my loyal towing of the NHM's corporate line (although I do have a line to toe too, obviously).

My lack of objection can be summarised succinctly: Dippy is a replica. Although an impressive object, and a stunning exhibit that beautifully compliments the proportions of Hintze Hall, Dippy is neither authentic, nor unique. Indeed, copies of Dippy can be seen in museums from Argentina to Berlin, so although its status as the first of these replicas to be put on display has strong historical interest, there are plenty of other casts out there as well as the original skeleton in the Carnegie Museum, Pittsburgh. The NHM has had a recent change of ethos, which is just starting to be implemented, to replace replicas and models in its galleries with real specimens wherever possible, to allow the public to interact directly with natural objects, a philosophy I think commendable. So, Dippy falls foul of this criterion (although I do object strongly to those media outlets that called Dippy a fake - it's not a fake, it's a replica).

Of course, I'd have have preferred to replace Dippy with a new impressive dinosaur exhibit - preferably a real Diplodocus (or other sauropod) skeleton, but a new dinosaur display was not within the scope of the project. However, the NHM also has other reasons for wanting to refresh the Hintze Hall offer - showing that our collections and science are societally relevant - hence the appearance of the Blue Whale as a focus for understanding our current biodiversity crisis.

Various rumours regarding Dippy's fate have been circulating, which have no basis in fact: the NHM is not selling Dippy, nor are we disposing of it in any other way. Dippy is a research quality cast of high scientific and historical value and is a formally registered part of the NHM's dinosaur collection (which means we treat it like any other object in the museum's collection). Moreover, it's not all bad news for Dippy fans. The NHM is keen to try and put Dippy on tour or on loan to other venues throughout the UK so people can get to see it in all its glory outside of London. Plans for these options are currently under discussion. However, if you want to see Dippy in pride of place in Hintze Hall the clock is now ticking ...

*Disclaimer: I am not personally involved in any of the project teams/committees that made or are implementing this decision.

Sexy stegosaurs?

Plate function in stegosaurs has been much debated, with early suggestions that they were defensive structures superceded by alternative explanations that have included use as convective fins for heat gain and loss and/or as visual signals for display and species recognition. A study just published in PLoS ONE by Evan Saitta of Bristol University adds a new twist to this discussion, suggesting that plate shape in Stegosaurus (= Hesperosaurus) mjosi differed between male and female individuals.

Determining the sex of a dinosaur skeleton has proved almost impossible in the vast majority of cases. Although living reptiles (including birds) do exhibit many obvious differences between males and females, a phenomenon termed sexual dimorphism, most of these differences relate to body size (with one sex markedly larger than the other), behaviour (e.g. different display strategies) and soft tissue anatomy (e.g. reproductive organs, skin patterning, feather types, etc.). By contrast, very few features of the skeleton  differ between male and female reptiles (except in terms of overall proportions) and applying these size and shape differences to fossil skeletons is difficult. For example, although sexual size differences are common, size also changes during growth - so are the size differences seen between fossils the result of growth differences, sexual differences, or even differences between adults of very similar species? Although there are methods for eliminating some of these issues, these problems are often so intractable that there are effectively no features of the skeleton that can be used to sex an extinct reptile reliably. There are only two exceptions to this pessimistic statement: both apply only to females. If intact eggs are found inside a dinosaur, and feeding can be ruled out (e.g. position of the eggs in the body, lack of evidence for digestion), you can be pretty sure it's a girl. In addition, female dinosaurs produce a special type of bone, medullary bone, which forms a reservoir for egg-forming minerals just before egg laying commences. If you slice open a dinosaur limb bone and see this bone type you have a female. However, if eggs or medullary bone are absent it just means that you either have a male or a female that wasn't about to lay eggs. Not very helpful, sadly. To date we know only of a handful of dinosaur skeletons that can be confirmed as female - none of the rest can be sexed at present.

