Tuesday, 7 April 2015

Forelimbs, Wings & Other Things

The following blog post was really scheduled for a couple of months ago but I just never got round to publishing it. Having said all that, the science is still cutting edge and just as fascinating as it ever was so I hope you find it of interest.

Forelimb reduction in theropod dinosaurs has long since fascinated. It is a constant source of interest that some of the largest carnivorous dinosaurs reduced the size of their forelimbs to such a degree that it would appear that they were almost becoming vestigial or, at the very least, were only capable of speculative rudimentary function. Chief amongst palaeontologists looking at this enduring mystery is Sara Burch of Ohio University.

To tackle these enduring questions, Burch approached the issue in quite a unique way – firstly by constructing a model of the ancestral forelimb muscle arrangement highlighting any associated plesiomorphies. Then, by looking at the phylogenetic signals generated by examining the evolutionary processes in various theropod lineages, Burch has come up with some useful data.

Both allometric and evolutionary trends suggest that there is no evidence for a general reduction in forelimb size throughout Theropoda. A clade by clade study also revealed interesting myological trends – particularly in Abelisauridae and Tyrannosauridae. Abelisaurids display a quite unique morphology and yet, despite their forelimbs appearing to be useless, the study reveals them to be still functional. It is unlikely that they were capable of much, however, and it may be that the forelimbs were used for sexual stimulation – speculative, of course, but not the first time this has been suggested for abelisaurids or, indeed, tyrannosaurids.

Tyrannosaurids themselves have robust and muscular arms and one suggestion to try and describe a particular use for these forelimbs was that it enabled the animal to push itself up from the ground when required. This particular hypothesis was modelled accordingly with the outcome that there is no justifiable support for the theory. But what about possibly using their arms for grasping or holding prey? Muscle correlation concludes that this was indeed possible supporting the evolutionary trend that reduction in forelimb size is not necessarily about vestigiality but rather to satisfy an evolutionary demand. As with abelisaurids, the theory that tyrannosaurids may have used their forelimbs intraspecifically remains untestable.

Pterosaurs currently remain the biggest flying animals of all time and yet was there a size limit that dictated how big a pterosaur could be and still manage to take off, fly and land? Colin Palmer, of the University of Bristol, and Mike Habib of the University of Southern California, have been addressing these very issues.

 Azhdarchids were the giants of the pterosaur world but estimates of their weight and mass vary considerably. For example, Chatterjee & Templin (2004) suggested a body weight in the region of 70Kg whilst Mark Witton (2008) and Witton and Habib (2014), more realistically for an animal approaching the size of a giraffe, estimated 260Kg. The general consensus is that the latter is probably correct.    

As for wingspan it appears that the most common sizes vary from 5 metres to 9 metres with an upper limit, perhaps, of twelve metres – true giants. Computer models were generated for pterosaurs with 6, 9 and 12 metre wingspans which were as structurally and aerodynamically as accurate as the fossil record allows bearing in mind most of the data is derived primarily from ornithocheirids.

For an azhdarchid to remain in the air depends, essentially, on the available power that is generated by the muscles. The model indicates that these pterosaurs were capable of generating sufficient power to maintain station once airborne and, interestingly, that the ability to stay up does not limit the size of the pterosaur. In other words, pterosaur maximum size is limited by the amount of tensile stress generated but is not limited by size alone. Therefore, it is quite feasible for a pterosaur with a 12 metre wingspan to remain airborne.

What about landing? A large extant bird requires a stopping distance of around 4 metres per second and the models predict that large pterosaurs also fall within this range and the authors point out that the robust hind limbs of azhdarchids make for a pretty sturdy undercarriage so it seems possible that a pterosaur with a 12 metre wingspan could also land safely.

But could a pterosaur of these proportions generate the sufficient power, technique and thrust to launch itself into the air?  It is safe to assume that pterosaurs utilised both forelimb and hind limb musculature to achieve take off and the computer models generated for this research reflect this although, interestingly, 80 to 90% of the required take-off thrust for both birds and pterosaurs is developed from the hind limbs.

Anhanguera forelimb musculature - from Witton & Habib 2010

Taking other factors into account such as oscillation and both launch speed and height indicates that it is problematic for pterosaurs to achieve take off as they get bigger since they could not evolve a sufficient muscular array that would be structurally efficient for take-off. The results suggest that we can predict with confidence that pterosaurs with a 9 metre wingspan could successfully take off but with a lesser degree of confidence that those with wingspans between 9.5 and 11.5 metres could achieve launch.

Thus this research is indicative that 12 metres is currently the absolute wingspan limit for pterosaurs – which we know of. This is really interesting research and it would be fascinating now to see the response if another pterosaur is found with perhaps a 14 or 15 metre wingspan. Unlikely of course but that would really put the fat into the fire because who would not want to know how that would have been achievable and what other factors would need to be considered.

Theropods come in all shapes and sizes and we are familiar with the various sizes and morphological differences in their teeth but what about the actual mandible itself? Is theropod jaw form representative of function or, indeed, is the taxanomic, morphological and functional diversity of the lower jaw a predictor of functional and biomechanical diversity? Emily Rayfield, of the University of Bristol, and her colleagues have been asking these very questions.

A sample size of 103 specimens was analysed using a combination of geometric morphometry and biomechanical metrics. The authors point out that the sample size, although relatively broad, is still nowhere near large enough but included a diverse group sampling which included, amongst others, non-tetanuran theropods, non-maniraptoran tetanurans and maniraptorformes themselves.
So do theropods that feed on different things have different shaped jaws? Apparently not since the authors discerned no particular signal from this analysis. What about functional traits in theropod jaws?  The authors recognised 19 traits in 68 of the taxa that are related to jaw robustibility and the enlargement of the coronoid process which contribute to the overall shape and biomechanical variation. As a side note it is worth pointing out the oviraptorosaurs, although included in the analysis, are quite distinct from this overall grouping and were obviously doing something very different.

