Restoring that sense of wonder

These can be depressing times for a paleontologist - funding is poor for most, the job market is dim for many talented friends and colleagues, and rhetoric-ridden battles for scholarly publishing rage. That's enough to suck the joy right out of the field. In instances like this, it's nice to step back for a second and think about the really cool stuff going on.

So, I've put together a list of wondrous things that have happened in paleontology over the past several years. Why are they cool to me? Mostly because they challenge ideas that I acquired while a little, dinosaur-obsessed kid. And they also challenge ideas I've acquired as an "educated" professional. Sometimes it's nice to have our comfort zone stretched.

Symbols of the new paleontological revolution: an eye-catching Sinosauropteryx crouches on top of mammoth DNA, overlain on a thin-section of dinosaur bone (sources at end)

In no particular order:

• We know what colors were on parts of the body of some dinosaurs. Really. How cool is that? Sure, it's not perfect, and there is lots we'll never know, but the mere fact that you can plausibly reconstruct parts of the pelage of a feathered dinosaur is amazing. Especially because I had always believed the truism that we'd know the texture of dinosaur skins, but never the color.
• I can download a genetic sequence from a woolly mammoth. Or a Neanderthal. Or any number of extinct organisms. I had always known that Jurassic Park would never be a reality. It probably never will be (at least for non-avian dinosaurs). But to stare at the A's, T's, G's, and C's of an extinct organism still gives me some goosebumps.
• I can listen to a Jurassic katydid. Yes, yes, there are some assumptions in the reconstruction. But let's suspend criticism for a moment, and accept that it's probably at least a decent approximation. These are noises that haven't been heard in 165 million years.
• We know the sex of some individual dinosaur specimens. Thanks to studies of medullary bone and comparative anatomy, the seemingly impossible is made real. Wow!
• Similarly, we know the age of some dinosaur individuals at death (give or take a few years). The notion that sauropods only got big because they grew for a century can't be supported anymore. Once again - wow!

This is just my personal list - what's on yours?

Sources for image: Mammoth DNA sequence in background from GenBank Accession FJ655900 (published by Enk et al., 2009); dinosaur bone histological section modified from Woodward et al. 2011 Figure 1C (colors inverted and adjusted); Sinosauropteryx modified from original by Marty Martunuik. Image released under Creative Commons Attribution-Share Alike 3.0 Unported license.

New Fossil Species of 2011 - A PLoS ONE Retrospective

What do sauropods, primates, crabs, cats, and crocodiles have in common? They're all animals in the fossil record that had new species named in PLoS ONE this year!

Chela (claw) of Geograpsus severnsi, from Paulay & Starmer, 2011

As 2011 winds down, I'm going to devote two posts to some navel-gazing at paleontology in the online, open access journal PLoS ONE. PLoS ONE really has been a ground-breaking publication, partly responsible for spawning the term "megajournal" as well as inspiring clones from the very publishers who invested some effort over the past few years in downplaying the worth of the PLoS ONE publishing model.

[Note before we continue: Although I do have an "official" volunteer role as one of the academic and section editors for the journal, any opinions in this post are entirely my own.]

Skull of Arenysuchus gascabadiolorum, from Puértolas et al., 2011

In any case, let's start our 2011 retrospective with a look at some of the new taxonomy that appeared this year. 17 new species of extinct organism were named on the "pages" of PLoS ONE this year, but these were not by any means distributed evenly across the tree of life.

Five out of 17 were mammals, only one was a non-vertebrate (a lonely, recently extinct land crab from Hawaii), and three - THREE!!! - were sauropodomorph dinosaurs. What kind of crazy world is this where sauropodomorph taxa outnumber crocodylimorphs, and arthropods? Dinosaurs as a whole did quite well, with seven new non-avian dinosaurs gracing the HTML code of PLoS ONE.

New Fossil Taxa Named in PLoS ONE - 2011
Arenysuchus gascabadiolorum (crocodyliform)
Boutakioutichnium atlasicus (theropod footprint)
Gaudeamus aslius (rodent)
Gaudeamus hylaeus (rodent)
Geograpsus severnsi (crab)
Kawichthys moodiei (chondrichthyan)
Khoratpithecus ayeyarwadyensis (primate)
Leonerasaurus taquetrensis (sauropodomorph)
Leyesaurus marayensis (sauropodomorph)
Linhevenator tani (troodontid)
Lycophocyon hutchisoni (carnivoramorph mammal)
Panthera zdanskyi (felid)
Paravipus didactyloides (theropod footprint)
Pissarrachampsa sera (crocodyliform)
Talos sampsoni (troodontid)
Tapuiasaurus macedoi (sauropod)
Tonsala buchanani (bird)

In 2012, I would love to see the following trends:

• An expansion in the number of new taxa published in PLoS ONE (assuming that high scientific standards are maintained - no junk taxa, please).
• Greater diversity in the taxonomic groups represented. Archosaurs are cool and all, but where are the plants? Where are the brachiopods? This will probably just take time, and perhaps a pioneer in each field of study to raise awareness of the journal. I first seriously considered publishing in PLoS ONE because a high-profile dinosaur worker published there, and I suspect other folks in other fields have similar thoughts.
• More authors taking advantage of the format of PLoS ONE when submitting their new taxonomy. With few or no practical limits on figures (color, size, number) and text, every new description could potentially (and should, with few exceptions) get the monographic treatment. I am happy to say that most authors did just this, but there is always room for improvement!

Skull of Tapuiasaurus macedoi, from Zaher et al., 2011

In the next post: PLoS ONE is now a major force in paleontological publishing. What were the overall trends in 2011? What might the future bring?

Hello, Spinops!

In case you haven't yet noticed, there's a new horned dinosaur in town: Spinops sternbergorum, yet another example of the ceratopsians' incredible evolutionary radiation.

Spinops sternbergorum, as envisioned by Dmitry Bogdanov

This animal has special significance for me, because it is the first new dinosaur for which I have been senior author. In a lot of ways, that's a childhood dream coming true!

