All Your Boss Are Belong to Us

If you ask me (you did, didn’t you?), it’s well past the time for a new blog post. Additionally, it’s been far too long since I wrote about my favorite group of dinosaurs: the ceratopsids. This is supposed to be a paleontology-focused blog, after all. You may recall previous series on horns
‘n’ spikes (Part 1, Part 2, Part 3, Part 4), my back-and-forth with Tracy Ford (Part 1, Part 2), and my love-it-or-hate-it critique of the “Toroceratops” hypothesis (Part 1 and Part 2) (I think I’m off Denver Fowler’s Christmas card list). Let’s do something different this time: let’s just talk about the animals. So consider this post to be the beginning of series of posts about my favorite ceratopsids, period. We’ll start with my second-favorite: Pachyrhinosaurus.

The partial, holotype skull of Pachyrhinosaurus canadensis was discovered in 1946 and named four years later by the great Charles Sternberg. He dug up a big ol’ skull that was missing the frill and rostral, and some other bits of skull from different individuals, in Alberta’s Scabby Butte formation. So different was this “thick-nosed lizard” than its horned colleagues (seeing as it lacked a horn) that Sternberg erected a new subfamily, the Pachyrhinosaurinae, to be held to the same taxonomic level as the Centrosaurinae and the Ceratopsinae (Chasmosaurinae). His life restoration, shown below, looks something like a Protoceratops with a drink coaster on its nose. More material was discovered at the nearby Little Bow River Formation, and Wann Langston, Jr. unearthed a second good skull Pachyrhinosaurus from Scabby Butte in 1955.

Langston continued working on the genus through the 1970’s, and determined that it was a member of the well-established Centrosaurinae, or short-frilled ceratopsids. Though to this day, no complete frills exist for the species, the 1955 skull does preserve some proximal aspects of the frill, and an associated bit of the parietal’s outer rim. During the 1970’s, somebody (anybody out there know?) suggested that the characteristic, though bizarre, nasal boss that defined Pachyrhinosaurus actually represented the base of a massive, broken-off nasal horn. The idea actually gained some traction, and in fact a DinoRiders toy of a particularly well-endowed Pachyrhinosaurus was produced and released to an unsuspecting public. However, the hypothesis was quickly overridden by the unfortunate fact that no Pachyrhinosaurus skulls had anything taller than a big, molar-shaped boss (and besides, the recently-described Rubeosaurus ovatus fulfilled the “giant nasal horn” dream quite nicely).

The morphology of the boss became especially clear in 1972, when Alberta school teacher Al Lakusta stumbled across a massive Pachyrhinosaurus bonebed in that province’s Pipestone Creek Formation. Dozens, if not hundreds, of individuals died there most likely due to an unfortunate river crossing. Plenty of skull material and postcranial remains gave paleontologists previously unthinkable clarity into the morphology and, importantly, ontogeny of this hornless horned dinosaur. Decades of work were put into the bonebed and, in 2008, Currie, Langston, Jr., and Tanke published the results: a new species of Pachyrhinosaurus called P. lakustai, named after the bonebed’s discoverer.

Apart from their temporal separation, P. lakustai is distinct from P. canadensis in a number of ways. The shape and structure of the nasal boss, and that boss’ relationship to the postorbital bosses, differs considerably. While P. canadensis has a molar-shaped boss that rises more or less vertically from its base, P. lakustai has a more rounded boss that tips in back and rises up from before ending in a “spout” (in some individuals) that overhangs the rostral comb. The nasal boss is clearly separated from the postorbital bosses, even in old individuals, whereas in P. canadensis, the three bosses come together late in life. As in most horned dinosaurs, however, the most telling differences are in the frill. Aside from the significant differences in P3 morphology, P. lakustai differs from P. canadensis in having a large “unicorn horn” growing from the parietal bar. This does not occur in all individuals and could be a sign of age or sex.

The growth of Pachyrhinosaurus is also bizarre. Juveniles start life with a narrow, though proportionately large, nasal horn, and small postorbital horns. As they grow, the postorbital horns are reabsorbed and the nasal horn’s base elongates (back-to-front). It assumes a pyramidal shape; then the weird stuff starts. In every other ceratopsid with a nasal horn, the horn grows more or less vertically. In Pachyrhinosaurus, that pyramidal horn grows laterally, its base becoming wider and its upper surface becoming rugose and honeycombed. With age, the boss’ structure changes further—in some individuals, it becomes concave as bone continues to be reabsorbed and remodeled. While the overall form of the parietal’s outer rim remained consistent in each example of that bone, a surprising amount of individual variation is present.

