Hypothesis or Proof?

 

Premiering back in 1980, Carl Sagan’s Cosmos led us on an enthralling tour of our universe and took us on a crash course of science. We watched as he strolled around the heavens and our planet as he guided us through the very essence of what it meant to be human in the natural order of things. Sagan was a wonderful guide who was clearly ahead of his time, highlighting such issues as the possibilities of nuclear Armageddon and global warming and there are many quotes by Sagan that are still cited today.

Chief amongst them and most often used by palaeontologists of today, is this one:

“The absence of evidence is not the evidence of absence.”

Most people would tend to agree with this, as would I, and yet should we? On the face of it this is a very strange concept since we are suggesting that we should accept certain issues as a given despite a lack of physical proof. In other words perhaps what we should actually be saying is:

“The absence of evidence is the evidence of absence.”

Let me explain what brought this on. The well documented, and almost universal, criticism of the makers of the already much hyped Jurassic Park 4 for not having feathered dromaeosaurids is scientifically well founded since we have extensive fossils now of these dinosaurs clearly displaying such coverage. It is bizarre that the producers have seen fit not to feather their raptors and their argument that it is best to maintain a form of continuum from the previous films is a weak excuse. Perhaps it is a blind to throw us off the scent and they will indeed unleash feathered dromaeosaurs but I fear not.

Then last week the trailer for the new Walking with Dinosaurs 3D movie went on line globally and generally met with a pretty good reaction. Scott Hartman, over at Skeletal Drawing, naturally enough featured a post about it since he was involved as one of the anatomy design team for the production. One of the comments on his blog mentioned the fact that there were no shaggy gorgosaurs in the trailer and Scott suggested that the movie world is not quite ready for that yet and I tend to agree with that statement.

In the comments section I pointed out the following:

“And yet, technically, the absence of shaggy gorgosaurs is correct since Tyrannosauridae is still fuzz free for now albeit phylogenetically likely. We cannot really moan about the film makers in this instance because they are depicting tyrannosaurids accurately - in as much as the fossil record permits.”

To which Scott replied:

”That doesn't necessarily follow - absence of evidence is not evidence of absence here. The phylogenetic data is really the only data we have, so it's what we should be relying on.”

Perfectly reasonable comment and yet my initial reaction was to be a little bemused. We can justly criticise film makers for not including feathered dromaeosaurs because there is ample physical proof and yet can we justify criticism of film makers for not including feathered tyrannosaurids when there is no actual physical evidence currently available?

The phrase itself demands closer scrutiny. In effect, and in the simplest of terms, the following shows a classic example:

Many people take glucosamine and chondroitin tablets to ward off the effects of osteoarthritis (OA) and yet there is no solid data that there is any form of relationship between the two ingredients and the prevention of OA. Therefore absence of evidence is clear but, in reality, those who manufacture or believe in the properties of these tablets would simply point out that just because there is no proof currently available it does not mean that the tablets do not work – therefore absence of evidence is not evidence of absence.

Now I confess that this has very little relevance in palaeontological terms but it does show the dichotomy and how easy it is to manipulate the lack of data into possibility – even probability. However, in the case of tyrannosaurids, we have a completely different picture. I suggested that since there is no physical proof of feathers or fuzz in tyrannosaurids then we should not necessarily take it as a given simply because, and as Scott pointed out, the phylogenetic data is highly indicative that they were.

So in this case, does the absence of physical evidence mean that there is no evidence for feathered tyrannosaurids at all? Well of course not – in fact virtually the whole coelurosaurian clade displays integument of one form of another and Tyrannosauridae is currently the last group devoid of physical evidence. Very important here – we are referring to tyrannosaur-ids and not tyrannosaur-oids of which there are indeed animals displaying integument of which the most famous in recent times is Yutyrannus (if, in fact, it is a tyrannosauroid).

So we have lots of phylogenetic data to support the probability of feathered tyrannosaurids but this still needs to be quantified and rigorously tested. When this is done then the dataset will provide a statistical probability of confidence in the hypothesis. If there is confidence in the dataset then you must turn the process on its head and try to prove that there is NOT a probability of feathered tyrannosaurids. This is an extremely important part of the process and lends substantial credence to the theory.

As a result, the phylogenetic signal is highly indicative that tyrannosaurids were indeed covered in some form of fuzz or feathered plumage. And yet for all that detail, all that probability – indeed all of this “evidence” – there is still no proof. And this is where we have to be a little careful since the available data is so compelling that we sometimes forget that physical evidence is required for confirmation.

BHI 6230 (Wyrex) - No feathers here...

 

The very essence of all science is based on this fundamental process and now the onus is on finding fossils of tyrannosaurids that may preserve impressions of fuzz/feathers. There are many specimens already in collections that need re-examining as well as those specimens that may still reside in their jackets and, of course, there are still many wonderful fossils out there awaiting discovery. And, if it exists, then we should be able to find the evidence since our detection techniques are much more advanced these days – especially with UV light.

