Posts Tagged 'birds'

The filamented Psittacosaurus

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By now most people with even a passing interest will be aware of the fact that there are now a number of specimens (and indeed species) of ornithischian dinosaurs that are preserved with some form of filament-type structure which, superficially at least, bear some resemblance to primitive feathers. However when the first candidate was announced, this specimen of Psittacosaurus housed in Frankfurt, it inevitably causes something of a furore with many suspicious of the data and suggestions that the filaments were simply coincidentally preserved plant stems or something similar.

The discovery of multiple specimens of Tianyulong inevitably make this rather more plausible as a real find, though of course a few more filamented Psittacosaurus would be nice. A third taxon is apparently now know but sadly illness led to a no-show at SVP so few have seen anything of this new find. Still, the original find is an impressive specimen, but doesn’t seem to have really been thoroughly described or illustrated too well and as I’m in a position to at least partially rectify that, here’s some photos I took of the specimen on my recent trip.

I have actually seen this before years ago but extremely briefly, and have also seen a superb cast of it in the Carnegie (my photo of which actually popped up in a dinosaur text book recently, [with permission I should add] such was the quality of the copy). However, I’d never really *looked* at it properly and actually spending a few minutes (even through a glass case) reveals some lovely details.

First off, it’s big. The biggest specimen I’ve seen by far for this genus, though the head is not that large compared to the rest of the body. Then there is skin pretty much everywhere – this does turn up in Liaoning not too infrequently, but rarely to this extent or quality. It covers large chunks of the animal and even completely covers large chunks of the bones in places (just look at the femur) and it looks like there’s a pile of gastroliths in the gut that are also covered.

While I’d be very cautious about interpreting the extent of the skin as being directly linked to other soft tissues, the extensive ‘flap’ behind the hindlimb would correspond with what you might expect from large retractor muscles there and so might well be genuine. Not only that, but there’s quite a bit of texture to the skin and in a couple of places it appears to have a different surface texture to others (see the underside of the base of the tail, and the area around the toes), which could also be genuine. On top of that, both the individual scales are clear in some places, and are even coloured differently (the larger ones are black) implying at least the possibility of this representing a pattern on the animal, and this changes along the body (look a the concentration in the tail, compared to the legs) though again:caution. It does look rather like this little patch that I featured years ago which is rather neat. Finally, this pattern also extend onto bones that are not obviously covered with skin (see the distal forelimb for example) with apparently the stains or some other taphonomic artefact of the scales left on the bones themselves.

And yes, then there are the filaments. Sprouting up off the base of the tail and extending most of the way along its (incomplete) length. They are rather thick and clearly somewhat stiff, but also flexible enough to bend under their own weight. While not a common reference, they look a lot to me in terms of  their apparent properties like the tail hairs of giraffe (though much, thicker). It’s a real shame they are at least in part cut off the edge of the slab, but certainly appear to have stopped appearing well short of the end of the tail, so their full extent does appear to have been preserved.

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I think that’s everything I can reasonably (or even unreasonably) speculate about this specimen without, yknow, actually going back and reading the original paper and associated commentary. However, the really key thing is of course that here’s some nice pictures of this and it gives a welcome opportunity to revisit this important and interest specimen.

Berlin Archaeopteryx

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I’m just back from a quick visit to Berlin and so once I’ve caught up with all the usual stuff that gets behind from being away there’ll be some blogs coming on the exhibitions, Berlin Tier Park and others. Meantime though, here’s the Berlin Archaeopteryx. I have seen this magnificent and legendary specimen a couple of times before and have some old analogue photos, but now have some nice shiny digital ones to put up here. Oddly this is the one obvious specimen that’s been missing from my ‘collection‘. It has been on here before thanks to Heinrich Mallison, but now I can add my own shots to flesh this out with a couple more.

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Archaeopteryx

It was suggested to me not too long ago that I might well have the best and most extensive collection of images of Archaeopteryx specimens online. Between having seen quite a few of these on display and having taken photos myself, plus the near endless collection generously sent on by Helmut Tischlinger of his UV works, nearly every specimen is on here and most with multiple views, close-ups and in UV. I am still missing a couple, but I’d have to agree that I’ve yet to see any online collection that can rival mine. Still, they are scatted around all manner of posts and so aren’t necessarily that easy to find. No more, here’s they are all are for convenience.

