Sunday, 22 December 2013

Tyrannosaurs at Christmas




Despite SVP being understandably mammal-centric this year, there was still plenty of dinosaur related presentations and posters to keep us all happy. As usual, I was focussing mainly on marine reptiles (not a lot this year unfortunately) and theropod research – particularly tyrannosaurids and, in this particular instance, there were a few really interesting pieces of research on show.
Regular readers are aware that I have often discussed the importance of the tyrannosaurid Daspletosaurus and how continuing research into this animal is important – especially when it comes to tyrannosaurine evolution and the dispersal of Tyrannosauridae throughout North America. We have known for some time now there are multiple species of Daspletosaurus and here, for the first time, Tetsuto Miyashita, of the University of Alberta, and colleagues presented their research into one of these new tyrannosaurids.
The new taxon is represented by multiple skulls and skeletons and displays several characters that are distinctive from Daspletosaurus torosus. These include features in the premaxilla, nasal, postorbital boss, and lacrimal (amongst others). Remains are found in both the Dinosaur Park Formation and the temporaneous uppermost Oldman Formation and are thus more recent than D. torosus.
The authors’ phylogenetic analysis reveals that this taxon, as well as Daspletosaurus sp. from the Two Medicine Formation, forms a clade which is comprised of tyrannosaurine tyrannosaurids that are more derived than those from Campanian deposits in Utah and probably New Mexico. Interestingly, this analysis also recovered Bistahieversor as a tyrannosaurid which is just what the comprehensive analysis recently documented in the Lythronax paper (Loewen et al 2013) also found.
Here it is interesting that the authors favour Daspletosaurus as being derived with both Tarbosaurus and Tyrannosaurus but Loewen et al regard Daspletosaurus as a basal northern clade and separate from the southern Laramidian radiation of tyrannosaurids. They favour a southern distribution for more derived tyrannosaurids and suggest that both Tyrannosaurus and the Asian Tarbosaurus evolved from this dispersal event in the south.
This is intriguing because there are obvious differences between these two analyses and it raises yet more questions than there are answers. Personally, I remain open minded about tyrannosaurid dispersal events and, make no mistake, there were probably several. But perhaps there is now more evidence about Daspletosaurus being “northern” and it comes in the form of another unexpected new tyrannosaurid announced at SVP.
Anthony Fiorillo and Ron Tykoski, both of the Perot Museum of Nature & Science in Dallas, presented their research on skeletal remains of large theropods in the Upper Cretaceous Prince Creek Formation of Alaska. The Prince Creek crops out along the bluffs of the Colville River and the sedimentology reveals deposits that were laid down in a wet/dry seasonal environment. There are several sites of which one, the Kikak-Tegoseak Quarry, has yielded some extremely interesting elements from a tyrannosaurid.
One of these, DMNH 21461, is a skull roof displaying a bifurcated sagittal crest and would seem to indicate a total skull length of around 0.6 metres. Other elements include a partial dentary and are indicative of a derived tyrannosaurine and are quite diagnostic indicating that a new taxon is involved. The authors are naturally enough a little wary at the moment about confirming or naming the new taxon and, when questioned about the height of the sagittal crest by Thomas Carr, declined to answer in public. That is fair enough but my observations of the fossils on display, and the sagittal crest in particular, suggest that this may yet be another species of Daspletosaurus. And there is more.
The Liscomb Bonebed, another site in the Prince Creek, has also yielded tyrannosaurid elements and these display an unusual condition for their size. These include specimens DMNH 2012-25-31 (a neural arch), DMNH 2012-25-30 (a partial radius) and DMNH 2012-22-20 (a pedal phalanx) and  their overall morphology is indicative that they represent an adult tyrannosaurid – but this particular individual is only about 40% the size of what a conventional large adult tyrannosaurid would be.
This should actually not be a surprise considering the conditions that would have been endured in the palaeoenvironment of northern Alaska back in the Late Cretaceous and dwarfism would have been a logical response when resources are limited. As research progresses it will be interesting to know how these tyrannosaurids relate to each other and, as I mused earlier, how they will further enlighten our knowledge of the tyrannosaurid radiation throughout the Late Cretaceous.
Thomas Carr’s contribution to SVP this year was a poster looking at the sister group relationship between Daspletosaurus and Tyrannosaurus. Just in case you are unaware, Carr is still working on a quite significant monograph on Daspletosaurus which was, when we were chatting at SVP, over 1000 pages long – a significant contribution. So it was not surprising to see this poster featuring his research into testing the evolutionary lineage of these tyrannosaurids and whether a case for anagenesis can be made.
A comprehensive cladistic analysis was undertaken to compare both phylogenetic and ontogentic sequences and patterns. Unsurprisingly, perhaps, there are several factors that are suggestive of an anagenetic tyrannosaurine lineage but, equally, there is that question of the dispersal of Tyrannosaurinae in the first place. As Carr points out, Tyrannosaurus is phylogenetically removed from Laramidian species by some Asian taxa in the first place and the fact that, as I have already alluded to, there were several dispersal events between Asia and North America and then the case for anagenesis in Laramidian tyrannosaurines becomes very complex indeed .
Interesting again is how this analysis tends to support that of Myashita et al from earlier and contrasts with that of Loewen et al which favours a southern radiation for Laramidian tyrannosaurines. The origins of these formidable tyrannosaurids looks set to be undetermined for some time to come.
Finally, and moving away from tyrannosaurids, Joseph Sertich, of the Denver Museum of Science & Nature, and his colleagues unveiled another giant theropod but this time in the form of a primitive abelisaurid. This specimen has proven to be remarkably popular and there were lots of extremely interested workers at SVP and, again, in the palaeoworld since the meeting.
The specimens derive from the Lapurr sandstone in the Turkana Basin of Kenya and are rocks of Maastrichtian age. Elements include some from the skull and those from both axial and appendicular skeleton. Unfortunately, a lot of this material is scrappy and poorly preserved but is diagnostic enough to be able to refer these specimens to the Abelisauridae.
However, the size of the animal is readily evident and is confidently predicted to be in the region of eleven metres long – maybe more but there appears to be no significant cranial ornamentation on this taxa unlike other abelisaurids. This large theropod was part  of a diverse fauna that is now coming to life as more fossils are found and include sauropods, ornithopods, theropods, pterosaurs and crocodiles and, despite most of the fossils that have so far been recovered being scrappy, there is every likelihood of yet more surprises to come from this intriguing part of Africa.
Footnote
Well it is the time of year when the season of goodwill should be the order of the day. It has been a very busy year for me and, as a result, I have not been able to post as often as I would like but, rest assured, I will always endeavour to post as often as I can. Between the amount of work I have and also looking after the interests of the group (which is important for all of us) time is of a premium just now - but we will get there in the end.
Thanks for all your support over the last year and now it just remains for me to say that, to those of you who celebrate it, I hope you all have a happy and peaceful Christmas. Enjoy!  

