How Mimsy Was Zanabazar?

No, not the early Mongolian Buddhist leader.

Above: Not a troodontid.

Zanabazar is the newly-coined name for the troodontid previously known as Saurornithoides junior. A new review of the genus Saurornithoides by a heap of authors including Mark Norell and Rinchen Barsbold himself (who named S. junior in 1974) found that the evidence linking S. junior to S. mongoliensis as each others closest relatives is lacking, so a new genus name was needed for junior (I would have gone with "Henryjonesius" in honour of Sean Connery).

Above: Zanabazar junior by FunkMonk, licensed.

But wait a second... there's been talk for some time now that S. junior may be synonymous with another small troodont, a contemporary from the Nemegt Formation with one of my personal favourite dino-bird names, Borogovia (after one of the nonsense creatures in Lewis Caroll's poem Jabberwocky.) I haven't read the paper yet so I'm not sure if this issue was addressed, but as it stands now, there still is no overlapping material to directly compare the two troodonts, so it's impossible to prove synonymy at the moment (Borogovia is known from leg and foot bones lacking the rest of the skeleton, Zanabazar is known from a partial skeleton lacking leg and foot bones). But if any further material for either species turns up, and they turn out to be synonyms, Borogovia will win the day as the older name. Not that Zanabazar isn't a cool name in and of itself. But how boss would it be to name a hypothetical new Nemegt therizinosaur (with their long necks, giant claws, and overall freakish appearance) after the Jabberwock itself? A mammal called "Momerathobataar"? "Tovia slithius" the nematode to complete the set? Will, 70 years later, an oviraptorid have to be re-named "Toviamaia"? Too many Nemegt fauna inside jokes? Yeah, I'll stop.

Above: The resemblance is uncanny! Left: Jabberwock by John Tenniel, 1871. Right: Therizinosaurus by Apokryltaros, licensed.

Nom nom nom

Above: Edmontosaurus skull, note teeth in back of jaw. Photo: Ballista / Wikipedia, licensed

Did hadrosaurs chew? A recently named lambeosaur called Angulomastacator ("angle chewer") would have us think so. So would a new paper by Williams et al. on an intensive study of hadrosaur tooth wear. As this article reports, the direction of hundreds of scratches were mapped in 3D to suss out what type of chewing method was used by hadrosaurs. The authors found that they employed an extinct form of chewing unlike any living animals, in which the natural kinesis (joints between the skull bones found in modern reptiles) forced the bones of the upper jaw outward, causing the tooth batteries to slide against each other in a sideways motion.

Sounds very interesting and a great step to resolving the ecologies of this well-known dinosaur group... or is it? A major paper that came out in the December issue of JVP argued convincingly that dinosaur skulls such as this didn't actually have any kinesis at all! As David Marjanovic summed up on the DML, the argument there was that people who have spent their careers studying modern reptiles and their kinetic skulls have assumed that dinosaurs followed the same pattern, and have grasped at straws to find evidence of kinesis where it doesn't actually exist (that is, that dinosaurs lost cranial kinesis at some point in their evolution from other reptiles, or never had it, meaning it's a novel feature of lizards and snakes). If that's the case, than the underlying assumption of this new hadrosaur paper is wrong. Another blow against their conclusions, as noted in the article above, is that reports of fossil stomach contents from hadrosaur mummies show food that had been sheared, not chewed. Gut contents also suggest a diet predominantly of conifers (pine trees etc.), while the tooth wear study suggests food was cropped close to the ground and may have been rich in silica, suggesting a diet primarily of ferns and horsetails.

Above: Edmontosaurus tooth battery, which was studied for wear patterns. Photo: Vince Williams / Univ. of Leicester

So then, how to explain the unique wear patterns on hadrosaur teeth? How can we rectify the conflicting evidence regarding diet? Surely another salvo in this controversy will appear in print in a few months.

Tracy Ford and the Kingdom of the Embellished Skull

It's a catch-phrase for Indiana Jones and a rallying cry for paleontologists and archaeologists alike...

"It belongs in a museum!"