Cast of the London specimen

The Berlin specimen

The Berlin specimen returns

The Munich specimen

Mayr with the Eichstaett specimen

Eichstaett, Thermopolis and Berlin in UV

Solnhofen, Eichstaett and ‘chicken-wing’ specimens

Close-ups of the Solnhofen specimen

Solnhofen specimen in black and white

The Thermopolis specimen

The Daiting specimen (and in UV)

The most recent (11th) specimen (and in UV)

More on the 11th specimen

Yet more Archaeopteryx – Chicken Wing, Haarlem and Maxberg

If you have others you are happy to share and have permission to distribute, do please let me know and send them on. This is simply there as a reference collection for people to learn and work with, but obviously more (or better, not all of these are great) would be lovely to have and make this still more useful. I know there are some scans and images out there and it’d be great to round this out as a clearing-house for people who want to see and compare these specimens.

Sciurumimus

Readers will remember a beautiful fossil from the Solnhofen being shown on here back in November of last year. People who have access to the internet will probably now now that yesterday the first formal publication on this animal came out. It’s now named Sciurumimus – the squirrel mimic – on account of the rather bushy tail. There’s already a ton of discussion on this online and quite some hefty coverage so I’m not going to dive into the ins and outs of feather distribution in theropods or the phylogenetic position of it. It is worth comparing it to Juraventor of course – sister-taxon to Sciurumimus in the analysis and from the same beds. Despite the obvious gross similarities, the authors do note a ton of small differences between the two that suggest they are genuinely distinct.

Of much more interest to the readers though will be the fact that once more Helmut Tischlinger has been generous enough to send me a variety of nice images with permission to publish them here. At least one of these isn’t in the paper and the res is pretty good so even those of you who’ve been able to peruse the PNAS paper might do well here, so enjoy. As usual my thanks to him for this very generous act and a reminder that these are his images and should not be reproduced without permission etc.

 

 

 

 

Academics on Archosaurs: Mike Habib

Michael Habib, University of Southern California
I primarily study the biomechanics of flying vertebrates, especially early birds and pterosaurs.

1. What first got you interested or involved in your research field?

I’m a classic – I declared loudly that I wanted to be a paleontologist at about the age of four.  The most important catalyst was probably the trips I took with my family to the National Museum of Natural History, in Washington, DC (I grew up in that region).

Perhaps a more interesting story is how I ended up in my particular speciality.  While I am really a rather general biomechanist, I think most Musings readers will know me as a pterosaur worker.  I’m quite pleased by that label, but it came as something of a lucky break – I really got rolling on pterosaurs after attending the 2007 Flugsaurier Conference in Munich, which I originally attended on something of a whim because I’d been playing with a few pterosaur bits at the USNM collections in between bird work. That was a real full circle moment because I’d loved pterosaurs as a kid.  Of course, as Musings folks will no doubt recall, Dave organized that conference!  Thanks Dave, it rocked.

2. What is your favourite piece of research?
Okay, no surprise here – I’m most pleased by the quadrupedal launch model for pterosaurs I proposed in 2008.  I think that has actually had a measurable impact on how we reconstruct pterosaurs, and it also seems to have affected how other scientists think about animal takeoff and flight evolution.  So that’s pretty darn cool.

To be fair, though, a paper I’m currently writing may end up being one of my all time favorites (it’s the much discussed anurognathid study with Mark Witton.  I know, I’ve been talking about it forever, but we keep adding stuff – this is going to be a wicked paper).

3. What do you think is the most interesting or important discovery in your field in recent years?
This is a much more difficult question for me.  For one thing, I’m not sure what my “field” really is.  If we assume it’s animal flight evolution, then I would have to list the discovery that functional wings existed in theropods outside Aves (which either means theropod flight should up more than once, or that theropod flight came before birds).  If we assume I’m a “pterosaur guy” then I suppose it would be the range of new soft tissue discoveries that have rapidly accrued, in part because of the outstanding UV imaging studies of individuals like Helmut Tischlinger.

4. What do you think is the biggest unanswered question in your field right now?

Within animal flight overall, the largest questions relate to the origin of flight in pterosaurs and bats.  While debate will range on about the details of the origin of avian flight, we have the base layer pretty well worked out now.  However, the early stages of flight in pterosaurs and bats are darn near completely unknown at this stage.  I’m waiting for some really excellent stem-pterosaurs to be discovered.

5. What advice would you give to students about research?
Remember that you are a professional writer.  You have to do good science to have things worthy of writing about, but at the end of the day, every academic scientist (and that’s practically every professional paleontologist) is basically a professional writer.  Own that fact, and live up to it.  Work hard to write well, and think carefully about your readership and how to reach the people you want to read your work.