Theropods that are herbivorous or exhibit omnivorous tendencies display different shaped jaws to traditional carnivorous types which is to be expected. Theropod mandibular evolution throughout the Mesozoic suggests that there is likely to be a link between form and function and this is supported by phylogenetics which does indeed exert a strong signal. However, this is probably exaggerated by the fact that Maniraptora filled many different ecological niches from the Late Jurassic onward which would have demanded more morphological variation. The overall link, therefore, between morphological change  and functional diversity is tenuous at best and suggests that perhaps the shape of the jaw does not always necessarily reflect the evolved and/or derived  state of different theropod jaw mechanics.  

Burch, S. 2014 Osteological, myological and phylogenetic trends of forelimb reduction in nonavian theropods. Journal of Vertebrate Paleontology, SVP Program and Abstracts Book, 2014, pp100. 

Chatterjee, S. and Templin, R. 2004. Posture, locomotion, and paleoecology of pterosaurs. Geological Society of America Special Publication 376: 1-64.

Palmer, C. & Habib, MB. 2014. All time giants of the air: new approaches to calculating the limits to the size of pterosaurs. Journal of Vertebrate Paleontology, SVP Program and Abstracts Book, 2014, pp200-201. 

Rayfield, E., Conium, R., Benson, R. & Anderson, P. 2014. Ecomorphological and functional variation in the theropod dinosaur mandible. Journal of Vertebrate Paleontology, SVP Program and Abstracts Book, 2014, pp212. 

Witton, M. P. 2008. A new approach to determining pterosaur body mass and its implications for pterosaur flight. Zitteliana Reihe B 28: 143-158.

Witton MP, Habib MB (2010) On the Size and Flight Diversity of Giant Pterosaurs, the Use of Birds as Pterosaur Analogues and Comments on Pterosaur Flightlessness. PLoS ONE 5(11): e13982. doi:10.1371/journal.pone.0013982

Saturday, 24 January 2015

The Lost Tyrannosaurid of Kazakhstan

Tyrannosaurids are best known from the Late Cretaceous deposits of North America and Asia and, it is fair to say, that we have a very reasonable fossil dataset from both continents. And it is also worth reiterating that our understanding of tyrannosaurid paleobiology and phylogeny is one of the fastest moving disciplines in palaeontology. This should surprise nobody as they are amongst the most interesting and impressive of all dinosaurs and, as such, will always inspire a fervent following – myself included.

In recent years we have seen the arrival of new tyrannosaurids such as Teratophoneus, Bistahieversor, Lythronax, Nanuqsaurus and Zhuchengtyrannus - and there are more to come. For instance we already know that there is a second species of Daspletosaurus in the pipeline for publication (Carr & Varricchio 2014) which I will, obviously, blog about in due course and there are one or two other surprises coming in the future as well. Even the relatively unknown Alioramus has undergone an extensive redescription recently due to new fossils being found (eg Brusatte et al 2009, Brusatte et al 2012, and Lü et al 2014) and we have a much greater understanding of the so called “narrow snouts” than we ever did.

So we appear to know a lot about them but, in real terms, we still understand very little and interpretation of the fossils is often subject to debate. Tyrannosaurids of all taxa are actually very similar animals and, to be fair to all the palaeontologists concerned, it is easy to see why there are so many discussions when so many of the anatomical details are often slight. One man’s new taxon is another man’s different ontogentic stage of a current taxon. Morphological change throughout ontogeny is, without a doubt, the biggest single determining factor in dinosaur phylogeny.
The origins of Tyrannosauridae and its distribution is also a matter of contention - some people prefer an Asian origin whilst others, by way of example, now favour a radiation that evolved in southern Laramidia. I favour neither nor disregard either and I believe that it is fair to say that there were obviously multiple migration events with taxa of different  groups from both Asia and North America moving back and forth across Beringia which, unsurprisingly, may also give strange or false phylogenetic signals on occasion.  

The earliest true tyrannosaurid is undoubtedly yet still to be discovered and we do not have the best dinosaurian fossil record beyond the Campanian and it would be terrific if there were fossils to be found in the Santonian and probably the Coniacian too – but where would be anyone’s guess.
So with all of this in mind it seems that, despite the relative wealth of fossil material that we have of tyrannosaurids, we are in need of a hell of a lot more to increase the dataset. So it can cause consternation amongst palaeontologists’ when what may be important specimens to science are sold off at auction. Thomas Carr recently highlighted a number of Tyrannosaurus specimens that are held in private hands and, as such, are off limits to professional researchers.

This is unfortunate. There are many who would say that since there are multiple specimens of Tyrannosaurus already in institutions then what is the point of having more? Without increasing the aforementioned dataset then we will continue to have large gaps in our knowledge and never be able to fully understand the paleobiology, morphology and ontogeny of these majestic creatures.

And just to amplify how important it is to have a large sample we need look no further than by using another Hell Creek giant, Triceratops, as an example. There are hundreds of skulls of this animal – hundreds! In fact nobody is really sure just how many there are but when compared with good skulls of Tyrannosaurus (perhaps 20?) then it is amazing that there is still debate regarding the amount of Triceratops species there are, whether Torosaurus is the adult morph of Triceratops and, indeed, the amazing morphological change that is displayed throughout ontogeny.  Indeed, this is just as applicable to other ceratopsians as well.

Hadrosaurs are another extremely well known group and, although there are many interpretations of their fossils, they do not appear to induce the often emotional discourse that follows tyrannosaurids and, to a lesser degree, ceratopsians. And we have not even got to the world of dromaeosaurids and troodontids for which there is a dearth of GOOD fossils but no shortage of opinion and speculation.

Therefore tyrannosaurid specimens are important – all of them and, as we can see, this relates to all clades of dinosaurs as well. So when I learnt that a rather stunning tyrannosaurid maxilla and premaxilla from the Republic of Kazakhstan had come to the surface I became rather excited. There is a diverse fauna of Cretaceous dinosaurs that are recognised from the ex-soviet republic including Hadrosauridae, Ankylosauridae, Sauropoda and Tyrannosauridae amongst others.

