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.

Paleo Project Challenge 2010: The Final Reckoning

Okay, folks. . .you've had three months and plenty of reminders and warnings. With that, the 2010 Paleo Project Challenge has drawn to a close. It's time to put down your pencils and hand in your tests.

What's that, you say?

You're not quite finished?

Well, here's your chance to bask in the abject humiliation of not finishing a project by the agreed upon deadline (don't worry, I'm feeling the warm glow, too). Or, if you're Dave Hone (my partner in founding and publicizing the PPC) and many of the rest of you, you can bask in the glory of advancing science. Or at the very least, not doing it any major harm.

I purposefully set my sights quite high for this one. Just like last year, I hit one square on (in fact, the reviews just came back!), and the other is going to need some work. My New Year's Resolution: don't let it be hanging around this time next year.

Below, I've given an updated list for the PPC. Those folks who are finished are marked in a congratulatory blue. The rest. . .are so close! If you completed your entry for the PPC (or didn't), drop a line in the comments, so I can mark it here! I'll be updating this entry for the next seven days.

Participants in the Paleo Project Challenge
Andy the Micropaleontologist - submit foram macroevolution paper; write draft of clade shape paper
Anonymous - find job; paper for Paleobiology; prep alligator fossil
Brian Beatty - paper on meningeal ossification in cetaceans
Robert Boessenecker - finished first draft of master's thesis
Martin Brazeau - finish redescription Ptomacanthus anglicus and include updated matrix
Andrea Cau - describe new theropod remains from north Africa
John Conway - finish Heterodontosaurus painting
DeinonychusDinosaur - restoration of Dryptosaurus [finished]
Andy Farke - finish paper for ODP [started!]; finish paper on ceratopsian anatomy [finished!]
Nick Gardner - submitted grant for Youngina part II
Casey Holliday - either a new croc species description or paper related to frontoparietal fossae [sent to coauthors]

Dave Hone - the necks paper [finished]
Jason - finish descriptions for Katian graptolite systematic paper.
David Maas - Illustrating Mallison's Kentrosaurus [so close!]
Heinrich Mallison - finish Plateosaurus CAE paper; sauropod rearing paper; sauropodomorph rapid locomotion paper
Jay - finished sauropod description
Jordan Mallon - Anchiceratops manuscript
Anthony Maltese - sharks scavenging on mosasaur paper; Niobrara ammonite paper

Eric Morschauser - finished theropod description
Paleochick - Cloverly paleobotany paper
Patty Ralrick - wrote paper on subfossil mass mortality site
Julie Reizner - submit Einiosaurus histology paper
Manabu Sakamoto - finish Pachyrhinosaurus drawing; finish and submit theropod bite force paper
John Scanlon - write up Oligocene lizards from Riversleigh; process and sort samples from Miocene microsite
Leo Sham - illustrate Raptorex; write cosmetic surgery review paper
Mark Spencer - finish paper critiquing model-based approaches to phylogeny reconstruction
Brian Switek - finished book proposal; polish and submit paper on Alabamornis; paper on Thoracosaurus specimen
David Tana - sign up for GRE; submit 9 pieces to Art Evolved time capsules; overhaul blog
Darren Tanke - finished biography of Oscar Erdman; finished paper on first helicopter lift of a dinosaur specimen; finished extended abstract on Hope Johnson
Mike Taylor - finally finish the Archbishop sauropod description
Matt van Rooijen - finish up Tarbosaurus bite pattern illustrations
Bruce Woolatt - 1/10 scale Quetzalcoatlus northropi flesh restoration

Citation Format Wars

Over at SV-POW!, Mike Taylor recently addressed the issue of how to format in-text citations. Writing in his inimitable style, he makes the case that PLoS ONE is simply doing it all wrong; the majority of commenters there have agreed. I posted a lengthy comment there, but realized that it would be appropriate to revise and republish those thoughts here too.

