Archive for March, 2012



Heads and tails – Microraptor feathers

From Li et al., 2012

Much has been said about the recent Science paper reporting on the possibility, or perhaps rather probability, that Microraptor had iridescent feathers. So much so awesome, but there are, for me, other interesting things that are buried in the supplementary data to the paper that I’ve not seen mentioned so far (not that I have widely read coverage of the paper, I mostly just read the paper).

First off, as seen above, the idea that things like Microraptor and others (Anchiornis being the most obvious candidate) had some little crest of feathers on the head. As shown by the X-ray, pigeons have a very similar arrangement of feathers and yet it’s simply part of the natural contours of the feathers and their position. Basically the feathers really are preserved as they were in life, and that this isn’t anything odd or expanded but that the shape of the head (with feathers) would be very modern bird-like.

Secondly, the tail was noted to have two rather elongate streamers in the midline and this looked familiar but I couldn’t place my finger on it. Now I have it, it is, for me, really quite similar to what you see in European magpies. There’s an obvious tail fan there, but in the middle, the feathers are rather longer, though not *that* exaggerated. Given the implications for signalling advocated in the paper, I’d be intrigued to know if people have looked at these feathers alone in magpies and how they are used or if birds are affected socially when they are trimmed or absent – could be something there to look at one day.

From Li et al., 2012

Li, et al. Reconstruction of Microraptor and the Evolution of Iridescent Plumage. Science 9 March 2012: 1215-1219.DOI:10.1126/science.1213780

Any more lost Solnhofen pterosaurs out there?

There have recently been a number of papers describing ‘lost’ or little known pterosaurs from around the world. I’ve covered the Rhamphorhynchus that sat undescribed in Dublin for over a century, and I’ve mentioned specimens on display in Japan that have never been in the literature. There are others too that are starting to come out, like a Pterodactylus in France and others in Hungary. While obviously some of these are making it into the literature, there are others that haven’t (like those in Tokyo and I know of one in Kiel) and I’m most interested in finding them.

There’s an obvious reason for this – completeness. While Peter Wellnhofer did a great job in the 70s of collating Solnhofen specimens and measurements in two major papers, a lot of time has passed since. New material has been discovered, and old material has come to light. I’m sure there’s a significant number of specimens now out there available for study that are either not in the literature at all, or are only mentioned or illustrated and have no good descriptions or measurements put down.

These are of course well worth knowing about. Pterosaurs remain rare and history alone means that the Solnhofen is the best studied and best known set of pterosaur fossils going. Combined with the presence of both pterodactyloids and more basal forms, and generally large numbers of good quality material it is perhaps our premier source of data right now. As such knowing what we have and maximising this is important for science and can allow us to do bigger and better analyses, or sort through what we have and select specimens that can be sacrificed for sampling or are worthy of further attention and preparation.

In my experience many of these ‘lost’ specimens are often on display, right there and easy to see (as pterosaurs are rare and often a prime piece worthy of exhibition). Provided of course you are in the museum to see them! The Kiel specimen I mentioned was one such – to my knowledge or that of any of my colleagues I’d spoken too, they simply didn’t have any Solnhofen material at all, none. So a pterosaur expert is rather unlikely to there to check out a tiny palaeontological collection which shouldn’t contain anything of interest and let’s face it, there’s a lot of museums out there.

Bearing that in mind, if you do come across a Solnhofen pterosaur in an odd and usual place (i.e. not the Carengie, or London NHM or the like) do please let me know. Sure it might turn out to be a cast, or even a well-known specimen, but the number that are increasingly coming out of the woodwork make me suspect there’s rather more out there and it would be great to try and track them all down and one day get them into the formal literature. If you have a photo or specimen number, even better, but a simple mention of what you saw in which museum would be a great start. I’m convinced there’s a significant number of specimens out there and they are well worth finding.

Flying Monsters in 3D

Sure this came out a couple of years ago now, and Mark Witton has dealt with it in detail (and for the record I basically agree with everything he said, almost to the letter), but I’m now in a position to comment myself. While I have seen this before, I have now seen it in the cinema in full 3D glory. More particularly, I saw this with an audience of school children (about 80 of them aged, I would guess about 7-90). I was there to handle a Q&A on pterosaurs after the show to help extend their experience and hopefully help them get a bit more out of the film.