Some remains can be locally abundant – hadrosaurs in particular whilst others are known from rather scrappy and indeterminate remains.  Averianov et al (2012) reported on a right dentary from an unspecified tyrannosaurine that was recovered from Late Cretaceous rocks in Kara-Cheku which is located in Almaty Province. This was collected back in 1950 and labelled as belonging to Tyrannosaurus sp. – actually delightfully labelled as “Tirannosaurus”.

Without decrying the specimen too much, it is not the most aesthetically pleasing example but it is, never the less, an important fossil and the authors were able to confirm its assignation to a tyrannosaurine tyrannosaurid. The fact that this is one of the better tyrannosaur fossils from Kazakhstan again reinforces how poor the record is from this country and we hope that more specimens will be discovered in due course.

So where on earth did this new specimen come from? The documentation, such as it is, is fairly vague. It was collected in, and, I quote “…the second half of the previous century...” from the Zhetysu region of Eastern Kazakhstan. If correct then this is certainly of interest since the eastern region has been considered fairly non-productive for Cretaceous vertebrates (Averianov et al 2012) so one wonders about the collecting locality of this specimen. The specimen itself is striking and represents a right maxilla with its accompanying premaxillary attached and is approximately 360mm in length albeit with about <>5% restoration . As you can see, there are at least 12 maxillary teeth in situ and it appears that the four premaxillary teeth are also present and correct. All the teeth are genuine and in position as found.

The maxilla displays a gently convex anterior edge but the posterior appears not to be as acutely convex as is the case in Zhuchengtyrannus (Hone et al 2011). The 12 maxillary alveoli is the typical count for both Tyrannosaurus and Tarbosaurus. The rugose surface is also common in derived tyrannosaurids although this sculpting is more heavily defined in mature specimens – which this does not appear to be.  The subnarial foramen is readily apparent but detail is hard to define. But then this is the real point about this specimen. In comparison with known tyrannosaurid material from Kazakhstan this specimen is actually quite spectacular and really important and we should all look forward to its description.

But there is a disturbing caveat here. The only reason I am aware of this specimen is that I was tipped off that it was going to auction and all this “detail” I have is only because I referred to the auction website and inspected the images. I do not intend to go into detail here but the specimen was sold into private hands for a not inconsiderate amount of money and these pictures I am sharing with you today may very well be the only public record of this specimen now that it has probably disappeared forever.

Now it may be that this specimen is not from Kazakhstan at all and when you have a specimen with so little recorded history then it is a little bit of a punt whether the specimen appears to be what it says it is. Regardless of this, and in the correct repository, careful research should be able to address the taxanomic issues and, perhaps, where the fossil originated from. If it is from Kazakhstan then it is important, important, IMPORTANT!

It does not matter what your opinion is on the buying and selling of fossils – for there are many but one thing remains absolutely certain. It is awful that important specimens, like this tyrannosaurid maxilla, are lost forever in the eternal blackness that is private ownership never to see the light of day and I wish that we could convince these people to donate these specimens to the correct repositories so that they are available for research and so that we can, indeed, fill in these missing gaps in our evolutionary history.


Brusatte SL, Carr TD, Erickson GM, Bever GS, Norell MA (2009). A long-snouted, multihorned tyrannosaurid from the Late Cretaceous of Mongolia. Proceedings of the National Academy of Sciences of the United States of America106(41), 17261–6. doi:10.1073/pnas.0906911106

Brusatte SL, Carr TD, Norell MA (2012). The osteology of Alioramus, a gracile and long-snouted tyrannosaurid (Dinosauria: Theropoda) from the Late Cretaceous of Mongolia.  Bulletin of the American Museum of Natural History Number 366, 197 pp., 82 figures, 11 tables Issued February 29, 2012.

Carr, T & Varricchio, D. 2014. A new species of Daspletosaurus from the Upper Two Medicine Formation (Late Campanian, Cretaceous) of Montana and evidence for anagenesis in tyrannosaurine evolution. Journal of Vertebrate Paleontology, SVP Program and Abstracts Book, 2014, pp103-104. 

Hone D, Wang K, Sullivan C, Zhao X, Chen S, Li D, et al (2011). A new, large tyrannosaurine theropod from the Upper Cretaceous of China. Cretaceous Research 32 (4): 495–503.  

Lü J, Yi L, Brusatte S, Yang L, Li H, Chen L (2014). A new clade of Asian Late Cretaceous long-snouted tyrannosaurids. Nat. Commun. 5:3788 doi: 10.1038/ncomms4788 (2014).

Averianov, A. O., Sues, H. D., & Tleuberdina, P. A. (2012). The forgotten dinosaurs of Zhetysu (eastern Kazakhstan; Late Cretaceous). Proceedings of the Zoological Institute RAS Vol.316, No.2, 2012, pp.139-147.

Wednesday, 31 December 2014

Some Late SVP Reviews

As 2014 draws to a close and time, as always seems to be the case for me this year, is at a premium and I have here my first reviews of some of the research presented at SVP in November. Normally I would have finished with my reviews by now but, on this occasion, I will carry on processing some posts – it is not like the research is already out of date after all.

The recent disclosure that palaeontologists were in possession of associated remains of Spinosaurus aegyptiacus caused a worldwide sensation when the news broke in September. A massive publicity campaign funded by the monetary power of National Geographic (NG) ensured maximum exposure for the authors, the accompanying Science paper and, of course, National Geographic themselves.

The animal is spectacular. The authors describe an almost dragon-like aquatic predator that has a reduced sized pelvic girdle supporting hind limbs that are drastically shortened in comparison with the standard theropod design. There are other adaptions described such as the shape of the skull, solid limb bones and the much discussed forelimbs which are very robust and powerful and all of these, plus other adaptions, appear to suggest that Spinosaurus was a very adept and powerful swimmer that preyed on the contemporary large fish of the time. Still nobody is quite sure what the purpose of the sail/hump was.

You will also know that this research has not exactly been universally accepted by all and that questions remain which is fair enough since that is what science is all about. There has been plenty of discussion about this in the Mesozoic Media so I do not really need to delve into this too deeply and, when I had read the SVP abstract, I was keen to attend the presentation and hopefully learn more about the animal and see what else might be revealed in relation to the upcoming monograph – in other words, I wanted to learn more.

