Friday, November 26, 2010

Youngina, Undergrad Research, and Nick Gardner

Last week, the online, open access journal Palaeontologia Electronica published a new issue, with a fantastic spectrum of papers. Much discussion has ensued on the blogosphere. For one, PE is unusual among paleontological journals in having its own blog (would that other major paleo journals follow suit!). A series of posts has detailed many of the articles in the current issue. Furthermore, Mike Taylor over at SV-POW! blogged about figures and the online journal, with a focus on PE. Not to be left off the bandwagon, here's my own contribution to the blogstorm.

Among other fantastic papers in the latest PE, Nick Gardner, Casey Holliday, and Robin O'Keefe have published their description of the braincase of Youngina. Youngina is an early diapsid (the group including crocodiles, dinosaurs, birds, lizards, snakes, and probably turtles), which was very lizard-like in appearance during life (its skull is pictured at left, modified after Gardner et al. 2010). It lived in South Africa during the Permian, and has been a key animal for understanding the early evolution of diapsids. Despite some excellent fossil material, the braincase of Youngina has never been completely described. This could provide important information for figuring out more precisely how Youngina is related to other early diapsids. Thus, Gardner and colleagues turned to CT scanning to see all of the details hidden behind the rock in a specimen of Youngina housed at the American Museum of Natural History.

Others (including Nick, Casey, and the PE blog) have blogged about some major aspects of the new paper. So, I wanted to focus on a different angle altogether: undergraduate research. Nick is a senior at Marshall University and has been active in research nearly from the beginning. The fact that he already has a first-authored publication (and a second-authored one) is going to serve him very well in applications to graduate school (and beyond!). Given Nick's successes so far, I thought I would ask him about his thoughts on undergrad research (along with some other OSP-relevant parts of the project).

It's pretty unusual for an undergrad to have lead authorship on a major project like this. How did you get started working on this paper?
I've always wanted to participate in doing research since I was younger. Casey [Holliday] gave me my first opportunities, assisting him in his lab working on lizard and croc head anatomy. Somewhere midway along that, Robin [O'Keefe] brought up redescribing Youngina, and I sort of just fell into it. The braincase project was mostly something I worked on during last summer after I got an institutional research fellowship for undergrads.

I see that you used the Amira software package in order to generate the reconstructions of Youngina's anatomy. Were there any particular challenges to working with this program, or the particular dataset?
I went with Amira because that's what I was trained on. There were some issues in getting the data to load properly at first, so I ended up having to get help from Witmer Lab to fix some issues with the individual slice files. The other big issue was the data was flipped along the sagittal plane, so that had to be corrected before I could do any real work on it. But that was a pretty easy fix for Ryan [Ridgeley; research associate at Witmer Lab]. The big issue was just loading it up on a computer where the data could be managed. It's a really big data set.

What, if anything, was the most fun part of the project?
The most fun for me was in segmenting. It was pretty amazing to sit and work on virtually digging out something that no one had ever seen before. Every day was more exciting, to see new bits of it come together. The braincase is mostly hidden by matrix in the holotype, and no one had ever seen what an articulated and almost entirely complete braincase of Youngina looked like.

What advice would you give to other undergraduate students who want to get involved with research at an early stage?
Find out what's available to you at your university, talk to professors who do research, and just get involved. Be careful, though, while doing research. Something I struggle with is maintaining balance between grades, work and research. It's best if you can get into a situation where you're paid for helping out as a research assistant. But when you're trying to juggle all three, that's where it gets tough.

Thanks, Nick! And to all of the OSP readers, don't forget to check out his wonderfully-titled blog, "why I hate theropods."


Gardner, N.M., Holliday, C.M. , and O’Keefe, F.R. 2010. The braincase of Youngina capensis (Reptilia, Dipsida): new insights from high-resolution CT scanning of the holotype. Palaeontologia Electronica Vol. 13, Issue 3; 19A:16p. [link]

Monday, November 22, 2010

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!

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

Big Pterosaurs Really Did Fly: Interview with Mark Witton Part II

ResearchBlogging.orgA new paper in PLoS ONE, by Mark Witton and Mike Habib, re-evaluates claims that big pterosaurs were too big to fly. To make a long story short, multiple lines of evidence suggest that giants like Quetzalcoatlus really did take wing! One of my previous blog posts summarized the paper and featured the first part of an interview with senior author Mark Witton. That part of the interview focused on many of the scientific aspects of the research. Today, we'll highlight some of the other highlights. I think you'll find it illuminating!

