The American Museum Brontosaur - A History In Pictures

The wooden model used to explore poses for the original
brontosaur mount is now on display beside the
revised mount at the AMNH. Photo by the author.

Here's one more post to commemorate the revival of the name Brontosaurus for the beast formerly known as Apatosaurus excelsus. As I mentioned in my last post, the mounted skeleton of the so-called "Nine-Mile Quarry Brontosaur" at the American Museum of Natural History, while it may or may not actually be a Brontosaurus, is probably the most iconic version of this animal, overshadowing even the archetypal brontosaur skeleton at the Yale Peabody Museum.


This is in no small measure thanks to the efforts of problematic Hitler enthusiast and highly successful paleontology promoter Henry Fairfield Osborn. Osborn became the first curator of the Vertebrate Paleontology department at the AMNH in 1891 and quickly rose to prominence, becoming the president of the museum in 1908. Osborn worked quickly to create a world-class collection of dinosaurs for the museum, both launching his own expeditions to collect fossils for display and making significant trades and acquisitions, such as the collections of E.D. Cope.

The Brontosaurus Club

Brontosaurus excelsus - the triumphant return.
By M. Martyniuk, all rights reserved.

By now, anybody who's interested in paleontology, and their mother, and their great uncle, have probably heard the news: Brontosaurus is back!

Of course, the more technically minded paleo fans will know that Brontosaurus never actually went anywhere. Ever since its first specimen was studied in 1879 by Bone Warrior O.C. Marsh, paleontologists have agreed that the species Brontosaurus excelsus* was unique among sauropods. The question soon became, however, exactly how unique. In 1903, Elmer Riggs decided that it was similar enough to another sauropod species, Apatosaurus ajax, that they should both be placed in the same category of sauropods, and since Apatosaurus was an older category ("genus") name than Brontosaurus, he reclassified the species as Apatosaurus excelsus. However, it was clear even to Riggs that Apatosaurus excelsus and Apatosaurus ajax were different species, and the decision to "lump" them together into one category was always subjective and non-scientific - these kinds of things are a matter of taste only.

What Does T. rex Say?

"Hissssssssssssssssss!"
T. rex holotype specimen. Photo by Scott Robert Anseimo, CC BY-SA 3.0.

It's an iconic scene in every dinosaur movie: the huge, conquering carnivorous theropod rears back and lets out a terrifying bellow. Sound effects artists spend huge amounts of time sampling vocalizations from various animals to create just the right mix to create an unfamiliar, otherworldly roar. And, of course, everybody knows that pterodactyls let out harsh, echoing, prehistoric sounding screeches.

But how close to reality are these sounds? Do we have any ways of using science to figure out what dinosaurs and other stem-birds may have sounded like? Do we have evidence that they made sounds at all?

Bruhathkayosaurus is Dead. Again.

 Above: Working sketches for a speculative B. matleyi reconstruction by Steve O'Connor. Click here for Steve's final drawing.

I don't know how common this knowledge is, but this is the first I've heard of it so humor me while I mourn the possibility of ever re-assessing the intriguingly large sauropod specimen known as Bruthathkayosaurus matleyi.

B. matleyi was known from fragmentary remains of the pelvis and limb bones found in the Tiruchirappalli district of Tamil Nadu, India. It was first described by Yadagiri and Ayyasami in 1989 as species of giant allosauroid. This classification was widely doubted online, but little follow-up work was ever done. The initial description is widely regarded as exceedingly poor in quality and not much can be discerned about the specimen due to poorly detailed drawings and insufficient text. Tom Holtz has even stated that "the hypothesis that this is no more than petrified wood has not been falsified yet to my satisfaction." However, Mickey Mortimer later noted that the tree trunk hypothesis "is questionable given the non-cylindrical bones preserved such as the ilium. Additionally, Chatterjee has personally examined the fossils, and while he has a bad record of misidentifying taxa, I give him enough credit to not confuse a tree for a limb bone."