However, I was bitterly disappointed since the oral presentation turned out to be nothing more than a boys own story about how the fossils were recovered and a broader advert for how wonderful NG was. Lead author Nizar Ibrahim broke with SVP convention and did not stand at the lectern presenting his research to his peers – rather he was free to walk about on the platform talking to the audience as if he was presenting a television programme. He was good at it mind and I imagine that the publicity machine behind the Spinosaurus campaign was delighted with him.

At the end of this talk, and after yet more copious thanks to NG, Ibrahim stood there expecting, I believe, whoops of delight and rapturous applause. However, the rather muted applause at the end of it was indicative that most delegates felt, as I did, that we had come to find out more about this enigmatic dinosaur and had learnt nothing – in fact there was not a single palaeontological detail of note.

This was unfortunate. Ibrahim and his co-authors have done (and are still doing) some sterling work in finally bringing Spinosaurus to life but the funding has come at a price and I have severe misgivings because of the circus that attaches itself to palaeontology when a big media operation provides the funding. Palaeontology needs as much funding as possible and I understand that when the opportunity arises then we need to grab it with both hands – but the price, in terms of reputation and respectability, may prove to be expensive. I hope that I am indeed wrong in this assertion.

On to the business in hand then. Dinosaur diversity prior to the Cretaceous end extinction has often been debated over the years with the more recent research appearing to confirm that dinosaurs were still significantly diversifying albeit with a hugely reduced taxa rate. Emily Bamforth, of the Roya Saskatchewan Museum and Hans Larsson of McGill University in Montreal, have also been examining this, but in a much wider context, by examining the palaeomacroecological signals in the latest Maastrichtian Frenchman Formation in Saskatchewan, Canada.

By examining a combination of  stratigraphic and palaeoclimatic data and cross referencing with over 7800 fossils from 38 microsites the authors were able to establish that overall taxanomic diversity, which includes the dinosaurs, displayed no overall shift in stability although there was evidence to suggest that some lesser groups were vulnerable and susceptible to change. Indeed, the majority of microsites examined revealed an extraordinarily high diversity of taxa. This adds to the hypothesis that the extinction event at the end of the Cretaceous was very likely catastrophic or was fairly rapid to say the very least.

In the same vein, Thomas Williamson, of the New Mexico Museum of Natural History, and his co-authors have been looking at the chronostratigraphy of the San Juan Basin in New Mexico with particular emphasis on the period around the KT boundary. This area is of particular note since it is one of the very few areas that contain the remains of animals from both sides of the boundary – and trying to constrain the ages of the relative formations and members has been problematic.

But by utilising a combination of magnetostratigraphy, thermochronology and mammalian biochronology the team has been able to provide the best date estimates yet provided. The top of the Ojo Alamo Sandstone is certainly Paleogene and the rest of this formation is almost certainly Paleogene too. The Naashoibito Member is confirmed as being uppermost Cretaceous and is contemporaneous with the much better known Hell Creek Formation.

Mammalian fossil remains prior to the extinction event indicate that their abundance and diversity was somewhat moderate. However, there is good evidence that life recovered incredibly quickly after what is generally accepted to be a catastrophic extinction event and that there was a diverse mammal fauna after only 160 thousand years and, incredibly, that there were large mammals in excess of 100Kg in weight after 300 thousand years.

I believe we all tend to believe that in the event of a catastrophic extinction event, such as that at the end of the Cretaceous, that life would take an incredibly long time to recover but we can now see that life is incredibly resilient and can both quickly recover and proliferate. I am still mystified, however, in what determined how certain groups of animals survived the KT event whilst others disappeared. In any event this is very cool radiometric dating and research and I found it of particular interest.

Limusaurus inextricabilis is a small gracile basal ceratosaur from the Upper Jurassic Shishugou Formation of Xinjiang in China and is perhaps known for its weird manus which displays strong bilateral digit reduction. Josef Steigler, of the George Washington University, and his colleagues have been delving deeper into the implications suggested by this bizarre little creature.

They examined multiple specimens entombed in two blocks (at least 14 articulated specimens) which represent the animal at various ontogenetic stages including very young juveniles and this may be indicative of parental care in Limusaurus. Having examined the remains, which includes CT reconstruction of a very well preserved three dimensional skull, allowed the researchers to reassess the phylogeny of ceratosaurs and found Limusaurus to be nested within Noasauridae.

Some of the featured anatomical details include unfused frontals, the C10 cervical vertebra, shown as an example, has short neural spines and is extremely elongate and the metatarsals of the pes are really quite slender. Further phylogenetic insights suggest that Limusaurus, Elaphrosaurus, Deltadromeus and Spinostropheus are all basal noasaurids. This is not that much of a surprise – Deltadromeus has been recovered as a noasaurid before (Wilson et al 2003) and all of the named taxa have generally been recovered as basal ceratosaurs anyway.

The superbly preserved megalosauroid Sciurmimus albersdoerferi, from the Upper Jurassic of Germany, continues to fascinate and Christian Foth, of the Bayerische Staatssammlung für Paläontologie und Geologie in Bayerische Staatssammlung für Paläontologie und Geologie in Munich, and his colleagues have been examining the specimen under UV light using various filters to glean new insights into the integument and feather preservation in this fascinating little theropod.

The tail feathers are best preserved and display long, gently curved filaments. There are obvious differences in the filaments whereby they overlap each other proximally but the distal portion remain unwrapped. The authors are quick to point out, and correctly so in my opinion, that this filament distortion and clumping may be due to taphonomic forces during fossilisation.

The UV study also reveals that the tail was completely covered in feathers. Other preserved feathers, however, consist of entirely uniform filaments and resemble those of other dinosaurs such as Dilong and Sinosauropteryx.  Other apparent filaments on the dorsal side of the tail are interpreted as being collagen fibres as opposed to feathers whilst others do indeed resemble filaments similar to those found in Psittacosaurus. In any event the authors stress that only the existence of monofilamentous feathers is proven in this specimen – nothing else.