Identification of sexual dimorphism in Stegosaurus plates would, therefore, be interesting and important: a feature that could plausibly identify male and female dinosaur skeletons consistently and easily for the first time. This new study is based on a spectacular new discovery: a group of at least five Stegosaurus individuals whose remains were preserved in a small area. Stegosaurus is usually regarded as a rare and solitary animal, so finding a group of these animals together would be newsworthy in itself. Following his study of these remains, Saitta (2015) concluded that these individuals all belonged to the same species (i.e. none belonged to the other species of Stegosaurus, S. stenops), they might have been a social group that died in the same event, and that the plates preserved with these skeletons fell into two distinct types. One of these plate morphs is taller than it is long, forming a narrow pointed triangle in side view (interpreted as female); the other is longer than it is tall, with a much larger area, forming a low rounded triangle (interpreted as male due to its larger size). This conclusion followed measurements of the preserved plates and comparisons to plates from other skeletons of S. mjosi and S. stenops in museum collections around the world. Alternative explanations, such as differences in growth, were considered but rejected by the author.

Although an interesting hypothesis, I'm thus far unconvinced by the arguments set out in the paper, for a variety of reasons.

1. Little relevant information is provided on the age of the individuals in the group. Although there is some work on the histology of the plates to look for growth rings, growth rings in armour do not record growth records in the same way as the widely used growth rings found in limb bones. As a result, it's unclear if there are differences in age between the different individuals in the quarry. As we know very little about shape change in stegosaur plates through growth, this is an important consideration.

2. Only 11 plates are preserved in the quarry, nine of which were complete enough to include in the study. This is a small proportion of the total number of plates that might have been preserved if the whole plate array was present for each individual (up to around 90 plates could plausibly have been present originally if the total count of plates was similar to that in S. stenops - but almost all of the plates seem to have been lost during the fossilisation process). As all of the remains in the quarry are mixed and jumbled it's not clear if the plates came from one of the five individuals present, or more than one individual. It could be that the two different types of plate belonged to one individual that possessed mixed plate types along the plate row, rather than from different individuals with different plate morphologies, or they might have come from individuals of different ages. The lack of intermediate plate types in the quarry, which was used as evidence to suggest the two types were very distinct and thus dimorphic, is perhaps unsurprising given the very small sample of plates available for study.

3. No previously described specimen of S. mjosi possesses a full compliment of plates – all are incompletely preserved with many parts of the skeletons missing. As a result, we have no roadmap to show what a complete set of S. mjosi plates should look like or how shape could have varied along the row.

4. Although all of the individuals were identified as S. mjosi, anatomical details for each specimen have yet to be published, so the possibility that this might be a mixed group of S. mjosi and S. stenops (or as as yet unknown species) has not yet been ruled out definitively. Although the identification of each individual might be solid, the evidence to support this was not fully set out in the paper so other scientists are unable to confirm this suggestion at present. 

5. No details were provided on the completeness or preservation of the plates used in the study and how this might have affected the results. Plates in many of the specimens used for comparison are at least partially restored and reconstructed, altering their sizes and shapes and no data is presented to show that only complete undistorted plates were used for comparison.

Given the above, it's possible that younger individuals of S. mjosi might have had different plate shapes from older ones or that in S. mjosi the plates differed in shape and size depending upon their position within the plate row (or between individuals). Neither of these possibilities was thoroughly tested in the paper: indeed, one of these possibilities can only be tested by finding a new complete skeleton of this species. By comparison, plate shape is known to vary somewhat along the body in Stegosaurus stenops and it's plausible that it varied in a different way in S. mjosi to incorporate two plate types (this would then become an additional way of distinguishing these two species). So, although a sexual difference is plausible, growth differences, individual differences and/or species differences are also equally likely on the basis of current evidence.

Although I remain skeptical, it would be really neat if future work on this assemblage could dismiss some of these concerns: it would be great to finally have a good example of clear sexual dimorphism in a non-avian dinosaur, even though it's likely that such obvious dimorphism would be relatively rare across the group as a whole (given we've not been able to identify in dinosaurs for which we have large sample sizes). The announcement of stegosaur sexual dimorphism seems a bit premature, but I would be very happy to be proved wrong. 

Reference

Saitta, E. T. (2015). Evidence for sexual dimorphism in the plated dinosaur Stegosaurus mjosi (Ornithischia, Stegosauria) from the Morrison Formation (Upper Jurassic) of Western USA. PLoS ONE 10(4): e0123503.

