Happy 90th Sir David

Today seems a good day to pen my first blog post in a while, in order to mark the 90th birthday of the most effective natural history communicator we've even seen: Sir David Attenborough. His work in the area, since the early Zoo Quest series, has been marked by his trademark enthusiasm and his deep connection with the natural world. In addition to this sense of wonder, he also carries the gravitas of a man who really knows his subject and let's not forget that in addition to being best known for his TV and radio work on natural history he was also one of the most influential figures in British broadcasting history. The fact that he gave up senior roles at the BBC to return to his first love of documentary making speaks volumes about his passion for communication. His enthusiasm is not the manufactured kind seen in the majority of presenters we see on TV, but is totally genuine and infectious, and he finds interest in both the broad picture and in intricate detail. I've been privileged enough to see him at work, both in terms of his broadcasting and in terms of his charitable/corporate outreach, and to meet and correspond with him a few times, which has been nothing short of fulfilling a childhood dream.

As a nerdy, animal-obsessed kid growing up in suburban London I had few opportunities to interact with the natural world and his documentaries were something I looked forward to almost obsessively. They were, without doubt, some of the most formative influences on my early interests and helped to shape my future career path. Two of his TV series stand out in my earliest memories: Wildlife on One, which showcased a different species in its natural environment each week, and Life on Earth, the landmark series in which Sir David covered animal evolution, from the origin of life through to the origin of modern humans. Life on Earth, in particular, exerted a considerable influence on me and, to quote Darwin, really showcased the "grandeur in this view of Life". Even the title sequence, with it's eerie, amorphous forms hinting at change through time, and the haunting primeval music from the now defunct BBC Radiophonic Workshop (also responsible for the Dr Who theme tune), can still raise the same goosebumps I got as a kid. The series first aired when I was around 8 years old and I can still remember most of the key sequences. It's combination of broad picture thinking, highlighting major evolutionary transitions, and the amazing footage of the animals themselves was revelationary. I begged my parents for the book for Christmas: even though they thought it was "too old for me", as it was written for an adult audience, they bought it anyway and I devoured it again and again, enjoying not only the prose but the amazing photos. It's still on my bookshelf 30 years later.

My copy of Life on Earth: a long treasured 9th birthday present from my parents

So, thank you Sir David, on many levels. Thanks for introducing me to the wonder of the natural world and the joy of discovery. Thanks for showing me that it was possible to follow this path myself and to make a career that involved finding out more about the history of life on Earth. Thanks for your enthusiasm and support (I really enjoyed our conversations standing around Sophie!). And finally, thanks for using your influence to be a voice of reason and sage council in a world where many of these amazing organisms are now under threat.

The shape of things to come...

As many of you will have noticed, the NHM's Dinosaur Gallery is currently closed for some much needed renovation work, and is due to reopen in late February 2016 (though it will open for the week of February half-term, before closing for a few more days after this to finish things off). This isn't a wholesale redevelopment of the gallery - that project is probably a few years distant (at least) and is dependent not only on raising the necessary funds, but also on some complex planning and the completion of several other large-scale museum projects that would need to be finished before the Dinosaur Gallery could be tackled. The current work is aimed at improving some aspects of visitor experience to the gallery (and to the museum as a whole) and in response to changing government health and safety guidelines, with which the museum has to comply.

So, what's changing? I can't reveal too much at this stage, but I can give some insights into what's going on. One of the major drivers for the work is to try and deal with the huge queues for the gallery, which currently lead to frustrating congestion in Hintze Hall. With 5.4 million visitors per year, the museum needs to find ways to enable the movement of people around the building more efficiently. Currently,  the popularity of the Dinosaur Gallery and the large queue that occupies Hintze Hall on busy days is a real barrier to this. The idea behind the current project is to find other ways of managing this queue, by moving it to other areas of the building and by providing a better experience for those people waiting in the queue. Another major driver behind the work is dealing with an engineering issue within the gallery that means some aspects of the way in which it's been used to date need to be altered.