This paper has received a fair bit of press coverage. Is there anything about the research that you wish had received more attention?
Our coverage was really good: as mentioned above, we ended up in the most unlikely of places along with getting pieces in much more familiar territory. In that respect, I can’t complain but, at the same time, the press really focused on the quadrupedal launch idea [illustrated at right, with a Pteranodon launching itself in this fashion; figure from Witton and Habib 2010] which, while still quite novel to most, was actually first proposed (in print) by Mike back in 2008. There was a fair amount of press coverage for the idea back then, too. Prior to that, though, both Mike [Habib] and Jim Cunningham, who developed the same idea independently of Mike, had given the idea considerable airing on the Dinosaur Mailing List. Bottom line: this latest paper really isn’t the first to comment on it in any capacity. We talked about it a lot, but we’re definitely not its origin. Still, the press really ran with it, despite the fact that the main thrust of our paper is that pterosaurs and birds are generally incomparable beyond very basic aspects of their flight mechanics, and that previous assumptions that they were had lead to probably incorrect assumptions about their way of life. Their disparate launch mechanisms are a particularly important part of our considerations, but they are only one part of many. It’s no big deal, really, but I’m a little concerned that some people will now associate quad launching with this paper and I really don’t want to steal the thunder away from Mike and Jim: they did the real work on it. I’m sure People in the Know will realise the score, but I’ve already had e-mails about the presentation of the quad launch in our new paper like we proposed it. Tell the world, folks: quadrupedal launch came from Mike and Jim! They’re the real geniuses here!

With you in the UK and Mike in the US, the paper is a very international collaboration. What sort of challenges, if any, were particular to this sort of cross-border work?
Mike and I met up twice during the work on the project at different conferences, but, that aside, we worked entirely through e-mail. Trite as it sounds, the internet is amazing: a project like this would be so much harder and longwinded without it. Throwing drafts of the MS at each other, bouncing ideas around and working on the figures was no sweat at all. We could have revisions done and sent back to each other as fast as we could turn them around. In that respect it was as efficient as working with someone in the same department, if not slightly more so, as meandering chats and tangential fieldwork anecdotes – always a risk of visiting the office of any academic – were largely kept out of our online conversations (we made up for it at conferences, though). The long duration spent putting the paper together, mentioned above, was mainly thanks to my workload with the pterosaur models, not anything to do with working internationally. The paper spent a long time sitting on my desk as my time for writing disappeared amidst a blur of fake fur, bluefoam and acrylic paints. So no, working internationally presented very few obstacles. I’m sure the story would be very different if we were working 20 years ago or so, but, today, you can work with whoever you want, wherever they are without a hitch. Well, assuming they check their in-box regularly, that is.

Thank you, Mark, for an informative interview!

Witton, M., & Habib, M. (2010). On the size and flight diversity of giant pterosaurs, the use of birds as pterosaur analogues and comments on pterosaur flightlessness. PLoS ONE, 5 (11) DOI: 10.1371/journal.pone.0013982

[full disclosure: I am an editor at PLoS ONE, the journal in which this paper appeared]

Thursday, November 18, 2010

Big Pterosaurs Really Did Fly: Interview with Mark Witton

ResearchBlogging.orgPterosaurs - winged denizens of the Mesozoic skies - get a bum rap. It's bad enough that their name is smeared by the general public, when animals like Pterodactylus are confused with dinosaurs in the news media and in just about every cheap set of plastic dinosaurs. Lately, some scientists have suggested that the largest of these animals just couldn't fly. Is it true that Quetzalcoatlus (pictured here; image from Wikimedia Commons), with its 10 meter wingspan, had wings that were too narrow, a body that was too portly, and bones that were too weak to support flight? Some of the most recent studies have certainly suggested this!

Yet, extraordinary claims require extraordinary evidence, or at least extraordinary scrutiny. Thus, a study by pterosaur experts Mark Witton and Mike Habib takes a close look at the idea of super-lame flightless giant pterosaurs. Using new body mass estimates, revised reconstructions of the wing dimensions, bone strength calculations, and many other lines of evidence, Mark and Mike argue that even the biggest Quetzalcoatlus could fly after all.