How to buy a dinosaur

Following from my previous post on buying and selling fossils, here's the text of a piece I wrote at David Hone's invitation for his blog hosted by The Guardian, for any that missed it:

Taking delivery of a dinosaur skeleton is not an everyday event – even at the Natural History Museum (NHM). So, when the opportunity arose to obtain a spectacular new specimen of Stegosaurus, the museum embarked on a project that took nearly two years from its conception to the appearance of this iconic dinosaur centre-stage in our Earth Hall. Elsewhere, I’ve talked about the original discovery of the specimen, and the skeleton itself, but here I’ve decided to give an insight into how and why the NHM acquired it.

The NHM's new Stegosaurus skeleton, nicknamed 'Sophie', photographed prior to its public display. Photograph copyright The Natural History Museum, London.

We first heard about the Stegosaurus when my colleagues Martin Munt, Tim Ewin and I attended the Tucson Rock and Mineral Fair in early 2012 – an annual event that is the largest commercial fossil fair in the world. During the fair, professional fossil collectors and dealers from all over the world buy and sell everything ranging from tiny trilobites to mammoths, exchanging information with each other and with professional palaeontologists. Buyers include retail outlets, private individuals and museums. While searching through the displays for interesting new material, we were impressed by a full-sized cast of a Stegosaurus and were surprised to learn that the original was for sale. Further discussions revealed that not only was it available, but also the best skeleton of this amazing dinosaur yet found. It had been discovered in 2003, by fossil collector Bob Simon in the Late Jurassic rocks of the Morrison Formation from Red Canyon Ranch, near Shell, Wyoming, and had been excavated and cleaned of its surrounding rock by a, Swiss/German team of professional fossil collectors headed by Kirby Siber of the Saurier Museum Aathal in Zürich. The completeness and high quality of the specimen made an immediate impression in terms of its potential for new science and a new dinosaur display. On returning to the NHM Martin and I began discussions with our colleagues to determine how feasible a purchase might be, how and where we might display the Stegosaurus, how we could use it for education and public outreach and, most importantly, what new science would result if we were lucky enough to secure it.

Some palaeontologists strongly oppose the buying and selling of fossils for a variety of reasons. Many countries have laws that specifically prohibit trade in fossils, as they want to retain these objects as part of their own cultural and scientific heritage. However, unscrupulous dealers and collectors have frequently poached fossils from these areas, exporting and selling them illegally, often without the contextual information on the fossil site that is necessary to exploit the specimen’s full scientific potential. Moreover, some illegal collectors have also ravaged and severely damaged scientifically important sites. Nevertheless, these unlawful collectors are in the minority and many professional fossil collectors and dealers have strong, positive relationships with museums and universities, and often collect to very high professional standards. Since its foundation the NHM has been strongly engaged with both amateur and commercial collectors. One of our duties is to bring scientifically significant material into the public trust, which we do by collecting ourselves, encouraging donations and by purchase – as long as the material we acquire has been obtained in line the highest legal and ethical standards. By bringing these specimens into the public domain we can make new scientific information available, which would otherwise be lost, and enable access to the specimen for other scientists in perpetuity. Equally importantly, we also use these specimens to inspire generations of visitors to the museum who see the material on display in our galleries.

The benefits of obtaining the skeleton were clear and it was an easy sell to get the project approved internally – at least in principle. A trickier question was how to raise the necessary funds – the NHM does not currently benefit from a large endowment to support the purchase of new material for the collection, so a donor had to be found. Luckily, our fundraisers are a tenacious bunch and after a few months were able to propose the idea to a private individual, Mr Jeremy Herrmann, who generously undertook to be the lead donor on the project and to find other donors to help support the purchase. With his support we began the process of trying to acquire it. Colleagues and I went to view the original bones, in order to check their quality and authenticity, which involved urgent trips to Salt Lake City to see the skeleton (as it was in a facility there where the frame on which it is mounted was being built) and Zürich to see the skull (where the skull bones had been cast and moulded to make replicas). Once the relevant legal niceties had been checked and double-checked, NHM Director, Sir Michael Dixon, was able to pick up the telephone and make an offer that secured the Stegosaurus. After a few more weeks of waiting for the frame to be finished, the Stegosaurus arrived at the NHM in December 2013.