First off, let's have a quick recap of the issue. When writing a scientific paper (or any paper, for that matter), it is essential to credit the sources of information and ideas. Not only does it allow the reader to learn more about the topic, it's the ethical thing to do. Rather than a simple reference listing at the end of the paper, most scholarly works also reference the relevant works within the text. This is called an in-text citation, and allows the reader to know precisely which information was associated with which author.

Two Worlds
Two styles of in-text citation dominate the scientific literature. The first of these is author-year, which looks something like this: (Farke, 2010). The second is numbered, which looks like this: [1]. This number then refers to a specific bibliographic entry at the end of the paper. Many variants of each style exist.

PLoS ONE uses numbered citations, in common with many other high profile journals (such as Nature), and in marked contrast to most of the paleontological, geological, and anatomical literature (such as Journal of Vertebrate Paleontology, The Anatomical Record, Geology, and others). The SV-PoW! post, of course, argues that the numbered format is vastly inferior to the author-year format. Let's boil the argument down to its essentials, and delve into the pros and cons of both formats in more detail.

Two essential reasons are given for why the author-date format are preferable: 1) ease of reading for authors familiar with the literature; 2) paleontologists don't like it. PLoS ONE thus chose a numbered reference format simply because they wanted to copy the glamour magazines. Do any of these arguments hold up?

Advantages of Author-Year (and disadvantages of Numbered)
Of course, there are some significant advantages to the author-year format. These include:

1. It's easy for readers who are familiar with the literature to know exactly what's being discussed. If I quote from my 2010 JVP paper on ceratopsian sinuses, "Less detailed descriptions have been published for other chasmosaurine and some centrosaurine ceratopsids (e.g., Gilmore, 1917; Lehman, 1990; Sampson, 1995; Sampson et al., 1997)," a long-time ceratopsian worker will know right off the top of her or his head that I'm talking about the Gilmore Brachyceratops monograph, Tom Lehman's paper in the Dinosaur Systematics volume, Scott Sampson's description of the Two Medicine centrosaurines in JVP, and the ZJLS paper with Scott, Michael, and Darren. I see pages from those papers when I close my eyes, and I could almost write the citation for each of them off the top of my head.
2. You don't have to flip back and forth between the main text and the reference list. For the ceratopsian expert described above, there's no need to waste time skipping around the paper (or PDF). It's just easier.
   
3. It helps readers new to the field to become familiar with the major names and papers. See the names "Wedel," "Taylor," "Wilson," "Curry-Rogers," and others often enough, and you probably have a good picture of a few of the major recent workers in sauropods.
   
4. It's easier for authors to keep their references straight. When writing and revising without use of a citation manager, the numbered system can get very unwieldy. If you add a reference in the middle of the paper, you not only have to renumber the entire bibliography after that reference, you also have to change the numbers within the manuscript itself. Miss one, and your readers are going to be grumpy when the number and citation don't match up.
5. It's familiar to the paleontological community. As mentioned above, "It's Got What Paleontologists Crave."
   

Disadvantages of Author-Year (and Advantages of Numbered References)
As you might have guessed, there are some disadvantages, too:

1. The author-year format is helpful only if you are already familiar with the relevant literature. Otherwise, you're still in the game of flipping back and forth to the reference section. Anticipating that most of my readers are savvy to vertebrate paleontology, but not to the latest in tectonics, contrast my above example in point 1 with this example (Najman et al., 1997, Geology 25:535-538): "Why is this so, as crustal thickening and metamorphism are thought to have occurred by this time (Frank et al., 1977; P. Zeitler in Hodges and Silverberg, 1988; Inger and Harris, 1992; Searle, 1996, and references therein; Vanny and Hodges, 1996)?" Although I understand the meaning of the sentence, the names and dates have absolutely no meaning to me, other than to help me find the appropriate citation in the back. I'm not familiar with that literature, so I'm annoyed by the extra text.
   
