Archive for February, 2012

Archaeopteryx Coin

Now sure the 150th anniversary of the description of Archaeopteryx was last year, but I’ve only just got my hands on one of the specially minted coins from the German mint. For this I have to thank Helmut Tischlinger who knew I was after one and extremely generously got hold of a spare and sent it my way, I am very grateful. You may well have seen one of these before however, as Larry Witmer got one early and included it on his big roundup of the whole schebang last year.

Not that I know much about coins (thought I’ve seen a hell of a lot over the years with the number of countries I’ve visited) but it is extremely well cast and the detail is impressive. It’s certainly a nice addition to my tiny collection of Archaeopteryx memorabilia (like this one), now I just need to find my Berlin medal….

Year of the ghost dragon – Guidraco

I try to eschew posting on other people’s papers and new taxa especially as these are things that tend to get picked up widely and blogged about. Occasionally though something a little special comes along and is well worth a mention, especially as for once no one seems to have leaped on the paper.

Guidraco. From Wang et al., 2012.

And here is the critter in question, Guidrao, a pteranodontoid (or depending on your systematic preferences, an ornithocheiroid) from, no big surprise, China. No matter how many pterosaurs get described the variety of head-crests and teeth seem to keep increasing and here we have rather unusual forms of both. The crest is very helmet-like and extends more or less straight up from the top of the head. It’s got a passing resemblance to that of Pteranodon sternbergi, but not that much and among the ornithocheirids it would pretty much stand alone.

The teeth are pretty special too. With the boreopterids we have recently seen some pterosaurs with hugely elongate teeth that massively overlap the upper and lower jaws. These have been thin and very needle-like affairs, but those here are every bit as long but also clearly rather robust and capable of resisting a fair bit of force one would imagine.

The analysis in the paper finds this as the nearest relative of the Brazilian Ludodactylus which also had some decent sized teeth and a crest at the back of the skull (if rather different in shape). This might surprise given the distance between the two localities but for me, well, pterosaurs, and especially all the Pternodon and Ornithocheirus-like forms could fly pretty well and were most likely ocean going. Ornithocheird remains are known from Brazil, the UK, China and even Australia so they clearly got around and you would expect them to.

All in all though a very interesting animal. The only real question is what is going to turn up next in this year of the dragon?

Wang, X., Kellner, A.W.A., Jiang, S. & Cheng, X. 2012. New toothed flying reptile from Asia: close similarities between early Cretaceous pterosaur faunas from China and Brazil. Naturwissenschaften in press.

Not a fossil

One occupational hazard of being a palaeontologist is that it’s quite a rare field to be in and yet fossils animals and especially dinosaurs are familiar to the public. Thus odd rocks and cattle bones can, to the untrained eye, look very exciting. With a regular feed on media stories along the lines of “Sam Smith found an odd bone on the beach and it turned out to be a new dinosaur” it’s no great surprise that people are eager to push these to the nearest palaeontologist or geologist, no matter how far fetched the idea or unlikely the interpretation. Pseudofossils cause particular problems, but any old chunk of rock or bone can be prized as a shell, dinosaur bone, mammoth tusk or usual shell.

It’s a common enough problem that people in the past have had to take action. I got hold of this recently from one of the curators at the Natural History Museum in London. It’s rather old (the fact that it has a telegram address is rather a give away, as is the style of the phone number) and shows that even what was (I’d guess) 70 years ago or more, that it was considered an important time saver to have these printed up with the most obvious candidates prelisted and ready to be checked off.

This is true of other fields as well. Archaeology perhaps unsurprisingly suffers from a near identical syndrome (prompting this piece of humour) but others get it too. I recall in Simon Singh’s superb book on Fermat’s Last Theorum that so many mad and bad attempted proofs of the theorum were sent to a university professor who was supposed to assess them that he had thousands of cards printed similar to that above that ran along the lines of “Dear…., the first error in your proof is on page….. line….., thus the proof is flawed”. It’s an ongoing struggle and one we cannot win. But in the meantime it can at least be fun.

How many eggs were laid?

Here is a nice pile of eggs on display at the IVPP. As is quite common in dinosaur nests, there are several layers here and while it is subtle, there is a curve to the arrangement of the eggs to give an indication that these eggs were originally laid in a broad circle.

Clearly this nest is rather incomplete and would have originally contained many more eggs. Taking an estimate of that total from this little is probably a bad idea but there are more complete nests out there and some are apparently absolutely complete and every egg can be identified and counted. Great news in general of course, but does this mean we know how many eggs were laid by the mother?

You might think ‘well, obviously’ but sadly the situation is far less clear than this. Looking to the birds a great many small passerines lay two or sometimes even more clutches a year. Just finding a nest of half a dozen eggs doesn’t mean that this was the some total of the eggs laid by a mother that summer. Other birds are communal nesters with lots of females all dumping their eggs together into a single nest. Or males can solicit females to lay in their nest and so accumulate eggs from multiple females, though perhaps only one or two from each.