References

Carr, T. 2013. Using ontogeny and phylogeny to test hypotheses of anagenesis in the vertebrate fossil record: a case study of the sister group relationship between Daspletosaurus and Tyrannosaurus (Dinosauria, Coelurosauria). Journal of Vertebrate Paleontology, SVP Program and Abstracts Book, 2013, pp101.
Fiorillo, A & Tykoski, R. 2013. Distribution and polar palaeoenvironments of large theropod skeletal remains from the Prince Creek Formation (Early-Late Maastrichtian) of Northern Alaska. Journal of Vertebrate Paleontology, SVP Program and Abstracts Book, 2013, pp127.
Loewen MA, Irmis RB, Sertich JJW, Currie PJ, Sampson SD (2013) Tyrant Dinosaur Evolution Tracks the Rise and Fall of Late Cretaceous Oceans. PLoS ONE 8(11): e79420. doi:10.1371/journal.pone.0079420
 Miyashita, T., Currie, P. & Paulina Carabajal, A. 2013 A new species of Daspletosaurus (Theropoda: Tyrannosauridae) from the Campanian of southern Alberta represented by a growth series of well-preserved skulls and skeletons. Journal of Vertebrate Paleontology, SVP Program and Abstracts Book, 2013, pp178.
Sertich, J., O’Connor, P., Seiffert, E. & Manthi, F. 2013. A giant abelisaurid theropod from the latest Cretaceous of Northern Turkana, Kenya. Journal of Vertebrate Paleontology, SVP Program and Abstracts Book, 2013, pp211.