A decision was made to keep the purchase confidential, to maximize the impact when Stegosaurus was revealed to the public and to give us a reasonable period in which to study the skeleton in detail, something that would be exceptionally difficult after it went on display. Keeping a dinosaur skeleton secret for nearly a year is no mean feat. The small number of external collaborators we asked to join the project for their expertise were asked to sign binding non-disclosure agreements and I wasn’t able to talk about the work with my closest friends and colleagues. The scientific work we carried out behind the scenes involved CT scans, 3D laser scans and thousands of photographs and measurements, as well as preparing a full anatomical description. Perhaps surprisingly, Stegosaurus is a rather rare dinosaur and has not received vast amounts of detailed attention, so the new skeleton was an exciting opportunity to bring our knowledge of its anatomy and biology bang up to date. All of these data are currently being analysed and compiled into a series of scientific papers, which will appear over the next couple of years. The first paper, on Sophie's body mass, has now been published and can be downloaded for free from the Royal Society's Biology Letters webpage. However, the science was only a part of the project. During this time we also had to consider where the skeleton would go, do some additional cleaning of the skeleton and make some adjustments to the frame, plan the removal of the former exhibits in the area chosen for the Stegosaurus, design and build the plinth and lighting for the display, work on the display panels and web content, and devise education and outreach activities and events, alongside many other critical tasks – all while carrying out the work in secret alongside the other work each member of the team had to do on a day-to-day basis. A dedicated project manager, Beca Jones, was needed to oversee and guide the entire scheme and did a sterling job in keeping us all on schedule, on budget and with every contingency accounted for – and this for a diverse team of scientists, builders, educators, designers, conservators, fund-raisers and artists. 

 Artwork created by Robert Nicholls that was commissioned  for the new display, with the proportions of the Stegosaurus modeled using Sophie's actual dimensions. Image copyright Robert Nicholls/The Natural History Museum, London.

This massive effort, involving over 100 people in total, finally came to fruition in December 2014, when we unveiled the skeleton to the public. For me, this came with a mix of emotions, notably a massive surge of relief – we’d delivered the exhibition on time with no mishaps. Moreover, I could now talk freely about something that had occupied a substantial portion of my time for nearly two years! I think everyone on the team feels justifiably proud of bringing this fabulous new dinosaur to the museum – and Stegosaurus will inspire our visitors for decades to come as well as adding significantly to our knowledge of dinosaurs and their world.

The trade in fossils: a practical position

I’m just back from a trip to the 2015 Tucson Rock and Mineral Fair, probably the largest commercial fossil fair in the world. I was there in my professional capacity, representing the museum along with my colleagues Martin Munt (our Head of Palaeobiology Collections) and Emma Bernard (our fossil fish curator). The museum has been sending mineralogical delegates to the show for many years whereas the palaeontologists have only been attending regularly for four years or so. This was my second time at the show. 

My colleague Martin Munt investigating one of the many stands at the Tucson Rock and Mineral Fair in February 2015

The logistics are impressive – the fair goes on for almost a full month and takes over much of Tucson. The fossil part of the fair covers several main sites (centred on hotels, giant marquees in convention centres, etc.) and there are numerous satellite shows that are set up in car lots and motels. The importance of the fair to the city is clear, from the numerous permanent rock shops in the city itself, to the large number of commercial dealers who live nearby and even in the murals on some of the town buildings. The palaeontological part of the fair forms only a small proportion of the total activity – most of it is devoted to rocks and minerals.

We were attending for two reasons: to purchase fossils and to maintain and develop our network of professional contacts within the legitimate fossil dealing trade. Many of my colleagues are strongly opposed to the buying and selling of fossils (more on that later), but museum policy at the NHM has always been to engage with professional fossil dealers with the aim of bringing scientifically important specimens into the public trust so that they can be cared for and studied in perpetuity. When purchasing a fossil we have a number of important criteria in mind: 1) Was the fossil collected legally and ethically; 2) Does it come with the relevant contextual information on geology and locality?; 3) It is scientifically significant?; 4) Does it add something else useful to our collection (does a fossil represent a taxon or locality our collections don’t currently include)?; and 5) Does it have potential for public engagement (i.e. exhibition, educational outreach, etc.).