Unfortunately, there are plenty of private collectors out there who don't heed Indy's sage-like advice. Many important fossils are lost every year to private individuals who rarely disclose specimens to experts for study. Even if specimens in private hands are offered to experts, many refuse to publish on them, partly because they see it as simply unethical and partly because most important provenance data (what rocks formation the bones came from, etc.) has already been lost by that point.


Take the case of the Mongolian tyrannosaurid Alioramus. This dinosaur is officially known from only a single decently preserved skull, though several more complete skulls are known to exist in private collections, making them all but worthless to science unless the collectors bequeath them to museums in their wills later on. Mongolia is notorious for losing specimens to collectors, and apparently many, many excellent, potentially very important finds and new species will never become known to the public for this reason.

Back to Alioramus. One such 'lost' skull was recently sold at auction in New York to an undisclosed buyer for over US$200,000 (story here). Photos of this specimen were posted to the Dinosaur Mailing List after the auction finished (see DML post here for links to all the photos. One is reproduced above).

This seems like a tragic sale, because the skull appears to be beautifully complete, so it would be quite a loss for it to end up under a glass case in some millionaire's bedroom. I say would, because it looks like the joke's on him or her...

Often ignored in the sale of private specimens inaccessible to science is that they're inaccessible to science. That means that embellishments often added to black market fossils can't be caught by trained eyes. Now, at first glance, even most experts wouldn't notice the enhancements to the skull pictured above without studying the fossil up close. Enter Tracy Ford: the original armchair paleontologist, he has made a name for himself in offering a subscription-based online dinosaur database, as well as producing numerous publications on dinosaur life anatomy, books on how to draw dinosaurs, etc. Ford is also an active member of DinoForum, and noticed something very familiar about the auctioned-off Alioramus skull. He'd seen it before, at the infamous Tuscon Gem and Mineral Show. Tuscon is a Mecca for fossil collectors and under-the-table deals on shady specimens. The show regularly attracts even pros, who can often come across amazing new finds.

Ford had seen this very skull at the show, and, as he reported on DinoForum:

• "I can saw with total confindance that this specimen is more than 80 percent reconstructed. The reason why I know this is that it was at the Tucson Rock Show about 3 or 4 years ago and I took several photo's of the specmen, which at the time was just the premaxilla, maxilla and tip of the dentary. Nether of the bones complete. So, just to get it sold they reconstructed it into its current state. Not as good as they claim it to be."

Others were astounded that someone would pay over 200 grand for a specimen that hadn't been checked for reconstruction or forgery. "Completing" partial skulls is common even in museums when prepping specimens for display, but you'd reckon this would significantly decrease the value of a specimen at auction, and I'd be very surprised if the buyer knew that only the ends of the jaws were composed of real bone. Here's a photo Ford took of the specimen years ago in Tuscon. Worth $200,000? You be the judge.

Empire of the Shark Teeth

Today saw the publication online of a paper finally re-describing Chilantaisaurus maortuensis, a theropod from mid-Cretaceous China. This species was assigned to the genus Chilantaisaurus in 1964 by Hu, and has been all over the map since then. Authors have variously considered it a tyrannosaur, an allosaur (linking allosaurs and tyrannosaurs, actually), and even a maniraptoran coelurosaur. While the exact identity of Chilantaisaurus proper remains a bit uncertain (latest word is that it may be a spinosaur), the new paper is pretty sure of its conclusion: C. maortuensis isn't Chilantaisaurus at all, but the first known Asian carcharodontosaur!

As the story goes (and as Steve Brusatte reported in a guest post at Archosaur Musings), during some down time in Beijing, and while working on his PhD thesis on tyrannosaurs, he got wind of this possibly tyrannosaurian specimen at a Beijing museum. It was immediately apparent to his eye that this was not a tyrannosaur, but a carch, which he and his colleagues finally renamed as Shaochilong maortuensis.