Best of all, it was a lot of fun to work with some respected colleagues. Michael Ryan (ceratopsian expert extraordinaire) and I enjoyed bouncing ideas off of each other (even if we haven't yet reached a consensus on epiparietal homology, as acknowledged in the paper), and Mark Loewen added another ceratopsian voice to the mix. Darren Tanke offered his historical perspective (particularly important for this specimen, which was found in 1916), and Dennis Braman's expertise in palynology was absolutely invaluable. All of us owe a huge debt to Paul Barret's efforts at the Natural History Museum (London), where the type material is held, as well as for his cladistic wizardry. Last but certainly not least, Mark Graham did a bang-up job with preparing the fossil. When I first saw the holotype parietal, it was upside down and embedded in plaster. Mark took this and made it beautiful!

The art was contributed by several different folks. Phil Hurst took some exceptionally high-quality photographs, and Lukas Panzarin rendered the bones with his usual finesse. Our first life restoration of Spinops was undertaken by Dmitry Bogdanov, and it deservedly has been shown widely in the press.

Speaking of art, our representation of Spinops is conservative. We don't know what the frill looked like to the outside of the big spikes, so it is quite possible that there were more than what illustrated. So to the paleoartists out there: make it as spiky as you want! Anything is possible (until we find more fossils that tell us otherwise).

The specimens of Spinops have a long and interesting history, which has been detailed elsewhere. So, I encourage you to check out Brian Switek's write-up at Dinosaur Tracking, an excellent story by John Mangels in Cleveland's Plain Dealer, a story in The Telegraph, the NHM's press page, the Cleveland Museum's press page, or my own museum's web site.

If you're looking for something completely different, check out The Gawker's take on Spinops. It's snarky and quite funny. Many folks have taken some offense at it, but I'm positively delighted to be featured amongst the celebrity gossip - the story is decidedly tongue-in-cheek!

Finally, if you're really interested in digging deeper, check out the original paper, published in Acta Palaeontologia Polonica. It's open access and free to read by anyone!

Citation: Farke, A. A., M. J. Ryan, P. M. Barrett, D. H. Tanke, D. R. Braman, M. A. Loewen, and M. R. Graham. 2011. A new centrosaurine from the Late Cretaceous of Alberta, Canada, and the evolution of parietal ornamentation in horned dinosaurs. Acta Palaeontologica Polonica 56(4):691-702. doi:10.4202/app.2010.0121 [link to the original paper]

Nedoceratops - Random Thoughts

The last two posts here have focused on my most recently published paper, fully describing the skull of the horned dinosaur known as Nedoceratops hatcheri and critiquing the hypothesis that it, along with Torosaurus latus, is simply an older individual of what we call Triceratops. Because I've already talked about the science of the paper, and some collegial interactions, I'm going to spend this final post in the series talking about a few odds-and-ends that just didn't fit anywhere else. Most of these are little windows into the process behind the paper - from writing to review to revision. And we'll start with. . .

Open Source Composition

I'm proud to say that every single step of the authoring process for my paper happened in open source software. I wrote the manuscript in OpenOffice.org Writer, formatted most of the references in Zotero, did initial image editing (contrast adjustment and background removal) in GIMP, assembled the figures in Inkscape, and submitted the manuscript through the journal website on the browser Firefox, all of which were running on various releases of Ubuntu. Score one for open source software (and open access publishing)!

On Organizing the Paper

I'm under no illusion that everyone (?anyone?) will agree with my conclusion that Nedoceratops is a valid taxon. In fact, I'm quite accepting of the possibility that I may be wrong. But even if this is the case, I still want my paper to be useful. So, I made my best effort to separate data from interpretation in the description section of the paper. Of course, I couldn't be completely successful on this point - after all, I had to compare Nedoceratops with Triceratops and Torosaurus (the most likely candidates for synonymy) - but I like to think that I mostly achieved my goal. If nothing else, I have pretty pictures. And. . .

Speaking of Pictures

My figures went through some pretty drastic changes during the evolution of this paper. In the first round of reviews, it was pointed out that in the text I kept referring to various structures illustrated in the figures, but only a ceratopsian geek could figure out what I was talking about.

For example, we have this lovely sentence:

The narial strut is inclined rostrally towards the dorsal end of the element, and enough original bone surface is preserved to indicate that a posterior internarial flange did not project from the caudal surface of this structure (Figure 4).

My original Figure 4 looked like this:

The photo is relatively pretty, but only a die-hard ceratopsian nerd could locate the narial strut or know where to look for a posterior internarial flange if such a thing even existed in this animal. So, for my next iteration I added some labeling:

Of course, all of the abbreviations are explained in the caption (not shown here). "ns" refers to the narial strut I was talking about above. Finally, the editor mentioned that I should do a better job of indicating the "cpf" (canal at the edge of the premaxillary fossa). It wasn't just at the tip of the arrow, but over a somewhat broader area. Thus, that brings us to version 3:

This, with the extra arrows showing the position of the canal, was the version that appeared in the paper.

If I learned anything from this experience, it was about the importance of good labeling and interpretive drawings for non-expert readers. Most of the labeled interpretive drawings alongside photographs (with the exception of parts B and D in Figure 1) were added at the direct request of the editor. Looking at the end product, this addition was a major improvement to the paper. Of course, I must also admit that having relatively unlimited space in an online journal allows this luxury!

Editorial Ethics

It's probably not a surprise to many of you that I am a volunteer academic editor at PLoS ONE. And those of you who have been paying attention probably noticed that the Nedoceratops paper was just published in that very same journal. This sounds pretty problematic on the face of it.

Thankfully, PLoS ONE has pretty strict editorial controls when one of their own editors submits a paper (in addition to a competing interests policy that covers this and similar situations). My experience as a submitting author was exactly the same as for any other author. Once the "submit" button was pressed, I had to wait just like everyone else. I couldn't control which editors handled it, who reviewed it, or even have a sneak peek at the reviews on-line. In other words, the system functioned exactly as it should.