While the authors state that almost every bone in the skeleton is represented, they do not provide a description of the post-crania (I can only assume that’s being saved for a later publication). I assume it’s similar to other related centrosaurines for whom relatively complete post-crania are known (Centrosaurus comes to mind). Of course, that old generalization may not be valid—-among the chasmosaurines, Anchiceratops has very different proportions from big bruisers like Triceratops.

Wonderful illustration of our new Alaskan species by Karen Carr.

As it turns out, Pachyrhinosaurus is not restricted to Alberta. No, sir, this ceratopsid lived all the way up on the North Slope of Alaska. A nice, but obliquely crushed, skull was discovered up there and provisionally described for Fiorillo in 2010’s big ceratopsid volume published by Indiana University Press. There’s actually a lot more unprepared material, just sitting in field jackets, and I can’t wait for that stuff to be described. Anyway, after extensive preparation, the holotype skull was written up and awaits publication in Acta Palaeontologica Polonica (where you can read the in-press draft). The authors of that paper have given this species a distinct name: Pachyrhinosaurus perotorum. It is the northern-most ceratopsid in the world, and also the youngest occurrence of the genus.

It differs from its more southerly cousins in not too many ways. In fact, it looks kind of like P. lakustai, but, again, it's the structure of the parietal that makes this guy different. The two P3 spikes are there, but this species expresses P1 spikes that grow down and overhang the parietal fenestrae, similar to the situation in Centrosaurus apertus and Centrosaurus brinkmani. This big guy would have lived in some cold temperatures in the winter--it probably got down below freezing for a few months a year, and believe it or not, the North Slope of Alaska was further north than it is today back in the Late Cretaceous, so that means even longer periods of darkness.

Exactly how Pachyrhinosaurus and its neighboring frozen north dinosaurs survived in these extreme conditions is unknown, but it certainly speaks to their hardy nature. Living alongside our boy here was a large form of Troodon formosus, good old Dromaeosaurus, Edmontosaurus, and one or possibly two tyrannosaurs--one of which was Albertasaurus.

UPDATE: I actually wrote this post a week ago, but only now found the motivation to post it. I may actually add to it later, including references. So look for that!

New Yard of Bones

It's the first Boneyard of 2011, kids. Let's make it a GOOD one. I'm honored to once again host this most esteemed paleoblog carnival, which has been taken up by everyone's favorite chasmosaurine lover, David Orr. In fact, let's start things off over at his humble blog: Our man has an interview with the originator of the Boneyard, published author, and dear colleague, Brian Switek! Dave also has a particular fascination (as do I) with old or interesting dinosaur art: Check it out and thank him later. Perhaps best of all, though, Dave's recently been featured as a guest blogger on Scientific American's website. The topic? How to name a dinosaur.

Albertonykus, of the Raptormaniacs blog, has put together an entertaining series of comics called A Christmas Caudipteryx. Makes me wish I was still drawing comics...keep it up, man! You've got the skillz.

Tony Martin, of The Great Cretaceous Walk blog brings us the answer to a question not many of us ask ourselves, but is probably important in the long run: Why Dinosaurs Matter. It's a great post, and it's good to get an ichnologist's point of view.

Remember Traumador the Tyrannosaur? Looks like he's taking a new direction for the new year. Oh, don't change, Traumador! We love you as you are! For more on the changes, check out Craig Dylke's blog for more information.


The big news this week has been Titanoceratops, a still unpublished "new" ceratopsid that might actually be Pentaceratops. Lots of people have been covering this, including myself, Dave, and Brian. Andrew Farke has voiced some concerns over this rather of electronically-named dinosaurs, a concern Bill Parker shares.

Have you been watching, over on Archosaur Musings, as Tyrrell's Darren Tanke takes us through the preparation of a Gorgosaurus skull and skeleton? It's fascinating stuff, and it goes quicker than I thought. Dave has also been making a good habit of posting excellent photos of pterosaur fossils. Among my favorites: Scaphognathus and Pterodactylus.


Over at Superceras, David Tana discusses the recent description of the incredible strange but cool Simosuchus and weighs in on the irritations surrounding the buzzterm "living fossil." I'm shocked this little croc isn't getting more blogosphere coverage. You're all aware of it, right? It's like nothing you've ever seen, seriously.