As far as I could tell, they thoroughly enjoyed it and there was a large, sustained and apparently spontaneous round of applause at the end. Certainly during the showing there was no chatter, fidgeting or anything else one might associate with them not being well engaged with the subject matter. So far so good.

The questions afterwards came thick and fast and were really of a better standard that I’ve come to expect of this age group. There were no overtly silly questions and most really were about the animals themselves and not about ‘who would win in a fight between’ or ‘which was the best’. Some were even great with ‘are archaeologists and palaeontologists different things?’ a personal favourite (all media outlets ever please take note).

The one thing that did strike me though was that the kids were still firmly happy with the idea that pterosaurs were dinosaurs (and so too, were the plesiosaurs and the like, but not birds, or at least not for most). This might sound rather inevitable, it’s a very common issue, but bear in mind they had just sat through a documentary on pterosaurs that had also featured dinosaurs, birds, Archaeopteryx and plesiosaurs. They had picked up on things like the launch of Quetzalcoatlus, and asked about how Pteranodon would get buried when surely the other animals would eat a dead one, or which ones ate which foods etc. They had grasped some of the trickier concepts and harder messages but missed a big one.

Thinking back though, I realised that this was never really stressed. While the documentary was careful to use the right terms in each case – which was good – they also never specifically drew attention to the fact. The knowledgeable audience member might spot the correct use of ‘marine reptile’ for plesiosaurs, but those who don’t know would probably miss this and not attach the importance to the fact that the word ‘dinosaur’ wasn’t used. For an hour-long program talking pterosaurs it does seem rather odd that at no point (confession, I missed the first 5 minutes) did they ever actually say ‘pterosaurs aren’t dinosaurs’. No, they never conflated them, but nor did they make it explicit.

With something so basic and so common an error, it does feel like a massively missed open goal. Sure, there are plenty of worse issues (as Mark details in his review), but still I can’t help feeling this would have helped the narrative itself – after all, they want the audience to appreciate pterosaurs in their own right, and making them distinct from dinosaurs would help that goal. Establishing them as their own group and in effect therefore somewhat more ‘special’ has the dual role of clearing up a great misconception and focusing the attention of the viewer.

So while I did work to clean that one up in the minds of those who watched the show, it clearly still is a major issue. It’s a shame that such a major effort to really push pterosaurs to a mainstream audience and bring them to the fore failed to address such a simple and critical concept.

A ropey Rhamphorhynchus

As I noted yesterday, one of the nice things about Chester Zoo was a series of signs that tried to place living animals in the context of their extinct relatives. In the case of the Tropical House that featured various reptiles and birds, this included mounts of archosaurs – this pterosaur, an Allosaurus skull and a Tyrannosaurus maxilla. Curiously though, these were sculpted and not casts.

As a result while the two theropod were quite good they were far from perfect and the Rhamphorhynchus was really quite odd. Some detail had been paid to things like the sternum and pelvis whereas the fingers and tail for example were really poor so it was an odd mix of accuracy and less-than-stellar work. What’s odd to me is why someone would do this – the zoo apparently bought them from some company and I can’t blame them for not knowing any better, but why were these created? There are good casts of pterosaurs and theropod bits available and they are not too expensive or hard to get hold of. I can’t help but think it would take a lot more time and effort (and thus cost) to produce these inaccurate reproductions than just to buy a replica which would of course be perfectly accurate.

 

Chester Zoo

Until this trip, my first and only visit to Chester Zoo had been back in 2000. I remember thoroughly enjoying myself then and that the place was large in scope and successful in execution. So I looked forward greatly to my next opportunity to visit and this was finally achieved last week. In general I was greatly impressed and had a great time and while there are some nit-picks coming, the experience was almost overwhelmingly positive.