My authorial feet were held to the fire by Leon Claessens, the handling editor for my submission. Leon, in my opinion, did a very professional job and didn't let me get away with anything (even sending the manuscript back to me a second time for a few last corrections and improvements). The reviewers - Michael Ryan and Peter Dodson - also did their jobs (in my opinion). And, as mentioned in my last post, comments by John Scannella and Jack Horner offered additional constructive feedback.

One thing I really like about PLoS ONE is that my competing interest - as an editor at the journal - is stated up-front in the paper. Although it's somewhat scary seeing it there, I think such notices are certainly appropriate.

Final Thoughts

It's nice to finally have this paper out there - these ideas have been floating around in my head for awhile, and I've always had a secret desire to be the person to describe Nedoceratops. I'm relatively pleased with the final product (of course, there are always one or two typos that slip through, and why couldn't some of the figures in the PDF have been bigger?), and look forward to the discussion that this paper generates. Thank you to all who helped out (see the acknowledgments for a comprehensive list)!

Nedoceratops - A Full Description at Last

Every group of animals has at least one notable yet neglected specimen. In horned dinosaurs, a particular example is a large skull at the Smithsonian discovered in Wyoming during the closing years of the 19th century. Unfortunately, this specimen has suffered a twisted and sometimes tragic history.

The skull of Nedoceratops hatcheri, modified from Farke 2011

The collector of the fossil, John Bell Hatcher, wrote a paper about the specimen, but died before he could publish it. So, the task fell upon Yale's Richard Lull, who gave this nearly complete skull the name of Diceratops hatcheri. It looked much like a Triceratops (the famous three-horned face), but differed from the standard "Trike" in having a tiny nose horn, several holes in the frill, and a handful of other characteristics. Later on, other scientists decided that these differences were probably just the result of individual variation, injury, or other illness. So, Diceratops became just another Triceratops to most workers (a 1986 paper by John Ostrom and Peter Wellnhofer was influential in this regard). Still, there wasn't unanimity in that thought - Cathy Forster, for one, published the opinion (in 1996) that Diceratops was indeed distinct from Triceratops.

Nedoceratops hatcheri, as restored by Nobu Tamura.

In 2000, the skull (which was on exhibit at the Smithsonian) was damaged when some rowdy museum visitors crashed through a barricade and broke the snout. Fortunately, the museum's preparators were able to fix it. As if to add insult to injury, it turned out that the name Diceratops wasn't unique. A German entomologist (coincidentally named Förster) had applied the name to an insect way back in 1868, so a new name had to be found for the dinosaur. Unfortunately, this didn't happen in the most organized way. Two researchers independently published the replacement names of Diceratus (in 2008) and Nedoceratops (in 2007). The second one, although less elegant (in my opinion), had priority because it was published first.

But wait - there's more! The story of Nedoceratops took an interesting twist last year, when John Scannella and Jack Horner suggested that it represented a life stage of Triceratops, halfway through its transformation into Torosaurus (see the figure below). This was not an evolutionary transformation, of course, but ontogenetic (one that happened as an individual animal got older). So, our three animals - Triceratops, Nedoceratops, and Torosaurus - were all just the same thing! Such revelations happen frequently in paleontology. For instance, the duck-billed dinosaur Procheneosaurus turned out to be young Corythosaurus, Lambeosaurus, Hypacrosaurus, and the like. But, not all horned dinosaur experts are convinced that this was what was going on with Nedoceratops and Torosaurus.

From left, life restorations of Triceratops, Nedoceratops, and Torosaurus (all modified after originals by Nobu Tamura). The arrows indicate the relative age of each animal, as proposed by Scannella and Horner. If they all are the same thing, Triceratops is the "young" life stage, and Torosaurus is the "old" life stage, with Nedoceratops being a transitional form. The big question: are these the same animal, or different species?

Named, renamed, renamed again, broken, pieced together, and declared invalid, Nedoceratops has had a checkered past. Yet, the skull has never received a fair treatment in the scientific literature. I'm not just talking about people's opinions of the specimen. Instead, I'm talking about a full description.

Descriptions - detailed accounts of a specimen's characteristics - are the data upon which much of paleontology relies. But, the skull of Nedoceratops was never fully described. A few paragraphs have been written about it here or there, but it turns out that many aspects of these were inaccurate or incomplete. Given the controversy over this skull, an accurate and complete description of the animal was particularly important. So, I set out to fix the situation. In my recent PLoS ONE paper, I published the first comprehensive description and illustration of Nedoceratops hatcheri.

At risk of boring you readers with endless details, I'll just mention a few minor points. For instance, it turns out that many of the early drawings of the specimen were inaccurate (missing bone was shown as present, for instance). I was able to correct these errors, and talk about areas of the skull that were well-preserved but never discussed in the literature before. My paper also includes detailed and never-before-published photographs of the skull in various views, which I hope will be useful for folks who can't see the skull first-hand.

Finally, and probably of the broadest interest, I go out on a limb and say that Nedoceratops hatcheri is a unique species - not the same as Triceratops or Torosaurus. In my opinion (and it is but an opinion), there are just too many features that are different between these animals, and few features can be chalked up to injury or growth changes. Will this opinion stand the test of time? Maybe, maybe not. My opinion on the validity of Nedoceratops is probably the most tentative conclusion I've ever published, so my feelings won't be terribly hurt if I turn out to be wrong (although of course, I'd rather be right).

And what about the idea of Triceratops being a junior version of Torosaurus? I argue that Torosaurus and Triceratops are indeed distinct species, not just old and young versions of the same animal. Why is this?