This paper, published in PLoS ONE [full disclosure: I am an editor for this journal], has been featured all over the mainstream news media and blogosphere. For a slightly different take on the matter, I decided to go straight to the source. Mark Witton (pictured below; thanks to Mark for the picture, copyright him) was kind enough to answer a few questions about the study - not just on its methods, results, and conclusions, but also on some of the behind-the-scenes doings that led up to this work.

I've split this interview into two parts. For starters, we'll talk about the genesis of the paper, and some of its major findings.

How did this study come about? Did any particular event spur you and Mike [Habib] into working on this issue of flight in giant pterosaurs?
I reckon a paper like ours has been a long time coming, really. There’s been a lot of talk in recent years that pterosaurs may not be what Greg Paul termed ‘ultralight airbeings’, and numerous blogs and internet forums have responded with comments what this may mean for their flight dynamics. It was only a matter of time before the flight of realistically massed pterosaurs was considered in the technical literature (well, beyond saying they couldn’t fly). We were kicked into action, though, when press reports of an abstract presented by Katsufumi Sato et al. were released in April 2009, saying giant pterosaurs couldn’t fly. Keen members of the palaeoblogsphere may remember this ruffled a fair few feathers when it was released, and their paper (Sato et al. 2009) followed shortly to similarly raised-eyebrows. Most folks even vaguely familiar with large pterosaurs were astonished to see them cap flight at such a low size: 41 kg and 5 m wingspans are very middling in the spectrum of pterosaur size (10.5 m spans and 250 kg body masses are considered maximum in our paper). Because plenty of clearly-flight adapted forms got much larger than this, I got to work on a response. Mike and I have fairly regular correspondence and were talking about the project soon after I started, and it wasn’t long before we realised that working together would make the project much stronger.

Plus, I had giant pterosaurs on the brain at that time. I’d just started work on a massive modelling project where I had to build several models of the largest pterosaurs going. The logistics and costs of building a 13 m span pterosaur against a 10 m span animal is quite something, so I figured a little checking of the wingspans of these poorly known animals wasn’t the worst way to spend an afternoon as it would avoid having to find a bigger workshop. The timing of this was spot on for the project with Mike, too, as it meant we could ensure the size estimates for our flight analysis were as accurate as we could make them. These two events combined to form the beginnings of the paper and reminds me that we started it well over a year ago: where did that time go?

What was the most surprising finding to you, and why?
The most surprising? Hard to put my finger on one thing exactly: we covered quite a lot of topics, and each had their own intriguing little revelations. I mean, the 13 m span estimates of Arambourgiania, the giant pterosaur from Jordan, always seemed a little iffy to me because they were based on a single neck vertebra, but not Hatzegopteryx. Being based on forearm material, I figured the 12 m span estimate for this critter was a sound bet but, no, the material just seems distorted to appear bigger than it actually is. The numbers generated in the flight analysis for the speed of flying giant pterosaurs were impressive, too. The thought of a giraffe-sized pterosaur pumping its wings to scream overhead at 75 mph is staggering: this is real ‘if I had a time machine…’ stuff.

That said, for all these little surprises, the biggest ones came from the paper’s release and press coverage: I was really blown away to see just how much interest we had. To be honest, we did want to make a splash because, following the Sato et al. abstract, the internet is awash with articles saying giant pterosaurs couldn’t fly. We wanted to balance it out a little (this is also, incidentally, why we chose PLoS ONE as our venue: we want interested people of all backgrounds to be able to see our rationale for flighted giants: open access is definitely the way forward, folks). However, I was truly taken aback when our work was quoted directly alongside some half-naked chick in the British tabloids newspaper, The Sun. How often do science stories penetrate that far into the press, let alone those dealing with relatively unimportant extinct flying reptiles? I can only assume that pterosaurs are becoming more exciting and cool with every new discovery, or it was a slow news day. Either way, I’ve not stopped telling people about that since.

Next Time. . .the ins and outs of trans-Atlantic collaborations, and what the media should have mentioned.

Sato, K., Sakamoto, K., Watanuki, Y., Takahashi, A., Katsumata, N., Bost, C., & Weimerskirch, H. 2009. Scaling of soaring seabirds and implications for flight abilities of giant pterosaurs. PLoS ONE, 4 (4), DOI: 10.1371/journal.pone.0005400.
Witton, M., & Habib, M. (2010). On the size and flight diversity of giant pterosaurs, the use of birds as pterosaur analogues and comments on pterosaur flightlessness PLoS ONE, 5 (11) DOI: 10.1371/journal.pone.0013982

Wednesday, November 17, 2010

Ancient Beavers in PLoS ONE: Interview with Josh Samuels

ResearchBlogging.orgAn earlier post here detailed a study just published in PLoS ONE, which focused on unraveling the relationship of an extinct Chinese beaver, Sinocastor, to its modern cousins in the genus Castor. Using a combination of morphometrics (shape analysis) and good old fashioned description, a team led by paleontologist Natalia Rybczinski concluded that Sinocastor is indeed quite distinct from today's Castor.