Over at History of Geology, David Bressan (too many Davids in this Boneyard) discusses the ichnofacies of the Bletterbach section. Like me, you may be wondering what the eff the "Bletterbach" section is. Well, I learned by clicking that link. I highly recommend you do, as well!

Head over to the relatively new home of Laelaps to get the skinny on giant goddamn storks and my favorite marsupial carnivore, Thylacosmilus. In a similar vein to the stork story, Ed Yong introduces us to Xenicibis, a bird that could have knocked you out...with its club-shaped hand.


Darren Naish regails us with tales of recent stegosaur controversies in an epic two-part post. More to come, I'm sure. At least...I hope! Stegosaurs don't get nearly enough coverage in the blogosphere or in the literature. Like David, Darren also got some time on the Scientific American blog, touting the virtues of Iguanadon taxonomy. Check out the three part series here, here, and here. Really great stuff! On a related note (sort of), if you've ever wanted to see the holotype of "Ultrosauros," your dreams can now come true thanks to SV-POW!

Head over to the Dinosaur Toy Blog to ogle with delight at Favorite Co. desktop model of Triceratops--I must have it! They also review a Bullyland version of one my favorite sauropods, Spinophorosaurus. Too bad it's such a horrible sculpt!

Good ol' Trauamador has some celebrity encounters to share from this last year: personal hero of mine Phil Currie, Dinosaur Train conductor Scott Sampson, the always amazing William Stout and Brian Cooley, and finally comic creator Ryan North.

On the Art Evolved side of things, look for the new Elephants gallery coming soon. Craig's got a preview up at his website, and the always reliable Peter Bond is showing off his work, too. Did you know I'M a member of Art Evolved too? I know, I was just as surprised as you are. I can't help but feel bad that I don't contribute more. Ah, life, you always manage to get in the damn way.

That's it for now. I'll have my own post up tomorrow. It's late and I'm beat. Thanks to everyone who submitted, and thanks to David Orr for helping me out with this edition. Happy reading, everyone!

First "New" Ceratopsid of 2011

The journal Cretaceous Research published an "accepted manuscript" by Nick Longrich in which he suggests that the McLargeHuge Pentaceratops specimen shown above (OMNH 10165) actually belongs to a separate genus, Titanoceratops, and that said genus is the earliest reprentative of the Triceratopsini, an end-Cretaceous group of giant chasmosaurine ceratopsids comprised of Eotriceratops and "Toroceratops."* Among other issues, Bill Parker has voiced his concern over the practice of journals posting unpublished manuscripts on their websites, a sentiment I share.

I'm going to hold off on my critique until Titanoceratops is actually published, but I'm a little iffy about the lines of evidence brought up in the manuscript. I had a few of the same problems with Mojoceratops, but I certainly wouldn't mind if the Austin Powers dinosaur remained viable, if only for it's awesome name. One positive is that the original skull of OMNH 10165 is lacking most of the frill--the reconstruction above is largely extrapolated. So, you know...there's that.

Godspeed, Titanoceratops. It looks like 2011 may be shaping up to be another good year for horned dinosaurs, valid or otherwise.

*Still waiting to see how this turns out. So sue me.

Gain +15 to Knowledge

My dear friend Ann Pache donated her stack of old JVP's to me today because she's cleaning house and doesn't really use them anymore. This will allow me to throw out a TON of printed PDF's that I've accumulated over the years, thus freeing up space in my filing cabinet, but I also like having these kinds of things in book form. So...exciting!

Say Hello to the New Guys

The Year of Ceratopsians continues with two new additions to the Chasmosaurinae: Utahceratops gettyi and Kosmoceratops richardsoni. I will give you two guesses as to where the former was discovered. Here's one hint: It's in the name. There was absolutely nothing about this animal that warranted a better, more imaginative moniker. Meanwhile, Kosmoceratops is heavily airbrushed, full of fashion advice, and knows the top ten ways to make your bull go wild in the bedroom. Another surprise is that Chasmosaurus irvinensis is renamed Vagaceratops irvinensis, as it turns out to be closer to Kosmoceratops than Chasmosaurus.