Not only is this the first Asian carch, but it fills a glaring hole in the Asian fossil record. Basal tetanurans dominated the large carnivore roles of Asia in the Jurassic, and tyrannosaurs like Tarbosaurus and Alioramus dominated in the Late Cretaceous. But what was going on in the mean time? Apparently, carcharodontosaurs, which were previously only known from the Americas, Europe, and Africa. This means that tyrannosaurs didn't arrive on the scene until the very end of the Cretaceous, much later than previously thought. Part of this has to do with the dating of the Ulansuhai Formation where Shaochilong was found. Previously thought to be Aptian-Albian in age, dating of underlying rocks shows that it must be at least Turonian (92 Ma), pushing the arrival of tyrannosaurs well into the Late Cretaceous.

So, did tyrannosaurs arise in Asia, migrate to North America, then migrate back to dominate Asia in the LK? We'll need more fossils to know the whole story. Given the Cretaceous age of Shaochilong, we can't be sure whether carcharodontosaurs originated in Asia or migrated there from Europe, Africa, or North America, all of which have earlier carch species. But, as a special bonus as Steve points out on the blog linked above, this presents the first evidence that carcharodontosaurs could have battled ceratopsoids (in the form of Turanoceratops), horning in (haha, get it?) even further on traditional tyrannosaur territory.

Speaking of Asian tyrannosaurs, have you heard about that gorgeous complete Alioramus skull recently auctioned off to a private collector and thus lost to science for probably ever? Well don't cry too much over it. More to come...

[Image: Chilantaisaurus from here.]

Panphagia & Aerosteon live!

An update to the previous concerns over the validity of the name Panphagia (see original post on the new species here, and the ICZN controversy here). In the comments section of the later post, an author of the Panphagia description in the online journal PLoS ONE, had this to say:

• "Regarding to the ICZN requierements, I let you know that PLoS made the printed copies. So, the problem of the validity or not of the new species is over."
  --Ricardo Martínez, Panphagia paper author

So there you have it, PLoS ONE, after the Darwinius debacle, is probably going back to correct any past oversights in this area. The name Panphagia protos Martínez & Alcober 2009 is officially valid and doesn't need to be emended (just note the change in exact publication date, in case some claim-jumper has published another name or alternate spelling or something in the mean time). EDIT: Aerosteon and Maiacetus have been similarly addressed. The official publication date for Aerosteon is now 2009 as far as the ICZN is concerned.

[Illustration Panphagia above is from here, copyright Jorge Gonzalez.]

Science Reporting Today: Sauropod Necks

And finally, we have the first of (unfortunately) probably very many entries under the heading of Science Reporting Today. That is, how god-awful it often is.

[Above: Cast of Diplodocus carnegii at the NMH in London. This mount has not been made obsolete!]

The big dino news today has been the paper by Darren Naish, Matt Wedel, and Mike Taylor (all of the glorious SV-POW! blog) that, contrary to studies in the early 2000s, sauropod necks were not constrained to a horizontal position. Note that, if you read the papers or their own blog posts, they're very careful to spell out that this is not to say that sauropods are just going from one constrained pose to another. I read one comment on a news story, where some poor dim soul honestly said the new study must be bogus, because if they held their heads up high, how did they drink? For serious, a human being, presumably without any mental defects, said that. For a second I thought I'd been frozen for 500 years and woken up in Idiocracy.

Generally, the problem with science reporting, as detailed in the comic I posted a few days ago, is that science reporters, who are rarely specialists in whatever particular area they're reporting on, must not only interpret the information given to them by experts, but they also feel the need to severely dumb the info down for a general audience (and, often, try to spice it up or over-exaggerate the importance of discoveries, so people who aren't interested in science will be impressed. See exhibit A).

Here are some examples of news stories discussing today's sauropod neck paper, and either getting things wrong or dumbing it down so much that they're misleading people rather than educating them.

• "Generations of children have been brought up on the idea that that long necked dinosaurs like sauropods, lumbered along with their necks stretched out horizontally." --Channel 4 News

Really? Generations of children. When I was a kid, every dinosaur book and toy I had depicted sauropods with an erect neck posture. This is the stereotypical brontosaur image, after all. This is the posture that lead people to mistakenly surmise that sauropods lived under water and used their long necks like snorkels. In reality, though some older museum mounts depicted sauropods with horizontal necks (mainly due to lack of ceiling space), the low-slung, horizontal necks didn't gain popularity until Walking with Dinosaurs was released in 1999. Ten years is hardly "generations." This is an example of exaggerating the impact of a find. It's important, sure, but not that earth-shattering, as its overturning a view that's only been entrenched a decade.