• Triceratops and Torosaurus have vastly different numbers of bony bumps - called epiparietals and episquamosals - on the edges of their frills. If Torosaurus is the younger version of Triceratops, this means that Triceratops added a bunch of these bumps to the frill during growth. Yet, there is no good evidence that any other horned dinosaur did this.
• Triceratops has a solid frill, and Torosaurus has big holes in its frill. In all other horned dinosaurs we know (such as Protoceratops and Centrosaurus), if adults have holes, the young ones have holes. Thus, it doesn't make a lot of sense that Triceratops/Torosaurus would only add these holes when it got really big. [of course, I will admit that just because something doesn't make sense doesn't mean it couldn't happen - just that it is much less likely]
• It was previously claimed that there were no good examples of "young" Torosaurus. But, a skull at Yale (collected by Hatcher, the same person who discovered the Nedoceratops skull) fits all of the characteristics of a young animal. Its skull sutures are all open, or unfused, and the bone has a smooth texture typical of young dinosaurs. In my mind, this is probably the best evidence that Torosaurus is not a grown-up Triceratops.

Undoubtedly, many other paleontologists will have something to say about these issues. Some will agree, some will disagree, some will show parts of my paper are incorrect, and others will present more supporting data (at least I hope, on all counts). I suspect the next few years will feature much, much more discussion on these fascinating horned dinosaurs!

Coming Up: It is safe to say that I have had more fun with this project than with anything else I've done recently. Why is that? In part, it's been due to some very stimulating discussions with John Scannella and Jack Horner, who recently published the "Toroceratops" hypothesis. See my next post for more!

Citations

Farke, AA (2011) Anatomy and taxonomic status of the chasmosaurine ceratopsid Nedoceratops hatcheri from the Upper Cretaceous Lance Formation of Wyoming, U.S.A. PLoS ONE, 6 (1) DOI: 10.1371/journal.pone.0016196

Forster CA (1996) Species resolution in Triceratops: cladistic and morphometric approaches. J Vertebr Paleontol 16: 259–270.

Förster A (1869) Synopsis der Familien und Gattungen der Ichneumonen. Verhandlungen des Naturhistorischen Vereins der Preussischen Rheinlande und Westfalens 25: 135–221.

Hatcher JB (1905) Two new Ceratopsia from the Laramie of Converse County, Wyoming. Am J Sci, series 4 20: 413–422.

Mateus O (2008) Two ornithischian dinosaurs renamed: Microceratops Bohlin, 1953 and Diceratops Lull, 1905. J Paleontol 82: 423.

Ostrom JH, Wellnhofer P (1986) The Munich specimen of Triceratops with a revision of the genus. Zitteliana 14: 111–158.

Scannella JB, Horner JH (2010) Torosaurus Marsh, 1891, is Triceratops Marsh, 1889 (Ceratopsidae: Chasmosaurinae): synonymy through ontogeny. J Vertebr Paleontol 30: 1157–1168.

Ukrainsky AS (2007) A new replacement name for Diceratops Lull, 1905 (Reptilia: Ornithischia: Ceratopsidae). Zoosystematica Rossica 16: 292.

Back to the Late Jurassic, With Chris Noto

If you ask the average person to imagine the Age of Dinosaurs, odds are quite good that they might envision a scene from the Morrison Formation. This Late Jurassic-aged (156 - 147 million year old) rock unit of the western United States has given us such dinosaur greats as Stegosaurus, Apatosaurus, Allosaurus, and more. Many of these animals are known from exquisitely-preserved, complete skeletons - and thus their anatomy has been described in pretty ridiculous detail. The functional morphology (how these animals moved, breathed, ate, and fought) has also gotten a lot of attention. But, this only tells us about the individual lives of the organisms. To really understand their world, we need to think bigger.

Chris Noto, my friend and academic brother (we had the same Ph.D. advisor), has devoted his scientific career to a big-picture understanding of dinosaur ecology. He has a special place in his heart for the dinosaurs of the Morrison Formation, and has been chipping away at their ecology for quite awhile now. Thus, it was really exciting to see his recent co-authored paper in PLoS ONE, about that very topic. Also of note was that this paper served as Chris's contribution to the 2009 Paleo Project Challenge!

Chris was kind enough to offer a little behind-the-scenes look at his project and the research results. I hope you'll find it enlightening!

How did you get the idea for your project?
Well, this involves going back a ways. I have always been fascinated by extinct organisms, particularly what they were like as living, breathing individuals in their environment. As an undergraduate at the University of Chicago I had the privilege of working with two really great scientists: Paul Sereno and Fred Ziegler. Paul is a well known paleontologist who has worked all over the world. Fred’s work was responsible for many of the paleogeographic and paleoclimate maps used today. Working with Paul got me thinking about how dinosaurs varied over space and time; working with Fred introduced me to global climate patterns and changes in continental arrangement.

Once I got to graduate school at Stony Brook University I was taught the fundamentals of ecological theory. I started formulating an idea for looking at variation in dinosaur communities (the collection of all the different types of organisms that live in an area) and how those differences may be related to climate, but wasn’t sure how to approach it. Enter my good friend (and coauthor) Ari Grossman, who suggested applying this method, called Ecological Structure Analysis, commonly used in the study of fossil mammals. After some discussion on the appropriate way to adapt this method to the type of information available for dinosaur fossils, we agreed to work together on this project.

What was the most challenging part of writing the manuscript?
Like many papers, this one languished half done for many years. This was a side project of ours, and unfortunately our dissertation research had to come first. Every time I started working on it again I would realize that the data needed to be changed or updated, and this would sometimes change the results and our interpretation. I am a stickler for details and want to make sure all the data are as accurate as possible. But this project was simply too cool to let go. Once I graduated I decided to finish this manuscript as a first priority. It actually didn’t take too long after that once I put my mind to it; in the end I think that the paper was all the better for it. I learned a lot in the meantime, which contributed to making it a stronger manuscript. The hardest part by far though was actually submitting it to PLoS ONE for consideration. No one likes to be rejected, especially after putting so much work into a project! But this is the way the peer-review system works.