But seriously, this is fantastically exciting. The paper was published in PLoS One and is thus freely available for all. Check out the paper by clicking this lengthy link, but don't be surprised if you can't see the pictures or download the paper as a PDF. It would seem that PLoS One went on hiatus the second this paper was announced, thus going from "awesome free-access journal" to "cocktease."

But don't cry about it--go to The Internets, where people have been blogging about these new dinosaurs all morning. Do you want to know more? Click these links to do just that!

Archosaur Musings
The Open Source Paleontologist
Dinosaur Tracking
Dinochick Blogs

Don't get too excited: they're probably all just ontogenetic stages of each other.

I Have Nooooo Idea

Have you ever sat down to write something, and it just turned into something completely different? This is one of those times.

The Story of Thalassocnus

One dreadfully hot Thursday, back in the Miocene, a ground sloth stared out into the endless blue ocean and thought to himself “Blorf,” which means (roughly translated):

“It looks so nice out there…peaceful. It’s so dreadfully hot. And that’s clearly where all this yummy seaweed is coming from, so maybe I should go out there and find my own plants without all this crappy sand.”

So the ground sloth took a swim one day. He swam out as far as he could go. His heavy hair made the journey exhausting, but the sloth was cool and happy. The long swim made him hungry, so the sloth dove underwater and tried to look around but he found that the salt water stung his eyes…He grubbed around on the rocky bottom, more through feeling than seeing, and tried nipping at various things. Fish swam away, coral didn’t taste good, and the plants were also full of sand! Then, in an instant, the sloth was eaten by a shark. Bit right in half, in fact. Fish and invertebrates spent the next few days scavenging his corpse.

The sloth’s remains washed up on that same beach the following Tuesday. His friends didn’t discover the rotting half-carcass until Friday, as they had traveled to the beach to look for seashells and skip stones. Though saddened and alarmed, none of the sloths in the community were particularly surprised that the sloth was dead, mostly because they hadn’t seen him in awhile, but also because the sloth had been spouting weird nonsense like “yornk yornk hazoo,” which means (roughly translated):

“The end is nigh! Repent sinners!”

None of the other sloths knew want “sinners” meant. They’d figured it was just a phase. Still, the entire sloth community was puzzled by their strange friend’s remains. They all assumed that some predator—possibly one of those irritating cats—had attacked and killed the sloth and then either covered his remains with seashells and coral OR thrown him headlong into the ocean after dealing the deathblow in an effort to hide the carcass from another predator, or possibly an owl.

Most of the sloths accepted one or both theories, but a group of three sloths decided to search out more evidence. The elder sloths warned against swimming out into the oceans, and they raised several good points: Sloths didn’t know how to swim; you never know what’s hidden under the waves; and seriously, have you ever even crossed a river? But the elder sloths were old and senile. Why, just last week, two of them wandered off in to an ice cream shop that had closed down like twenty years ago and their families had to drop everything and wandered around looking for them for like two days. Goddamn elder sloths. So anyway, several sloths swam out to sea, convinced that their dead friend’s remains were somewhere out there and would tell them not only the method of death, but also the identity of the cat that killed him.

Three of the sloths were also eaten by sharks, but one made it back alive. He didn’t have as much hair as his compatriots, and so was not as weighed down. As remains of the other three washed up, more investigations were held (sloths are very particular), and this hilarious, though tragic, scenario repeated for several months. On the upside, it was a very good year for sharks. Eventually, the only sloths that were left were the freaks that could at least swim to and from the crime scene. Their investigations concluded that sharks were the culprits in almost all cases, save for the cat who doubtlessly murdered the original sloth before trying to hide the remains below a blanket of crustaceans, seaweed, and bits of coral. The twelve remaining sloths were all deformed in different ways: one was hairless, a few just had very short hair, one had webbed feet and hands, and one was unusually skilled with a harpoon which had fashioned, ironically, from the bones of the original washed-up sloth.

These weirdo sloths, free of oppression from the “normals” of their society, formed a new government based around living in and around the sea, a place where their deformations were celebrated instead of looked down upon. The sloths decreed that the only allowable land-based activities involved sleeping, shagging, and playing charades, which the sloths found difficult underwater. Within just a few years, the sloths had procreated and their children were also happily frolicking in the waves. Their children had an even easier time navigating the sea than their parents did, since so many of the unfortunate deformities had begun adding up in individual children. One of the young sloths was especially adept underwater: he was hairless, had webbed feet and hands, and had developed an unusually long snout which he used to grub around in crevices for food. Not even his mother could look at him straight, but the founding sloths knew that in just a few generations, their entire race may very well look something like that hideous freak. One group of young sloths invented water polo while others began building impressive structures with volcanic rocks and seaweed. Near-shore environments were preferred, as the sloths were quick to notice that anybody who ventured into the darker waters beyond the continental shelf were usually eaten by sharks (or, as sloth legend has it, semi-aquatic cats).