In short, even finding a nest of a couple of dozen eggs being brooded by an animal is no great guarantee that those eggs were laid by one female, or that was all she laid. It’s not, I hasten to add, a poor assumption but equally it’s far from certain. Which is rather a shame as obviously and understanding of the reproductive output of an individual (and thus a conceptual one for a species) can really help our understanding on dinosaur biology and ecology. I wouldn’t argue against using this kind of data, but I’d be quite cautious about how it could be used.

Cranial pneumaticity

Anyone vaguely familiar with saurischian dinosaurs or pterosaurs (or birds for that matter) will know about pneumatic bones. Extensions of the lungs penetrate the bones and fill part, or a great deal, of their internal volume leaving them with hollow vertebrae, humeri, and even ribs and furculae. However pretty much all tetrapods (I’m sure there’s one exception somewhere I don’t know about or I’d say all) have a pneumatic skull. The sinus are a large cavity inside a bone (OK series of bones in the case of the skull) that attach to the lungs (if from the other end of the trachea). These can be quite complex however, and this is not as much as a cheat as it may sound.

The photo above if from the palate of a mammal. Although there’s no scale in the image I think it is reasonably clear that in places the bone is really rather thin (especially the broken piece at the top centre) and around the middle there are obviously fine filigrees of bone and large spaces beyond. It may be a major surprise to learn that this is the skull of an elephant, and yes those bone really are just a mm think or less – it’s quite a delicate structure and with a lot of space behind that first layer of bone. Despite the size of the animal and the thickness of the bone in other places in the skull, the sinus is still a massive cavity with some very fine bone in there that is, basically, air filled.

With nasty big pointy teeth….

Modern birds do not have teeth. So much so simple, but that doesn’t mean that their beaks need be simply shears or forceps. The keratinious beak can be quite complex in shape and a good number of birds have serrations along the margins that increase their cutting abilities or grip. I’ve been bitten by a penguin and they have brutally serrated beaks that I can assure you slice open human hands most effectively. Pictured (courtesy of the Optimistic Painter himself) is an emu and while it is small, the lower right part of the jaw is well framed against the light background and the small serrations are clearly visible. Another little reminder that bones (sadly) can’t tell us everything about important details of the shape of he living animal and that the real appearance could in cases be quite different to what we expect.

Journal Abbreviations

It would be most uncharacteristic of me to miss out on the opportunity to have a good whinge about something and yesterday’s post provides the perfect platform. Those well versed in academic literature will know that some journals demand the use of abbreviated journal titles in the reference list. So ‘Journal of Vertebrate’ Paleontology might appear as ‘J. Vert. Paleo.’. This was obstensibly done to save space I assume, though I recall at least one journal that used this system while wasting acres of space by not running articles together on a page so anything that crept over by a couple of lines would have an a near blank page below it.

However it never seemed to save very much at all, and with the vast majority of research taking place as PDFs these days it seems increasingly irrelevant (much like numbered references). However, they do hold sway in a few outposts at least and for me at least, they’re very annoying. It’s never quite clear how you’re supposed to abbreviate journals (after all, I’ve never come across any form of standardised list or guidelines as to how many characters or syllables to save), but more importantly it’s not always easy to work out what a journal was from the abbreviation.

Sure, plenty of them are obvious enough and if you work in vertebrate palaeontology you’ll know plenty of the papers themselves let alone the journals. Others can be tracked down by the rest of the reference and especially with online search engines things get a lot easier. But there are still masses of old, obscure and especially foreign journals that are hard if not impossible to work out from the few letters that are often afforded. This of course only gets harder when you move outside of your usual field and want to track don something a little unfamiliar. As noted yesterday there’s plenty of overlap between all manner of fields and there are for example papers in maths, physics and engineering journals that relate to flight for example. But working out what they are is going to be pretty hard unless you’re well versed in the literature of that subject.

In short it’s all a bit of a pain. It doesn’t really save space (after all, many journals have short names that cant really be abbreviated, or huge lists of authors or long titles that mean even saving a few letters on a journal name doesn’t do much) and can make finding references really difficult. So it’s hard for me to work out exactly what purpose it serves these days. I’d gladly see the back of them and I can’t imagine I’m the only one.

The incredible links across science

A few days ago I discovered that the paper on the flexion of theropod wrists in the ancestors of birds I contributed to has been cited in a journal I would never have expected. Namely ‘Frontiers in Psychology’ and then intriguingly title paper “Sea Slugs, Subliminal Pictures, and Vegetative State Patients: Boundaries of Consciousness in Classical Conditioning”. The paper appears to be open access so you can read it here if you so wish. Naturally this is quite cool and odd, but it does make the point about just how connected very disparate bits of science can be. When we wrote the paper we were thinking purely in terms of bird anatomy, evolution and behaviour and no thought ever passed that this would be linked to sea slugs let alone psychology.

I’ve been asked enough times (generally in a friendly, rather than confrontational manner) why we should fund palaeontology etc. with no apparent applications to mankind. Three are two stock answers to this. First that knowledge should be cherished in its own right and we should try and learn about or world and it’s past, present and future. The second, which I think is more intriguing, is that it’s hard, even impossible, to see how some bits of science might fit together. I’d never have predicted our work would be used to make a point in a psychology paper.

