Blue Collar Scientist

Zach Miller at When Pigs Fly Returns has an outstanding post called An Edmontosaurus named Dakota. Dakota is a fossil dinosaur mummy that is getting news coverage yesterday and today for no immediately apparent reason.

Leveraging the power of TIVO, I watched a National Geographic Channel show on this dinosaur a couple weeks ago. It was promoted with high-hype breathlessness as a major discovery that had completely overturned our knowledge about dinosaurs - or at least hadrosaurs - and I got sucked in. Unfortunately, the actual show disappointed me.

From memory, there were only two things the program asserted had been learned from Dakota:

• Dakota had differently-sized scales in patterns that are similar to the way differently-sized scales in lizards indicate differently colored areas of skin.
• Dakota’s tail vertebrae were not fused nor in contact with one another, but were separated from each other by about 10% of their length (so my memory of the graphic would suggest, at least).

The documentarians showed a reconstruction of a hadrosaur with the tail vertebrae in contact with one another, and this mount was seized upon by Daktoa’s principle investigator, Phillip Manning, to make a dramatic - dare I say histrionic? - statement on-camera along the lines of, “we thought we had this all figured out, but we were WRONG!”

Well, first off, of course we were wrong. Ignorance has a way of doing that. Until you find an articulated fossilized hadrosaur skeleton, you’re likely going to make a few mistakes putting such things back together. Second, if you spend any amount of time at all working in science, you are going to find out that you are wrong all the time, and that this is neither very dramatic nor very significant. But finally, and more fundamentally, I’m virtually certain I’ve seen hadrosaur mounts that have the tail vertebrae separated by an inch or two. It made me suspect that a straw man was being cooked up by the documentarians. Are we to understand that one incorrectly-done mount signifies a serious and drastic error throughout the whole of dinosaur paleontology? Or is my recollection false, and it really was is thought that hadrosaur tail vertebrae were in contact in life?

Or maybe the mount that was shown was one that Manning had put together himself and he was shocked at having made such an error? I’m really not sure. Anyway, Manning came off as smarmy - and in another part of the documentary, as unprepared and a little less than competent.

Manning and his team took the mummy to Boeing, where they have a giant CAT scanner. The idea was to fit the mummy on the scanner, scan it, and see what was inside. The program gave the impression that the process was largely a debacle. The largest piece of the mummy (which is apparently in at least two pieces) could barely be lifted by the lifting equipment. Once that problem was solved the piece couldn’t be fit on the scanner. I think this was solved by knocking off some excess matrix. (Did anyone think about using a tape measure before hauling the fossil all the way out there? The documentary didn’t say.) When they finally got the specimen on the scanner, with inches of clearance at most, they couldn’t see anything inside. There was too much matrix, I guess, or maybe the fossil itself was too extincting of the X-rays. In any case, they got some images that were perfect specimens of noisy astronomical CCD images with no signal - dark frames, in the parlance.

Couldn’t an assay of extinction at the energies of the CAT scanner have been done prior to hauling the mummy halfway across the country? I would have thought yes, that doing this would have been easier than moving the fossil, but what do I know.

And why didn’t they just try for a CAT scan after the matrix had been removed? My vague understanding was that they wanted to use the CAT scan results to guide the removal of matrix, but that impression might be a result of a desperate mental need to find sense and meaning in the inexplicable spectacle that I was seeing. I’m not suggesting that Manning’s team was incompetent in fact; but the documentary made it look that way, by playing up setbacks as dramatic moments without also discussing the kinds of preparation that the team undertook and the reason the risks were being taken.

So much for the big piece of the mummy. A smaller piece was scanned as well, and lo, there were the aforementioned tail vertebrae. And that was about that. The mummy was sent to another location and preparators worked on taking off the matrix. I walked away from that documentary thinking that they had a potentially nice specimen, but that watching an hour of TV about it had been a pretty pointless thing to do.

Now Zach weighs in on his blog:

This fossil has been known since 1999, its genus was just released today, and its species is still unconfirmed.