I do not very often discuss sharks here except to mention their teeth that we recover in both Jurassic and Eocene deposits – sometimes the occasional spine. But the renowned mega-shark, Carcharocles megalodon, is never mentioned here but, Discovery Channel notwithstanding, perhaps we should because this is just about as awesome an ancient predator as any theropod or pliosaur. Catalina Pimiento, of the Florida Museum of Natural History, has been looking at the body size patterns and reasons for the extinction of these giant sharks.

C. megalodon had a rather cosmopolitan distribution and swam in the seas throughout the Miocene and Pliocene periods before its disappearance around the Pliocene-Pleistocene boundary. Using Optimal Linear Estimation, which enabled the author to cross reference temporal distribution with body size estimates obtained by the examination of fossil teeth and vertebral centra from around the world, enabled a novel method to determine the point at which time this shark became extinct.

It appears that that the lineage leading from Otodus to C. megalodon (assuming you are a supporter of the Carcharocles lineage as opposed to a Carcharodon evolutionary line) increased in size exponentially and maintained a pretty stable size median throughout its existence and, as such, likely had no detrimental effect on its decline. However, the research does confirm its disappearance across the Pliocene-Pleistocene boundary and this ties in nicely with the disappearance, at the same time, of smaller sized prey animals and the increase in predatory competitors.

It is no coincidence that whales increased significantly after the disappearance of the giant sharks and is indicative of how the disappearance of a large apex predator can affect the balance of the ecosystem on a global scale – something we have discussed here before when looking at the effects of specific theropod extinctions throughout the Mesozoic. More importantly, however, are the implications that the disappearance of a top predator can have in modern ecosystems and it is sadly the case that it is again the shark that is being eliminated in the seas throughout the world that will likely have massive implications for us in the not too distant future.

Have a great new year everyone!


Bamforth, E. & Larsson, H. 2014. Terrestrial biodiversity immediately prior to the end Cretaceous mass extinction in central Canada: Patterns and processes. Journal of Vertebrate Paleontology, SVP Program and Abstracts Book, 2014, pp85.
Foth, C., Haug, C., Haug, J., Tischlinger, H. & Rauhut, O. 2014. New details on the integumental structures in the juvenile megalosauroid Sciurumimus albersdoerferi from the Late Jurassic of Germany using different auto-fluorescence imaging technique. Journal of Vertebrate Paleontology, SVP Program and Abstracts Book, 2014, pp131-132. 

Semiaquatic adaptations in a giant predatory dinosaur. Nizar Ibrahim, Paul C. Sereno, Christiano Dal Sasso, Simone Maganuco, Matteo Fabbri, David M. Martill, Samir Zouhri, Nathan Myhrvold, and Dawid A. Iurino. Science 26 September 2014:345 (6204), 1613-1616. Published online 11 September 2014 [DOI:10.1126/science.1258750]

Pimiento, C. 2014. Extinction and body size patterns of the giant shark Carcharocles megalodon. Journal of Vertebrate Paleontology, SVP Program and Abstracts Book, 2014, pp205. 

Stiegler, J., Wang, S., Xu, X. & Clark, J. 2014. New anatomical details of the basal ceratosaur Limusaurus and implications for the Jurassic radiation of Theropoda. Journal of Vertebrate Paleontology, SVP Program and Abstracts Book, 2014, pp235. 

Williamson, T., Peppe, D., Heizler, M., Brusatte, S. & Secord, R. 2014. Chronostratigraphy of the Cretaceous-Paleogene transition in the San Juan Basin, northwestern New Mexico. Journal of Vertebrate Paleontology, SVP Program and Abstracts Book, 2014, pp255-256.  

Wilson, Sereno, Srivastava, Bhatt, Khosla and Sahni. (2003). "A new abelisaurid (Dinosauria, Theropoda) from the Lameta Formation (Cretaceous, Maastrichtian) of India." Contr. Mus. Palaeont. Univ. Mich.31: 1-42