But, for the sake of argument, what if we never find a feathered tyrannosaurid? What then? I mean we have the phylogenetic data but still no proof. So we will rerun our data, perhaps add more updated information and check and double check – but still no fossil. And then we will question ourselves again since we keep performing the science and keep coming out with the same results. And then if we still find no fossils then what? Perhaps we have to consider the possibility we may be wrong.

But this is unlikely to happen and we will continue to search for feathered tyrannosaurids because they must exist – the phylogenetic data insists it to be true. And this is the point – we must not then fall into the trap of “just because there are no feathered tyrannosaurids, this does not mean they did not exist”.

“Absence of evidence is not evidence of absence” must not become a given in science – not without the proof to back it up. Circumstantial evidence, no matter how strong, can lead to the wrong conclusion and we must all be aware of this. What this lack of feathered tyrannosaurid fossils does indicate, however, is that they are, if they exist, at the very least exceptionally rare but this, again, is not actually proof!

There are so many variables as well – sampling and preservational biases are probably the biggest issues here. It is also worth pointing out that the phylogenetic dataset also has vast gaps in it although there is still a wealth of relevant data available. As usual more fossils are required – especially when you consider how few tyrannosauroids are actually known throughout the Cretaceous.

So “absence of evidence is evidence of absence” is kind of true but, at the same time, is as equally fallible as the other. I accept the near certainty that tyrannosaurids had some form of integument but it is not enough to merely want to believe. In the end we have the data, we have the hypothesis and all we need now is the proof.

Tyrannosaur Forelimbs ......... Again

 

Let me set the scene. It had been a long day and as I walked through the front door of my place I thought I would head straight for the sofa and have a five minute chill before getting some dinner ready. As I lay on the sofa and relaxed I looked upward and there was something that caught my eye that made me realise something about tyrannosaurid forelimbs.

Allow me to explain. Above the sofa there are two wall mounted shelves which have a few fossils on display. These include a mosasaur dentary, a woolly rhinoceros cervical vertebra, a piece of wonderfully preserved tree bark from the Oxford Clay and one of those polished belemnites from Morocco. But central to the display is a cast of a right forelimb from Albertosaurus libratus and, as I looked up, I saw the wickedly hooked manus unguals peering over the edge of the shelf and it occurred to me that tyrannosaur forelimbs were actually very functional. In fact they were not vestigial at all.

Let me explain. I have discussed theropod forelimbs before – particularly those of tyrannosaurs – and one of the more common explanations for the reduction in the size of  tyrannosaur forelimbs was that they actually served no use anymore and that they were, indeed, becoming vestigial. There is a school of thought that had the dinosaurs escaped the end of Cretaceous extinction then tyrannosaur forelimbs would have disappeared altogether.

There is a wonderful depiction by palaeoartist Greg Paul that features in the popular Scientific American Book of Dinosaurs (2000) in which he depicts how dinosaurs may have evolved post Cretaceous and, central to this typical Paul-ian scene, are derived tyrannosaurs with only little stubs remaining where there were once forelimbs. Interesting but I suspect probably incorrect (I would share this image but suspect this may cause a problem).

 

From Lambe 1917.

 

The forelimbs of theropod dinosaurs have undergone significant evolutionary change throughout the whole of dinosaurian history. They have displayed various morphologies and evolutionary trends that, although at first they may appear to follow a convergent path ie reduced size due to bipedalism, actually demonstrate significant differences.

For instance, dromaeosaurids and other similar small theropods have well developed, highly functional forelimbs whilst tyrannosaurids, as we are all aware, appear to have highly reduced and less functional forelimbs but, as we have only recently been examining, large theropods such as the therizinosaurs and Deinocheirus, despite them being Late Cretaceous theropods that were contemporaries of tyrannosaurids, evolved spectacular and large specialist forelimbs.

So there is obviously an element of specialisation displayed here. This can evolve in a number of ways that includes loss and/or modification of digits and carpals, the various morphologies in the manus claws and the variable ways that the muscle framework attached.  As far as tyrannosaurids are concerned (and most other large theropods for that matter) the reduction in the size of the forelimbs was largely due, in part, to their large size but this is only part of the story.

The Late Jurassic Ceratosaurus displays a robust, albeit short, forearm adorned with four digits – a primitive trait retained not only by ceratosaurs and abelisaurs but even primitive tyrannosauroids. It is strange that the derived Late Cretaceous abelisaurids, such as Carnotaurus and Majungasaurus also retained the condition since, if these forelimbs were becoming vestigial, one would expect that, since there is around 85 million years of evolution between Ceratosaurus and Majungasaurus, that the forelimbs would have long disappeared – or am I being over simplistic?

We understand, especially from the well sampled Late Cretaceous faunas of North America that the duration of a species, on average, was between 0.9 to 1 million years – in some cases less. Of course, there are exceptions and, by way of example, the hadrosaur Prosaurolophus maximus appears to have survived over a period of 1.6 million years (McGarrity et al 2013) but this, for now, is the exception rather than the rule. It would seem likely that rapid species turnover and evolution would have accelerated the loss of the forelimbs if they were indeed, vestigial.