Whoah. Nine years just to identify the genus. I hadn’t been aware of that. The documentary kind of glossed over the fact that they didn’t really know what dinosaur they had on their hands.

…it’s curious that not a single peer-reviewed publication exists about Dakota, yet two books have been penned (one of them a kid’s book, one an awful popular science book). The National Geographic channel has aired two specials about Dakota, too. Dakota needs to be studied and published.

I hadn’t been aware that nothing scientific had been published. Again, the documentary kinda glossed that over. This is insane, to be fast approaching the decade anniversary of the fossil’s discovery, and still have nothing in the scientific literature about it at all. It is true that a thorough study of a good dinosaur mummy will probably take twenty years or more, but you need to start somewhere. Twenty years are half up and the PI has no results.

Zach rightly points out that Manning, or his funding sources, appear to be trying to do science by press release with this mummy. Someone, like his scientific peers perhaps, needs to give Manning a kick in the pants to actually publish something. If an astronomer had sat around on similarly significant discovery for ten years without publishing anything, their institution or funding sources would probably have kicked them off the job and found a new PI for the project by now.

Virtual-friend of BCS Zach Miller has posted his impressions of the NOVA Microraptor documentary that I wrote about a couple weeks ago in what has somehow become one of the most popular posts on this blog. With Zach’s thoughts on his blog, you shouldn’t be wasting your time reading what I had to say, although it is worth reading Zach and Scott’s comments there.

My favorite bit from Zach’s blog:

Norell et al. create their skeleton by measuring and averaging the lengths and structure of every single bone in the animal’s body, based on more than 30 specimens (I was unaware that so many were known!). Martin uses a single specimen that was crushed by a Cretaceous steamroller.

Not surprisingly, Norell’s team creates what appears to be a normal theropod skeleton, while Martin’s model looks like a paper airplane.

Hilarious. And dead-on accurate.

So I’m enjoying a low-pressure Saturday afternoon, clicking the “StumbleUpon” button, and it takes me to the Dinosaur Facts site - specifically, the page about Eudimorphodon. On that page I notice the following text:

The Eudimorphodon was a flying dinosaur that lived in the late Triassic period.

Now, I’m not an expert on dinosaurs. What I know about dinosaurs and carry about in my head would not be too much trouble to write down. But it seemed to me that Eudimorphodon was not a dinosaur, but in fact was a pterosaur. The picture certainly looked like that of a pterosaur. And I hadn’t really heard of non-feathered flying dinosaurs anyway. And one last objection - a flying dinosaur in the late Triassic? Not impossible, I suppose, but I don’t recall hearing of such a thing.

A quick look at Wikipedia seemed to confirm that Eudimorphodon is a pterosaur.

Now if there’s one thing that motivates me, it is finding errors. Having found this one, I decided to read the rest of the page. I read to the end and then I look at (what in print media would be called) the sidebar, which is titled Did you know, and which contains this gem:

Eudimorphodon was a pterosaur, not a dinosaur.

Er, ok then. Contradictory information on the same page just bugs me, but that’s the web for you. At least this time they had the right answer.

But here’s the thing. I don’t actually know what a Pterosaur is. Yes, I know that it is a flying Mesozoic reptile - I just don’t find that to be very meaningful. So I did a little web searching, and I quickly realized that for me, “what is a pterosaur” is answered not by the mantra about flying reptiles, not by their morphology, but by their phylogeny. Their phylogeny is not yet super-well established, which makes drawing firm conclusions chancy, but nevertheless cladograms exist. Looking for one led me to this image (from here):

So Pterosaurs are closer to the dinosaurs than crocodilians, but diverged before the dinosaurs originated. Nice. That’s actually a perfect answer - it tells me exactly why pterosaurs aren’t dinosaurs, and also suggests some attributes of Pterosaurs that it wouldn’t share with dinosaurs, or crocodiles.

So, why are we still using the mantra “flying reptile” to describe a Pterosaur? Phylogeny and phenotype together do a much better job, yes? Why do none of the benchmarks or standards used by the teachers I work with include cladograms? I’m sure this concept can and should be explained to 9-12 students.