Sankar Chatterjee did indeed apparently examine the material and told George Olshevsky and Tracy Ford that he believed it to be a titanosaur, as reported in 1999 here.

Holtz responded to these appeals by noting that "not all units are the Dinosaur Park or the Djadokhta. In some preservation is really, really, really crappy. You might get all sorts of authigenic growth on the fossils, or alteration of the original material. In outcrops like that, it isn't out of the question to be fooled into thinking bone is wood and vice versa, especially from simple surficial appearances. This is why a section of the fossil would help resolve if it is bone or wood." So, there's that. We'll now never be able to take that section.


While B. matleyi was a near-mythical celebrity among "semi-apocryphal gigapods", its legend loomed larger than (published) reality. While most online sources (such as the DML posts quoted above) had long since agreed that the specimen was probably a gigantic sauropod and not a gigantic carnosaur, no actual published reference to the species as a sauropod existed until five years ago (Krause et al. 2006).

And what a sauropod it was, maybe! Obviously with such a paltry footprint on the scientific literature, reliable size estimates for such a poorly described specimen are hard to come by. Luckily, some researchers have done the best they could with the available data and determined that, if B. matleyi was indeed a titanosaur with similar proportions to say, Argentinosaurus, it would have been very large indeed. Matt Wedel over at SV-POW has estimated the size of this animal in life at 139 tons. Mickey Mortimer has estimated its length at up to 34 meters. That would position it as one of the largest species of land animals ever, second only to Amphicoelias fragillimus, possibly.

And now, it appears that B. matleyi has suffered the same fate as its atlantosauroid rival for the record. In the comments at another SV-POW post about semi-apocryphal gigapods, Wedel reports that the type and only specimen of B. matleyi was at some point washed away in a flood.
UPDATE: Thanks to Fabrizio in the comments pointing out a source closer to the horse's mouth. Artist "palaeozoologist" at DeviantArt posted an apparent personal correspondance from Kumar Ayyasami last January, in which he reported that the specimen was lost in heavy rains several years ago. (There's some more discussion of the specimen and the author's publication record here, including the suggestion that Dr. Ayyasami may now be deceased--that is, if you can get past the inexplicable Ali G speak). So it sounds like not only was the specimen poorly described, but nobody had bothered to actually collect it from the field site in the ~15 years since its discovery, and it was (predictably and inevitably) lost to erosion.

Any hope of verifying the stupefying claims about this species' size now seem to be lost. And unlike A. fragilimus, which was described and well-illustrated by a mostly reputable source with no obvious errors, the poor state of the B. matleyi description will forever doom this creature to the realm of dubious claims. After all, given the poor state of the description, it seems possible that a simple scale bar error or other mix-up could have tainted the data, and therefore all of our size estimates.

So here's to Bruthathkayosaurus matleyi, a beast (or possibly, a tree?) that died 70 million years ago, raised its spectral head (or crown?) again for one tantalizing moment and then, like Hitchcock's Ornithichnites, sunk back beneath the earth before we could really learn anything about it.

Brontodiplodocus

Above: "Ah love filter feedin' thorugh mah beak! Om nom nom." Apatosaurus louisae (or not?), photo by Tadek Kurpaski, licensed.

Dan Chure on the DML alerted us to this new, privately published monograph published without peer review (probably?) by an independent fossil digging/selling organization. It concerns a pretty damn remarkable looking bonebed from the lower Morrison Formation with several complete diplodocid specimens of various ages. This line from page 21 pretty much sums it up:

"The traditional approach would have provided us with two new species to add to the Morrison list of sauropods. Instead we employed a novel approach by attempting to fit previously reported Morrison fossils within the context of the A. brontodiplodocus sample. The results are astoundingly radical by comparison with previous studies."