The caveat here is that, if we use the Dinosaur Park Formation as an example (Mallon et al 2012), theropods actually remain quite stable taxa-wise whilst all around them the mega herbivores are in an almost constant state of evolutionary flux. And yet time and evolution wait for no dinosaur and theropods were no exception. Environmental, ecological and biological pressure would still have driven evolutionary adaption and change.

So was theropod forelimb evolution destined for vestigiality? Hard to quantify but it would appear there is something else going on here. Perhaps one thing that does support vestigiality is the uniform reduction in digit size in these more primitive forms – that is they all appear to be shrinking at the same rate. But this is where tyrannosaurids differ.

Despite having been discussed at length by palaeontologists over the years, the function of the tyrannosaurid forelimb is still no closer to being solved although there are a few good possibilities. However, the one thing that everyone agrees on is that, despite their size, the tyrannosaurid forelimb was actually robust and quiet strong, capable of sustaining high stress loadings and (if it was feasible) able to lift a considerable weight.

 

Not exactly "vestigial".

 

So, being simplistic again, if the forelimb was becoming vestigial then why reduce the size of the forelimb only to retain significant strength and power? Of course the dichotomy here is that despite being reasonably functional the reduced size of the forelimb greatly reduces their use! This can drive you to distraction but there are factors worth considering.

First of all, and as we have already mentioned, theropods evolved smaller forelimbs because bipedalism demanded it – that is an undeniable fact. Evolution then had the careful balancing act of ensuring that the forelimb complemented the animals’ lifestyle without compromising balance and agility. This was remarkably successful, not only in terms of dinosaurian evolution, but as one of the greatest terrestrial body plan designs of all time. Theropods were amongst the first and amongst the last dinosaurs ever to exist and this basic blueprint lasted for the duration of their tenure on the planet.

Interestingly, the well-publicised paper looking at the evolution of posture, morphological change and the driving forces behind them in bird-line archosaurs (Allen et al 2013) again highlights the exceptional adaptability of the theropod body plan. One of the key findings in the paper is that as the forelimbs of these bird-line theropods became larger, their centre of gravity edged forward and the gradual evolution of the extant crouching bird position came into effect.

It was originally thought that it was the lightening and shortening of the tail that was the locomotor behind the development of the crouch but this excellent research using sophisticated three dimensional modelling techniques clearly demonstrates that the forelimbs were the major contributing factor.

It came as a surprise to find out just how much influence the forelimbs had on balance and posture especially when compared to the tail but the trend was clear. This new research also has implications for tyrannosaurids in as much as it confirms what we already knew – that is that tyrannosaurs, despite being closely related to the maniraptoran line, retained the large powerful tail to counterbalance the enlarged head and that the reduced forelimbs were clearly not as important to them as it was to those theropods that were heading down the avian road. Obvious I know but nice to have it confirmed by the science.

And yet, just to ensure that there are still more questions to answer, John Hutchinson highlights the fact that since the forelimbs were influential in the development of body mass distribution, then they equally affect how the hind limbs developed and functioned. In other words we have to assess the whole locomotor structure rather than just part. This is obvious in so many ways and yet it is something that we all miss when discussing these kinds of topics. One simple evolutionary trend affects the whole of the animal – everything is affected, everything changes – even if we have no fossil evidence. It is not always easy to remember this but it is always true.

Is it possible then that the tyrannosaurid forelimb affected the balance of the animal? Could they have conceivably had any influence on the agility and stability of a tyrannosaur in motion? It hardly seems possible that these small forelimbs could have any realistic effect and yet I am reminded by the halteres in two winged flying insects. These tiny club-shaped structures are situated behind the wings and enable the insect to maintain a high degree of equilibrium. Insects are not dinosaurs and yet perhaps we should not completely dismiss the possibility of tyrannosaurid forelimbs acting as a balancing aid. 

So if some theropods were clearly evolving their forelimbs for, grasping, flapping, flying and, in the case of Deinocheirus and therizinosaurs, for some as yet undetermined functional use, then tyrannosaurid forelimbs  do appear underwhelming  and yet we have other odd closely related theropods with strange arms – the ornithomimids.

Gallimimus

These appear, on the face of it, to be long and highly adaptable – especially for grasping and yet these forelimbs are surprisingly weak when compared to tyrannosaurs. They demonstrate a surprising lack of manoeuvrability due to an under developed antebrachium (that is the area between the elbow of the wrist) and this limited their ability to pronate or supinate. So, despite their impressive appearance, it appears the arms of ornithomimids were best suited for simple reach-and-grasp use.

The thing that should grab your attention with tyrannosaurid forelimbs is not their relative small size but actually that they are quite robust and that the unguals (claws) are potent barbs although in more derived tyrannosaurines such as Tyrannosaurus they do become blunter. Despite the fact that there only the two digits represented, there is a remnant third metacarpal present and indeed does become more vestigial as tyrannosaurids became more derived - so much so that in taxa such as Tarbosaurus it is nearly completely fused with metacarpal 2.