Yesterday I caught up with one of the co-authors of the study, Josh Samuels. Josh is an expert on fossil rodents (especially beavers) and morphometrics, working as a paleontologist at John Day Fossil Beds National Monument. He was kind enough to answer a few questions about his part in the project.

You have quite a track record of working with beavers and other rodents. How did you get interested in this group in the first place?
Ever since I was a kid, I have been interested in understanding how extinct species lived. In college I became interested in studying the evolution of mammals, particularly their dietary and locomotor specializations. I learned that rodents are the most species rich group of mammals and have amazingly diverse ecologies, with everything from semi-aquatic carnivores to gliding herbivores and blind burrowers. Despite their diversity, the evolution of rodents has not been as well studied as some other groups. Beavers, in particular, are known for their dramatic impact on ecosystems and have an excellent fossil record. Given their importance today, I find working to understand their evolution to be quite fascinating.

The PLoS ONE paper certainly was a collaborative effort - what role did you play in the research?
Some of my past research used geometric morphometrics to examine how skull shape in rodents relates to their ecology. Natalia approached me about the possibility of using similar techniques to examine how Sinocastor was related to living and extinct beavers. I helped design the methods and ran most of the analyses, and writing the paper was definitely a group effort. Having a group of collaborators with different skills really helped the project come together smoothly.

Was there anything particularly surprising to you about the results?
Given the broad geographic range of Eurasian and North American beavers today, I was surprised to find subtle, yet consistent differences in shape among species. One of the specimens in our analysis was from a peat bog in England, but its skull shape was almost identical to individuals from China and Russia. This really gives me hope that these techniques could be used an effective way to look at the phylogenetic relationships of extinct species.

Thanks, Josh!

Rybczynski, N., Ross, E., Samuels, J., & Korth, W. (2010). Re-evaluation of Sinocastor (Rodentia: Castoridae) with implications on the origin of modern beavers. PLoS ONE, 5 (11) DOI: 10.1371/journal.pone.0013990

Full disclosure: I am an editor at PLoS ONE
Image credits: National Park Service website

Tuesday, November 16, 2010

Re-Evaluating Ancient Beavers

ResearchBlogging.orgBeavers are some of the most distinctive (and largest) rodents around today. Two species of the extant beaver, Castor, are found throughout the northern hemisphere, and these animals have an enormous effect on their landscapes. Beavers are perhaps most famous for their dam-building activities, altering the flow of streams and generating valuable wetlands used by other animals. Surely, the impact of this group extends far back in geological time.

Many early beavers were fossorial, or burrowing, with little indication of aquatic tendencies. For instance, the 25 million year old Palaeocastor produced giant spiraled burrows known as "devil's corkscrews." Perhaps the acme of beaver evolution occurred during the Miocene (~23 to 5 million years ago). At least 12 genera lived worldwide; only one of these, Castor, survived to the present day. An obvious question for paleontologists thus concerns the when and where of modern beavers' origins.

Enter Sinocastor. This genus was named in 1934 by famed Chinese paleontologist C.C. Young, for several species recovered in China and Mongolia from rocks deposited during the last 5 or 6 million years. Almost immediately, other authors lumped Sinocastor into Castor, and there Sinocastor has stayed for the most part. Was this a valid opinion, or did such lumping obscure a more interesting paleontological pattern?

Fortunately, the exquisitely-preserved type (first described) specimen for Sinocastor anderssoni was recently restudied by a team of paleontologists from Canada and the United States. Led by Natalia Rybczynski of the Canadian Museum of Nature, the paper describing their findings appeared this week in the open access journal PLoS ONE.

The authors of the new paper used geometric morphometrics, a type of shape analysis, to see just how similar the skull of Sinocastor (at right) was to modern and recently extinct Castor. For additional comparison, the early European beaver Steneofiber castorinus was also thrown into the mix. Points on the various skulls were digitized from photographs and run through computer programs that calculated the similarity between the specimens.

