Saturday, December 23, 2006

Happy Christmas, from gigantic Spanish sauropods... or, alas, poor ‘Angloposeidon’

I said the last post would likely be the last before 2007. I lied, as while checking my emails this morning, something came up that I just can’t resist commenting on. As regular blog-readers will know, back in 2004 I and colleagues described a large cervical vertebra from an Isle of Wight sauropod dinosaur (see ‘Angloposeidon’, the unreported story: part I, part II, part III and part IV). Belonging to a large brachiosaurid closely related to the Upper Jurassic Brachiosaurus and Lower Cretaceous Sauroposeidon, the Isle of Wight specimen is 745 mm long, which suggests a total length exceeding 20 m. That made it the largest published European dinosaur (Naish et al. 2004). However, when the time came to talk to journalists about the discovery, I mentioned on several occasions the fact that even bigger European dinosaurs were due to the published in the near future. As I said in part IV

During the long period of time in which the [‘Angloposeidon’] manuscript was in preparation I spoke to several European colleagues who told me of new sauropods from Portugal and Spain that would easily outclass MIWG.7306 in terms of size. I had this on my mind all the way through the submission process, and at any time I expected there to be some report of a new European sauropod that had a total length exceeding 30 m. But even today such discoveries have yet to materialise, and having now seen some of the specimens in question I know that they fail to come close to the 20 m + estimated for MIWG.7306.

The news, of course, is that one of these Iberian giants has just been published (Royo-Torres et al. 2006): its the new taxon Turiasaurus riodevensis from the Villar del Arzobispo Formation (Jurassic-Cretaceus boundary) of Riodeva (Teruel Province, Spain) [many thanks to those who have sent the pdf!]. And it doesnt fail to meet the hype: it really is immense (so, the other Iberian giants that Ive seen were mere pretenders). Turiasaurus has a humerus about 1.8 m long and an estimated weight of over 40 tons. This makes it quite bigger than ‘Angloposeidon’ and in fact one of the biggest sauropods in the world, almost on par with immense titanosaurs like Argentinosaurus and Paralititan. Furthermore, phylogenetic analysis indicates that Turiasaurus belongs to a new clade located close to the origin of Neosauropoda (the macronarian-diplodocoid clade). Galveosaurus (named in 2005, and previously regarded as a cetiosaurid*) and Losillasaurus (named in 2001 and regarded as a diplodocoid, but since suggested to be a mamenchisaurid**) also seem to be turiasaurians. Thats pretty interesting, though it has to be said that the statistical support for turiasaurian monophyly is not overwhelmingly impressive.

* And later renamed Galvesaurus by a different group of authors. I will cover the Galveosaurus-Galvesaurus issue some time in the future.

** The correct term for the group dubbed omeisaurids by some.


Furthermore, the fact that Turiasaurus is represented by good, associated remains means that it might help clear up some of the mess represented by isolated remains (see previous post: Obscure dinosaurs of the Kimmeridge Clay). Scattered throughout the European Jurassic and Cretaceous record are assorted sauropod teeth that roughly resemble the teeth of better known forms, such as camarasaurs and brachiosaurids, but also have a unique look about them. Examples include the huge, beautifully preserved tooth named Oplosaurus armatus (from the Isle of Wight*) and the unusual specimen Cardiodon rugulosus from the Middle Jurassic Forest Marble Formation of Bradford-on-Avon, Wiltshire. It now turns out that these teeth are similar to those of Turiasaurus, which raises the interesting possibility that they are further representatives of this newly-recognised group. That would be cool.

* For more on Oplosaurus and other Lower Cretaceous English sauropods go here.

Anyway, Ill have more to say on turiasaurians and other Iberian sauropods in the future. And it really is relevant as I and colleagues (Barbara Sánchez-Hernández and Mike Benton) currently have an article in press on dinosaurs (including sauropods) from the Villar del Arzobispo Formation. Maybe some of the material we have belongs to Turiasaurus? Well see...

Finally, in other dinosaur news, youll note from the big picture above that Tom Holtzs big dinosaur encyclopedia is finally being advertised. I discussed it previously here.

All the best for Christmas and the New Year. My new year’s resolution? To finish writing all those blog posts I’ve been promising for the last year. Controversial mammals from Borneo, the passerine supertree, rhinogradentians, giant Australian feral cats, temnospondyls, more on tupuxuarids, agamas and sea snakes, the biggest slow worms, fake Chinese turtles, amphisbaenians, and loads more on sauropods, theropods, pneumaticity, flightless birds, bizarre pterosaurs, and giant eagles. And keep an eye on Tetrapod Zoology’s 1st Birthday... Goodbye 2006!