And this is where we came in. Ceratosauria appears to demonstrate a uniform reduction in digit size throughout their long history although I confess to being mystified as to why it would take so long to lose their forelimbs IF they were becoming vestigial. Tyrannosaurids on the other hand clearly lost their digits in sequence – so much so that we find two digits appearing to gradually disappear throughout the tenure of Tyrannosauroidea although there are massive gaps in the fossil record so we must be cautious. The gradual fusion of metacarpal 3 onto metacarpal 2 in derived tyrannosaurids clearly demonstrates this process as digit 3 disappeared.

Metacarpal 3 (bottom) slowly disappearing in Albertosaurus

But the remaining two digits are clearly of importance to tyrannosaurids and, as always, it is difficult to ascertain what and why they were used. In my previous discussion about tyrannosaur forelimbs I speculated that if tyrannosaurids were feathered to some degree then perhaps they were used in courtship rituals – a kind of “don’t eat me – I’m here to mate” signal. You would think that tyrannosaurids must have had some form of intraspecific communication – even if it was just for the mating act.

Indeed, it was gratifying to hear Thomas Holtz Jr during his recent talk at the Burke Museum in Seattle a short while ago suggest exactly this and the more you study these structures the more intriguing they become. However I have been leaning toward a similar but subtly different use for them.

Pathologies in the forelimbs we have are not uncommon and they demonstrate various fractures, remodelling and scarring right through the entire forelimb right up to, and including, the furcula. There are various reasons for these pathologies and they could be as simple as the animal falling down and breaking an arm. Tyrannosaurids are huge animals and a fall onto a forelimb could have caused considerable damage and pain.

However, it occurred to some of us that perhaps the forelimbs were used to assist in copulation and gave the males some purchase during the act – as well as helping to fend off an over aggressive female. This made some sense since trying to hang onto a large multi-tonned female during copulation would have caused considerable stress to the forelimbs and injury would appear inevitable.

Gorgosaurus sp. (BHI#126846) displaying
 acute pathology to the scapulacoracoid

However, as pointed out by others (eg Rothschild & Molnar 2008), this would seem unlikely since the T. rex Sue (FMNH PR2081) shows considerable pathologies to the humerus and scapulacoracoid and – of course – this specimen is widely accepted to be a female. It is still worth pointing out that sexual dimorphism in tyrannosaurids is unproven although it does appear that there are specimens that display both gracile and robust features so dimorphism seems likely.

But I do not believe that this should disqualify the mating hypothesis since tyrannosaurids led such a hazardous life and multiple pathologies are found throughout their entire skeleton. It is entirely conceivable that the forelimb was used in the act of mating and, at the same time, was equally susceptible to injuries that occurred during hunting, falling and the other day to day hazards that befell any carnivorous dinosaur during life.

Of course (and how many times have I said this?) this is all behavioural inference and likely to be unproven and yet the more you look at these enigmatic structures the more you realise that there is so much more to them than meets the eye. For me, I just cannot accept that what is actually a robust and derived specialist bit of equipment was actually vestigial. But, as always, I remain open minded and look forward to the next hypothesis regarding these extraordinary forelimbs.

And a word of thanks

The viewing figures for this blog recently crashed through the 100,000 mark and I feel really humbled by that. Bloggers, such as myself, who want to make a contribution to our science will never have the aura and pulling power of the uber bloggers such as Dave Hone, Brian Switek and Darren Naish but we all contribute in our own way and long may that continue.

So a very big thank you to all of you who have taken the time to read these pages - it really does make all the difference.

 

References

Allen, V., Bates, K.T., Li, Z., & Hutchinson, J.R. (2013) Linking the evolution of body shape and locomotor biomechanics in bird-line archosaurs Nature DOI: 10.1038/nature12059

Lambe, L. 1917. The Cretaceous theropodus dinosaur Gorgosaurus, Memoirs of the Geological Survey of Canada. 100, pp. 1–84.

Lipkin, C., & Carpenter, K. (2008) Looking again at the forelimb of Tyrannosaurus rex. In: Tyrannosaurus rex, the tyrant king. Larson, P. & Carpenter, K. (eds.). Indiana University Press. Bloomington & Indianapolis, Larson, P. & Carpenter, K. pp.167-190.

Mallon, Jordan C., Evans, David C., Ryan, Michael J., Anderson, & Jason S. (2012). Megaherbivorous dinosaur turnover in the Dinosaur Park Formation (upper Campanian) of Alberta, Canada Palaeogeography, Palaeoclimatology, Palaeoecology Volumes 350-352 pp. 124 – 138.

McGarrity, C.T, Campione, N.E. & Evans, D.C. (2013) Cranial anatomy and variation in Prosaurolophus maximus (Dinosauria: Hadrosauridae).Zoological Journal of the Linnean Society 167(4): 531–568

Paul, G.S. (Editor) 2000. The Scientific American Book of Dinosaurs. St. Martins Press. pp. 384-385. ISBN-10: 0312262264

Rothschild, B. M. & Molnar, R. E. 2008. Tyrannosaurid pathologies as clues to nature and nurture in the Cretaceous. In: Tyrannosaurus rex, the tyrant king. Larson, P. & Carpenter, K. (eds.). Indiana University Press. Bloomington & Indianapolis, Larson, P. & Carpenter, K. pp.287-304.