I don't know what to say about this paper. It wouldn't surprise me THAT much if something like this were true but... really? Really guys? Fingers crossed that SV-POW or some some other sauropod experts take a look at this bad boy, though the stigma concerning privately held specimens may simply prompt everyone to ignore it. This is what Mike Taylor suggested on the DML, since he (correctly) pointed out that the hypothesis of the paper (all Morrison diplodocids are congeneric) is essentially unverifiable as long as the specimens are in a private collection and haven't been described in a peer-reviewed paper.

As it was independently published, questions about the newly named taxon's validity have been raised. But, really, is this any different from what Cope and Marsh were doing back in the 19th Century? If anything, cheap and easy publication has simply brought us back to those Wild West days of do-it-yourself science, spurious results and all.

Taxonomy aside, the baleobiological conclusions in this thing are... just... fascinating. and probably will NOT help the author's case.

You can read the pdf here:

Galiano, H. and Albersdorfer, R. (2010). "A new basal diplodocid species, Amphicoelias brontodiplodocus, from the Morrison Formation, Big Horn Basin, Wyoming, with taxonomic reevaluation of Diplodocus, Apatosaurus, and other genera." Dinosauria International, LLC. 44pp.

Dinogoss: Trendsetting

One more really short post... Because it's time to claim tenuous credit for starting a trend!

This is another image that caught my attention today as I finally took some time to catch up on my Google Reader blog subscriptions. Also at Michael Ryan's Palaeoblog, I found the above size comparison of the cool new sauropodomorph Seitaad with a human. But not just any human, it's the Pioneer Dork's girlfriend!

Above: The Dork poses dorkily with the smallest dinosaur, Anchiornis huxleyi. Say, "Hi dork!" Image by Matt Martyniuk, licensed.

The Pioneer Dork is of course the male figure from the gold plaque sent along with the Pioneer probes 10 and 11. When I first started doing size comparison diagrams for Wikipedia in 2006 or '07, I used this public domain image for the human and have done so since (and so have a few others). We Wiki editors lovingly referred to him as the 'Dork', due to, well, his dorky pose. Several Wiki readers have posted comments on talk pages noting how hilarious it is to depict a happy, waving man inches away from the maw of a charging Albertosaurus. But they just don't understand the Dork's simple charm. There was a brief push to replace the Dork with something a bit edgier, namely a silhouette of Catherine Zeta Jones. Cooler heads prevailed and pointed out that dammit, Jim, this is an encyclopaedia, not a trucker's mud flaps! (I, however, have opted to use her in the scale charts I make for my own site).

I choose to believe the Dork's female counterpart was done as an homage to those Wiki scale charts and will not listen if somebody comes up with an alternate explanation. Note that this must be a press release only image, as the skeletal in the free open-access paper lacks a human figure. Bummer. Maybe the next paper can include CZJ to make up for it.

Above: Yowza.

Oh Giraffatitan, where art thou?

Above: Skull of Brachiosaurus altithorax (right, from Carpenter & Tidwell, 1998) and "B." brancai (left, by Gunner Rias, licensed).

A curious bit of goss, and potential drama?, teased out Mike Taylor and crew at SV-POW.

In recent posts about a new brachiosaurid announced last week, Qiaowanlong (or is it a brachiosaurid? See SV-POW for in-depth coverage), Mike Taylor consistently reffers to the genus "Brachiosaurus" brancai.

The goss stems form use of the quotes. As we all know, when discussing scientific names, the genus and species are always put in italics. The exception to this are nomina nuda, which are names not properly described or coined. Another exception is when a genus and species combo is found to be invalid for whatever reason. For example, the name Ingenia, for an oviraptorid, is preoccupied and has not yet been renamed. But the species name yanshini is still valid. So, when we talk about this species, we might write it as "Ingenia" yanshini to indicate that the genus name is going to change.

Similarly, this same notation is used for species previously assigned to one genus but are no longer considered related to that genus' type, and are pending reclassification under a new genus name. For example, the species "Dilophosaurus" sinensis is probably not closely related to Dilophosaurus wetherilli, so it gets quotes until a replacement name is chosen. This is also the current situation with "Brachiosaurus" brancai. Many people have suspected that this African sauropod is not the closest relative of the North american type species, Brachiosaurus altithorax, given that a B. altithorax skull has been identified that differs from the African species (see photos above), among other differences in skeletal shape and proportion.