Monday, 24 November 2014

SVP Reflections

Well two weeks has already passed and that is SVP over another year and, on the face of it, it seems to have been yet another very well received meeting. From a personal standpoint I can honestly say that I enjoyed it again and, despite the amount of amazing and totally inspiring research that is going on throughout the world, it is the people at SVP that make the difference and make it such a wonderful event.
There have been several discussions regarding certain issues raised at the meeting this year, many of which are still going on even now. Essentially they focus on the fact that this meeting gets bigger and bigger every year and it is hard to manage so many people efficiently – especially when it comes to the poster sessions and the provision of both food and liquid refreshments.
I am actually not too fussed about being in such a crowded situation during, for example, the poster sessions since you are mixing with essentially likeminded people who are all doing the same thing – we are all keen to learn from each other and discuss the research presented as well as making new friends and thus taking part in a real social event.
However, as I had alluded to in my previous post, the format of the poster layout was certainly problematic. The vertical layout of the poster boards themselves in tandem with the fact that they were situated on a 90° degree angle to each other, made the sessions manic. I noted that the more popular posters sometimes swamped the posters that were opposite to them so that one author was particularly busy whilst the other was boxed in and often looked uncomfortable with the situation.
And not only authors suffered as the amassed ranks of palaeontologists attempted to look through each other and across each other to even glimpse some of the detail presented. The format was also problematic and some posters began at the very top of the board and travelled all the way to the floor – I suspect neck ache became an issue for some and those people who were not as tall as others would have struggled to see anything at all.
This was unfortunate but, as I have already pointed out, there were no issues that I am aware of and most people made the best of it. Indeed we, and many others, cottoned on quite early, to check out the posters throughout the day so that you could spend time reading them properly – especially those that you were really interested in. Certainly my habit of marking out both oral and poster presentations well in advance in a hard copy of the abstracts book pays dividends time and time again.
The oral presentations were par for the course although, on a personal level, I thought that the mix of topics and/or symposia could have been better spread throughout the four days as I found myself being really busy for two days and fairly quiet on the others. But this is very much a personal view and, indeed, there was only one marine reptile talk and only one tyrannosaur-related talk as well (which was about teeth) – so not an abundance of talks concerning my favourite beasties .
For some reason I thought there was an entire session of talks missing as well but I was assured there was only ever three concurrent sessions at SVP – goodness knows why I thought that then. Interestingly, however, that too has been raised in the aftermath of this meeting – that perhaps there should indeed be a fourth session although it was pointed out that it is hard enough chopping and changing during the current three sessions, let alone four. The fifteen minute time slots and no slack gives you little room to manoeuvre.
Strangely I felt that the biggest criticisms during the meeting concerned the lack of coffee supplied during the afternoon. Sure there is the morning break but nothing in the afternoon makes it a long session without a coffee fix. One would imagine that it would not cost that much to provide a secondary supply of coffee in the afternoon and it does not have to necessitate a break such as there is in the morning. I suspect most people would prefer to have coffee as and when during the afternoon anyway. The lunchtime food supply did not appeal either at first as vast cues built up on the first day but it soon settled down and I think the catering staff managed that quiet well.
The biggest criticisms were levelled during the reception at the Museum für Naturkunde on the first evening of the conference. I don’t believe that there is anyone or anything to blame for the situation but the cues for both the food and the drink were a nightmare. The sheer amount of people made the situation impossible for all concerned and, I suspect, is the primary driver for the current debate about the size of the conference these days.
It was quite funny to see people eating a dessert prior to eating something warm at the currywurst kiosk because the cue for that kiosk happened to pass the dessert stand and they were waiting so long that they had to eat something to keep them going! It did not help that most people were milling about in the main dinosaur hall and many did not know that there were other kiosks further along in another wing – a bit of signage or ushering would have helped. 
The biggest debate proliferating the boards on Twitter and the DML concerns the ethics of live tweeting during the conference and the use of electronic devices to surreptitiously record or photograph someone’s poster or oral presentation. Perhaps surreptitiously is a misnomer since most of it is actually quite blatant.
I do not intend to go into great detail on this matter since, as I mentioned, this is an ongoing discussion on the DML and I advise you to check out Jon Tennant’s excellent blogpost here and take the time to wade through the comments as well which will give you an idea of the extent and various opinions on the issue.
I believe this to be a difficult issue and nearly everyone agrees that the society will need to clarify its rules regarding live tweeting and social media – in fact all forms of electronic communication. But presently we are notified that information can indeed be disseminated once the presentation is underway so people cannot realistically be criticised now – not as the rule currently stands.
Secondly, I believe the society has also made a rod for its own back by releasing the abstracts to the public. When I first joined the society, the abstracts volume/PDF was only available to members only but last year I was amazed when the abstracts were available on an open link. Now I am a proponent of open access as much as anyone but when the society did this then every man and his dog was able to read the abstracts and any hope of maintaining a reasonable embargo was gone.
I know that I actually made a couple of appeals on specific sites to ask people to refrain from discussing the abstracts to help protect the authors work but I knew it was to no avail and that the cat was out of the bag. In light of this then, how realistic can it be to expect delegates of the conference not to “live tweet” when the abstracts and the overall points of the research have been in the public domain for weeks?
The concern over photography and/or video footage of presentations/posters is yet another point of contention. And yet it shouldn’t be since the society states “Still photography, video and/or audio taping or any other electronic recording at the SVP Annual Meeting is strictly prohibited.” And yet this rule has been quite openly and blatantly flouted by a minority which has also encouraged others to break the rule. Of course the biggest concern here is that research could possibly be stolen, utilised and maybe even published before the original author(s) has hardly had time to finish and proof read his own work.
Probably the biggest single factor here is that there is no official (or unofficial for that matter) form of policing at the conference. I accept that as members we should all be considered Police but nobody challenges anybody about use of mobile phones, ipads and cameras – not once have I seen it. I have seen the blatant use of tablet–like devices or ipads being held aloft to take video footage of presentations as well as photographs. I have never said anything to be honest but then nobody else has either.
And, I have to confess, that I have actually photographed a couple of posters for my own benefit as well since I was getting frustrated at watching others continually flouting the rule. In retrospect, this was a stupid thing to do and is something I would not do again but demonstrates my earlier point that unless rules are enforced then others are likely to jump on the bandwagon.
I must emphasise that the images I took were for my benefit only and are not, nor will they ever be, in the public domain but unless we do something, then I am sure there is a chance that somebody’s intellectual property may very well duplicated or plagiarised although I believe that possibility is absolutely minimal. In general we are a pretty decent lot.
So we simply need a clarification from the society regarding what is permissible and what is not and then we have to enforce it. Whether it is about social media or photography there must be some form of structure that is crystal clear and made apparent to all and maybe even a form of sanction for a serial offender. But I genuinely hope that this never needs to happen.
So next up comes a review of some talks and posters that caught my eye and made my ears prick up. One animal I will not be discussing, based on my observation at SVP, is Spinosaurus and I will reveal why next time.

Saturday, 1 November 2014

SVP 2014 - Berlin

 Well it is that time of year again and, despite not being able to blog as much as I would have liked to have done, I am still delighted to be able to attend this year’s Society of Vertebrate Paleontology’s conference. This year it is a fairly local event for me being held, as it is, in Berlin in Germany and continues the society’s’ recent commitment to hold the event outside of the USA every fifth year. On the first occasion (2009) it was held in Bristol in the UK and I understand that the society was looking outside of Europe initially for this meeting but events transpired that required it being held in Berlin.
As usual I have been going through the abstract volume marking out what I want to see and there are far more posters of interest this year although there are still many oral presentations that I am keen to see. It will be interesting to see how the vertical presentation of the posters will affect the ability of people to see them clearly and I know that this is causing some concern amongst a few of my colleagues but until we see how it goes it is probably best not to be too alarmist.
Again, what stands out for me, is the degree of research that features further progressive, and I have to say, impressive futuristic technology that is enabling palaeontologists to be able to reveal information that even five years ago would have been impossible to ascertain. This is an exciting and dynamic branch of our science that shows no signs of abating and simply by comparing research presented at last year’s conference, with what is being presented in Berlin, highlights the relentless pace of technological progression and enhancement that is wonderfully inevitable within this field. I cannot wait to see what wonders will be revealed over the next ten years and beyond.
The trip also enables me to visit the wonderful   Museum für Naturkunde – something I have always wanted to do but never quite got round to doing. Although the welcome reception for the meeting will be held at the museum on the Wednesday evening, we do intend to go to the museum on the Tuesday for a much more laid back look at the collection and I can hardly wait to see the fabled material from Tendaguru – one of the truly great dinosaur bone collections in the world.