Obviously not a true comparison but interesting none the less.

Deinocheirus - The Truth ( Sort of )

From Osmolska & Roniewicz (1970)

 

Well I must say that I was glad that my April fool’s post was taken in the spirit I intended.  I was a little apprehensive since this was my first prank as a blogger and did not want to ruffle anyone’s feathers. I needn’t have worried and it made a pleasant change to have a bit of fun.

However, what the post has proven is that many of us have this insatiable thirst for the truth about Deinocheirus. It’s not hard to understand why. Since those forelimbs were recovered way back in 1969 we have all wondered about this enigmatic animal. I mean these forelimbs are eight feet long – eight feet!

Many of today’s palaeontologists and bloggers grew up in the dinosaur renaissance period – when dinosaurs really came to life as living, breathing, highly active animals. Throughout this period many dinosaurs went through rigorous reanalysis and restoration and we all got carried away with the hot blooded dinosaurs. Despite the renaissance somewhat levelling off throughout the eighties,  in 1993 Jurassic Park was released and was the spark for a whole new wave of interest and research into dinosaurs which has continued to proliferate into today’s fast moving science. And yet, in all of this, the truth behind Deinocheirus has remained hidden and the animal has held station as a more or less unknown quantity - except in phylogenetic analyses.

Before the onset of modern day cladistics and phylogenetics there was always the possibility that Deinocheirus was indeed a mega-theropod – built along the same basic blueprint as any theropod. But because it could not be imagined that any theropod could be THAT big it was thought that Deinocheirus may have been built along similar lines as a giant ground sloth and used its long arms in a similar way.

Of course, and in the same vein, the claws of therizinosaurs were also known at this time (in fact known since the 1940’s) and this animal too proved to be problematic for many years, initially being identified as probably being a turtle-like reptile. It was over twenty years before they were realistically identified as belonging to a theropod dinosaur. Fast forwarding a further twenty five years and new specimens turned up that allowed a pretty accurate restoration of therizinosaurs as a group.

But the so-called deinocherids have still not yet been satisfactorily classified and this for many, myself included, is really frustrating. So they may be primitive ornithomimosaurs but, realistically, we have not really progressed any further in nearly fifty years. Why is this?

Well, for me, and perhaps at the risk of sounding obvious, we do not have a lot of material. There is only the holotype that we have good material for and that, in real terms, is not a lot. However, back in 2008, Phil Currie relocated the holotype quarry, which was reopened, and there were was more bone collected. What this material consisted of is unclear but certainly some elements were subject of a paper published in 2012 (Bell et al 2012) which looked at feeding traces on these bones which were most likely made by a tyrannosaurid.

Now whether there is still more significant material from the quarry still being described is unclear at this moment in time but, as is the way, rumours persist. It may very well be that the Bell paper represents all that was recovered from the site and that maybe that. Until something concrete is published then Deinocheirus will remain the great unknown.

For me, this lack of fossils is actually one of the most interesting points regarding Deinocheirus and suggests that this animal most likely inhabited a completely different environment from the rest of the better known Nemegt fauna. Tarbosaurus, in comparison, is extraordinarily well known and fossils of this tyrannosaur are not uncommon. Tarbosaurus and its contemporaries lived in a warm, meandering fluvial environment and, for me, this is highly indicative that Deinocheirus was living elsewhere.

If Deinocheirus preferred a different, more upland environment then it could go a long way to explaining the lack of fossils. Dinosaur skeletons need to be buried quickly if they are to fossilise and the chances of any skeletal remains from any dinosaur making it through to fossilisation in an upland environment are massively reduced.

 

From Osmolska & Roniewicz (1970)

 

There is further, somewhat unfortunate evidence, to support this. Poaching and vandalism in the Nemegt is not uncommon and we are all aware of the stories. There are many instances, especially with Tarbosaurus, of skulls being removed from some good articulated specimens and the rest of the skeleton being vandalised or completely destroyed. This is very hard to police and despite the many vociferous displays of condemnation, fossils from Mongolia still end up on the open market whilst the very best examples are probably smuggled out and sold privately to the highest bidder.

But this does highlight just how rare any example of Deinocheirus must be. With the amount of illegal excavating there has been over the last twenty years, it is inconceivable that, if any decent material had been recovered, that someone would not have heard anything by now. There would be rumours - someone would know.

So unless anybody knows any different, then it is extremely unlikely that there is any other significant material from Deinocheirus in circulation. Of course it is possible that there may some material in an unopened jacket waiting to be discovered in the bowels of some institution but this is unlikely. So for me Deinocheirus will remain an enigma for some time to come.

Of course, we may simply be looking in the wrong place……..