Wednesday, 4 December 2013

Guest Post: A Night With a Legend


 
Ever wonder what it would be like to spend some time with probably the worlds’ greatest living naturalist, Sir David Attenborough? I was delighted when my friend and colleague Mark Graham, preparator at the Natural History Museum in London, offered up this wonderful post describing his time with Sir David and a film crew as they filmed various sequences for the upcoming documentary,  David Attenborough’s Natural History Museum Alive 3D.
The post brings to life what it is like for a large institution like the NHM to cope with the rigors of a fully loaded professional film crew whilst all the time looking out for the specimens in your care and, of course, being able to converse with Sir David. I know I speak for so many in saying that I would absolutely love to be able to do that one day and I am incredibly jealous!
But this is the next best thing so read on and enjoy. Please note that all images are courtesy of the Natural History Museum and are used WITH PERMISSION.
 
A Night with a Legend...  
 
16 & 17th August 2013
 
I jumped at the chance to be present in the lab for a filming session by Sir David Attenborough ( surely a candidate as 'the greatest living Englishman'), even though it meant working right through Friday night and into Saturday morning. Arianne Burnucci, my conservator colleague, was also excited to meet the great naturalist and, although only we two wanted to  be on hand throughout, everyone in the Conservation Centre got involved and spent a great deal of time during the week in clearing up the lab in readiness for the film crew.
 This was no mean feat as the Conservation Centre services the needs of  the entire museum, following a restructuring which saw its remit change from fossil preparation and conservation as  the 'Palaeontology Conservation Unit' to that of  a facilities function for all the earth and life sciences, including for example, mineralogical,  zoological and botanical specimens. And the facility, which is a busy and well-used space, is showing its age, so getting it to look fit for state of the art 3D filming by the world's favourite naturalist (and everyone's favourite uncle) took up an enormous amount of everyone's time.
 
Before the floor could be deep cleaned by an external contractor (which itself had to be spread over two early start mornings) a mountain of plastezote (support foam) and cortex (corrugated card) offcuts had to be graded, stored or disposed of and a multitude of tools and other paraphernalia put away out of sight in various cabinets, drawers and adjoining offices. Work benches were stripped of their old worn paper covers and fresh new ones cut and taped into place. Fume cupboards, grinding booths , cutting tables and sinks were cleared and then attention turned to the various specimens around the lab, as each would need to be protected from potential damage during the organised mayhem that  results from a fully kitted out film crew going about its business.
 
These included a full sized stuffed lioness, a stuffed adult stag, hyaena and a deer - not to mention both marine reptile and dinosaur fossils as well as botanical specimens. And there was the small matter of bringing an adult sauropod femur up from the dinosaur collection in the sub-basement to the lab, which took 3 people and a hydraulic forklift.
 
Apart from one specific specimen (which I will not disclose as it would spoil everyone's fun), the selection of fossils for 'dressing the set' was left to me. The production company wanted a selection of skulls, dinosaur bones, trilobites and other interesting three dimensional fossils and so, with the help of curatorial colleagues, I plundered the collections for some of the best and most iconic specimens.


Bones awaiting preparation.

 
The film crew and their attendant entourage (amazingly around 40 people) turned up in their lorries around 7pm at our loading bay and traipsed through the lab and upstairs for a briefing. Arianne accompanied them and the lab was suddenly quiet again, when in walked Sir David and the production company director. It was a wonderful moment when I introduced myself to them and made them comfortable in one of the lab offices, which served as David's private space for the duration (I asked his PA and he prefers to be addressed as David - not 'Sir David', which didn't surprise me). He is very informal and easy going around everyone, which made for a great atmosphere straight off the bat.
 
