Dinosaur Sunday: Good + Bad + Ugly

Above: The T. rex has not thought this through.

Last night, the first part of a new Discovery Sunday special aired, Clash of the Dinosaurs--sort of a slightly more rigorous and scientific-sounding version of the horrible Jurassic Fight Club. Hopefully, any DinoGoss fans will know that these types of CGI action-fests are only loosely connected to reality. One of the main criticisms of these shows, often pointed out online by the very experts featured as "talking heads," is that the writer will latch onto any speculative aside a scientist might have tossed around, and then present it in the show as a concrete fact. Apparently, audiences don't want to know about the process of science or that there may be debate (or no solid evidence at all) for some of these hypotheses. It's more exciting if we just know, man!

Anyway, in this post I'll go over a few things I noticed watching the show, informed by chatter on the DML today from some of he scientists featured and what they thought of the show. I'll also talk about the (very cool if very inaccurate in some very weird ways) show that followed (which I hadn't heard about!) all about Spinosaurus.

First, Clash of the Dinosaurs:
This species tried a bit harder than others to illustrate why we think dinosaurs were the way they're portrayed based on anatomical studies. Each CGI model came with a see-through version to show off the bones, muscles, gastric system, etc. While not perfect, they looked ok, though the show seemed to only focus on the brain for most dinosaurs. It also missed a good opportunity to highlight little-known aspects of anatomy, like the air sac system (especially in the sauropod and pterosaur).

External anatomy was even better in most cases. The T. rex looked great, much better than the god-awful Walking With Dinosaurs or slightly less awful Jurassic Park versions. The sub-adult Triceratops were cool looking despite the extra front foot claw, and from what we saw of the ankylosaur, they obviously did their research (hey, Ken Carpenter was one of the talking heads) rather than just giving it a random arrangement of nodes and scutes. The Quetzalcoatlus was decent, about on par with the When Dinosaurs Roamed America version, but it was not only naked but scaly, a complete departure from known science. Nice to see the leapfrog launch and terrestrial stalking papers come to life. However, the wings looked too much like simple flaps of skin, as in a bat. And the "X-rays" and narration gave no indication that they were anything but skin. No mention of the complex system of muscluature, inflatable sacs, etc. that made these structures true organs, rather than dermis.

Above: Nice pycnofibres, dork.

The discussion of Quetz's eyesight is a good spot to illustrate one of the points I mentioned above. The show asserted that Quet could see in UV, following urine trails etc. of its prey on the ground, and that it would have been eagle-eyed, hunting mainly from the air. The reason all this was in the show, is that expert Mike Habib (one of the talking heads) had a quick back and forth with the interviewers, who asked him if its eyesight would be as good as birds. Mike said it was plausible that it would have had similar eyesight to storks and hawks, and that (since it apparently hunted prey on the ground) maybe could have spotted food from the wing. This translated to Terminator-vision and rock-solid factual statements that it could see for miles. Of course, we have no way of knowing, but I would have said that it would be more stork-like than eagle-like, hunting on the ground, not on the wing.

The sauropod segments were especially good, and the show obviously benefited from having Matt Wedel of SV-POW! as a talking head. It did a good job explaining the age segregation of juveniles, and their "flood out the predators with food" reproductive strategy. Even the CGI models of Sauroposeidon were very good, with the correct number of fingers (though the back of the front feet were still elephantine and not concave as they should have been, but they're trying!).

Above: The role of Deinonychus is played by Heath Ledger. Why so serious?

What I can't forgive is the Deinonyhcus models, which while better than usual (certainly leagues better than JFC) still looked like ugly, overgrown lizards rolled in glue with feathers slapped on willy-nilly, very unnatural, with artificially "mean" looking faces (and apparently, Joker makeup for that extra serial-killer punch). The wing feathers were barely visible, and for a while I thought the arms were naked. What's the point of retaining wings for display (as we know for a fact medium-sized dromaeosaurs did) if you can barely see them? Basically, while CGI animators are getting better at following the facts (raptors had feathers), they're not getting the implication (they should look like giant Archaeopteryx, not mini T. rex with fuzz).

Summing it all up is an excellent quote from Tom Holtz (also featured on the show):
"The documentarians often take anything that any of the talking heads speculated about, and transformed these into declarative statements of fact. In some cases this is particularly egregious, because I strongly disagree with some of these statements and believe the facts are against some of these (say, about tyrannosaurid cranial kinesis...) and they present these as facts rather than suppositions."

For the record, on that cranial kinesis point, dinosaurs could NOT flex their jaws open like pythons. Lawrence Witmer, another consultant on the show, has demonstrated this thoroughly in print, but was not given a say on the matter, which is especially bad since it implies all the experts agree with Dr. Bob on this. Really, I imagine the producers must have loved having Bakker as a talking head, since it gave them license to depict all kinds of zany speculation as fact. I owe a lot to Bakker and idolized him as a kid, but I'd hesitate to call what he does 'science' and not 'unsubstantiated speculation to hype science for kids.'