One of the most obvious changes will be a new entrance to the gallery and an altered route for visitors through the various exhibits. However, there will be relatively few alterations to the actual content, so that the vast majority of current exhibits will still be on show. We are taking the opportunity to make some updates, however, with the removal of a few very dated displays, updates to information with specimens where required, a deep clean of all the exhibits, and some other changes reflecting the bird/dinosaur more accurately. So, although the project involves a lot of work, it's mainly an exercise in updating the current gallery rather than a large-scale redevelopment and rethink.

While the gallery is closed it's still possible to see dinosaurs in other parts of the museum - most obviously Sophie the Stegosaurus in our Earth Hall, but also the original Archaeopteryx specimen and Iguanodon teeth in our Treasures Gallery. More dinosaur content can also be found in the From the Beginning Gallery - alongside fossils of many other groups that are otherwise not found elsewhere in the public galleries.

A productive year for the lab!

It's the time of year when we're all taking stock and looking back at the accomplishments of last year as well as looking ahead to the opportunities and travails of the year ahead. With this in mind, here's a summary of what the lab got up to last year: a bit dry I'm afraid, but it gives a reasonable picture of the sorts of research that's been going on and what we've been up to...

A big shout out to my postdocs David N. and Charlotte, to my PhD students Simon, Matt, David B., Terri, David F., Amy, Serjoscha, Selina, Omar and Richard, and to a large number of collaborators all over the world (you know who you are)... Here's looking forward to an even more productive 2016.  

Arrivals & Departures

A sad farewell to Dr Charlotte Brassey after over a year of working full-time on Project Sophie. Charlotte has moved on to a research position at the University of Manchester in Bill Sellars’ research group.

Congratulations to Dr David Button on submitting his dissertation and passing his PhD viva in 2015 and on getting a new post in the Butler Lab at the University of Birmingham.

Welcome to Richard Fallon (University of Leicester), who’s co-supervised by Paul (alongside Gowan Dawson, Leicester and Will Tattersdill, Birmingham), and is doing is PhD on public responses to dinosaurs and other extinct reptiles in the Victorian period.

Journal Articles

Apostolaki, N., Rayfield, E. J. & Barrett, P. M. 2015. Osteological and soft-tissue evidence for pneumatization in the cervical column of the ostrich (Struthio camelus) and observations on the vertebral columns of non-volant, semi-volant and semi-aquatic birds. PLoS ONE 10: e0143834. doi:10.1371/journal.pone.0143834

Baron, M. G. 2015. An investigation of the genus Mesacanthus (Chordata: Acanthodii) from the Orcadian Basin and Midland Valley areas of Northern and Central Scotland using traditional morphometrics. PeerJ 3: e1331. https://doi.org/10.7717/peerj.1331

Barrett, P. M, Evans, D. C. & Campione, N. E. 2015. Evolution of dinosaur epidermal structures. Biology Letters 11: 20150229. doi:10.1098/rsbl.2015.0229

Barrett, P. M., Nesbitt, S. J. & Peecook, B. R. 2015. A large-bodied silesaurid from the Lifua Member of the Manda beds (Middle Triassic) of Tanzania and its implications for body-size evolution in Dinosauromorpha. Gondwana Research 27: 925­–931. doi:10.1016/j.gr.2013.12.015

Bates, K., Maidment, S. C. R., Schachner, E. R. & Barrett, P. M.  2015. Comments and corrections on 3D modelling studies of locomotor muscle moment arms in archosaurs. PeerJ 3: e1272. doi: 10.7717/peerj.1272

Brassey, C. A, Maidment, S. C. R. & Barrett, P. M. 2015. Body mass estimates of an exceptionally complete Stegosaurus (Ornithischia: Thyreophora): comparing volumetric and linear bivariate mass estimation methods. Biology Letters 11: 20140984. doi:10.1098/rsbl.2014.0984

Brusatte, S. L., Butler, R. J., Barrett, P. M., Carrano, M. T., Evans, D. C., Lloyd, G. T., Mannion, P. D., Norell, M. A., Peppe, D. J., Upchurch, P. & Williamson, T. E. 2015. The extinction of the dinosaurs. Biological Reviews 90: 628–642. doi:10.1111/brv.12128

Choiniere, J. N. & Barrett, P. M. 2015. A sauropodomorph dinosaur from the ?Early Jurassic of Lusitu, Zambia. Palaeontologia africana 49: 42–52.