NewsDaily, Shortnews, and a bunch of other outlets are reporting that Rhys Nichols has discovered dinosaur tracks while walking on the beach near Scarborough, North Yorkshire, with his father. Rhys is eight years old, proving the oft-repeated adage that paleontology and astronomy are the two disciplines to which amateurs commonly make scientific contributions.

It is reported they are probably Iguanodon tracks from the Jurassic.

“This is a great find as dinosaur prints are not normally that clear,” archaeologist Will Watts said, “Looking at the size of the prints, the dinosaur was probably the same size as Rhys.”

Umm - archaeologist?

Microraptor fossil. The image is from Wikimedia Commons, where it is licensed under the Creative Commons Attribution ShareAlike 2.5 license. Unfortunately, no author name is provided.

I’ve just finished watching the latest Nova, which aired last night (all praise be to TIVO). The episode was about Microraptor.

The early part of the documentary set up some controversy by contrasting the ideas of Larry Martin with those of various AMNH paleontologists and staff, and their collaborators at other institutions. Martin proposes that the development of flight from ground-dwelling dinosaurs¹ doesn’t make much sense, without really giving any compelling reasons. He also says that this model is necessary for the evolution of birds from dinosaurs, and again, I don’t fully understand why he thinks that. As I’m fond of saying here, just because you say something doesn’t make it true. I’m unable to think of a reason that arboreal dinosaurs developing flight means that birds can’t have evolved from dinosaurs.

He did make a reproduction of Microraptor which featured splayed femurs. The documentary covered pretty convincingly why the reproduction was not plausible - even I could see that Martin’s pelvis was flatter than a pancake. The documentary covered the similarity of the splayed rear-limb model to lizard anatomy, but I don’t think I really understood why Martin believed - even if everything else he said was true, which I wasn’t convinced of - that Microraptor could not have secondarily splayed rear limbs.

Anyone?

The AMNH team certainly seemed to be doing the better science from what Nova presented. Not only was their model constructed with some pretty rigorous methods, they recruited a multidisciplinary team of experts in various fields and hiked out to a wind tunnel to test it. It made Martin’s approach look a bit parochial. The latter half of the documentary seemed to abandon any further coverage of Martin’s work.

The wind tunnel scene was pretty interesting. I’ve been part of similar groups of scientists trying out and testing new ideas, and what Nova showed is pretty much how scientists act - on the whole very competitive, but very collegial and with few exceptions willing to admit it when the data proves them wrong. As usual, Nova was well worth watching.

1. the “ground-up” model, as he puts it, which for some reason has me picturing dinosaurs flying into airplane propellers end ending up as ingredients in my hamburger [↩]

I recently did a little public outreach about astronomy, and because there were no clear skies to be had, we did a little lecture and question-answer session instead. In the last year or so, I’ve been making it a habit to start off the talk with a brief presentation on an unrelated science subject that is in the news. This time, I talked about Mesozoic crayfish and trace fossils from Australia. I hope to have the presentation file downloadable from here shortly; stay tuned.

Regular readers might remember that I covered this subject before - and now I have more of the story.

Dr. Anthony Martin, paleontologist at Emory University, is an acknowledged expert on trace fossils - that is, fossils that don’t preserve the body of an organism, but do preserve some indication of its anatomy and its behavior, such as footprints, burrows, and droppings. He’s also an expert about dinosaurs. He’s written important books about both subjects, as well as being heavily published in journals, mostly as the principal investigator.

He visited the Dinosaur Dreaming fossil site in Australia back in February, 2006. As he was walking around looking at the site on his first day, he discovered two large theropod dinosaur tracks. On the second day, he found a complex of crayfish burrows.

Crayfish burrows, 116 million years old, from Dinosaur Dreaming, Victoria, Australia. The scale card in this image is 10 centimeters long, or about four inches. Photo courtesy of Anthony Martin. Click to enlarge.