Above: Sauropods... in... space!

One last pet peeve, then stay tuned for Spino. I'd estimate the CGI segments of the show totalled about 5 minutes of footage, with clips repeated over and over and over and over again to illustrate different points. I'd gladly accept lower-quality CGI if we could at least get some actual 'action' sequences that last more than 5 seconds apiece, and it makes me wish they'd bring back cheaper methods, even stop-motion. Some of the pieces showed even more skimping, like the baby Sauroposeidon with Walking With... Dimetrodon syndrome. That is, the hatchlings use the same model as the adults, making it look like they shrunk down, Mario style. Even worse, the Sauroposeidon hatching sequence takes place at night, on a wide sandy featureless field. With no sense of scale, it looks a herd of adult brachiosaurs emerging from the soil on the moon, which is actually pretty cool.

Oh well. At least they didn't put a Suchomimus head on their T. rex, but more on that later...

Toro! Toro! Toro!

Above: Ceratopsian skull specimen AMNH 5116. Triceratops, Torosaurus... or both? Read on...

By now, all dino fans have probably heard the buzz on the indicator: Jack Horner and team are working on a paper which attempts to prove that Torosaurus and Triceratops are the same thing, and that in general, growth series in dinosaurs are often misinterpreted as numerous similar species (something that has long been acknowledged in pterosaurs and recently in early birds like Archaeopteryx and, probably, Confuciusornis).

Here's the quick and dirty background: Triceratops was named by O.C. Marsh in 1889 based on a pair of horns and skull roof collected in 1887 from Colorado. Numerous complete specimens followed, making Triceratops the archetypal horned dinosaur with its two long forward-pointing brow horns and single short, forward-pointing nose horn, in front of a relatively short (by ceratopsian standards), solid frill. The frill is notable: most ceratopsians, including close relatives of Triceratops, have long frills with large openings, or fenestrae, in the bone.

Torosaurus was described a few years later in 1891, also by Marsh, based on two skulls. Unlike Triceratops, the Torosaurus skulls had long frills with the standard fenestrae. Its frill was also smooth around the edges: many Triceratops specimens show that they had small, bony scutes adorning the frill's edge, called epoccipitals.

According to Horner's talks at SVP, which he also summarized in an interview on the podcast The Skeptic's Guide to the Universe (available here), those differences are not due to species variation, or even sexual dimorphism as previously hinted. Rather, Torosaurus is nothing more than the most mature growth stage of Triceratops. The paper isn't out yet so all the data isn't available, but presumably Horner will demonstrate based on microscopic bone growth studies that all the specimens currently assigned to Triceratops are not fully mature, and that like modern birds, some secondary sexual characteristics (such as the expanded, chasm-filled frill) pop up quite suddenly at the 'last minute' in the animal's growth, after it has already reached nearly adult size.

Above: Diagram of a 'classic' Torosaurus skull. By William Diller Matthew, 1915. Public domain.

We can already see heaps of major changes taking place as Triceratops grows. Juveniles have backward curving horns, which completely change to point forward during growth. Remember those epoccipital fringes, the lack of which is so diagnostic of Torosaurus? We already see them becoming reduced from tall, pointed osteoderms in younger forms to smooth and rounded, and finally merging with the frill itself and smoothing out so as to be almost invisible. Indeed, in these oldest individuals, the bone in the center of the frill can also be seen to thin like a man's receding hairline. Given that we already know all of this about Trike's growth, it's not a very huge leap to recognize a long, smooth, holy frill as the next logical step, and those just happen to have been named Torosaurus for 110 years.

The goss has been flying over this online, and a few interesting tidbits have come up. Having grown up in the Northeast US, the most interesting to me concerns the mistaken identity of some specimens of Triceratops. For me, the quintessential Triceratops is the one in the American Museum of Natural History (specimen AMNH 5116). However, as many have pointed out on DinoForum and elsewhere, it's also among the most... well, un-Triceratops like.

Above: Triceratops skull 'classic' vs. specimen AMNH 5116. By Ed T. and Michael Gray (right), licensed.

Compare the images above. On the right is my beloved AMNH Trike. On the left is a 'classic' Triceratops skull. The frill on the AMNH specimen is longer, and lacks epoccipitals. The frill is also tall and back-swept, not flared out to the sides, as in most Triceratops skulls. Not only that, but as you can see in the image at the top of this post (which is a more contrasty view of the same AMNH skull), almost all of the frill has been restored in plaster to conform with what a Trike should look like. There are significant gaps in the middle of the frill entirely filled with plaster... exactly where the fenestrae of Torosaurus go. If Torosaurus and Triceratops are indeed separate species, the AMNH Trike is no Trike at all... it's a Torosaurus in disguise!