After a little while, as the crew were setting up the cameras and deciding where various fossils were to be placed, I was asked if I could give David a look around the collections as he loves to see behind the scenes. And so we wandered off - (the godfather of natural history, whose programmes, DVDs and books have enraptured me for all my adult life, and me), down to the dinosaur collection - accompanied by a cameraman who was shooting 'making of the programme' footage.
 
But what to show someone who has been everywhere around the world and has seen everything in the natural world? I decided to re-acquaint him with two specimens that I knew he had an association with; a sauropod he helped collect on a field trip during the 1980s, Baryonyx, which he had seen during its preparation and Spinops, which I had prepared 5 years previously. And, just like all of us who work with dinosaurs, he was completely absorbed. Then, as he had mentioned an incident in our acid lab many years ago, when, following a series of time- lapse photographs, he had dropped his camera into a tank of acid and ruined it, I took him there to see some resin transfer fossil fishes that I am currently acid preparing.
 
After showing him back to one of the offices where he could relax between filming, I found myself much in demand from the crew members - could this bench be moved out of shot, could that specimen be angled differently, would it be ok if we described what you do in these terms, could I find some colourful equipment to put on display, could the air extractors be switched off, could the lab doors be set open, could the hydraulic table be lifted to show the large specimen to best effect - so on and so forth. But it was great fun and, more importantly they all treated the specimens with absolute respect, which was my main concern and they went about their business carefully and very professionally, so I felt confident that nothing untoward was likely to happen.
 
The first shot was set up and out came David to take his position by the main specimen and prop (I won't say what they were as I don't want to spoil the surprise for anyone ahead of broadcasting). 'Clap' went the clapper board and suddenly, in a nano-second, there was that so familiar voice, part science buff, part actor, all enthusiasm. I was grinning from ear to ear - entranced and not quite believing that here I was involved in helping one of my heroes. After three or four takes the crew were satisfied, and David got up and went back to the office, with his PA 'guarding' the doorway while he read the script and notes.
 
The crew went back into overdrive, moving all the camera tracks, lighting and sound gear to the next part of the lab. Several 'set pieces' were organised to enhance the special effects and, for the next shoot, David showed off his acting prowess - and he had everyone laughing in the process.

Specimens laid out for filming
While all this was going on, other crew members, who had set up a super-high definition camera in one of the collection areas, requested the first of the iconic dinosaur specimens that I had selected with them earlier. So, down I went with Ari and a trolley to the collections and out came the massive left dentary of T. rex, which we positioned carefully under the slow whirring camera that took a full 20 minutes to scan the specimen. One of the crew, a young guy, was absolutely in awe of the great jawbone with its array of killer teeth "it's the first time I've got a real sense of the timescales involved with these fossils" he said to me - he was almost dumbstruck to be standing inches away from the wrong end of the Tyrant King - it really affected him.
 
At some point (just before midnight I think) the catering crew announced that a curry was ready, and everyone went up to the common room to eat. We all sat round and David discussed the lives of some of the Victorian scientists associated with the museum and all manner of things palaeo.
 
Surprisingly, I was asked by the producer to be interviewed and the roving cameraman, who was taking the 'making of the film and behind the scenes' footage spent about 20 minutes asking me  questions about the museum and the filming experience - I hope that at least a few seconds make the final edit for posterity!
 
Next up for the hi-definition camera treatment was the Baryonyx claw - more open mouths from the crew...
 
The filming took 12 hours and, at the end of it all, David was understandably looking a bit tired and was ready to get away.  I felt a bit embarrassed, but he had earlier agreed to sign a couple of books for me and I also got a photo taken with him.
 
I'm happy to say that the old adage 'you should never meet your heroes' didn't hold true in this instance - he was as interesting and charming as I knew he would be and it was one of those very special experiences that I'll always remember and cherish.
 
Then, the crew quickly packed up all their kit, made a point of thanking us and made their exits and Ari and I set about placing the specimens back in their cabinets, tidying up and securing the lab before we left on Saturday morning.
Note 
David Attenborough’s Natural History Museum Alive 3D premiers on New Year's Day on Sky 1, Sky 1 HD and Sky 3D.
 


 
Mark and the great man himself.