The headline of the Times Online article:

• Natural History Museum's sauropod exhibit 'anatomically wrong': The Natural History Museum's flagship dinosaur exhibit may be misleading because sauropods held their heads up high rather than keeping them low, claim scientists.

"May be misleading", well that's arguably true, but anatomically wrong? No. Of course sauropods could achieve a horizontal position. Here's an example of a headline making a bold, exaggerated, and incorrect claim, and only backpedaling if you read the fine print (i.e., the actual article).

Anyway, those are just the first few examples I noticed. The SV-POWsketeers are keeping track of news stories about their research here, if you'd like to play along at spotting shoddy science reporting practices. If you find anything truly ridiculous, drop it in the comments!

Also, bear in mind that this is not a criticism of science reporters per se. Whenever trying to communicate complex ideas in a simple way, you're going to mislead some people. Take a look at the graphic I did for the previous post (linked at the top). Big ol' red X over the WWD Diplodocus. What I meant to convey is that this is no longer the standard, default posture for these animals. Will somebody look at that and think I meant they could not hold their necks horizontally? Unfortunately, it's possible. But maybe it's a problem inherent to the whole approach all the science news outlets seem to be taking. Rather than "New discovery disproves conventional view of sauropods," wouldn't a better tack be, "New discovery shows sauropods had greater range of neck motion than previously thought"? Or does that not sound earth-shattering and controversial enough for Joe Average to care?

Put Your Heads Up For Detroit!

A quick note on a new paper out today on sauropod anatomy. Always exciting stuff, obviously, but today especially so.

As many of you may have heard, the days of sauropods with their heads held high and proud came to a crushing end in 1999, when Kent Stephens, using his DinoMorph computer anatomy program, found that contrary to decades of portrayals in art and museum mounts, sauropods did not carry their heads much higher than their shoulders. The neutral pose of the long neck was found to be that of a vertical beam, dipping towards the ground to mow down field after field of ferns, not a high, swan-like S-curve.

Enter the SV-POWsketeers, the new guard of sauropod experts who made a splash a few years back by starting a collaborative blog about nothing more than Sauropod Vertebrae (Pictures Of the Week, hence the acronym).

In thier first formal paper as a team, the SV-POW! guys became the first to really challange Stephens' findings, which had by now become the orthodox view, represented in such pop culture icons as Walking with Dinosaurs. Stephens stated in his paper that no modern animals normally held their necks out of neutral pose, except to drink, display, etc. When just walking around, they were, as Zapp Brannigan said with disdain, "So beautiful, yet so neutral."

But, were they? And are they? According to the SV-POWsketeers, who looked at living animals from all major tetrapod groups using X-rays and studies of the existing scientific literature, no. Living animals never walk around with their necks in a neutral pose. In fact, far from being disgustingly neutral, the normal position for most animals is to flex the head and neck as much as possible! Doing this to sauropods means that (barring any unusual, unknown specilizations, like pressurized air sacs in the neck), not only can the poor things reach the ground to drink, they walked with heads held high, able to browse from the treetops as traditionally depicted without having to rear up onto two legs (though they could do that too, at least the diplodocids).

Note that this still rules out the traditional swan-curve. Everybody seems to agree that the neck vertebrae acted sort of like a long, rigid pole that would have been straight along the whole middle section, just bent severely at the base of the neck and at the head.

Read more about it in the scientists' own words over at SV-POW!

[Images used above are of Diplodocus carnegii, from Walking with Dinosaurs and SV-POW, copyright the BBC and Mark Witton, respectively.]

References:

• Taylor, M.P., Wedel, M.J. and Naish, D. 2009. Head and neck posture in sauropod dinosaurs inferred from extant animals. Acta Palaeontologica Polonica 54(2): 213-220.