I noticed that you used the program PAST for your statistical analyses - how did you decide on that program? Were there any particular challenges to using this software?
I was attracted to PAST because it could perform the analyses I needed to do without a lot of unnecessary complication. Best of all, it was free, and I was a poor graduate student at the time. Most commercial statistics programs are expensive and difficult to use. PAST has a relatively simple interface and the results are easy to interpret, which is important. The major challenge with using PAST is in data management. If the data are not arranged in exactly the right way the analysis will not work correctly. Therefore it requires arranging the data first in a program like Microsoft Excel, and then copying and pasting it into PAST.

What was the most interesting thing you learned while doing your research?
First of all, I wasn’t sure what to expect when I started doing this research. No one has looked for large-scale patterns like this in dinosaurs before. One interesting thing I learned is that such patterns exist in the fossil record and are preserved over the immense spans of time between when these communities existed and when they were recovered. The most exciting result for me has to be the fact that the proportion of different “ecomorphs”, such as high-browsing herbivores vs. low-browsing herbivores or bipeds vs. quadrupeds, varies with climate. So, we can draw a connection between the climate, environment, and adaptations of organisms living in an area (see figure below). This is no surprise for any ecologist working today, but has not been shown in a terrestrial ecosystem as ancient as the Jurassic (~155 million years ago). This opens up new areas of research into the role climate change plays on the structure of ecosystems over time.

Cartoon showing variation of environment and dinosaur ecomorphs. Drier conditions are on the left, where very large herbivores dominated among relatively sparse plant life. Communities under seasonal conditions are towards the center, and include a greater diversity of feeding modes among increased ground cover. To the right are moister conditions, where smaller herbivores are more prevalent within a more densely vegetated environment. Green=high browser, orange=intermediate browser, blue=low browser, red=ground forager. After Noto and Grossman 2010.

Thanks, Chris! For more about his research, check out his web site.

[Disclaimer: Although I am an editor at PLoS ONE, I had no role in the handling of this paper]

Citation
Noto, C., & Grossman, A. (2010). Broad-scale patterns of Late Jurassic dinosaur paleoecology PLoS ONE, 5 (9) DOI: 10.1371/journal.pone.0012553

Welcome, Hippodraco and Iguanacolossus!

Iguanodonts certainly have been a fertile ground for study lately - for a short summary, check out Darren Naish's excellent posts here, here, and here. Although the European iguandonts (such as the classic Iguanodon) get much of the attention, their North American cousins were also apparently pretty speciose.

Today, a new study headlined by the University of Pennsylvania's Andrew McDonald names two genera and species from the Early Cretaceous-aged Cedar Mountain Formation of Utah - Iguanacolossus fortis and Hippodraco scutodens (pictured below). [full disclosure: I was the academic editor at PLoS ONE who handled this manuscript]

Hippodraco scutodens (left) and Iguanacolossus fortis (right); modified from original artwork by Lukas Panzarin, in McDonald et al. 2010. Scale bar equals 1 m.

Each animal is known from a rather nice partial skeleton, allowing relatively confident phylogenetic placement of the two animals. McDonald and colleagues did a fantastic job describing and illustrating both taxa; all of the known elements are shown in some detail, which will be a huge help for other researchers who may not have easy access to the original material in Salt Lake City. The PDF weighs in at 35 pages, and 39 high resolution figures can be downloaded from the PLoS ONE web page for the paper.

Although there are already three other iguanodonts named from the Cedar Mountain Formation (Eolambia caroljonesa, Planicoxa venenica, and Cedrorestes crichtoni), McDonald lays out substantive morphological and geological evidence for the distinctness of the new taxa. Odds are good that there will be (or are) differing opinions from other paleontologists, so I suspect we're going to be hearing much more about the Cedar Mountain iguanodonts in the near future!

Citation
McDonald AT, Kirkland JI, DeBlieux DD, Madsen SK, Cavin J, Milner ARC, Panzarin L (2010) New basal iguanodonts from the Cedar Mountain Formation of Utah and the evolution of thumb-spiked dinosaurs. PLoS ONE 5(11): e14075. doi:10.1371/journal.pone.0014075

Book Review: The Princeton Field Guide to Dinosaurs

When I was little (9 or 10 years old), my two favorite dinosaur books were Bob Bakker's The Dinosaur Heresies and Greg Paul's Predatory Dinosaurs of the World (PDW). I was lucky enough to get a copy of the former as a birthday present, but never owned a copy of the latter until recently, having to satisfy myself with ordering it via interlibrary loan. Both of these lavishly illustrated books portrayed dinosaurs as active, dynamic animals. Needless to say, my interest and imagination were sparked. I learned that Tyrannosaurus could cruise along at speeds approaching 45 miles per hour, that Velociraptor and Deinonychus were the same genus, that all dinosaurs had mammalian metabolism, Pterodaustro was pink from its diet of shrimp, and that some dinosaurs had feathers.

It was a tragic day when I realized that most of my dinosaur facts were wrong.

But, it was also an important stage in my growth as a scientist. I learned that publication in a book, or scientific job title, or pretty illustrations, weren't sufficient to establish scientific fact. Some really cool and exciting ideas (like the sprinting T. rex) couldn't hold up to scientific scrutiny, or simply weren't testable. And other ideas (like the feathered theropods) just needed the right specimen (which eventually arrived).

Despite their shortcomings, The Dinosaur Heresies and PDW were momentous publications for my generation. They inspired many young paleontologists and spun off numerous artistic clones (you don't have to look far to see the influence of Greg Paul's "running theropod" pose, for instance; see the example at right). Thus, it was with some excitement that I got my copy of Greg Paul's The Princeton Field Guide to Dinosaurs (hereafter just the "Field Guide") in the mail. In many respects, this is the modern heir to PDW.

The book itself is quite pretty, in a durable yet inexpensive hardcover format (I got my copy for under $25). The pages are chock-full of illustrations, ranging from black and white skeletals to full color paintings. The first part of the book includes well-written, succinct text (although certainly with a "Paulian" spin to its claims) that provides a birds-eye view of dinosaur biology. The highlight of the book, however, is the "Group and Species Accounts."