2. Not every reader wants to become an expert on a given subspecialty. Believe it or not, I may not be reading a plate on Indian tectonics (or sauropod vertebrae) because I want to become an expert on said subject. Let's say that I'm chasing the above-mentioned example from Najman because I want to know the context for some fossils I found in a format described in that paper. I just want the bare minimum of info, and I don't care about Frank, or Zeitler, or Hodges, or Silverberg, or Inger, or Harris, or Searle, or Vanny. Sure, maybe I'll chase some of those references for alternate opinions, but once that's done the names will probably never cross my mind again. This leads to the next point. . .
3. The author-year format clutters the text. I'm not the first person to state this, and I'm not the last. By editing my ceratopsian quote above, you now get: "Less detailed descriptions have been published for other chasmosaurine and some centrosaurine ceratopsids [1-4]." Try the same with the Najman quote. Much shorter and more easily readable. A comment on the SV-POW! post by Zen Faulkes gives some more nice supporting opinions.
4. Most of the rest of the scientific world uses numbered citations. I think people are giving Science and Nature a little too much credit for driving the numbered citation game. Yes, they certainly are the most visible journals to those of us in paleo/geo/zoological sciences, but that's a rather myopic view. I did a quick survey of the other 99 percent of the scientific literature, and numbered citations simply dominate. Even arXiv - the epitome of digital presentation with no real standard format - has a vast majority of papers with the [1,2,3] style (in fact, the only counterexamples I found were in a handful of biologically-oriented papers). The medical literature (medically oriented papers are the great majority of PLoS ONE submissions), computing literature, physics literature, etc., most often use numbered citations. Let's face it - paleontologists are not the biggest fish in the sea. It doesn't mean we're wrong or can't change things, just that it's a very uphill battle.

Closing Words
So, I have to say that the arguments for author-year and against numbered references are not as simple as one might hope. Major advantages and disadvantages characterize both formats. In the end, I suspect much of it comes down to "what we were born into." I like the author-year format because that's all I've ever known. My spouse, who is a physicist, surely thinks otherwise, but then again all she has ever known is the numbered format. She also thinks paleontologists are silly because we don't use LaTeX (and good luck getting that instituted, no matter how easy it would make things for us).

Interestingly, I came into this with a strong preference towards the author-year citation format, but after thinking about it I'm not sure that numbered citations are the Great Evil that they have been made out to be. What are your thoughts?

Update: The above-mentioned Zen Faulkes has a post strongly coming down on the side of numbered references. He argues that numbered references decrease overall manuscript length, greatly improve readability, and level the playing field for both readers and cited authors. The last argument is particularly novel, and strikes at the heart of the true purposes of citations. I'm not sure I totally agree, but it's definitely food for thought. [12 January 2011]

(As an interesting side-note, the author-year referencing style may be so common in the paleontological and zoological literature because of a historical accident - the format was apparently invented by a Harvard zoologist, and spread throughout the zoological part of the literature. I suspect the weight of the Harvard name didn't hurt.)

Disclaimer: Although I am a volunteer editor at PLoS ONE, this posting is written strictly as my private opinion.

Thank you to the many commenters at the SV-POW! blog, whose thoughts inspired this post.

Last Day of the Paleo Project Challenge!

As 2010 draws to a close, so does the 2010 Paleo Project Challenge (PPC). It sounds like some folks are doing well, others haven't made much progress, and others have made some. We'll have the final check-in next week!

Common Mistakes in Scientific Writing [or, A Pedant's Paradise]

In scientific writing, proper terminology is everything. I learned early on that many of my favorite turns of phrase were technically incorrect - and I have been working to improve my writing and editing ever since. Below, I've included some of my "favorite" stylistic oddities. . .hopefully this is useful for at least a few readers! This may be old hat for some of you - in that case, please post a comment with your own grammatical grumblings.

"Outcrops" as a verb

Despite rampant misuse, there is no verb form of "outcrop."