This does show just how interlinked very different branches of science can be and how they can interrelate. Ultimately all science is linked of course, but it need not be just by the obvious slight overlaps between say dinosaurs and fossil birds to living birds to flight to biomechanics to aerodynamics to physics etc. but that huge leaps across the science network are possible, even if they’re not that common.

 

 

A return to the crocodilian panoply

As I was going to be away for a few days, I put up this post of a whole series of photos of various crocs and left the readers to guess at their identities. Here I shall attempt to reveal all (assuming I get it right):


We start off with a fairly obvious one, the American alligator: Alligator mississippiensis


The another alligator, this time the Chinese dwarf: Alligator sinensis

Now the very little seen dwarf caiman: Paleosuchus palpebrosus

The next two (above and below) are of the false gahrial: Tomistoma schlegelii

This gaping animal is the first piccie of a saltwater croc: Crocodylus porosus

And then we get a Nile croc: Crocodylus niloticus

These two (above and below) are the New Guinea crocodile: Crocodylus novaeguineae

Followed by another couple of C. porosus

Then we have a couple of photos (above and below) of the Siamese crocdile: Crocodylus siamensis

And here are two spectacled caiman: Caiman crocodilus

This one is a West African dward croc: Osteolaemus tetraspis

Then another spectacled caiman, though this is rather a young one.

Then another Siam croc.

And we finish with another Chinese alligator.

All in all, a more than healthy collection with 10 different species represented and covering more of the lineages. Sadly I’ve yet to see a true gharial and I do have hardcopy photos of mugger crocs and black caiman but couldn’t dig them out in time to scan them for this (though that’s a job for the future clearly). Obviously having a series of photos like this (despite all the photography issues and different degrees of zoom and angles) does make it much easier to compare them and the shapes of the snout and position and shape of major scales and scutes does make it easier to help separate them out and identify the different species.

Random tracks

One thing about being in palaeontology is that you tend to cover quite a diverse range of subject. Working with the material available means that even specialists in one group or on one method with often dabble quite widely in other areas of research. There’s not too many theropod guys who haven’t at least looked at ornithischians or sauropods or even crocs, pterosaurs and lizards and have probably published on a few of them. So too it is with things beyond bones and again a lot of people will have had some involvement with work on eggs or trackways.

In my case this means that for all my interest in all living things and my tendency to take in local pigeons and squirrels as much as species in zoos and museums, I now also get interested even by things like random footprints in bits of sand. Even this little can provide a bit of food for thought. Here for example the bird tracks are rather deeper than those of the cat and seem to interact with the substrate in a different way. The sand hasn’t changed as such between the two sets being laid down but of course could have been wetter or drier at different times – even a single base can react very differently according to local conditions and affecting how tracks are made and, by extension, how we interpret them.

A panoply of extant crocodilians

I have always liked crocodilians, but as a child only ever saw the odd large American alligator in a zoo or Nile crocs on TV. For a very long time I had no idea just how diverse the living crocodilians were and despite my interest in all things vertebrate would probably struggle to name more than a handful of species.

A combination of getting to a lot more zoos, and zoos generally becoming more eclectic in their collections means that I have now seen more than a dozen species at one time or another (though only two or perhaps three in the wild). For a while I’ve been building up a collection of photos of various taxa with a mind to doing some form of identity quiz. Darren Niash planned to host it at one time, but the last time we mentioned it was two years ago now I think, so I doubt I’m causing him any great problems by doing it here.

So, below the fold are a ton of croc photos from various zoos (sadly not all of them are great images for various reasons but should be good enough). Not all are different taxa (and nor are the photos of a given species consecutive), but there are around 10 different species represented here. Feel free to try and guess what they all are in the comments and more importantly, lots of crocs: cool!

Continue reading ‘A panoply of extant crocodilians’

Qinglongopterus

Many months ago Lu Junchang was kind enough to send me this draft figure that was intended to go with a  description of a new pterosaur he was naming. The paper came out a while back so I’m finally in a position to show this. The specimen is effectively complete, though as with many of these Middle Jurassic beds, the bones have split between plate and counterplate, so you’re more looking at the internal moulds and fragments of bones than their surfaces.

What should be clear even from this picture is that this is a very young animal (look at the size of that heard and the sclerotic ring!) and f you know the scale bar is 10 mm then that helps a bit too! The head is remarkably similar in anatomy (well, as far as can be seen) to young specimens of Rhamphorhynchus, and indeed the whole animal is. Nevertheless, there are differences and thus is named as Qinlongopterus (you can guess where it’s from, right?).

Lü, J.C., Unwin, D.M., Zhao, B., Gao, C., Shen, C. 2012. A new rhamphorhynchid (Pterosauria: Rhamphorhynchidae) from the Middle/ Upper Jurassic of Qinglong, Hebei Province, China. Zootaxa 3158: 1-19.


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