Pretty much every known dinosaur is included, and a great number are illustrated. Images include shaded skull reconstructions, black and white skulls, complete skeletal reconstructions, and color pencil drawings. This is classic Greg Paul (see his website for some samples), with the poses and attention to skeletal detail that we all expect. Many of these have never been widely available in any form - a boon for dinosaur enthusiasts! A number of his paintings are also included; most have been published before, but some are updated based on new information. I am not sure if I like the color pencil drawings as much of the rest of the artwork; many of them lack the "pop" of the skeletals or paintings. Some of this could be a consequence of the scale at which they are reproduced; I get the sense that many of the illustrations would look better if printed at a smaller size.

The species accounts are generally pretty good, although of course there is not sufficient space to go into the supporting evidence (or not) for some statements. For instance, the talk about "enemies" of some taxa is perhaps a little colloquial but at least vaguely supportable - one would think that similarly-sized herbivores and carnivores in a formation were indeed "enemies". Other facts - like stating that ceratopsids defended themselves by "rearing like a bear and tilting [the] frill up to intimidate [the] attacker, followed by a short fast charge with horns and/or beaks" (p. 257) are pure (if plausible) speculation. To his credit, Paul (p. 62) notes that the "reliability of these conclusions varies greatly." Unfortunately, I'm afraid this caution will be lost on the average reader.

My only real major beef, which has been echoed by many others (see this thread on the Dinosaur Mailing List, for instance), is with the taxonomic games played in the book. I do not think that the work is a Major Disaster in taxonomy; as Paul readily admits, the Field Guide is a popular book that is not intended as a valid nomenclatural statement. Publishing scientists are generally going to ignore any taxonomic assessments. One major reason is that many of the generic lumpings form polyphyletic or paraphyletic groups. For instance, Paul's Chasmosaurus (including Chasmosaurus, Mojoceratops, Agujaceratops, and Pentaceratops) is hopelessly paraphyletic by all recent phylogenies (see the Sampson et al. one, for instance, or even Lull's 1933 phylogram, if you're not a fan of cladistics). Similar problems plague the hadrosaur naming scheme in this book - it's not just a matter of having one's "genericometer" set to "broad". On the last point, though, one wonders why the rather morphologically conservative and firmly monophyletic "leptoceratopsids" all got to retain their separate genera! Prenoceratops and Leptoceratops are far more alike than Styracosaurus and Pachyrhinosaurus (all lumped in Centrosaurus by Paul!).

Rather than a scientific issue, the primary problem is that this stuff is going to be soaked up uncritically by the lay public (as we saw with Dinosaur Heresies and PDW). I don't think it's a catastrophe on the scale of Jurassic Fight Club (most of the basic content in the Field Guide is accurate), but it will still be a nuisance in the long term. I'll have to deal with kids who want to know why I'm following an outdated ceratopsian classification, but that's probably about the worst that's going to happen. A dino fanboy (speaking with a voice a la Professor Frink) will tell me that prosauropods slashed their enemies with razor-sharp claws, because he read it in a book by a paleontologist. The world is not ending. My hope is that discussions about what we know and don't know will inspire the next generation of researchers!

Flaws aside, every dinosaur enthusiast should get a copy of The Princeton Field Guide to Dinosaurs. The skeletals alone are worth the price of admission. This book is visually appealing, fun, and a great reminder of why we all loved dinosaurs in the first place.

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The Princeton Field Guide to Dinosaurs, by Gregory S. Paul, 320 pages, published by Princeton University Press. ISBN13: 978-0-691-13720-9. $35 list price.

Horned Dinosaurs: When It Rains, It Pours

2010 will surely go down as the annus mirabilis of horned dinosaur research. Between the publications of the horned dinosaur symposium volume (with its myriad new taxa and other exciting pieces of research), a "bagaceratopsid" in Europe, a true ceratopsid in Asia, the hypothesis that Torosaurus and Triceratops are growth stages of the same taxon, and more, it's really tough for a "ceratophile" (to borrow Peter Dodson's term) to keep up!

Today continues the embarrassment of ceratopsian riches. With my co-authors Scott Sampson, Mark Loewen, Cathy Forster, Eric Roberts, Alan Titus, and Josh Smith, I'm pleased to introduce you to Utahceratops gettyi and Kosmoceratops richardsoni (at top and bottom, respectively, in the image at right), freshly published in PLoS ONE. Although it's been a long time coming, our hope is that these new critters will really knock your socks off!

So what's so special about these two animals? Well, for one they're new dinosaurs. And new horned dinosaurs at that. On a broader note, our new critters (along with careful radiometric dating of the Kaiparowits Formation, the rock unit in southern Utah from which they originated) provide important evidence for dinosaur provincialism during the Late Cretaceous. In other words, these big, elephant-sized dinosaurs weren't traveling far. They're the same age as dinosaurs known from much further to the north, yet represent a very different part of the horned dinosaur family tree. This is strange, especially when you consider that today there is only one (or maybe two, depending on whom you ask) elephant species in all of Africa! 75 million years ago, there were three or four closely related species of horned dinosaur living simultaneously on that little strip of beachfront property that comprised western North America. And that's not counting a few more less closely-related horned dinosaurs (centrosaurines) that lived at the same time! Truly weird.

There's been a lot said more eloquently elsewhere about these animals, so I'm just going to close with an answer to the question that should be at the top of many people's minds. Given the possibility that Torosaurus and Triceratops might be growth stages of a single species, how do we know that Utahceratops and Kosmoceratops aren't just growth stages of one species? After all, they lived at the same time in the same place, and end up somewhat close together on the phylogenetic analysis. Well, we certainly haven't done much in the way of histology yet, which would lay the issue completely to rest. However, as readers of the paper will note, we have obvious juveniles (based on sutural fusion and cranial element size) of both species. Although these remain to be published, in my opinion they pretty firmly demonstrate that both species of dinosaur were very different very early on in their development.

So, go read the paper!