So what's wrong with using quotes when talking about "B." brancai? The African version has already been given a new name! In a 1988 paper, Greg Paul coined the name Giraffatitan for a distinct "subgenus" containing the African species. This was later formalized as a genus name, I believe by Olshevsky in his Mesozoic Meanderings, but correct me if I'm wrong.

So wy write "Brachiosaurus" brancai when, if considering this a separate genus, it should rightly be Giraffatitan brancai? I asked Mike about it, and apparently a paper explaining will be coming out in a week or so. The goss at SV-POW for quite some time has been that the SV-POWsketeers favor a separate genus for "B." brancai, but the assumption was always that this would be Giraffatitan. Mike is playing coy for now--is it simply that the authors don't like the name Giraffatitan? Mike says this is the only paper he's seen in which the acknowledgments contain an apology, so it sure sounds like that is close to the truth...

But a valid name can't be rejected simply because an author doesn't like the sound of it. It would have to be argued away on technical grounds. Is the fact that Giraffatitan was originally a subgenus, not a proper genus, coming into play and allowing Giraffatitan to be re-named? Is the apology directed towards George Olshevsky (maybe the authors don't consider his self-publications valid?). I don't know the ins and outs of priority when it comes to subgenera and subspecies. But we'll know shortly...

My Sauropod is Bigger

There is a new record holder for second-longest dinosaur, longest if you only count bones that currently exist. Skip past the long-winded intro if you want to get to the point!

New mounted skeleton of Mamenchisaurus, in Tokyo, the longest mounted dinosaur skeleton in the world. Image by Shiziuo Kambayashi from the AP.

What is it about pissing contests over the largest dinosaurs? Who cares if Spinosaurus is a few metres longer than Tyrannosaurus? Does it really matter which super long-necked, long tailed giant sauropod is slightly longer than its nearest competitor?

Of course it does!

Well not really, but it can be a fun part of armchair paleontology to keep track of these things. I created the Wikipedia article Dinosaur Size to try and help people keep tabs on this issue using peer-reviewed sources (though for a while there a few too many Internet sources were creeping in, but we've put a stop to that).

Now, everyone gets their shorts in a bunch over the biggest theropod, because even though sauropods are nearly always bigger, they're not the ones who will try to eat Jeff Goldblum. This is evidenced by the fact that one of the biggest theropods in terms of sheer mass, Therizinosaurus, is almost always ignored in these competitions because it was probably herbivorous and looked like a giant porcupine goose with a beer belly. However, despite how cool theropods may be (i.e., extremely cool), sauropods are without a doubt the group where we find the largest dinosaurs.

So which dinosaur was largest? Well, define large. Do you mean length, height, or mass? In modern animals, mass is usually what counts. The African elephant is considered the largest land animal, even though the giraffe is taller and the reticulated python is longer. The most massive, and therefore largest, dinosaur known from decent remains that still exist is a bit of a tie game right now. Traditionally, the largest sauropod known is cited as the titanosaur Argentinosaurus, with rational mass estimates ranging between 78 and 83 tonnes. However, several other titanosaurs were about the same size, if not bigger, including Puertasaurus and the horrifically named Futalognkosaurus (note that the official name even includes a misspelling, yikes!).


Scale diagram showing several of the largest dinosaurs discussed in this post. Green: Diplodocus. Orange: Supersaurus. Purple: Argentinosaurus. Blue: Sauroposeidon. Grey: Bruhathkayosaurus. Red: Amphicoelias. Scale bar = 40m. Image by Matt Martyniuk, licensed.