References

Bell, P.R., Currie, P.J., & Lee, Y.N. (2012). Tyrannosaur feeding traces on Deinocheirus (Theropoda:? Ornithomimosauria) remains from the Nemegt Formation (Late Cretaceous), Mongolia. Cretaceous Research (37) pp. 186-190.

Osmólska, H. & Roniewicz, E. Deinocheiridae, a new family of theropod dinosaurs. Palaeontologica Polonica 21, 5-19 (1970).

 

 

 

 

 

 

 

 

 

 

 

 

 

Newly Discovered Skeleton of Deinocheirus Reveals Mega-Theropod

 

A new, virtually complete, specimen of the enigmatic theropod Deinocheirus mirificus, discovered in the Nemegt Basin of the Gobi Desert in Mongolia looks set to shake the world of theropod phylogenetics to the core. This specimen of Deinocheirus was recovered from Upper Cretaceous deposits not too far from where the original specimen was found at Altan Ula III and provides undisputed evidence that this animal represents a new gigantic sized coelurosaurian clade.

The specimen is currently being described and will be officially published later this year in the Proceedings of Earth Sciences – this current press release appears to be a taster of what is to come and is typical of some of today’s fast moving media-driven palaeoresearch.

 

“This has completely surprised us and we could hardly believe our eyes as the skeleton slowly emerged from the rock. A complete specimen of Deinocheirus is a palaeontologist’s dream and to find it so close to the quarry where the holotype was found is rather fitting.” said palaeontologist Dr. Pol T’Othewan, leader of the excavation and research team at the Nemegt Basin Research Centre (NBRC) in Dalanzadgad, Ömnögovi Aimag in Mongolia.

Deinocheirus is most famously known because of its huge forelimbs which are around 8 feet long. Although clearly a theropod dinosaur, the phylogenetic affinities of Deinocheirus have long been debated and the animal has been tentatively assigned as a megalosauroid, coelurosaur or, indeed, something in between the two. The most recent phylogenetic analyses return Deinocheirus as a basal ornithomimosaur but this new specimen looks set to confound the experts.  

“When Deinocheirus was originally discovered it was thought that because the forelimbs were so big that the rest of the animal could not possibly be of the same stature otherwise its size would defy imagination – they were wrong” said co-worker and palaeontologist Gotya Sukker – also of the NBRC.  “What we have now appears to represent an offshoot coelurosaurian clade displaying both primitive and derived characters and that Deinocheiridae is, indeed, a very distinct family. The size of the animal is astonishing and the skull alone makes the skull of Tarbosaurus look maniraptoran in comparison.”  

The specimen, which appears to be a fully mature individual, was found in the sandstones of the Upper Nemegt Beds and, despite being largely disarticulated, is essentially all there and appears to have suffered very little erosion which suggests that it had only been recently exposed at the surface before being discovered. The specimen was immediately identified as Deinocheirus, whose name means “terrible hand”, when the enormous forelimbs were excavated.

“Close examination has revealed several characters that are totally unknown in other dinosaurs – let alone other theropods. Certainly there is extensive remodelling in the vertebral column and a degree of pneumaticism only previously seen in sauropods and the hind limbs are incredibly long and strong” said another member of the team, Luke Anyulsee, of the University of Kehlsdorf in Austria.

Deinocheirus has always been an enigma in dinosaurian palaeontology but this skeleton, because of its completeness, will give us new insights into coelurosaurian evolution and has significant ramifications for dinosaurian phylogenetics as a whole.

“It has generally been accepted for some time that Deinocheirus was probably an over-sized ornithomimosaur with similar habits and lifestyle to its smaller cousins” Sukker said. “This specimen shows that, despite displaying ornithomimids traits in some parts of the skeleton, it was obviously something completely different. The skull is enormous – far bigger than any previously known theropod skull and the dentition is frightening. Deinocheirus would have unquestionably been the hyper-carnivore of its time”.  

Adult tyrannosaurs too, by comparison, were enormous animals and Tyrannosaurus was around 40 feet long with a skull approaching 5 feet long. Spinosaurus, despite being poorly known, is estimated to be around 50 feet long. When asked how they compare with Deinocheirus, T’Othewan is remarkably blunt in his response.

“They don’t – there is no comparison. Deinocheirus would have them sliced and diced and ready for breakfast before they knew it. This is now THE mega-theropod of the Mesozoic.”

This research is being funded by the Avril Tromper Foundation in Paris.

The Prep Room

 

By now you will have gathered by the somewhat irregularity of my posts that I am a little busy right now. There are so many things on the go at the moment that it has been a case of having to prioritise what needs to be done first and, unfortunately, the blog suffers as a result but I hope this will eventually sort itself out and I will be able to blog regularly again real soon.

However, one task that I have been busy with is the setup of a preparation room that is slowly beginning to take shape. This is not a large laboratory by any means but, when it is finished, will provide a good quality work station for one technician and will provide enough room and facilities accordingly.