Full disclosure: I am a section editor at PLoS ONE, the journal at which this new paper was published. However, I had absolutely no involvement in the handling of the manuscript (assigning the academic editor, selecting reviewers, making a publication decision, etc.).

Image credit: Lukas Panzarin

Citation
Sampson, S., Loewen, M., Farke, A., Roberts, E., Forster, C., Smith, J., & Titus, A. (2010). New horned dinosaurs from Utah provide evidence for intracontinental dinosaur endemism PLoS ONE, 5 (9) DOI: 10.1371/journal.pone.0012292

Welcome, Seitaad!

I am pleased to announce the publication in PLoS ONE of Seitaad ruessi, a new sauropodomorph dinosaur from the Lower Jurassic Navajo Sandstone of southern Utah. Sauropodomorphs are (mostly) herbivorous dinosaurs that lived from the Triassic all the way until the end of the Cretaceous. Although most people know the giant quadrupedal sauropodomorphs like Brachiosaurus and Apatosaurus ("Brontosaurus"), many of the early sauropodomorphs were bipeds smaller than humans. Seitaad fits in the latter category. For reasons explained below, this is a really cool little animal and a truly rare find.

I have a personal connection to this fossil on two levels. First, the authors of the article, Joe Sertich (at left, pictured with the specimen) and Mark Loewen, are good friends and colleagues of mine. So, I was really excited when they told me that they wanted to submit their manuscript to PLoS ONE (full disclosure: I am an editor there; for obvious reasons, someone else handled their submission). I'll confess that I did little to discourage them. Congratulations, Joe and Mark, on a great paper!

Second, I was one of the lucky people who got to carry the block containing Seitaad from its original resting place, way back in 2005. This thing was heavy! It took a crew of 12 people (8 carrying at a time, and 4 resting for rotation back in) to haul it out. After several years of preparation and study, the new animal is finally named!

I queried one of Seitaad's authors, Mark Loewen, for his thoughts on the find (Joe Sertich is out of the country, so wasn't able to contribute). Here's what Mark had to say.

Briefly, what is the most significant aspect of the new find reported in PLoS ONE?
Seitaad is the first dinosaur discovered from the Navajo Sandstone of Utah and one of the oldest known dinosaurs from Utah. The Navajo Sandstone is a dominant rock unit exposed all over the west. . .and is hiked by thousands of people every year. Fossils in this formation are extremely rare. Prior to its discovery our entire view of the fauna of the Navajo consisted of a partial tritylodont, three chunks of crocodylomorphs, parts of a small theropod, [and] two fragmentary sauropodomorphs. Seitaad is the most complete fossil from the Navajo and through comparisons with taxa across the world gives a much better picture of the largest herbivore in the sand seas of western North America at the same time that large true sauropods had evolved in other parts of the world.

How did you choose the name that you did?
Seitaad was found by Joe Pachak [pictured at left, with the specimen], a local archaeologist and artist from Bluff, Utah while hiking Comb Ridge to document petroglyphs and pictographs. He reported the specimen to the BLM, who alerted us at the Utah Museum of Natural History. We went down to check it out, and immediately started to excavate the specimen. With a crew of 12, including Andy Farke, we hauled out the jackets and began preparing them at the UMNH.

The area around Comb Ridge is covered with numerous archaeological sites and cliff dwellings from the ancestral Puebloan (Anasazi) culture. In fact, Seitaad was located directly below a dwelling called the Eagles Nest. The people who lived in the area at the time would have recognized the white bones of Seitaad eroding out of the cliff if they had seen them. A nearby cliff dwelling has a slab with a dinosaur track incorporated into the window sill. I’m confident that the person who [put] this stone into the window had awareness and appreciation for the fossils preserved in the Four Corners region.

"Seitaad" is derived from Seit’aad, a sand-desert monster from the Navajo (Diné) creation legend that swallowed its victims in sand dunes. The skeleton of Seitaad had been "swallowed" by a fossilized sand dune. The [species name] "ruessi" is derived from Everett Ruess, the famous young artist, poet, historian, and explorer who disappeared in southern Utah in 1934. Ruess is celebrated for his love of the region, its people, and for his free-spirited and adventurous lifestyle. Everett Ruess loved the red rock country of Utah and spent a lot of time exploring the Navajo Formation, so we thought it was fitting to honor him in the taxonomic name.

Why did you choose PLoS ONE as a venue for your research?
We chose to submit to PLoS ONE for several reasons. The open-access format of PLoS ONE and rapid turn-around were major factors. Another factor was the opportunity to reach a broader audience and the rising impact and recognition of PLoS ONE within the paleontology academic community. Another consideration was the lack of limits to figures and unrestricted use of color. The unlimited use of color became a concern during the preparation of our manuscript, when it became clear that black and white photos were not revealing proper contrast between white bones of Seitaad and the pink sandstone of the Navajo Formation.

Is there anything about this find that didn't make it into the scientific paper?
When we first saw photos of the skeleton in the cliff wall we thought it was a pterosaur. The v-shaped ischia looked like dentaries. It wasn’t until UMNH preparators got into the block that we changed our identification to theropod. Then when we got to the hand, we know from the thumb claw that it was a sauropodomorph.

Mark Loewen with the skeleton of Seitaad ruessi

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Check out the original article for free at the PLoS ONE website. As always, you can leave comments or rate the article there.

Citation
Sertich, J.J.W., & Loewen, M. (2010). A New Basal Sauropodomorph Dinosaur from the Lower Jurassic Navajo Sandstone of Southern Utah PLoS ONE, 5 (3) DOI: 10.1371/journal.pone.0009789

Other Readings
The paper is all over the news and blogosphere; check out Dave Hone and ReBecca Hunt's blogs for more.