Chester combines all the things that, for me, make a zoo great. There is a good diversity of species – both classics (lions, elephant, rhinos) and rarities, species big and small, covering the vertebrate spectrum and with a respectable number of invertebrates, the enclosures are big and more importantly well designed and well maintained, and the animals are generally in large numbers and uniformly well looked after and happy, and finally, the signs and educational content was good. In short, it should please pretty much everyone, from those looking for a typical family day-out to those who are after seeing new and unusual species, or school trips and the like.

Great things to see were for example the elephant and wild dog paddocks (colossal) the ape set-ups (very big, and very cleverly executed) and tropical house (a mixture of free flying birds and cages for bigger birds and various herptiles). I can’t remember the last time I saw oranges so active and so content and the chips acted as normally as I’ve ever seen. The aquarium was tiny but well stocked, and there was a dedicated butterfly house with quite a diversity in there.

The overwhelming positives were the ‘new’ and unusual species. As a veteran zoo-goer I can suffer from burn-out of Asian short-clawed otters, meerkats, Humboldt penguins and Siberian tigers. While these were not in short supply, there were lots of things less rarely seen in UK zoos like warthogs, cheetah, congo buffalo, caecelians and, yes, both tuataras and a Komodo dragon. But even for me there were several species I’d not seen before like sitatunga, giant otters, Montserrat frogs, Galapagos tortoise and rhinoceros hornbills. In short, it was hard not to be impressed and excited by the diversity of things on display.

Like many zoos that bear repeat visits, it also has some real gems. Small hidden-away enclosures or sections such that even traveling between major exhibits there will be an odd aviary or set-up with a few more birds, or local wildlife or similar so that even the walks are broken-up and there’s a chance to see something else interesting. Sure the jaguars might not be out, but there’s a tank of fish or snakes next to the main window to keep you occupied if you want to give it five minutes and hope for them to show.

The educational side was pretty good too with lots of signs. They were a bit mixed to be fair, as while there were identifiers for pretty much everything and the odd detailed signs (why to tapirs spray urine, how to zebras feed etc.) ‘basic’ info like the what the animal in question eats, where it’s from, how long they live etc. were in rather short supply. One great addition though was the regular mention of fossils and extinct relatives and in one case a few (dodgy, but well meant) sculpts of theropod and pterosaur bones to accompany these. It’s certainly very welcome to see Embolotherium and the woolly rhino mentioned in the context of the modern black and white rhinos.

As for the nit-picks one personal disappointment was the fact that the dik-diks were off show (something I’ve never seen) but that can hardly be helped. More annoying was that some of the signposts were a bit confusing and the routes between various places were not easy to follow. I had to backtrack quite often to get from point to point or cover three sides of a large building to get around it, in a zoo that size (it’s massive) it’s frustrating and tiring.

Overall though it was a great visit and for me ranks among the top zoos in the UK. Quite simply it ha a diversity of species and a level of care and enclosure set-up that all but guarantee a good visit. You’ll see lots of things, they will be active and interested and happy, you’ll learn things too. It’s hard to wish for much more than that in a zoo, though of course it’s rather harder to achieve than it sounds.

Looks like I picked the wrong week to quit writing about pterosaurs being killed…

Surely this can’t be serious? Yeah you wait years for a paper about pterosaurs being munched on by other vertebrates and then two come along at once. A paper? What is it?

In this case it’s an online publication, which is nice (PLOS again so freely available, reference and link below). This time it’s from (very) occasional Pterosaur.net contributors Helmut Tischlinger and Dino Frey. It seems the large Solnhofen fish Aspidorhynchus may have had a thing for pterosaurs.

While other specimens are apparently known of a similar interaction, a new specimen has come to light showing individuals of each species being intimately linked. Nope, it’s not that Rhamphorhynchus had a drinking problem so much as it got grabbed and dragged under by the fish. Too big to eat and with its wing membranes stuck in the teeth of the fish, the two were locked together. Drifting into the anoxic zone of Solnhofen lagoons (little use for loading or unloading there) would have killed them both, still locked together (and is also how you get things like this).

Interestingly, while Aspidorhynchus had tried to have ‘chicken’ for dinner, the flying pterosaur had had fish (incidentally I had lasagna). There’s a fish in the throat of the pterosaur, suggesting it had only just caught one at the surface of the water when it was snagged by the bigger fish below.