Paleontologists had been walking past the burrows for fourteen years, but either nobody noticed them, or nobody appreciated what they were. Martin saw them mainly because he was experienced and educated about what to look for - as they say, luck favors the prepared. At about 116 million years old, the burrows were an important find. Crayfish currently live on every continent except Antarctica and Africa. But many of the continents that crayfish are found on today are separated by large expanses of salt water, where crayfish can’t survive. Therefore, scientists thought that crayfish evolved and dispersed at a time when the continents they are found on were crammed together.

At the end of the Jurassic and beginning of the Cretaceous, Australia, Madagascar, South America, and India were all connected, but they had begun to move apart. If southern hemisphere crayfish had originated in Australia in the early Cretaceous, they would have had only a short time to expand to other continents. If this hypothesis were true, it suggests some specific predictions that could be made: Africa was already separated, so they wouldn’t be found there - and they aren’t. They might not have had enough time to make it to India, so they may not be found there either. It turns out that crayfish aren’t found in India, and neither are their fossils. So far, so good. And crayfish are found on Madagascar, South America, New Zealand, and Australia - all of which were connected, so this is consistent with the continental features of the time.

Another prediction can be made from this scenario: If southern hemisphere crayfish originated in Australia and expanded out from there, it would make sense if Australia to had more crayfish species today than its southern hemisphere neighbors. If it didn’t, that wouldn’t falsify the hypothesis, but if it did, it would lend it some support. And it turns out Australia does have more crayfish species - about 85% of all southern hemisphere crayfish species are found there.

There was a problem, though: although some crayfish fossils from around 150 million years ago are known from the northern hemisphere, none older than about 40 million years had been known from any of the southern continents. If southern hemisphere crayfish originated in Australia, the prediction of evolutionary theory and the theory of plate tectonics would be that crayfish body and trace fossils should be found from the early Cretaceous in Australia - fossils from sometime before 90 million years ago.

So with this discovery of 116 million year old crayfish burrows, these predictions are fulfilled. The burrows are of the right size and configuration for crayfish, and no other organism is known to produce just this morphology in their traces. In addition, the geology of the area supports a freshwater habitat favorable for crayfish. Everything was pointing to a significant find.

Having recognized the crayfish burrows, Martin asked the site director, Lesley Kool, the obvious question: “Do you have any crayfish body fossils from here?” It turns out they did not, but a crayfish body fossil had been dug up in Dinosaur Cove, another fossil site in Victoria, almost twenty years before. It had been sitting in the Museum of Victoria unstudied all that time.

Crayfish fossil, 106 million years old, from Dinosaur Cove, Victoria, Australia. Photo courtesy of Erich Fitzgerald.

One of the remarkable things about this fossil is how close it came to being destroyed by a rock saw. You can clearly see the slot sawed into the rock coming up from the bottom of the picture, slicing through the pincer, and heading toward the crayfish abdomen. There’s another saw cut that took out a chunk of rock that made up this crayfish’s upper back. It just goes to show that not all fossils - and not all important fossils, at that - are as clean and polished as the dinosaurs we see in museums. In addition to this fossil, fossilized claws from two other crayfish were found in the museum’s collections.

So, as a result of happening across the burrows, which led to asking about body fossils, Dr. Martin was able to describe the only crayfish fossils from the age of the dinosaurs in the southern hemisphere. Having written the paper, he saw it rejected twice, but got it published on the proverbially charmed third try.

In such haphazard ways is human knowledge advanced. In a lot of cases, paleontologists have already found interesting and important fossils - they just haven’t had an expert on that field around to recognize them or appreciate their significance. Gaps in our knowledge are caused not only by not having discovered important fossils (yet!), but also by not having studied the ones that have been discovered. This is how science works - it isn’t always in clean labs with white coats and microscopes, and it isn’t usually with perfect specimens. Sometimes it is considerably harder - and luckier - than that.