Image Credits: Mark Loewen and Utah Museum of Natural History

Four-Winged, Psychedelic Dinosaurs

When many of us think of viewing things under a "black light," we either think of those psychedelic posters from the 1960s or else the displays of fluorescent minerals that nearly every science museum has. It's also virtually mandatory to have a scene involving the use of "black light" in the popular CSI television programs - many bodily fluids show up nice and pretty under these conditions. "Black light," more properly known as "ultraviolet (UV) spectrum light", is just outside the visible light spectrum for us humans (past violet, hence the name). And, through some neat tricks of physics, many objects will brightly fluoresce under intense UV light when they wouldn't look like anything special under your standard sunlight or incandescent light bulb.

Oddly enough, many fossils fluoresce under UV light (certain minerals in fossils, including phosphates, are behind this phenomenon). Thus, this technique has been used to look for otherwise hidden features of some exceptionally well-preserved fossils. Historically, it's been the domain of invertebrate paleontologists (looking at crustaceans from the Jurassic of Germany, for instance), but vertebrate paleontologists have used the technique to identify forged fossils (like Archaeoraptor), study Archaeopteryx, and much more. What might be a very subtle or invisible structure under regular light (such as a feather shaft, or antenna, or soft tissue outlines) sometimes shines nicely under UV light.

Thus, Beijing paleontologist Dave Hone and colleagues applied the UV light technique to some of the spectacular fossils coming out of the Cretaceous-aged beds of China. In particular, they were interested in a little critter called Microraptor. A dromaeosaur (part of the same group including Velociraptor), Microraptor is relatively well-known as the "four-winged dinosaur." Spectacular fossils with feather impressions show the standard pair of bird-like wings on the arms and a second set of wings on the hind limbs. This suggests to some researchers that birds went through a four-winged flight phase early in their evolution, and the two-winged flight with which we are familiar only happened later.

Cast of the type specimen of Microraptor gui, from the Wikimedia Commons, reproduced under a Creative Commons Attribution-Share Alike 2.5 Generic license.

Although the fossil looks spectacular, many paleontologists speculated that appearances might be deceiving. Were the feathers on the legs actually in place, near their life position? Or had they gotten moved around from somewhere else on the body? A pale halo of sediment (probably from the decomposition process) obscured the contact of the feathers with the bones, so the issue remained unresolved. Either way, it had major implications for avian evolution.

Hone and colleagues wondered if the full anatomy was obscured under visible light. So, they turned a UV light source against the specimen. It turns out that the feather structures fluoresce quite nicely - and can be traced right through the "halo" and up to the very edge of the leg bones. So, the feathers really are in place. Problem solved! [image, showing full skeleton, modified from Figure 2 in Hone et al. 2010]

Now that we're more confident that Microraptor really was four-winged (and not just an accident of fossilization), the conversation can move forward. And, this is a great rallying cry for other researchers - who knows what structures we might discover with UV light!

Close-up of hind legs of Microraptor under UV light, with arrows indicating feathers. The yellow stripes leading up to the leg bones are portions of the feathers visible only under UV. Modified from Figure 3 in Hone et al. 2010

Read the full paper in the freely-available, open access journal PLoS ONE (full disclosure: I was the editor who handled this manuscript). You can post comments or ratings for the article there, too! In the blogosphere, check out Dave Hone's posting on his article and this follow-up, Adam Yates' write-up, as well as ReBecca Hunt's interview with Dave.

Citation

D. W. E. Hone, H. Tischlinger, X. Xu, & F. Zhang (2010) The extent of the preserved feathers on the four-winged dinosaur Microraptor gui under ultraviolet light PLoS ONE 5 (2) : 10.1371/journal.pone.0009223

Dinosaur Running and Endothermy in PLoS ONE

On a personal note, I have recently stepped up as "Section Editor" for paleontology at PLoS ONE. This means that I'll be coordinating the editorial flow for most paleo-themed papers that come the journal's way.

One of the real joys of editing for a major journal like PLoS ONE is getting a "sneak peak" at some pretty nifty research. Today, Herman Pontzer, Vivian Allen, and John Hutchinson have a new paper that should be of interest to this blog's general audience [full disclosure: I was the academic editor for this contribution]. As always, papers at PLoS ONE are free to download, comment upon, and rate.

The abstract and citation are copied below; for more info, check out the press release or Ed Yong's excellent blog post on the topic.

The bipedal and presumably endothermic Velociraptor. From the original by Matt Martyniuk, licensed under a Creative Commons Attribution ShareAlike 3.0 license.

Citation: Pontzer H, Allen V, Hutchinson JR (2009) Biomechanics of running indicates endothermy in bipedal dinosaurs. PLoS ONE 4(11): e7783. doi:10.1371/journal.pone.0007783

Abstract
Background
One of the great unresolved controversies in paleobiology is whether extinct dinosaurs were endothermic, ectothermic, or some combination thereof, and when endothermy first evolved in the lineage leading to birds. Although it is well established that high, sustained growth rates and, presumably, high activity levels are ancestral for dinosaurs and pterosaurs (clade Ornithodira), other independent lines of evidence for high metabolic rates, locomotor costs, or endothermy are needed. For example, some studies have suggested that, because large dinosaurs may have been homeothermic due to their size alone and could have had heat loss problems, ectothermy would be a more plausible metabolic strategy for such animals.

Methodology/Principal Findings
Here we describe two new biomechanical approaches for reconstructing the metabolic rate of 14 extinct bipedal dinosauriforms during walking and running. These methods, well validated for extant animals, indicate that during walking and slow running the metabolic rate of at least the larger extinct dinosaurs exceeded the maximum aerobic capabilities of modern ectotherms, falling instead within the range of modern birds and mammals. Estimated metabolic rates for smaller dinosaurs are more ambiguous, but generally approach or exceed the ectotherm boundary.

Conclusions/Significance
Our results support the hypothesis that endothermy was widespread in at least larger non-avian dinosaurs. It was plausibly ancestral for all dinosauriforms (perhaps Ornithodira), but this is perhaps more strongly indicated by high growth rates than by locomotor costs. The polarity of the evolution of endothermy indicates that rapid growth, insulation, erect postures, and perhaps aerobic power predated advanced “avian” lung structure and high locomotor costs.