Refs - -

Naish, D., Martill, D. M., Cooper, D. & Stevens, K. A. 2004. Europe’s largest dinosaur? A giant brachiosaurid cervical vertebra from the Wessex Formation (Early Cretaceous) of southern England. Cretaceous Research 25, 787-795.

Royo-Torres, R., Cobos, A. & Alcala, L. 2006. A giant European dinosaur and a new sauropod clade. Science 314, 1925-1927.

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18 Comments:

Anonymous David Marjanović said...

Has someone sent you the pdf and the supp. inf. yet...?

1:37 PM  
Blogger Darren Naish said...

Nope - are you offering? Thanks if so.

Academic things tend to be sent to my UOP email (darren.naish@port.ac.uk), which I can't access from home. So please send anything to the eotyrannus at gmail dot com address, thanks.

1:56 PM  
Anonymous Interested said...

"All the best for Christmas and the New Year. My new year’s resolution? To finish writing all those blog posts I’ve been promising for the last year. Controversial mammals from Borneo, the passerine supertree, rhinogradentians, temnospondyls, more on tupuxuarids, agamas and sea snakes, the biggest slow worms, fake Chinese turtles, amphisbaenians, and loads more on sauropods, theropods, pneumaticity, flightless birds, bizarre pterosaurs and giant eagles. And keep an eye on Tetrapod Zoology’s 1st Birthday... Goodbye 2006!"......



Don't forget the giant australian feral cats!

Merry Yule!

7:44 PM  
Blogger Darren Naish said...

Oh yes... and those giant Australian feral cats.. (still waiting for news on DNA work). Best wishes, and thanks for your interest 'Interested'!

9:27 PM  
Anonymous Andrew said...

it'd be good to see more on pneumaticity and Angloposeidon - hopefully together. I flounder a bit sometimes - I work developing health policy - but you've got one of the best science blogs around.

Have a great Christmas and New Year!

10:51 PM  
Anonymous Tristram Brelstaff said...

Isn't that Rudolph the Red-Nosed Dinosaur on the cover of the book?

10:32 AM  
Blogger Chris said...

I'm a former botanist, and delighted to have found your blog. You are writing well and entertainingly on a variety of fascinating topics, and while sometimes I'm a bit lost in the specialized dinosaur subgroup lingo, I look forward to each new entry.

I just wish someone was doing the same for some of the weird, controversial, and fascinating plants out there, but as far as I know, no one is. (And my botany is pretty rusty at this point, or I'd want to do it myself.)

One thing I'd be happy to see is some pieces on what the ancestors of turtles were like, before they became turtle-fied. Ditto some of the other modern groups that are really very weird when you come to look at them closely, even though we take them for granted. I've noticed your columns about rabbits and whales, for instance.

I also find the vast re-arrangements of taxa due to newer cladistics and supplemented by DNA studies to be very interesting. I know much the same thing has happened in plant taxonomy -- when I left grad school, the grand mix-up of the grasses was just beginning, for instance. (The nice, visible-with-a-hand-lens characters we'd all been keying on for years turn out to be more or less irrelevant to real relationships.)

Anyway, keep up the good work and write more of it, please.

12:51 AM  
Anonymous Another Interested said...

Dear Darren,
together with the season's greetings, thanks for your blog.

A question though: is the way theropod dinosaurs are portrayed the proper one according to recent discoveries?
Or, in other words, did they have feathers or not?
What is your opinion on the matter?

What about a post on this question, in the New Year?

8:37 PM  
Blogger Darren Naish said...

Many thanks Andrew, Chris and 'Another interested' for your comments. Time permitting I have a lot more stuff to add to the blog, so there's lots to look forwards to. Andrew: pneumaticity expert Matt Wedel and I are due to work together some time in 2007 on the skeletal and soft-tissue pneumaticity in sauropod and theropod dinosaurs, so I will certainly be blogging about this subject in the near future. As a brief intro on this subject to the uninitiated, you all know that birds have air-filled sacs (connected via tubes to their lungs) located within their bones and within their body cavities, right? Well, at least some non-avian dinosaurs (notably bird-like theropods and sauropods) had these too, as did most pterosaurs. The full story is long, complicated and fascinating, and with lots of implications for the biology of the animals concerned.

Chris: thanks for the kind words, and I too wish that someone was popularising the plant world in the same way. We all know (though we zoologists rarely admit it) that animals aren't really that special when you think of the sort of stuff that plants get up to... Remember that the blogosphere is still young, and it's surely just a matter of time before the right sort of person comes along. Your suggestions about proto-turtles and so on are duly noted, and added to the list! I will warn you, pre-emptively, that the affinities and ancestry of turtles is one of the most controversial subjects within tetrapod zoology....