Incorrect: "The Barstow Formation outcrops in southern California."

Correct: "The Barstow Formation crops out in southern California."

"Monophyletic clade"

A clade is, by definition, monophyletic. So, save your space and only use one of the two words!

Incorrect: "Dinosauria is a monophyletic clade."

Correct 1: "Dinosauria is monophyletic."

Correct 2: "Dinosauria is a clade."

"Data is. . ."

The word "data" is plural; "datum" is the singular. You're bucking against popular culture, but think of how delightfully smug you can feel whenever you use the words correctly.

Incorrect: "The data is overwhelming."

Correct 1: "The data are overwhelming."

Correct 2: "The datum is overwhelming, which is odd because it's only a single measurement."

"e.g." and "i.e."

"E.g." is an abbreviation from the Latin "exempli gratia", basically translating as "for example." "I.e." is the abbreviated form of the Latin "id est", translating as "that is." The meaning for the former should be pretty clear; the latter is used when one wishes to provide further clarification of a point.

Incorrect 1: "Many dinosaurs are found in the Hell Creek Formation (i.e., Triceratops and Tyrannosaurus)."

Correct 1: "Many dinosaurs are found in the Hell Creek Formation (e.g., Triceratops and Tyrannosaurus).

Incorrect 2: "Bird skeletons are pneumatized; e.g., they are filled with air sacs."

Correct 2: "Bird skeletons are pneumatized; i.e., they are filled with air sacs."

Lower/Upper vs. Early/Late

Unless you have had a solid introduction to geology (and even then, it's easy to forget), most people probably don't know that there is a major nitpicky difference between Upper Cretaceous and Late Cretaceous. The Upper/Lower designation refers to lithostratigraphic divisions of rocks; they are not the same as the geochronologic ages of the rocks. In other words - Upper Cretaceous refers to a physical lump of sedimentary rocks; Late Cretaceous refers to the age of these rocks. Whenever I try to figure out which word to use, I concentrate on whether I'm talking about time (Early/Late) or position in the rock column (Lower/Upper).

Incorrect 1: These Early Cretaceous rocks are full of fossils.

Correct 1: These Lower Cretaceous rocks are full of fossils.

Incorrect 2: Tyrannosaurus is Upper Cretaceous in age.

Correct 2: Tyrannosaurus is Late Cretaceous in age.

Want some more? The style guide for Journal of Vertebrate Paleontology (available in PDF format) has lots more great hints and tips!

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

The Curse of the Nonexistent Dinosaurs

You all probably remember Darwinius, that little extinct primate that caused such a huge fuss last year (the image at left is from the original paper). In addition to the massive hyperbole surrounding the specimen (much of which has now been tempered by additional analyses from other researchers), an early issue concerned the validity of the name Darwinius itself.

Scientific names for new animals, living or extinct, are governed by a set of rules from the International Commission on Zoological Nomenclature (ICZN). This body - which has no real authority, other than that granted it by us scientists - is by its nature a rather conservative entity. This isn't necessarily a bad thing, particularly because stability in our naming system is so critically important. When I say Kosmoceratops richardsoni, everyone else should know I'm talking about. But, this conservatism also means that the ICZN has been very, very slow to react to electronic publishing. Right now, names published in electronic-only form are not valid! A paper version, even if it is otherwise identical to the electronic version, must be created (although the ICZN is working to change this).

So back to Darwinius. . .when the name was initially published, it was only in electronic form, and thus not "real" in the eyes of the ICZN. Vigilant eyes noted this, and the problem was rapidly broadcast in the blogosphere. Some wags suggested naming Darwinius out from under the authors, but thankfully cooler heads prevailed. PLoS ONE, the journal in which Darwinius was published, was able to produce a paper copy of the article in order to satisfy the ICZN. It took a few days, but finally Darwinius was "real"!