Of course one of the best things about SVP is the chance to catch up with so many friends and colleagues from around the world and it looks like many of them are going to be there so I am really looking forward to a great event. This enables you to be able to network with colleagues and discuss future research and field work and is a great opportunity for our group to continue to register its presence in the palaeoworld.
This will be my last SVP meeting for two years so I will not be in Dallas next year but I hope to be back in Salt Lake City in 2016. However, the fact that I have managed to attend the last three, including Berlin, represents a nice run and I am constantly aware of how lucky I have been to attend these wonderful meetings – I never take these things for granted.
And the reason for not going to Dallas in 2015? Well next year will represent a great opportunity for me and I am hopeful that I will be spending three weeks doing field work in the USA which is, of course, subject to changes that can occur when these things are first planned. But the outlook is positive and I am excited by the prospect.
So it is my intention to report on this year’s meeting and some of the research that will be presented and hopefully to blog about it on my return but for now – onward to Berlin! 

Saturday, 11 October 2014

From the Toarcian to the Callovian - Addendum

Since publishing the final instalment below I have received some rather interesting feedback from palaeontologist and colleague Dean Lomax in relation to the locality discussed in the first part of the post. Firstly let's clear up where this location is - it is indeed Kettleness, a well known fossil bearing locality on the North East Jurassic Coast that is famous for producing superb fossils of ammonites and is best known for the amount of marine reptile remains it has produced over the years.

Well it appears that the spot I reached in thirty minutes is NOT the main fossil producing spot at Kettleness. Rather it appears that you need to walk around the headland as seen in the above image and then, after a further 40 minutes walk, you will arrive at your destination. Who would have thought that? The cave and waterfall are always mentioned in relation to fossil hunting at Kettleness so it is not surprising that I made the mistake. To make me feel a little better about this, Dean also mentioned that he got caught out by this on his first visit as well.

So it appears that the information that it is a good hours walk to the fossil bearing strata was indeed  correct and I apologise that I may have misled some of you with the report in my previous post. So there a few more thoughts here of which one includes the fact that, despite the revelations above, the first bay I came to is still fossiliferous and I found a few nice ammonites here so do not discount it by any means. This also means that I will now have to return at some point to check out the "true" Kettleness so that next time I can provide you with some proper information and relevant data!

Lastly, and this is by far the most important aspect here, that you appreciate that the walk from Runswick Bay to the actual fossil grounds is most assuredly an hour and ten minutes so you MUST prepare accordingly. Leave nothing to chance - check the weather forecast right up to the last moment and, of course you must know the tide times and time your visit to optimise the amount of time you have to look for fossils and still allow time to walk back before the tide returns.

I would also remind you that if you have any amount of fossils in your rucksacks that the weight will tell on your return journey and you will naturally be walking more slowly after hours of fossil hunting so you need to factor this in as well. It goes without saying that a fully charged mobile phone is essential.

So, as I mentioned previously, many thanks to Dean for putting me right and allowing me to correct those points I made in the previous post. Most of all, do not be put off and I hope some of you make the effort and visit this truly classic location for there still many fossils waiting to come to life.