The new goss here though, to finally get to the reason for this post, is that the record for longest dinosaur has changed... sort of (see final paragraph, below). When I was a kid, I was enthralled by the longest known dinosaur according to several of my books, the "Seismosaurus" (earthquake lizard). This monster diplodocid (whip-tailed sauropod) was said to be over 130ft in length. Well, those initial estimates were a little too hopeful, and based on the mis-identification of a tail bone which threw the estimates off by up to 30%. More reasonable estimates place its total length at a mere 33.5m (110ft), and furthermore, it turned out to likely be just a slightly oversize specimen of Diplodocus anyway.

The downsizing of Seismo--er, Diplodocus left the length champion to its cousin, Supersaurus. As the preparation of a fairly complete skeleton nicknamed "Jimbo" by Scott Hartman showed, Supersaurus probably reached a total length of 34m, or 112ft, surpassing both Diplodocus and weight champion Argentinosaurus by a meter or two (in the process robbing the titanosaurs of their clear victory in both units of measure).

However, now a new champion emerges by a neck (I'll be here all weekend folks!). A new specimen of the mega-necked Chinese sauropod Mamenchisaurus unearthed in 2001 was initially reported as the largest of its kind at a respectable, but short, 30m (98ft). However, a surprise came when they assembled a reconstructed skeleton for a new exhibition opening in Tokyo: the specimen actually measures a whopping 35m long, or 115ft, beating out Supersaurus for the title of longest known dinosaur. See photo at top of this post.

Extraordinarily accurate (down to the scales) illustration on Mamenchisaurus by Steve OC, licensed.

That is, if you don't count Amphicoelias. This monster, known from a single partial vertebrae that was 8ft tall and would have been 12 if complete, was very similar to Diplodocus and, scaling up from the same bone in that animal, Amphi would have been at the very least 40m long (131ft) and probably in the area of 120 tons, easily trumping all other contenders in every category: length, weight, and height (read the Wiki I started and wrote most of on Amphi here). So far the only contender to that throne is the even more dubious Bruhathkayosaurus, which is known from a poorly preserved, poorly published, and basically never studied leg bone sometimes thought to be a tree trunk, and even if the size the describers said it was is probably vastly overestimated in published surveys. For now, Amphi is the king, but its smaller cousins with better remains are inching closer.

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.

What's In A Name? Brontosaurus Returns?

To elaborate on the previous story:
As you all probably know, the reason the name Brontosaurus was abandoned in the first place is that it turned out to be a subjective junior synonym of Apatosaurus. (NB: It was NOT because it was a chimera. The whole "wrong head" thing is a separate issue and overstated anyway. That head was a decent educated guess at the time!) Basically, Apato was named first, people decided they belonged to the same genus (note: not species), and so the name Brontosaurus was sunk since it was coined second.

[Image: Apatosaurus mount at the AMNH. According to he SV-POW goss mentioned previously, this will remain Apatosaurus even after Brontosaurus is resurrected. Photo by Erika & Shannon, from Wikipedia, some rights reserved.]

If you're really observant and know something about taxonomy, you can see why this was not an open and shut case or a definitely permanent change. First of all the synonymy was subjective, not objective. Apato and Bronto appeared to belong to the same genus, but were not named for the same exact specimen, so the synonymy was more of an opinion. Especially given that it was generic, not specific synonymy. When species get sunk, it tends to stick. Whether two species belong to the same genus, however, is entirely dependent on whether you're a lumper or a splitter. Tom Holtz coined the term "genericometer" for the mental device people use to demarcate genera, and to illustrate just how subjective it is. With a finely-tuned genericometer, every genus only has one species (often over-splitting taxa). Loosen the settings on yours, and suddenly Daspletosaurus torosus is looking a lot like it should get renamed Tyrannosaurus torosus (probably a case of over-lumping).

This whole business has been simplified somewhat by phylogenetic taxonomy. Broadly, when all taxa should also be clades, it's easy enough to split and lump based on relationships. Daspletosaurus is less closely related to Tyrannosaurus than a few other species, so if you lump one you must lump all (or else the taxon Tyrannosaurus would become polyphyletic, an unnatural grouping), which doesn't make much sense and is not very useful in communicating about dinosaurs.