Right, I’ve got to go take a call on my white phone to do an interview about Microraptor colours, and it’s not a big pretty white one with a red stripe down the side.

Frey E, Tischlinger H (2012) The Late Jurassic Pterosaur Rhamphorhynchus, a Frequent Victim of the Ganoid Fish Aspidorhynchus? PLoS ONE 7(3): e31945. doi:10.1371/journal.pone.0031945

Images for this post kindly provided by Helmut Tischlinger.

Eoraptor and Eodromaeus


Going though some old files I realised that I’ve still not got round to showing off everything from the Dinosaur Expo in Tokyo last year! There’s still a handful of exhibits with are worth putting up on here and chief among them is this pair of very basal dinosaurs Eoraptor (above) and Eodromaeus (below).

I did once see a cast of the Eoraptor holotype briefly and it did look rather flattened, though mostly complete, so I assume the mount above is a fair representation, though I also assume it’s mostly sculpted rather than cast. Hard to tell really from a distance and this was one of the things I didn’t have time to examine in detail so I’m afraid I don’t know. As for Eodromaeus, a look through my files tells me I don’t have a copy of the paper with me on my laptop but a quick google suggests it’s mostly complete and preserved in a pretty good condition.

As usual for things this close to the base of a major radiation, the exact phylogenetic status of these animals is not entirely certain. Described as a basal theropod, Eoraptor has since been recovered as a basal sauropodomorph and I don’t think it would be a major surprise if Eodromaeus ever moved a few nodes around the tree at some point.

What’s in John’s freezer?

Most people interested in dinosaurs will be aware of the research done by John Hutchinson and his group on tyrannosaurs and other Mesozoic critters with regards to their anatomy and biomechanics. But feeding into this research John does a lot of work on big extant animals (like elephants, crocs, rhinos and ostriches) both alive and in various pieces.

It’s this latter aspect of his work which has now made the leap into cyberspace and John has taken the plunge and started blogging. The title (as for that of this post) is ‘What’s in John’s freezer?’ to represent the odd and occasionally gruesome collection of animal parts he has in his walk-in freezers at the Royal Vet College in London.

Unlike most new blogs, John already has more than a token ‘here’s my new blog’ post up, so head on over there to see his first efforts looking at scanning giraffe legs. Enjoy!

 

More on dromaeosaurs vs azhdarchids

Yesterday I covered the basic introduction to my new paper about a Velociraptor specimen with an azhdarchid element preserved in it’s gut. Today I want to move on from the basics (what is there) to what this potentially means and how this is inferred. Most of my recent research is based around theropod ecology and behaviour (like this, this and this for example) and specimens like this one can provide new information and evidence for how these animals were acting. The obvious question here is why is this inferred as scavenging and not predation? As usual with such questions going so far back in time, it’s hard to be definitive, but this is the better supported inference.

First off there is the relative sizes of the animals. While it’s not unknown for predators to tackle other predatory animals, or relatively big prey it’s certainly not normal. Lions don’t routinely hunt leopards or bears go after wolves. This is relevant here since azhdarchids were most likely active predators themselves and so a potentially dangerous animal to attempt to kill. Moreover, the azhdarchid in question was most likely 9 kg in weight with a 3 m wingspan (and could have been considerably larger), while the Velociraptor was a sub-adult of around 13 kg. In short if this was a predation it was no mean feat – perhaps the equivalent of a small coyote bringing down a big eagle. Sure it’s possible, but it’s not unreasonable to think this was really very unlikely. It’s more likely this was a young carnivore scavenging on the carcass of a dead pterosaur, as indeed was inferred for a similar previous specimen from Canada.