Thankfully, it's more than likely that there is no such thing as Torosaurus, any more than there was a Brontosaurus. It's all Triceratops baby, and we can conclude that this famous last of the ceratopsians was indeed last, the only one of its kind in the Lance and Hell Creek Formations that date to the very end of the Mesozoic era.

But... wait... isn't there another named ceratopsian from the same time and place? Named BEFORE Triceratops?? If there was only one Lance/Hell Creek ceratopsian, then Torosaurus get sunk into Triceratops as a synonyms. Does Triceratops then have to be abandoned in favor of... Agathaumas!?

Above: Painting of Agathaumas by Charles R. Knight, 1897. Public domain.

Dun dun duuuuuun!

Meet the Megaraptors

Above: Illustration of the megaraptoran Australovenator by T. Tischler, licensed.

Well, that all came together...

The history of Megaraptor is long and sordid. It was first described as a gigantic dromaeosaurid (hence the name), on the basis of a large sickle-claw found in Argentina. In fact, I remember a time when rumors circulated that the newly described Unenlagia might turn out to be a juvenile form Ironically, an ACTUAL gigantic unenlagiine dromaeosaurid from almost the same time and place was later found, in the form of Austroraptor. Not to be confused with Austrovenator, which, see below...

Then, a complete Megaraptor forelimb was found that crushed the dreams of every 12 year old Jurassic Park fanboy who had already adopted Megaraptor as their personal mascot: The giant claw came from the hand, not the foot, and it was no raptor at all: but what was it? The first thing that comes to mind is the similar story of Baryonyx ("heavy claw"), named for a similar giant claw that was similarly thought to come from the foot of a dromaeosaur, and similarly later found to come from the hand (have we learned nothing?). Baryonyx was actually a spinosaur, and the large hand claw seemed to be a unique feature of that group. So, was Megaraptor a spinosaur? Opinion was divided for years, with Megaraptor being placed either among the spinosaurs, the carcharodontosaurids*, or in some weird, new family of tetanuran theropods.

Above: Replica of a Megaraptor claw. Photo by Haplochromis, licensed.

The picture got clearer with a few discoveries in just the past year from 'Stralia. First, a large claw that looked suspiciously like the hand claw of Megaraptor, followed by a more complete specimen of a similar animal, named Australovenator. Australovenator looked like a good cantidate for a Megaraptor relative, and studies showed it was in fact an allosaur, somewhere between Allosaurus and carcharodontosaurids.

Well, a new study online today helps clarify the situation a whole lot. Benson, Carrano and Brusatte ran a massive phylogenetic analysis of allosauroids, and recovered a monophyletic clade that happens to include almost every oddball misfit theropod in the book. Called Neovenatoridae, this new clade includes the titular Neovenator (at times thought to be an advanced allosaurid or primitive carcharodontosaurid) and the enigmatic Chilantaisaurus, also previously thought to be a spinosaur. Neovenatorids more advanced than those two are placed in the advanced unranked clade Megaraptora (a nice compliment to the dromaeosaurid clade Microraptoria), which includes Megaraptor and Australovenator as well as perennial phylogenetic stragglers Aeroseon, Fukuiraptor and Orkoraptor. This true identity for Orkoraptor (previously thought to be a coelurosaur) is particularly interesting, since it lived so recently--only 70 million years ago, close to the end of the Mesozoic, showing that derived allosaurs lived right to the end, rather than dieing out in the mid-Cretaceous as previously thought.

All in all, this new paper is pretty major. It reveals a new clade of theropods of a type not really known before, even though none of the constituent species is actually new. What all the megaraptors have in common is a light, gracile build with often hollow bones (seen in the extreme case of Aerosteon), relatively long front and hind limbs (indicating a fast-running lifestyle) and large, hooked claws on the hands for grappling prey. Basically, this advanced line of "coelurosaur mimicking" allosaurs survived in the southern hemisphere while coelurosaurian carnivores were dominating the northern continents, during and after the time of their traditionally carnosaurian relatives carcharodontosaurids.

* I had to stop myself from writing "carcharodontosaurian" instead of "-id" a few times. See, neovenatorids and carcharodontosaurids are sister groups, and the clade containing both has been named Carcharodontosauria. So, technically, Megaraptor is a carcharodontosaur after all, just not a carcharodontosaurid proper.

The Near-Bird Cometh

Above: New specimen of Anchiornis and skeletal showing feather proportions, from Hu et al. 2009. Click to embiggen.