This facility has been designed to work on material already extracted from their jackets or indeed those that are in smaller, more manageable jackets that can be satisfactorily handled by one technician. As a result the space needed to extract specimens out of a jacket is small in comparison to those in the larger facilities that may sometime deal with extremely large and heavy blocks. I am currently looking at a mobile bench arrangement that needs to be strong and will probably be a form of scissor lifting table which will be of  benefit to both  the technician  and the specimen but,  in truth, this should be seldom required.

The workspace itself is spacious and well set out. Because of the nature of the specimens that will be prepared the technician will be able to use the one space for the majority of the preparation. There is room for a microscope and there will be a flat screen mounted on one side to stream images which will be incredibly useful. If you are considering a similar set up then remember to provide the screen with appropriate protection since one stray piece of matrix can cause substantial damage which most labs can ill afford!

Adequate ventilation and extraction is provided and the prep room is remarkably temperature stable and humidity virtually non-existent. There is ample space provided for a variety of tools close to hand. A separate space is provided for the various glues and consolidants but this too is close to the operative and easily accessible.

At SVP last year Greg Brown, of the University of Nebraska State Museum, discussed the various merits of different lighting for microvertebrate preparation and this too is being looked at. As well as conventional illumination, we will be experimenting with LED’s (which have received mixed reaction) and will definitely be using polarised lighting in one form or another.  Unfortunately, the room has no windows or natural light which is a shame since I know from experience that you can often discern detail in this light that can be occasionally missed by other light sources.

Seating is another high priority that has yet to be finalised. It is not enough to simply have an operators chair and believe that is that. So many things need to be considered including ergonomic design, practicality and that it provides adequate support and comfort to the technician. Poor posture needs to be eradicated as much as possible and the correct seat will help do this. Ensuring regular breaks from repetitive operations will benefit any preparator and the technician must be encouraged to manage themselves accordingly. It goes without saying that personal protective equipment (PPE) is available and includes safety glasses and face masks as standard.

Aside from the practical side of things there is also the paperwork side of things to maintain but this will not be situated in the prep room and is located more or less next door where there is a computer, files, records and both camera and video equipment for the entire project.

So all in all this should be a simple but practical preparation set up and will help us be more progressive as we continue our research into our chosen subjects. Despite marine reptiles featuring heavily in preparation there just might be the odd fish and dinosaur from time to time so it will be a good idea to watch this space because there is definitely some very interesting material coming up for prep. 

Project Daspletosaurus 2013 - Almost There

Just a quick reminder to say that there is still time to chip in with a donation to Dave Hone's research project into possible cannibalism in the tyrannosaurid Daspletosaurus. The  response from the paleocommunity, yet again, has been terrific with just about $200  more needed to reach the target. If you haven't heard about this (where have you been?) then I urge you to head over to the page here , donate and be part of some very cool research.

Well done to everyone who has already contributed - I hope that this will encourage similar projects in the future.

The Perils of New Age Palaeontology

 

Let me say straight away that this post is in no way intended to offend anybody whatsoever in the palaeontological world! Rather it is just an objective look into how some people’s perception of palaeontologists may lead to an unfortunate stereotypical opinion of science whilst, at the same time, may also be indicative of the odd failing in our community.

I’ve been thinking about this post for a while now which was initially prompted by a comment by Jon Tennant that he had been told by a palaeontologist that bloggers such as ourselves and our other fellow web publishers are unqualified to make any relevant comments regarding the science since, that before you could make a comment, “…..you have to be an author of a study or you are under qualified”.

Whether this was tongue in cheek or not is neither here nor there but I wondered how prevalent this attitude may be throughout the palaeoworld. A very recent comment by fellow blogger Ian Garafalo, of the Other Branch, that he didn’t “…..really fit in with the rest of the online paleo community” was also suggestive that anybody who did not conform with the norm as established by the general paleo community was somehow disconnected from the larger community as a whole. This may simply be a matter of perception but it may also harbour one or two divisive points that we can and should address.

I like to think that all of us in the paleo community share a common bond and we all want to make a contribution in some form or another. At the bottom end of the scale is the ordinary guy in the street who has a passing interest in palaeontology such as when, perhaps, there is a new dinosaur announced and he wants to know more about the animal, what it was like, what it ate and where  and when it lived.

At the other end of the spectrum are our very best palaeontologists, many of whom are world renowned, and command the respect and admiration of the rest of us. These are the men and women who are as familiar to us as a Hollywood star would be to everybody else – people such as Benson, Brusatte, Horner, Holtz, Currie, Witmer etc. These are at the very top end of the paleo tree.

And in between these two groups are the rest of us – other palaeontologists, the preparators, the avocationists, the bloggers, the students, the museum volunteers, the artists – the list goes on. Each of us, in our own way, make a contribution to our science and, regardless of the size and merit of that contribution, are all therefore equally important.

However, professional palaeontologists are the most important contributing group in our community. It is through them that we get the very latest information that is brought to us through the various journals and conferences and, on occasion, that big story that breaks on a worldwide scale and is brought to us via the various media outlets.  Let’s face it – all of us thirst for the next paper that  bring us that detail we have been  waiting for and, even better than that, when something breaks that many of us did not even know of or had heard about. These are great moments and the buzz in the paleo world when this happens can last for days, sometimes weeks and then the cycle begins again as we wait for the next story to break. 