Even if we assume that it was a kill, other things don’t add up well to support this. Theropods don’t tend to consume large amounts of bone like this. They might consume relatively large items (like a whole small prey item) but not large chunks of bone like this. And it is a pretty big chunk of bone, probably the same length as the skull of the dromaeosaur. Moreover, we also know that theropods can be really quite delicate feeders, including other velociraptorines. The tendency seems to be to scrape meat free of the bones, now chew up and swallow whole ones (like modern birds of prey, they’ll swallow a mouse, but will pull chunks off of rabbit or sheep). Carcass consumption patterns by modern vertebrates also show that whole big bones like that don’t tend to be swallowed. Finally, the pterosaur weighted at least half and potentially more than the dromaeosaur. Given their apparent skill at stripping a carcass of meat I don’t think I dromaeosaur would be swallowing whole bones (and ones that would be pneumatic, not filled with marrow) when much of it’s own weight was sitting there in muscle and viscera.

In short, predators don’t normally predate other predators. Predators (including theropods) don’t usually seek out large prey. Predators (including theropods) don’t usually consume large bones of large prey unless they are a bone specialist or there’s nothing left. Even when there’s not much meat left, theropods tend to scape this free to eat rather than swallow bones. Sure all of these could hit the ‘least likely’ option and it’s a who-knows-what to 1 chance that a small dromaeosaur took on a big azhdarchoid, killed it and started swallowing big bones. But it’s far more reasonable to infer that it scavenged the last bit of a carcass it chanced across.

We are then left with scavenging as the most likely explanation as to why this animal was swallowing whole bones. Interestingly, we do also see shed teeth being a common feature of dromaeosaur (and indeed theropod in general) feeding yet here every tooth in the skull is intact. That is admittedly merely a soupscon of evidence for scavenging, but one might well expect a tooth or two to be lost during a fight with such a big adversary. or even biting through bones to swallow them again suggesting it just picked up and swallowed what it could find without much or any oral processing.

Uncoloured version of Velociraptor feeding. Courtesy of, and copyright to Brett Booth.

Moving on from this issue then, what does this tell us about the ecology of dromaeosaurs? Well to  degree, not much we didn’t know already. There’s already evidence for both predation and scavenging in the dromaeosaurs, and indeed already evidence they were eating pterosaurs. Even so, more evidence is always good, and it does at least reinforce the existing evidence we have. It also therefore takes us a little further away (sadly) from the idea that dromaeosaurs were some kind of hyper-carnivorous super-predator that spent their time knocking down huge prey items with all their claws and teeth. I say sadly, because it’s a great idea and a wonderfully romantic notion, but sadly these animals were every bit as opportunistic as other carnivores and clearly were not beyond taking the odd, or indeed regular, free meal through scavenging. Indeed given the number of specimens we now have supporting a scavenging interpretation, this does seem to have been a pretty common part of their behavioural repertoire as carnivores.

Velociraptor scavenging an azhdarchid pterosaur

Image courtesy of, and copyright to Brett Booth.

So yesterday at short notice I rushed up this teaser post which seemed to do the trick, and now I’ve got a bit more time on my hands, I can start putting down a proper post on the subject. Yep, I have a new paper out and this time featuring dromaeosaurs and pterosaurs. Long time readers will remember that almost exactly 2 years ago I had another paper out on dromaeosaur scavenging featuring shed teeth and bite marks on some Protoceratops material. Coupled with the famous fighting dinosaurs specimen we have pretty good evidence for dromaeosaurs, and specifically Velociraptor for feeding on this dinosaur. The record of dromaeosaur predation and feeding is actually pretty good compared to other theropods groups and there is also an isolated pterosaur wing bone from Canada with shed dromaeosaur teeth and bite marks.

This ‘new’ specimen marks the first record of gut contents for Velociraptor and the first record of a pterosaur bone as gut content in a theropod. (The ‘new’ is becuase this specimen was actually found in the 1990s, but has yet to be described, though I’m told there’s a photo of it in Luis Chiappe’s recent birds book). Thus we do have rather exceptional evidence for a Velociraptor chowing down on an azhdarchid.