[Image: Drawing of the Brontosaurus skeleton by O.C. Marsh, 1896. Public domain.]

On the other hand, Apatosaurus and Brontosaurus are each others closest relatives, so you're not leaving anything out by lumping them. It forms a natural group, so it makes sense.

Or do they form a natural group? When a new paper was published on Supersaurus in 2007, the authors pointed out that it shared many features with apatosaurs, and belonged to the clade Apatosaurinae. In an offhand way with little elaboration, they mentioned Supersaurus has some characters that link it to Apatosaurus louisae in particular. This is significant, since that's the non-Brontosaurus species. If Supersaurus is closer to A. louisae than to A. excelsus (aka Brontosaurus), that means Apatosaurus would not form a natural group unless Supersaurus was also sunk into Apatosaurus, which, like in the tyrannosaur example, makes little sense.

Word on the tubes is that this is exactly the case. Supersaurus is likely closer to Apatosaurus than either are to Brontosaurus, and that means Brontosaurus needs to be brought back as a valid name. Sources say exactly this is in the works now, and a new paper will show that Supersaurus does indeed split up the Apatosaurus band. Look for news media sources trumpeting the return of one of the most famous dino names ever in the next year or so.

Stay tuned for more Bronto- related news, Brontosaurus, and otherwise... (hint hint?).

Fire up the BBQ, Fred Flintstone:

Hear that? There's like a rumbling on the horizon, a "suuwassa" if you will...

Brontosaurus is on it's way back.

At least, if the SV-POWers that be have anything to say about it.

Vague, tantalizing comments here.

[Image: Apatosaurus excelsus by ДиБгд from Wikipedia, modified by N.Tamura and M.Martyniuk, public domain.]

Further goss on Panphagia

Quick update on the new, primitive sauropodomorph Panphagia:

Adam Yates, at his blog Dracovenator, has his own post about this critter with a juicy bit of goss that applies to the old, early dinosaur favorite Eoraptor. Eoraptor is variously considered to be a primitive member of the theropod branch of the saurischian tree. Makes sense, since it's a small bipedal carnivore like all other primitive theropods.

Apparently Panphagia and Eoraptor are so similar that Yates reckons the authors of Panphagia are implying that Eoraptor might actually be a primitive sauropodomorph itself! This would be a mighty cool turn of events, giving us the most primitive of primitive sauropods and a very theropod-like, fully carnivorous one to boot. There's no solid phylogenetic evidence for this yet but it hasn't really been tested for either. Keep an eye on how this shakes out in the future.

Picture of Eoraptor is public domain from Wiki Commons.

New species: Panphagia

First up on the Goss, here's a new species of basal sauropodomorph. Panphagia protos (meaning "first all-eater," as in it's the earliest known member of the group and was likely omnivorous, unlike the later sauropods which ate only plants). (Note: it does not mean "chimp eater," contrary to a joking post at DinoForum! Pan is, of course, also the genus name of chimapnzees.).

Normally I'd write a bit more about it but this guy was published in the journal PLoS ONE, which is free, online, and licensed under Creative Commons, so I can even post pics:



Doesn't look very sauropod-like, but that's the idea. It's a very primitive form, close to the common ancestor of all dinosaurs, so you'd expect it to be pretty similar to other early dinosaurs like Saturnalia, Eoraptor, and the near-dinosaur Silesaurus.

Read the whole paper or download a pdf here.

Early Goss:
Thanks to the comment system on PLoS ONE, comments on the paper are already rolling in. The paper suggests the discovery of such a primitive sauropod in the early Carnian pushes the origin of dinosaurs back into the Landinian stage of the Triassic. Randy Irmis, however, pointed out that the dating system used to date the formation Panphagia comes from (Ischigualasto) is known to have been miscalibrated. It's actually from the mid-late Carnian stae, which means it's still possible dinosaurs arose in the Carnian after all.

Stay tuned for more hot Panphagia goss as it unfolds!