Colleagues that oppose trade in fossils have good reasons for doing so. Some have a strong philosophical perspective that fossils are part of humanity’s shared cultural property and regard trade in these objects as infringing that ideal. Others have more pragmatic concerns: some unscrupulous fossil dealers have looted and severely damaged important sites; others have engaged in unethical and illegal practices in the excavation and import/export of material; in many cases dealers have not collected important contextual information; and this practice has placed a monetary value on fossils. The latter is particularly pertinent to rare or spectacularly preserved fossils that may, therefore, sell at prices that prevent museums and other academic institutions from obtaining them: more than a few really nice fossils have disappeared into the mansions of wealthy private collectors, never to be worked on by scientists. All of these are legitimate concerns, which I share, and all of my colleagues (myself included) could list examples where the subject was not served well by the fossil trade.

However, there are also good reasons for engaging with professional fossil collectors rather than casting them as pariahs, as some of my colleagues often do. Firstly, there are simply more fossils than palaeontologists: if it were not for professional collectors (and they devote much of their time to this activity, not for the few weeks a year most palaeontologists can manage) many interesting fossils would simply never be found or erode away in the field. Thus, in some sense, a careful professional collector who records all of the relevant information and makes it available is doing the subject a service in recovering this material. Secondly, a constructive dialogue with professional collectors, such as discussing with them what information is important, can lead to collection practices that really enhance the information available. Indeed, many commercial collectors are often happy to take scientists into the field to see their sites and make observations. Thirdly, most of the commercial collectors I meet really care about their material – they can discuss it in detail and often aspire for it to go to museums and to be studied. They excavate it and prepare it to a high standard (its in their interest after all, they want to sell them) and so often produce really good material for study and exhibition.

There is an important flip side to this: as a community we should definitely not engage with those collectors that do not have the highest legal and ethical standards, nor with those who do not provide the necessary contextual information. There is evidence that this engagement and intervention is working: after the high profile Tarbosaurus trial, which led to the jailing of one fossil dealer and the repatriation of material to Mongolia, it’s obvious that the trade in this kind of material has dwindled. When I first visited Tucson a number of dealers exhibited Mongolian (and Chinese) material, but specimens from both countries were conspicuous by their almost total absence at the fair this year, a trend that I’m sure will continue. This is a phenomenon that was brought about by high profile community pressure (both from palaeontologists and from ethical dealers), rather than any change in legislation.

There are other nuances in this debate that are often glossed over but are worthy of discussion. If fossils are viewed as cultural or heritage objects, why is it OK to trade in antiques and old masters? These are also of great communal benefit and are limited resources. Some laws protect art, antiquities and anthropological artefacts from sale, but fossils are generally excluded. If palaeontologists want laws to try and get protected status for at least some fossils, discussions have to take place on how this might best be done and international agreements (not just national ones) have to be put in place. Also, many museum collections around the world are built partially on the purchase of material from professional dealers or private collections. For example, the NHM collection includes material purchased from Anning, Mantell, Nopcsa, the Sternbergs and Cutler, not to mention Archaeopteryx. Many North American museums include numerous specimens that were also purchased historically (e.g. AMNH, USNM, ROM, Field Museum), often with less locality information than a modern dealer would provide. Even those museums who claim to have ‘collected’ large numbers of specimens often engaged professional fossil hunters on their pay roll to do so (which is not really that different from buying from a dealer - the scientists themselves rarely went into the field on these expeditions for any significant length of time). Thus, there is a certain amount of hypocrisy in terms of condemning the sale of fossils, when this trade has actually formed the foundation of many major collections. Some of my colleagues have even opined that they would rather see specimens left to rot in the field than have them collected by a dealer (where there would be at least a chance they’d make it into a public collection), an attitude I find astonishing. Finally, let’s not forget that we are also talking about people’s livelihoods – in some parts of the world fossil collecting provides a much needed boost to local economies and provides jobs for numerous workers and there are many interesting conversations to be had on this theme alone.

In this case I think the subject would best be served by a large dose of pragmatism. The subject can benefit strongly from good relationships with those dealers that collect and prepare material to high ethical and professional standards, whereas the community should work together to exclude those that do not.