So our palaeontologists are important and are nearly always busy but, like all of us, they are all human beings and suffer the same trials and tribulations as the rest of us. This is extremely important and something that the rest of us must always consider. They have to deal with every day work and family issues and, as a result, suffer the same failings as the rest of us.

So it should come as no surprise that, on occasion, the busy palaeontologist may be unable or unwilling to talk to us, answer an email or share his data with others. Indeed, with some research, it is essential to maintain an element of discretion and only their fellow workers would be privy to that research.  And they will have bad days – real bad days.

And herein lies the problem in as much that these occasional lapses may be interpreted by Joe Public as a form of elitism. The palaeontologist (in fact any scientist in any discipline)  can be seem as if to be keeping things to him or herself, unwilling to discuss or share unless with their intimates and, to  the layman, this behaviour can be interpreted as disingenuous and unwelcome.      

But is elitism a totally bad thing? In many ways our elite palaeontologists are exactly that because they are the best at what they do. They have spent years of toil and study to get where they are and the academic selection process enables them to progress onward and upward and they are, therefore, selected as elite by achievement.

Having reached this status, the palaeontologist then has a delicate balance to maintain and, on occasion, this may not always appear palatable. They may choose not to disseminate data, can be obstructive and, as we have already heard, perhaps disregard other peoples work or comments because they are not “real” palaeontologists.

Sometimes this attitude may also be directed at their fellow palaeontologists and I actually find this to be more disturbing than actually, for example, being directed at someone like me. Just because you believe or even know that you are right should not give anyone the right to disregard somebody else’s hypothesis because since,  and before you know where you are, splinter groups arise and the harsh spectre of  tribalism raises its ugly head  and, as I have said before,  a couple of factions throwing insults around about each other benefits nobody. Unfortunately this scenario has occurred on occasion and I know of at least two rather high profile cases.

However, as unfortunate these cases are, they are still relatively unusual but when a similar attitude is reflected upon those outside the professional sphere then we have a problem. Why should any reasonable comment or theory be dismissed just because they are not published in an approved journal? And, even worse in some quarters, what if they are published in a non-approved publication?

No matter who you are, you should not be ostracised because you are not a “real” palaeontologist and you should certainly not have your ideas discredited – not because they are wrong – but because that they are published in a blog or in a non-sanctioned journal. Indeed, online publishers face a far greater critical audience and they know, or should know, that when you put your work, opinions and ideas up for public scrutiny that you will attract attention and you should be prepared to accept this criticism. Critique the work yes but do not ignore it or regard it as below status. 

Importantly, interpretation of data from all quarters needs to be fair and as accurate as possible. Unfortunately palaeontology, or indeed any science, is seldom a straight forward affair. In an ideal world we would find our fossils, prepare them, measure and research them and this would enable us to form our hypotheses about them whilst, at the same time, being able to disqualify others – the data supports the hypothesis – simple.

As we are all aware, however, this is seldom the case and the palaeontologist again needs to maintain a delicate balancing act.  In our science, because we are dealing with fossil remains, there are many occasions when a theory can only be formed because of subjectivity and all of us – but all of us – will do this. The trick is not to let any biases or any preconceived ideas influence your decisions. This is never easy since data can be notoriously erroneous and deciding which data is useful and that which is not can make and break a theory. Indeed, testability is crucial.

It is up to the palaeontologist to try and present the facts in a clear and concise way that in no way has had the data bent or twisted to accommodate the hypothesis. This is the very essence of good science because then the palaeontologist is not only understanding his own research but is always questioning himself about it time and time again before he is happy. This is a discipline to be admired since it must take a long long time to develop.

Having said all this I have to say that the vast majority of my experiences within the palaeontological community have been nothing but good at all levels of the science. There has been the odd occasion where I think I may have been a little hard done by, unfairly criticised or ignored but these are extremely few and far between. Indeed, over the years, I use these experiences to learn about how the palaeoworld works and, more importantly, to learn about myself as well as others.

Palaeontology of today is global. We are able to communicate with each other in ways that are unparalleled when compared with the past. Avocationists, amateurs and everybody else are able to communicate with palaeontologists of all levels via the social networks, the blogs and the conferences.  Once we were only able to watch these guys on the occasional TV program or when reading the odd magazine article or book – today we communicate with each other on a surprisingly regular basis.

We know who is in the field and where they are, we get instant notification of new discoveries and the same with new publications. Everything we see and do is disseminated instantly amongst all of us and I, for one, would not want it any other way. Palaeontology of today is fast moving, fluid and ever changing and where we will be in fifty years’ time blows the mind.

So we have to accept that there will be times when things do not quite go as we want, when people do not quite respond in the way we would expect and our friends and colleagues may appear a little short sometimes. This is the price we all pay for today’s instant communication and when you consider how rare these discretions are in the palaeoworld then surely it is a price worth paying.