I am sitting in the airport in Portland, Oregon, fresh from an outing to the Oregon Museum of Science and Industry. I was fortunate to fly first class from Anchorage to Orlando and back for the princely sum of twelve dollars (thanks to frequent-flier miles), but the cost of getting such a good ticket for such a good price is a lengthy ten-hour layover in Portland. Careful advance research revealed that the exhibit of China’s dinosaur and bird fossils, called China’s Ancient Giants, had opened at OMSI just a week ago.

Naturally, I left the airport and hopped a cab for this. I even packed my carry-on very carefully - with a maximum of, uh, minimalism, so that I could comfortably spend the day at OMSI.

First, let me report that OMSI gets crowded on a Saturday. Incredibly crowded. I stood in line for about twenty minutes to pay my admission. About 3/4 of the human beings in the place were under 12 years of age, and to them all the other people in the joint were completely invisible. Most of the kiddies were accompanied by what I presume were their genetic forebears - I deliberately don’t say parents, because from what I could see the reason many of them had brought their children to the museum was to preserve their living rooms from destruction by transferring the damage to a public place that had a high probability of overstimulating their unruly progeny.

Well, it’s my bad for going on a Saturday.

The quality of the exhibit was decidedly mixed. Many of the specimens were casts, and I have no problem with that - in fact, as I’ve said elsewhere, I think exhibiting casts of megafaunal fossils is a good thing. The thing is, they have to be good casts. Some of these weren’t. There was at least one fossil with most of the knee joint surface wiped out by what I presume was an internal support, which was colored as though it were bone, and which made the whole knee anatomy suspect to me. Also, casts should be declared as such, and these weren’t. Only the actual fossils were disclosed, and I’m pretty sure there were a few actual fossils I saw that weren’t labeled as such (because you wouldn’t mount casts with such heavy ironwork, I wouldn’t think). Finally, the specimens were poorly interpreted by the signs. The curator should go check out the Orlando Science Center and see how it should be done. I was grateful that I had carried a lot of my own dinosaur knowledge into the place and didn’t have to rely on the signs.

On the other hand, they did have actual fossils of actual Liaoning birds and feathered dinosaurs, which were most impressive. These were, by and large, in large display cases off to the side of the large mounts, and relatively neglected by the children. That’s a mixed blessing, if you ask me. It was great that I was able to take long looks at these fossils without getting jostled out of the way by an insistent seven year old boy whose mother is training her son for a career in the demolition derby. But it is a tremendous lost opportunity to not have children seeing, and understanding, these fossils that were only discovered in the last 15 years or so.

In some of these fossils, the wishbone was conspicuously visible. In others, it was conspicuously absent. Right there you’ve got an accessible educational opportunity, but most of the adults I chatted with about the specimens didn’t know what the difference was and couldn’t have cared less.

Still - I’ve now seen fossils of feathered dinosaurs. With obvious feathers, right there in the rock, where anyone can see them and say “hey, that’s a feather.”

That’s way cool.

I’ll also give them full credit for hanging some cladograms of dinosaurs, and for having some excellent interpretive material on dinosaur hips and pelvises. This is fundamental evolutionary information, right out of a 101 class (and fully understandable by sixth graders), and it is always nice to see an exhibit like this take the opportunity to do some teaching about details such as these.

The rest of the museum was well designed and I think better maintained than most examples in the genre. All of the little electrical gadgets that I played with were in good working order, which is not the norm at most science and technology museums. They also had a substantial amount of floor space devoted to ecology, and human anatomy and development. They also have a planetarium and something called an Omnimax movie theater, neither of which I sampled.

It was a great way to spend an afternoon - especially considering the alternative of sitting around in an airport all day, but it was good in its own right. I’d recommend the museum to anyone in Portland, or anyone who visits the city. I’d also recommend not going on the weekend - museum staff assures me that today was typically busy for a Saturday.

The Blue Collar Scientist and the Blue Collar Mom were at the Smithsonian Museum of Natural history today. This is my first trip to Washington, DC for pleasure - I was here about fifteen years ago on government work and got to see absolutely nothing in the way of attractions during the brief time I was here. This time, it’s all for fun.