In the end, the skull of Sinocastor fell well outside the anatomical range for modern and even most extinct beavers. Rather substantial shape differences distinguish Sinocastor from Castor; for instance, the snout is shorter and the braincase broader in Sinocastor. Although genera are always somewhat subjective, Rybczynski and colleagues argue that the major differences between Sinocastor and the species of Castor warrants the retention of Sinocastor as its own genus.

Based on several other lines of evidence (including tooth anatomy), it is suggested that Sinocastor may be the sister taxon (closest relative) to modern beavers. In concert with dated fossils, this means that the common ancestor of these two kinds of beaver may have originated in eastern Asia and then spread westward into Europe and eastward into North America. The arrival of modern beavers on that landscape must have had massive ecological consequences - only more investigation of the fossil record will tell!

Stayed tuned: Tomorrow, an interview with Josh Samuels, one of the paper's authors!

Rybczynski, N., Ross, E., Samuels, J., & Korth, W. (2010). Re-evaluation of Sinocastor (Rodentia: Castoridae) with implications on the origin of modern beavers PLoS ONE, 5 (11) DOI: 10.1371/journal.pone.0013990

Full disclosure: I am an academic editor at PLoS ONE, the journal at which the paper described here was published.
Image credits: Image at top from Wikimedia Commons (by Steve); fossil skull modified from Figure 14 in Rybczynski et al., 2010.

Friday, November 12, 2010

Paleo Project Challenge Check-In

It's been nearly two months since Dave Hone and I initiated the 2010 Paleo Project Challenge. Turn-out has been fantastic, from all echelons of the paleo world - artists, researchers, preparators, casual fans, combinations of these. . .exactly who we wanted!

What is the Paleo Project Challenge, you may ask? All of us have some project that we started, nearly finished, and then forgot about. It's probably sitting on your hard drive, or a shelf somewhere, or in a sketch pad. The only thing that's stopping us from finishing it is the threat of public humiliation.

So, PPCers - you have committed to finish your project by January 1, 2011. You've signed on the dotted line (or submitted a comment). You're held accountable. If you don't finish it, you shall suffer crushing embarrassment on The Interwebz. In a show of solidarity, I have myself put forth two contributions! These, along with everyone else's, are listed below.

With that, it's time for a status check. In the comments below, tell us a little about what you've been up to! If you have a blog, we certainly encourage you to blog the process - just make sure to tell us about it, so we can link back to you! [Dave Hone has posted his impressive update already!]

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
- finish 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
- restoration of Dryptosaurus
Andy Farke
- finish paper for ODP; finish paper on ceratopsian anatomy
Nick Gardner
- paper piggybacked with one of Casey's
Casey Holliday
- either a new croc species description or paper related to frontoparietal fossae
Dave Hone
- the necks paper
- finish descriptions for Katian graptolite systematic paper.
David Maas
- Illustrating Mallison's Kentrosaurus
Heinrich Mallison -
finish Plateosaurus CAE paper; sauropod rearing paper; sauropodomorph rapid locomotion paper
Jay - finish sauropod description
Jordan Mallon - Anchiceratops manuscript
Anthony Maltese - sharks scavenging on mosasaur paper; Niobrara ammonite paper
Paleochick - Cloverly paleobotany paper
Patty Ralrick - 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 - finish 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 - finish biography of Oscar Erdman; finish paper on first helicopter lift of a dinosaur specimen; finish 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

Haven't signed up yet? It's not too late!

Thursday, November 11, 2010

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.
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.

Saturday, November 6, 2010

A Flood of Paleo Articles in PLoS ONE

It has been pretty incredible to see the rise of PLoS ONE as a major outlet for articles on paleontology, and it has been equally incredible to ride along as an editor for that journal. The past few months have seen many scientifically important and interesting papers wend their way into publication. I haven't had a lot of time for blogging lately, but wanted to take this opportunity to highlight the latest paleo-themed research in PLoS ONE. The following list is in reverse chronological order (newest to oldest), covering work published in the last three months.
Slater GJ, Figueirido B, Louis L, Yang P, Van Valkenburgh B (2010) Biomechanical Consequences of Rapid Evolution in the Polar Bear Lineage. PLoS ONE 5(11): e13870. doi:10.1371/journal.pone.0013870
The authors present and interpret finite element modeling results for polar bears and brown bears, showing that the skulls of polar bears are generally weaker than those of their close cousins. Furthermore, these differences probably accumulated rather rapidly.