Tuesday, 7 October 2014

From the Toarcian to the Callovian Pt.4

The following morning I headed off to the final venue for the week. By reputation it was difficult to reach and, for me, this reason alone was why it would be worth the attempt since it would follow that those spots that are hard to get to are probably more likely to throw up some nice specimens. The most direct route was to scale a more or less vertical cliff with the help of only a rope that is permanently in situ there.
Well I cannot speak for others but I actually don’t fancy risking my neck to find a fossil. Sure, it saved time, was very direct and dropped directly onto the fossil beds but, in my opinion, it was not worth the risk. Trying to manoeuvre down a cliff face by using a rope that is constantly exposed to sea salt and the elements does not imbue you with confidence. Add to that you have at least a shoulder bag or rucksack on your back to make things even more imbalanced as you climb down which will probably become quite heavy with any amount of fossils you may find and make the ascent back even harder. And if the rope breaks and the tide comes in – you are going to drown.
Having quickly decided that I was not going to do that I set off on the reputedly long walk to the fossil grounds. I double checked the tides and the weather and, going by the information I had researched, nothing would be left to chance. It was a beautiful morning and I made goodtime as I circumnavigated the main cove which was all sand and then, as I approached a large stretch of boulder strewn coastline, I was pleased to be able to negotiate this stretch without too much trouble.
I rounded the headland and was gobsmacked to see that I had already reached my destination. At first I doubted myself that I could not have possibly been able to reach this spot in such a short time – but I had. It took me thirty minutes to get here and I could just make out the rope from the top of the cliff coming down the face to reach the shoreline and, right in front of me, the very well-known small cave with a delightful waterfall falling behind it.
Just why this trip has been made out to be such a tough and long walk to partake is anyone’s guess but perhaps it is perpetuated by local fossil hunters to dissuade people from visiting the site. This may seem harsh but I can think of no other reason. Thirty minutes from car park to site walking at a reasonable rate - but not over the top. The terrain is a little awkward in only one or two spots but the rest is easily negotiated. However, I would reinforce that it is still essential to plan the trip knowing the tides and weather – it is still easy to get cut off unless you take extra care and pay attention to the time. Never take chances.
As I approached the beds I was delighted to be, yet again, the only person around and it was such a beautiful day. The tide was going out, the sun was pleasantly warm and there was a gentle breeze – I could not believe my luck. I quickly found the fossil bearing spot and began to search and soon found one or two odd bits of ammonite. This area was very similar to my other regular haunt and was also not that big an area.
It consisted of boulders, rocks and gravel and these were intermingled with large dislodged sections of shale that had broken off from the wave cut platform and were slowly being eroded away by the ceaseless tides of the North Sea. Amongst this there was a lot of seaweed that had taken hold in the nooks and crannies and, all in all, this seemed to represent quite a challenge to locate fossils.
I need not have worried and continued to find bits of ammonite but I only kept a couple of fragments since I had loads from the other coastal spots I had been frequenting. Pretty soon, however, I found my first nodule which seemed likely to hold a reasonable ammonite and then found another one in quick succession. As I got my eye in, the fossils came in little hot spots where I would find two or three fairly close to each other and then nothing for quite a while. The same issues here were the same as at the other stretches – namely there was lots of cracked nodules where other fossil hunters had been here before me and, again, there were a couple of nice specimens that had been completely destroyed by reckless hammering.
As the tide moved out I checked the platform but this was extremely difficult to walk on and there was copious amounts of seaweed in place that covered the shales in vast swathes of green. I persevered for a while for I knew that vertebrate fossils were not too uncommon here but I could find only flattened ammonites and a few belemnites. Ichthyosaurs are the most common reptiles found here and a fairly complete skull had been removed only a few years prior.
After I gave up the search on the shales (mainly because I did not want to slip and break something!), I returned to the foreshore and continued the search there. The fossil bearing stretch slowly widened out and became more difficult to search but it was apparent that it was not rich at all and I returned to the more constrained area to look for more nodules.
Despite not being as rich as I first imagined I still managed to find some nice pieces that are likely to yield one or two nice specimens and I felt quite happy with my finds. I also looked further up shore and had a tentative look in the cliff face but I could find very little. That weather was still wonderful and I decided to call it a day and begin the walk back. Again I reiterate that the walk is not as long or as tough as is made out by others – just be sensible and pay attention to the tides and weather. I soon found a pub and enjoyed the view for today was my last day in the north east but although this week was ending, tomorrow I would be heading south to an undisclosed and disused quarry to look in the clays of the Callovian seas.
I left the north very early and headed south down the A1. After I has stopped for a much needed breakfast I arrived at the quarry around nine o’clock and met up with a few colleagues from our research group to see what we could find. Conditions were fine – blue sky, not too hot and a gentle breeze but there had been no rain here for many a day and the terrain looked harsh. Compared to what I had been experiencing over the last week with the ever encroaching tides revealing new treasures each day, this looked very likely to be a hard day. A dry arid basin swept before us with the ancient clay sea glistening white amongst the copious amount of vegetation that was now growing rapidly.
Add to this I knew that this venue had been visited only recently by another group and without a change in the weather, I felt our chances of finding things were low to say the least. As we began searching we immediately came across a vast plain of mud cracks, many of which were already desiccating and others were curling up and were now loose on the surface. Everything looked grim.
We found a spot that looked like it may be promising and a couple of us dropped down onto our hands and knees for a closer inspection of the exposed surface. The clay looked completely bereft of fossils and I was just about to move on when I spied a tiny black fragment pushing through the clay. I carefully cleared the sediment from this speck of black and was amazed to find a partial tooth from the hybodont shark Asteracanthus. Considering the conditions this was completely unexpected.
We gradually looked around the same spot gently sifting through the clay and were rewarded with two further partial fragments of teeth from the same shark. Associated remains? Possibly but considering this quarry had not been worked for some years now it is hard to be sure.
After this brief moment of interest we spread out to see what else we could find. It had really turned out to be yet another nice day but it was proving difficult to find anything. A lot of the old spoil now was like concrete and had formed almost a solid crust on the surface. As you broke into it, the old shales simply disintegrated - everything was so dusty.
Eventually, one of the crew found an unusual, what appeared to be, compressed mollusc. We had seen these on occasion but only rarely and the general consensus is that they are actually the compressed remains of a nautiloid – perhaps Paracenoceras. In any event this turned out to be quite a rare fossil and now resides in the collections at the NHM in London.
Unfortunately this find turned out to be the exception rather than the rule. The ever increasing amount of vegetation (you could almost describe it as scrub) was making things really difficult and, for all our prospecting abilities we could only muster up a couple of scrappy bits of bone and couple of fish scales although there was one more interesting fossil that turned up.
From L - R Two bits of bone, three fish scales with the Asteracanthus tooth above and the coprolite at the far right.
Coprolites are extremely abundant in the Oxford Clay. Most are from fish which are small, generally a pasty off white colour and of little interest. Large ones from animals such as the marine reptiles are much rarer but these too, apart from their size, are also of little consequence.
But every now and then one turns up with inclusions which are normally representative of the animals most recent meal – and these are very interesting indeed. They normally show up as black and shiny against the pasty background of the coprolite and represent various food sources that would have passed through the food chain.
Many of these inclusions are unrecognisable but some can be readily identified. One of the more common elements found are the remains of belemnites and some of the hooklets appear as pristine today as they may have been over 160 million years ago. But, on occasion, a coprolite can reveal something extraordinary and I was fortunate enough to find just such a fossil today.
This coprolite reveals, remarkably, several pieces of fish bone including a perfect little vertebra. A couple of inclusions looked like small teeth but were revealed to be a scale and a small bone. There were other indistinguishable inclusions as well and this coprolite is the first one of its kind that I have found – maybe not as spectacular as big teeth or bones but no less of equal fascination.
In the end we decided to call it day and headed home – for me the first time I had been home in a week. All in all it had been a great week that I had spent with friends, both old and new, and I was very lucky with the weather which had been very spring-like. I had also found a good quantity of ammonites in the north east although vertebrate fossils had eluded me on this occasion but I had managed to find a nice shark tooth and coprolite on the very last day so you cannot complain about that.
Most of all I loved the fact that I had begun the week searching for fossils in the Toarcian seas of 180 million years ago and finished up looking for the creatures of the Tethys Ocean, in sediments  around 16 million years younger than where I had first started prospecting simply by driving a few miles in my car. Ancient worlds brought to life by the tools of the modern world.