Velociraptor specimen with a pterosaur bone as gut content (black arrows). From Hone et al., 2012

And here it is, well part of it. The Velociraptor in question was remarkably well preserved and complete which allowed the preparation of it with the chest cavity as a single articulated piece with the vertebrae, sternum, ribs, gastralia and even uncinate processes all intact and in their original positions. The bones are really well preserved and much of the material has been prepared free of the matrix entirely. One obviously example is the skull which, bizarrely, is on display in Barcelona so at least some reader might have already seen that, though sadly I haven’t and had to rely on some superb photos kindly sent by Fabio Dalla Vecchia. It’s hard to show the bone off properly what with the whole ribcage in the way (which is, incidentally, a broken ribcage, one of the ribs took a huge battering and shows a healed break – white arrow in the above picture). S you’ll be delighted to know there are also some close-ups in the paper like this one (below) and even some CT scans in the supplementary data.

Close up of the bone. From Hone et al., 2012

As you can see the bone is incredibly thin-walled which is the major reason that it’s inferred to be an azhdarcid pterosaur, though their presence in the Late Cretaceous, including a related formation, and the general absence of other pterosaurs in the Late Cretaceous helps support this identity. Given what is around and the thinness of the bones, it’s pretty unambiguous as indeed is the identification of the dromaeosaur as Velociraptor given that we have basically the whole thing. In short, this is about as convincing a case as one could make that a Velociraptor had eaten an azhdarhid. But was it really scavenging? Well that and other issues I’ll be talking about tomorrow, as there’s quite a lot more to say on this. Stay tuned.

Finally, my thanks to Brett Booth for more awesome artwork for me to use, and you can see more of this and my interview with him on his dinosaurs here.

Hone, D.W.E., Tsuhiji, T., Watabe, M. & Tsogbataar, K. Pterosaurs as a food source for small dromaeosaurs. Palaeogeography, Palaeoclimatology, Palaeoecology, in press. Horrible uncorrect proof and behind a paywall, but the abstract, figures and other bits are visible to all.

What’s all this then?

Well at least of what it is should be pretty obvious based on the picture (which comes courtesy of and copyright to Brett Booth, of Carnosauria fame). I’ll be explaining all more fully as soon as I get the time, but after having been sitting on this for quite some time and then suddenly getting the opportunity it seemed a shame not to put up this beautiful picture right away. More to come very soon, promise.

Arthur Conan-Doyle on Mesozoic reptiles

No, not as you’d imagine, The Lost World but another mention. While Conan-Doyle rightly gets a lot of praise for really helping to excite the public with tales of live dinosaurs (and pterosaurs and the rest) and is commemorated with his own pterosaur (Arthudactylus conandoylei if you were wondering) it’s not the only time they get a mention in his works. I suspect it’s largely unknown, but Conan-Doyle wrote several more stories based around Ed Malone and Professor Challenger, and generally featuring Lord Roxton and Professor Summerlee from The Lost World too.

One of these is a short story of just a dozen pages entitled The Disintegration Machine. It’s a real favourite of mine and when I stumbled across the compendium of Challenger-based stories the other day I reread it. Lurking just a couple of pages in is this little statement from the Professor:

“It was in the course of your somewhat fatuous remarks concerning the recent Saurian remains discovered in the Solenhofen [sic] slates.”

The story was first published in 1929 and Conan-Doyle was a doctor by training and clearly had more than a passing familiarity to the sciences and anatomy. He tended to write about the contemporary world so it’s not unreasonable to suppose he was discussing some relatively recent development or discovery. While obviously the term ‘saurian’ is more than a little general, it does at least rule out quite a lot. A quick search shows that there was no obviously monumental discovery in the 1920s (things like Archaeopteryx, Compsognathus and Pterodactylus having been unearthed long before). I’m not expert enough to delve through the literature of the crocodylomorphs or more basal reptiles from the Solnhofen, though intriguingly Anurognathus was described in the 1920s and Germanodactylus cristatus was erected to generic status just a set years before the story came out.

OK, so it’s a bit of a longshot that we can even vaguely identify a taxon or specimen that Conan-Doyle was thinking of (assuming of course he even did have something specific in mind). Still, it is clear he did know that this was a place famous for its reptilian remains and presumably thought the general public would know it and recognise the name check. If nothing else it’s simply nice to think that he didn’t just dabble in dinosaurs for his one classic, but kept these animals in mind and perhaps even kept up with the science enough to use them again another time.


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