Xu X, Wang K, Zhao X, Sullivan C, Chen S (2010) A New Leptoceratopsid (Ornithischia: Ceratopsia) from the Upper Cretaceous of Shandong, China and Its Implications for Neoceratopsian Evolution. PLoS ONE 5(11): e13835. doi:10.1371/journal.pone.0013835
Zhuchengceratops inexpectus is introduced; this small horned dinosaur is actually among the largest of its kind, the "leptoceratopsids." Interestingly, it showed up in a big bonebed in eastern China, along with truly giant horned dinosaurs and duck-billed dinosaurs.

Longrich NR, Horner JR, Erickson GM, Currie PJ (2010) Cannibalism in Tyrannosaurus rex. PLoS ONE 5(10): e13419. doi:10.1371/journal.pone.0013419
Bones of Tyrannosaurus with T. rex tooth marks are described; the implications are pretty self-evident (see the title of the paper, if you're still trying to figure this out). This paper received considerable media attention; Brian Switek has one nice write-up at Dinosaur Tracking.

Cisneros JC, Gomes Cabral U, de Beer F, Damiani R, Costa Fortier D (2010) Spondarthritis in the Triassic. PLoS ONE 5(10): e13425. doi:10.1371/journal.pone.0013425
Summary: Suffering from what is described as the earliest known example of arthritis, an early archosaur had a pretty rough time with some fused vertebrae. Diagnoses of disease in fossil organisms can be pretty controversial; I shall be interested to see how this particular case study plays out.

Smith ND (2010) Phylogenetic Analysis of Pelecaniformes (Aves) Based on Osteological Data: Implications for Waterbird Phylogeny and Fossil Calibration Studies. PLoS ONE 5(10): e13354. doi:10.1371/journal.pone.0013354
Summary: Here, the relationships of pelecaniform birds (including pelicans, cormorants, boobies, and more) is addressed in great detail. The group is not found to be monophyletic, and the unstable nature of the position of several key taxa means that ornithologists will be talking about this question for some time.

Han J, Kubota S, Uchida H-o, Stanley GD Jr, Yao X, et al. (2010) Tiny Sea Anemone from the Lower Cambrian of China. PLoS ONE 5(10): e13276. doi:10.1371/journal.pone.0013276
Summary: What the title says. The authors suggest that their new animal, called Eolympia pediculata, is a stem member of the group including corals and sea anemones. The image at right shows the authors' reconstruction of Eolympia.

Peterson JE, Lenczewski ME, Scherer RP (2010) Influence of Microbial Biofilms on the Preservation of Primary Soft Tissue in Fossil and Extant Archosaurs. PLoS ONE 5(10): e13334. doi:10.1371/journal.pone.0013334
Summary: This article presents experimental support for the idea that microbial biofilms form a protective layer that allows preservation of deeper soft tissue structures in dinosaur bones and other fossils-to-be. Read more about the research here. Interestingly, the article by Peterson et al. disagrees with an earlier paper published in PLoS ONE (written by Kaye et al.), stating that any alleged soft tissue preserved in fossils is a microbial film alone. Thus, the bacterial biofilms exist - but they're not the only biogenic structure in these bones!

Holliday CM, Ridgely RC, Sedlmayr JC, Witmer LM (2010) Cartilaginous Epiphyses in Extant Archosaurs and Their Implications for Reconstructing Limb Function in Dinosaurs. PLoS ONE 5(9): e13120. doi:10.1371/journal.pone.0013120
Summary: Things aren't as they appear; the big dinosaur bones that we see in museums today were probably much longer in life, supplemented by giant cartilaginous caps. Lead author Casey Holliday presents more information here, and Mike Taylor at SV-POW also has stuff to say about the topic.

Oxnard C, Obendorf PJ, Kefford BJ (2010) Post-Cranial Skeletons of Hypothyroid Cretins Show a Similar Anatomical Mosaic as Homo floresiensis. PLoS ONE 5(9): e13018. doi:10.1371/journal.pone.0013018
Summary: Yet another round in the discussion about the "hobbits" of Flores, Indonesia. I get the sense that Oxnard et al. are very much in the minority opinion, but I also get the sense that this debate is going to drag on for awhile more.