The Museum is an old-style natural history museum - there were a few outdated dioramas (e.g., showing Tyrannosaurus standing upright and balancing on its tail, though the actual mount was done right), lots of stuffed specimens in the Hall of Mammals, most of the megafaunal mounts on display were of actual fossilized bone rather than casts (with accompanying heavy steel supports), some of the descriptions on the interpretive signs are out of date (and are corrected by supplementary signs), and the whole place has the musty, dusty vibe of a natural history museum of the late ’50’s.

It was so cool.

I went immediately to the hall of fossils and dinosaurs, because that’s my thing - I’m as enthusiastic about paleontology as I am for astronomy. Almost immediately, I noticed that there was something that looked roughly like this Devonian starfish labeled as an “asteroid” (Devonaster sp). Made me feel right at home.

I was pleased to see the Museum is unabashed about displaying their specimens with evolution in mind. They exhibit a cladogram for marginocephalian (fringe-headed) dinosaurs, for example, and also have on display an impressive cladogram for proboscidians (elephants, basically) built around miniature sculptures of each species. Cladograms are really cool - they are diagrams showing the ancestry of species, based on evidence from anatomy, biochemistry, genetics, and so forth. A cladogram shows which species gave rise to which others, and what species are in a modern species’ ancestry. The tool is so powerful that there is a movement within biology to classify living things cladistically, rather than with the modernized Linnean taxonomy that is currently widely used.

I had something on my mind during my visit, inspired by comments that people left (but were never published) on my post about the Atlas of Creation - you know, that book that advocates creationism that (presumably mistakenly) used photographs of fishing lures to represent actual insects. A number of creationists, apparently in an attempt to gloss over that widely respected creationist authorities don’t know the difference between insects and fishing lures, tried to post strident, tiresome rants about how there has never been a single transitional fossil found - not one, not even one! Of course this is wrong - tons of transitional fossils have been found, otherwise we wouldn’t have cladograms. But I was wondering about this claim during my visit, and I resolved to keep my eyes open for examples of transitional fossils on exhibit for everyone to see - not buried in some obscure museum archives, but out in the areas of a museum open to the public.

And I was not disappointed:

• Ten transitional horse fossils.
• Six transitional fossils of genus Homo.
• Thirty-four transitional fossils of fishes from primitive ray-finned fishes, to teleosts.
• Over a dozen transitional fossils from fishes to amphibians.

etc. All right out there for everyone to see. And I remember that a bit over a week ago at the Orlando Science Center I noticed two transitional fossils of birds on exhibit.

How could anyone miss all these?

The answer of course is that the creationists lie. It is as simple as that - the people who say this are either lying, or have been lied to by people that they trust and are willing to repeat. Under the traditional definition, transitional fossils are fossils that have some characteristics of older organisms, but have some new features as well. There is no mistaking a transitional fossil. You can’t look at a fossilized toothed bird skull and fail to notice that some characteristics look like dinosaurs (the teeth, for example), and other characteristics look like modern birds (the beak, for example). This kind of thing is incredibly obvious and a mistake in this arena simply cannot be made in good faith.¹

Of course, we recognize today that every single fossil (and every living organism) is by definition transitional - but even under the traditional definition, finding transitional fossils is apparently pretty easy - the hard work is done, and I found over fifty of them in my first hour in a natural history museum that was new to me.

So, people - don’t let them get away with this kind of thing. When you hear a creationist point out that there are no transitional fossils anywhere, please let them know that the Smithsonian Museum of Natural History has over 50 on exhibit that they can find in less than half an hour. If necessary, let them know that they can get to the Smithsonian on the Blue or Orange lines of the DC Metro and see for themselves.

Remember, be nice. You won’t convince them. But you might convince the people around you who are listening in on the conversation.

1. I grant that some of the more obscure characteristics of fossils may be legitimately missed by people who aren’t specialists and argued over by those who are. What I’m saying here is that any ordinary person in possession of a basic sense of honesty will not fail to notice such obvious characteristics as the presence or absence of teeth. [↩]