If you've been carefully combing Dave Hone's blog for the last nine months or so (and who hasn't been?), you'll know that the initial reports on headless fossil of an interestingly bird-like supposed avialan named Anchiornis were just a warning shot. Dave reported in December of last year that protobird fans could look forward to several more complete specimens that had been recovered and not yet described. Well, it looks like the first of these is pending: J. Brougham over at Wikipedia has published a few details and a full cite from the upcoming October 1 issue of Nature, which contains the description of a nearly complete specimen preserving such cool details as a complete skull, Microraptor-style hind wings and head crest, and a phylogenetic anlysis that finds Anchiornis is in fact a basal, mid-late Jurassic troodontid (!), totally stealing Scott Hartman's thunder. If this is the case, that is, if Anchiornis can actually be demonstrated as a troodont (or even just non-dromaeosaurid) with large airfoils on the hind legs, the argument that all deinonychosaurs or even all birds went through a gliding tetrapteryx stage and are secondarily flightless to some degree just got pretty darn rock solid. Greg Paul, throw yourself a party, and set a place for William Beebe.

Being a protobird fan myself, this prompted me to immediately go to the nature.com online preprint section and start clicking refresh faster than you can whip a ram at Brewfest. Needless to say I was dissapointed and will have to start hounding J. about the paper until something pops up on the DML to whet my appetite for photos so I can get started drawing this thing. More to come one I have a chance to read the paper and collect some goss!

UPDATE:
Just been informed that not only is this on Nature's front page, but the pdf appears to be free? Or is it because I'm logged in?

Raptorex update

Above: Recon of Raptorex by Todd Marshall, from CBC News.

Quick taxonomic update: Having just gotten the paper, I can comment that Bill Parker's concerns over the name Raptorex kriegsteini (see previous post), echoed on the DML, are based on misrepresentation of the issue by the newspaper reports. At least one news story said that Kriegstein named the species after his parents, so by ICZN rules the species name needs to be R. kriegsteinorum (-orum being the correct suffix for a name honoring multiple people). However, the paper explicitly states that the species is named only for Roman Kriegstein, so the current name is correct. For the record, here's the entire etymology section from Sereno et al. 2009:

Etymology: raptor, plunderer (Greek); rex, king (Greek); kriegsteini, after Roman Kriegstein, in whose honor the specimen was secured for scientific study.

Also, the paper makes clear that, unlike I speculated before, Guanlong, Dilong and friends are still recovered as tyrannosauroids in the paper's cladogram, though more basal than Raptorex.

Raptorex. For serious, that's a real dinosaur now.

Above: Paul Sereno with a model and skull cast of Raptorex, possibly the most ridiculously named dinosaur of all time. Photo from Chicago Tribune by Nancy Stone.

Headline: DeviantArtist Honoured with Dinosaur Name

Well not really, but surely raptorex must be stoked that his (let's face it), fun but pretty ridiculous username is now the name of a real life dinosaur, Raptorex kriegsteini.

The mini-tyrannosaur is from the Yixian ash beds (not the more famous lake sediments that preserve feathers), and is a bit improbable in other ways than its name. It looks like a mini-Tarbosaurus, with short, two-fingered hands and long, running legs, all things expected from a juvenile tyrannosaurid, rather than a (supposed) primitive tyrannosauroid like Dilong or Guanlong. I wonder if this has implications for their position as basal tyrannosaurs--the paper, supposedly released in the online edition of Science today, is nowhere to be found, for my part.

Raptorex also has a sordid past. Apparently, the fossil was smuggled out of China and sold at (where else) the Tuscon fossil show to a private collector for tens of thousands of dollars. The collector, ophthalmologist Henry Kriegstein (whose family name is honored in the specific name of the new dino), had specialists in Utah prep it out of its matrix so he could mount it in his Massachusetts living room. Upon discovering the specimen was not a juvi tarb as advertised, but rather a full-grown individual, Paul Sereno (so that explains the name!) was called in for further advice, and recognized it as an important discovery. Kriegstein soon agreed to relinquish his purchase to science (with a bonus in the form of naming rights, of course. At least he wasn't a big Bambi fan).

In a bit of taxonomic goss, Bill Parker over at Chinleana notes that, as Kriegstein technically named the genus for his parents, not himself (which is frowned upon), the ICZN mandates that the species name needs to be emended to kriegsteinorum, so watch for that change in the future, likely published by George Olshevsky or a similar stickler for proper Latin.

And, of course, Jack Horner has weighed in. In an email to Wired.com, Horner explained that he thinks the small, fleet-footed Raptorex, because it has the same body plan as larger tyrannosaurs, somehow proves that tyrannosaurs evolved into pure scavengers early on, and that the authors are jumping to conclusions in thinking that long, speed-designed legs somehow imply "predator." Keep on keepin' on, Horner.

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...