Rando JC, Alcover JA, Illera JC (2010) Disentangling Ancient Interactions: A New Extinct Passerine Provides Insights on Character Displacement among Extinct and Extant Island Finches. PLoS ONE 5(9): e12956. doi:10.1371/journal.pone.0012956
Summary: A recently extinct finch, Carduelis aurelioi, is named and compared with its fellow prehistoric finches (some of which are still alive today). Evidence is presented to suggest that the effects of ancient competition between the species still reverberate today. The image at left shows a life restoration of the new species, as imagined by A. Bonner.

O'Rourke CT, Hall MI, Pitlik T, Fernández-Juricic E (2010) Hawk Eyes I: Diurnal Raptors Differ in Visual Fields and Degree of Eye Movement. PLoS ONE 5(9): e12802. doi:10.1371/journal.pone.0012802
Summary: It's not strictly paleontology, but the methods here present actual experimental validation of the true visual fields for extant birds of prey. It would be interesting to compare the visual fields as calculated from the osteology alone with the experimental results - and then see what this means for similar calculations performed for extinct dinosaurs.

Sampson SD, Loewen MA, Farke AA, Roberts EM, Forster CA, et al. (2010) New Horned Dinosaurs from Utah Provide Evidence for Intracontinental Dinosaur Endemism. PLoS ONE 5(9): e12292. doi:10.1371/journal.pone.0012292
Summary: Utahceratops gettyi and Kosmoceratops richardsoni, two new horned dinosaurs, are named, and their implications for Late Cretaceous biogeography in North America are discussed. This paper, on which I was a co-author, received a substantial amount of media attention. See my blog post on the subject as a starting point for more information.

Kraatz BP, Meng J, Weksler M, Li C (2010) Evolutionary Patterns in the Dentition of Duplicidentata (Mammalia) and a Novel Trend in the Molarization of Premolars. PLoS ONE 5(9): e12838. doi:10.1371/journal.pone.0012838
Summary: Here, the authors propose new ways to interpret the anatomy and evolution of rabbit teeth, based on some previously undescribed fossils.

Noto CR, Grossman A (2010) Broad-Scale Patterns of Late Jurassic Dinosaur Paleoecology. PLoS ONE 5(9): e12553. doi:10.1371/journal.pone.0012553
Summary: The Jurassic was an age of giants. The structure of some old, old ecosystems is reconstructed by classifying and comparing the ecomorphotypes of a number of dinosaurs from this time.

Degrange FJ, Tambussi CP, Moreno K, Witmer LM, Wroe S (2010) Mechanical Analysis of Feeding Behavior in the Extinct “Terror Bird” Andalgalornis steulleti (Gruiformes: Phorusrhacidae). PLoS ONE 5(8): e11856. doi:10.1371/journal.pone.0011856
Summary: Terror birds are pretty much what the name says - imagine something the size of "Big Bird" from Sesame Street, preying on Mr. Snuffleupagus. This article, which also received broad media coverage (see the Witmer Lab blog as a starting point), finds that the skulls of these big birds were quite strong in the up-and-down direction, but not so strong from side-to-side.

Lindgren J, Caldwell MW, Konishi T, Chiappe LM (2010) Convergent Evolution in Aquatic Tetrapods: Insights from an Exceptional Fossil Mosasaur. PLoS ONE 5(8): e11998. doi:10.1371/journal.pone.0011998
Summary: A spectacularly-preserved ancient sea reptile shows skin impressions, bronchial tubes, possible skin coloration, and even potential traces of some internal organs. Feathered dinosaurs may get all of the attention, but the specimen described here rivals them in "wow" factor!
Some parting thoughts:
  • In my (biased) opinion, most of these papers are presenting some pretty solid science (or at the very least, stimulating science). Now that PLoS ONE has an impact factor (and thus presumably more people interested in submitting to the journal), I hope that the quality of the submitted work is maintained.
  • There is a pretty major skew towards papers on vertebrates - 15 out of 16 (94 percent) of those mentioned above primarily concern things with backbones . Six out of the 16 papers mentioned above (38 percent) are about non-avian dinosaurs. Let's get some more variety, folks!
  • Some interesting work on functional morphology and other aspects of evolutionary biology (only a handful of which are sampled above) has been appearing lately. I strongly recommend subscribing to content alerts (start the process here) or regularly browsing the journal's website, in order to keep up on the latest and greatest work that might be relevant to you.
  • I look forward to more stimulating papers appearing in the near future. And if you haven't submitted something to PLoS ONE yet, please consider doing so!
Full disclosure: I am a section editor at PLoS ONE.