'Another interested': yes, non-avian theropods undoubtedly had feathers, just as Greg Paul and others have been saying for several decades. But not all of them. True feathers, so far as we know, were restricted to maniraptorans (the theropod clade that includes oviraptors, dromaeosaurs and birds), but simpler, filament-like integumentary structures appear to have evolved much earlier within theropod history, probably at or around the base of Coelurosauria. We now know that primitive tyrannosaurs and compsognathids had a covering of these structures. Anyway, I've been rather quiet on non-avian theropods so far, and will blog about them some more in 2007, including on the subject of feathers and so on.

Thanks again for the nice words and the support. Let me remind everyone that I would write MORE blog posts if only I had the time and opportunity. Best wishes for the new year!

8:54 PM  
Anonymous David Marjanović said...

Phylogenetics using DNA is cladistics. Except when it's not (neighbour-joining, or the extinct UPGMA); then it's phenetics ( = a mere measure of similarity in %, without even trying to tell retained from derived features).

Turtle ancestors... MWA HA HA HA HAAAAH! Basically, in the recent literature there are four possibilities for what the closest known relatives of the turtles might be; I consider two of them likely, can't exclude a third, and am supposed to explore all four as part of my dissertation from next year onwards, as well as (at least) three more that were suggested in earlier times. I suppose a complete skeleton of the Middle Triassic turtle Priscochelys hegnabrunnensis would help; so far this animal is (apparently) only known from a carapace fragment that's just big enough to tell it's not from a placodont.

11:58 PM  
Anonymous Keith Bennett said...

hi Darren reading your article on wall lizards L/muralis there was quite few around the precincts of Farnham castle in the 1950S and I had caught them myself after diverting from a days sand lizard safari at Frensham little pond before the destruction of prolific sites that abounded the area and have now gone forever due to pine tree planting, also ther was reports of a in colony at Newdigate also in Surrey what I did not follow up.

5:45 PM  
Blogger CHIC-HANDSOME said...

good picture

5:48 PM  
Blogger Darren Naish said...

David: you're doing turtle origins for your phd? Well, good luck.

9:17 PM  
Anonymous David Marjanović said...

Well, I'm supposed to start with a revision of the placodonts and then, "if time allows", to bloat this into an amniote phylogeny. My supervisor is Michel Laurin... the placodonts are a means to an end (testing the Rieppel School hypothesis that euryapsids and turtles and lepidosaurs are close relatives). Clearly a very interesting topic, but I'll need the good luck you're wishing me!

2:50 PM  
Blogger Darren Naish said...

Well, make sure you get hold of the most useful bit of literature on placodonts yet published...

Naish, D. 2004. Fossils explained 48. Placodonts. Geology Today 20 (4), 153-158.

Just kidding, it's only a semi-technical review article. And you'll probably need to get John Merck's thesis (unless you already have it).

8:46 PM  
Blogger Jaime A. Headden said...

Darren, you wrote:

"* And later renamed Galvesaurus by a different group of authors. I will cover the Galveosaurus-Galvesaurus issue some time in the future."

While I understand that you and Sánchez-Hernández are colleagues, I must correct a minor detail here. The authors of Galvesaurus — as opposed to Galveosaurus — never referred to the prior work, and thus it doesn't constitute a renaming. As Sánchez-Hernández herself states (2006), this paper was online and set to an earlier date than hers was published, although technically she argues it wasn't available until December, after her August date. This issue has, however, been contested by Barco et al., who seem to be appealing to the ICZN on this matter. They argue, for example, that Sánchez-Hernández ignored (or was unaware of) workers in the museum in which the material was housed to publish on a specimen and name it without notice, who were themselves preparing a manuscript naming the taxon (of which name was available in musuem labels).

Sánchez-Hernández claims (in her 2006 report on the synonymy) that it was a "coincidence". Additionally, she state that her paper was widely read an available, but this is rather tricky: It is possible for a paper, as in whole reams of Chinese journals, to be unknown to the West for months after publication, and will lead even to different Chinese-based groups of paleontologists nearly simultaneously or years apart to independantly name the same specimen.

6:29 AM  
Blogger Darren Naish said...

Many thanks for your comment Jaime. But you haven't got the whole story, sorry. Like I said, I'll cover it in future.

12:59 AM  
Blogger Jaime A. Headden said...

For the most part, I am referring to what has been put into print. So while I am not on the inside here, it is my understanding that the authors named their respective taxa on their own, not while referrencing another taxon, which means neither, even barco et al.'s, would have been accounts of "renaming".

8:38 PM  

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