Cleary, T. J., Moon, B. C., Dunhill, A. M. & Benton, M. J. 2015. The fossil record of ichthyosaurs, completeness metrics and sampling biases. Palaeontology 58: 521–536. http://onlinelibrary.wiley.com/doi/10.1111/pala.12158/abstract

Evans, D. C., Barrett, P. M., Brink, K. S. & Carrano, M. T. 2015. Osteology and bone microstructure of new, small theropod dinosaur material from the early Late Cretaceous of Morocco. Gondwana Research 27: 1034–1041. doi:10.1016/j.gr.2014.03.016

Evers, S. W., Rauhut O. W. M., Milner A. C., McFeeters B. & Allain, R. 2015. The morphology and systematic position of the theropod dinosaur Sigilmassasaurus from the ‘middle’ Cretaceous of Morocco. PeerJ 3: e1323. doi:10.7717/peerj.1323

Foth C., Evers S. W., Pabst B., Mateus O., Flisch A., Patthey M., Rauhut O. W. M. 2015. New insights into the lifestyle of Allosaurus (Dinosauria: Theropoda) based on another specimen with multiple pathologies. PeerJ 3: e940. doi:10.7717/peerj.940

Maidment, S. C. R., Brassey, C. & Barrett, P. M. 2015. The postcranial skeleton of an exceptionally complete individual of the plated dinosaur Stegosaurus stenops (Dinosauria: Thyreophora) from the Upper Jurassic Morrison Formation of Wyoming, USA. PLoS ONE 10: e0138352. doi:10.1371/journal.pone.0138352

Nicholson, D. B., Holroyd, P. A., Benson, R. B. J., & Barrett, P. M. 2015. Climate-mediated diversification of turtles in the Cretaceous. Nature Communications 6: 7848. doi:10.1038/ncomms8848

Nicholson, D. B., Mayhew, P. J., & Ross, A. J. 2015. Changes to the fossil record of insects through fifteen years of discovery. PLoS One 10: e0128554. doi:10.1371/journal.pone.0128554

Porro, L. B., Witmer, L. M. & Barrett, P. M. 2015. Digital preparation and osteology of the skull of Lesothosaurus diagnosticus. PeerJ 3: e1494. 0.7717/peerj.1494

Upchurch, P., Andres, B., Butler, R. J. & Barrett, P. M. 2015. An analysis of pterosaurian biogeography: implications for the evolutionary history and fossil record quality of the first flying vertebrates. Historical Biology 27: 696­–716. doi:10.1080/08912963.2014.939077 

Awards & Grants

Amy: Student Poster Award, The Micropalaeontological Society Foraminifera and Nannofossil Meeting; University of Bristol Alumi Foundation Travel Grant.

Matt: Jackson Student Travel Grant to attend SVP in Dallas.

Selina: Winner, Three Minute Thesis Competition, MAPS Faculty UCL.

Serjoscha: SYNTHESYS grant for 10 days research at SMNS in Stuttgart; Rodney M. Feldmann Award of the Paleontological Society for Australochelys Project in South Africa; NERC Impact and Innovation Award (through Oxford DTP) for CT scanning project in Chicago; University College Oxford Research Training Fund for academic travel.

Conference Talks & Posters

Amy: Talk on on Cretaceous turtle niche modelling at GSA; poster on foram niche modelling at TMS foram and nanofossil meering; poster at the International Biogeography Society.

David: Talk on on turtle palaeolatituduinal distributions at GSA and at PalAss.

Matt: Poster on Lesothosaurus postcranium at SVP and a talk on the same subject at Prog. Pal.

Paul: Talk on turtle palaeolatitudinal distributions at SVP.

Serjoscha: Poster on Rhinochelys at SVPCA and a talk on Allosaurus pathologies at the Paläontologische Gesellschaft.

Simon: Posters on Middle Jurassic dromaeosaur teeth at SVP and on the Woodeaton fauna at SVPCA and PalAss.

Terri: Poster on Mesozoic and Paleogene squamate diversity at PalAss.

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.