Thankfully, PLoS ONE learned its lesson. Their publication policies (full disclosure: I am an editor there) have been revised to accommodate the needs of the ICZN, and all is happy now. Or is it?

It turns out that other journals haven't necessarily learned this tough lesson. Time and again, scientific names invalid in the eyes of the ICZN are being published by some pretty major journals. This "zombie nomenclature" walks among us, even today. Here are just two examples.

Raptorex (image by Nobu Tamura)

On September 17, 2009, Science posted a preprint of a paper naming a new small tyrannosaur, Raptorex kriegsteini. As near as I can tell, this name existed only in electronic form at the time, and thus was not yet valid in the eyes of the ICZN. Raptorex was very well publicized (and rightfully so - it's a neat specimen), yet no paper edition appeared until October 16, 2009 - a month later. For four weeks, the name Raptorex was in taxonomic limbo.

Koreaceratops (image by Nobu Tamura)

This early horned dinosaur is hot off the digital presses. As you can probably guess, it hails from South Korea, and the authors hypothesize that it may have been aquatic. Koreaceratops appeared on November 17, 2010, as an online preprint at Naturwissenschaften, and some media attention started popping up earlier this week. Yet. . .the name is not yet valid in the eyes of the ICZN! Until Koreaceratops appears on the printed pages of that journal, the name has no real weight. Hopefully this will get resolved soon!

Cryptovenator (image by Charles R. Knight)

Dinosaurs (and Darwinius) aren't the only organisms afflicted by digital naming issues. On September 16, 2010, the genus Cryptovenator appeared on the website for Acta Palaeontologica Polonica, as a new kind of early synapsid (closely related to the fin-backed Dimetrodon, depicted at right). It hasn't yet appeared in print - so remains "undead" according to the ICZN.

Some Thoughts

The rise of online pre-prints is a Good Thing. It speeds the flow of scientific information in a way that just wasn't possible before. Yet, it also creates a bit of a headache for authors. The window of time between pre-printing and real-printing is a dangerous place for a new scientific name. Although the threat is slight, there is nothing to stop someone from accidentally or intentionally "scooping" the rightful authors. As near as I can tell, the proposed ICZN rules won't do anything to fix the situation, either.

So, what solutions are there?

1. Don't publish pre-prints of papers with nomenclatural acts. This is the simplest solution in some ways, but also produces the undesirable effect of slowing down scientific communication. Canadian Journal of Earth Sciences has adopted this strategy (hat-tip to Hans-Dieter Sues for the reminder on this one).
2. Petition the ICZN to give priority to the first appearance of the name in the first widely disseminated pre-print of a paper. This would be a nightmare on multiple levels - an addendum to the Code could take years, and how would one decide which version of a paper containing a name is the authoritative one?
3. Continue to publish pre-prints, assume that all is going to be well, and worry about it when something bad happens (taxonomic scooping, perhaps?). Highly undesirable, but basically the course of action that we're on now.
4. Expunge the names from the paper in its pre-print form (suggested by Martin Brazeau at another venue). This does solve the problem, but it requires someone to go through the paper and remove all mentions of the taxon. Despite all of the talk from commercial publishers about "value added", I suspect it's either the unpaid editorial volunteers or unpaid authors who would get stuck doing this. Removing names is not so tough in the text, but figures (such as phylogenies) would be a bear. Also, we're left with multiple versions of the same paper floating around.

What thoughts do you have on the matter? Is it really an issue? Or am I making a mountain out of a molehill? Speak up in the comments section!

Disclaimer: Mention of the "invalid" names above is not, not, not an invitation for paleontological wannabes, ethical miscreants, or rabblerousers to wreak havoc on paleontological nomenclature. Although I hesitate to draw attention to particular instances, I feel that without some concrete examples, my arguments would be less effective. Furthermore, the names are already out there in some very widely read venues! Leave the names for the authors; the situation is not their fault.

Update December 31 2010: Bill Parker over at Chinleana has a great post relevant to this issue.