Academics on archosaurs: You Hai-lu

Dr Hai-lu You, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences
Specialist in dinosaurs, especially Cretaceous ornithischian dinosaurs.

1. What first got you interested or involved in your research field?

By chance. I applied my Master degree for paleoanthropology, but was suggested to switch to dinosaurs.


2. What is your favourite piece of research?

My favorite piece of research is on the re-discovery and research on Gansus, an Early Cretaceous bird from northwestern China that at the beginning of the branch leading to modern birds. Before our research, only a partial foot was discovered, and our team now excavated ~100 specimens. Our result was published in Science, and the various medias reported it, including a documentary by Science Channel.

3. What do you think is the most interesting or important discovery in your field in recent years?

“Proto-feathers” from China , which changed our view on the concept of birds, and the evolution of the function of feathers.

4. What do you think is the biggest unanswered question in your field right now?

The using of PhyloCode, which will have fundamental influence on our view of the tree of life.

5. What advice would you give to students about research?
Go through everything on dinosaurs, from the field to preparation to research to museum activities.

The giant, feathered tyrannosaur Yutyrannus huali

So perhaps inevitably the fossil beds of Liaoning in China have coughed up yet another fascinating feathered dinosaur. Yutyrannus huali (which translates as the ‘beautiful feathered tyrant’) is big – as big as some of the Late Cretaceous tyrannosaurines with the largest specimen being around 9 m long and estimated to have weighted close to 1.5 tons. In short, this was big. And feathered. While they are not brilliantly preserved, they are clearly present in places and directly associated with the skeleton as should be expected.

There are a few interesting things about this and I’ll go over them in turn, though as ever the first port of call should really be the paper for the real nitty gritty. First off, the specimens themselves – there are three of them, so this is already a well known animal, and two are basically complete. There’s a lot of anatomy right there and yes, I have to confess, rather more than some other tyrannosaurs I could mention. Indeed two of them are preserved together, as a pair, which nicely hints at least (well, I’m going to say so) at the possibility of sociality (theropods being more social than previously suggested, how interesting?).  Multiple specimens are always great and animals this size being preserved at all are quite rare in the Jehol, so it’s pretty impressive we have three of them. They are also preserved in that psuedo-3D manner I mentioned the other day so there’s really quite a bit of detail there and they are not badly crushed or mashed (as you can see in the pictures below).

Now it is of course already known that tyrannosaurs were feathered, with the basal Dilong being preserved with feathers. The question is of course, did the bigger ones like T. rex have them? There’s been suggestions that they didn’t as they could overheat and there are hints of scaly, feather-less skin from impressions refereed to Tyrannosaurus. So while at least some tyrannosaurs certainly had feathers, and large ones certainly could have done, this is definitive evidence that they genuinely did. The size issue is of course interesting since indeed, very large animals tend to reduce insulation to avoid overheating (elephants, rhinos, hippos etc. are not that hairy and indeed elephants can struggle to keep cool). The obvious exception being animals that live(d) in cold climates like mammoths, and the researchers note that actually the environment Yutyrannus lived in was likely rather cooler on average than that occupied by a number of later tyrannosaurs, so this may indeed have helped them stay warm.

Below are some pictures of the various fossils. While you’ve probably seen a number of these before on all the other sides my insider contacts means I’ve been sent a few to use which were neither in the paper nor press release. So there’s something novel here for everyone, even if it’s not in the text.

Top image by Brian Choo (used with permission) and the rest courtesy of Xu Xing and colleagues.

Xu, X. et al. 2012. A gigantic feathered dinosaur from the Lower Cretaceous of China. Nature. doi:10.1038/nature10906

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

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!

 

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.

Bits of Archaeopteryx

What’s a bit more Archaeopteryx between friends eh? After the ‘clearing house’ that was the last two posts, I’ve since found yet more photos of specimens that I have never used. This is the generally somewhat horrible to be honest Burgermeister-Mueller specimen, though while the head and body of this one are not great, as you can see here, the hands and feet are actually pretty good (though my pictures could be better).

Munich Archaeopteryx

While writing yesterday’s little post about the Berlin Archaeopteryx, I realised that of all the specimens I had covered on here, somehow the Munich one had never made it. A dig though my files turned up a couple of far-from-perfect photos of this very-nearly-perfect cast on display at the BSPG. I’m still a couple short of the full set, but especially given all the UV stuff I have kindly been loaned, I can’t help suspect this is collectively the most complete set of Archie photos online. It was never an intention, but does seem to have happened.


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