In time, the sloths began basing their society around the sport of water polo. They fashioned balls out of coconut shells and built surprisingly sturdy nets out of seaweed and vines the jungle. As sloth society grew, so too did the number of teams who competed in regional water polo matches. Unfortunately, sloths were pretty unimaginative, and team names tended to blur together: “The Fightin’ Sloths,” “Seasloths,” and “The Fightin’ Seasloths” were all legitimate teams. Adding home-base monikers did little to help. “The Fightin’ Sloths” soon became the “Big Piece of Rock Out by the Pink Coral Reef Fightin’ Sloths.” Not surprisingly, early experiments with announcers and color commentators failed spectacularly.

As the millennia passed, sloth scientists began predicting that ocean levels would drop significantly as the planet became cooler. They suggested that water would actually freeze and that, because of this “freezing” effect, the amount of available liquid water in the oceans would drop, and thus the oceans would recede, and sloth society would be in terrible danger. If the water levels dropped below the continental shelf, the sloths would either have to figure out how to protect themselves against the now largely-mythical sharks or return to life on land. The majority of sloths didn’t find either alternative appetizing, and chose instead to argue about illegal pinniped immigrants and whether or not their sloth king was actually born on the beach. It is generally believed that this useless bellyaching proved the downfall of the marine sloth, which scientists now know as Thalassocnus.

The Summer in Review

Well, a shitty summer that has been indistinguishable from autumn has finally given way to that actual season. September brings with it rain, dropping temperatures, ever-shorter days, and raking. Oh, the cursed raking. And it really was a terrible summer for the town of Anchorage: we broke a state record for most rainy days in a row (29), and days that weren’t filled with water were overcast. There were four or five really gorgeous summer days, of course, but overall it wasn’t a fantastic season. I did get through a good deal of my gaming backlog, which is always nice. I also stupidly added to it: Bayonetta was on sale and I can’t for the life of me put down Dragon Quest IX. I was slaughtered by the final boss yesterday, so it’s back to grinding for gear, alchemy ingredients, and experience. I might even change vocations, although that would mean more tedious grinding. Just last night, I realized that a single-player expansion for Bioshock 2 was released on PSN, which I now have to buy and play, because I love Bioshock. Have you seen the Bioshock Infinite trailer? Holy frigging crap.

One highlight of the last few weeks has been receiving an early review copy of Metroid: Other M and playing it to total completion, Hard mode and all. I gave the game a 7.0 at Nintendo World Report. It’s not a bad game, it just suffers from control and story issues, and it’s incredibly linear. The post-game content is great, but Hard mode is disappointing in that there is no reward for what’s essentially a lot of work. I also collected all of the Star Coins in Worlds 1-8 of New Super Mario Bros. Wii, then basically gave up on three of the World 9 stages because they’re honestly just not fun, requiring a level of precision that I’m simply not willing to put myself through. In July, my brother-in-law Justin and me played the ever-living crap out of PixelJunk Shooter, an excellent PSN game and completed it to 100%. I’m only missing one freaking trophy, which I’m still trying to nab.

I’ve also started doing Figure Reviews for two reasons. First, figure-collecting is a hobby of mine, and this blog reflects my hobbies. Second, when I’m getting ready to buy a figure, I like to look online for reviews. Sometimes reviews are surprisingly scarce, so I figured (HA!) there’s no harm in contributing. I’ve posted quite a few now, and I have more to cover. After I get done with my girls, I’ll probably start with my other figures, like my NECA TMNT figures.

On the paleo front, this blog’s been pretty quiet on the whole. My biggest “contribution” has been a series of posts about Toroceratops, which has received mixed reviews (check out the comments of those posts). I also did a good post about the semi-aquatic Psittacosaurus theory from Tracy Ford & Larry Martin. I tried to make it semi-serious, and Tracy was a good sport and responded…which I then responded to. Scott and Raven and I also attempted a monthly paleo-themed podcast called “Dino-Rama,” which fell apart almost immediately. In point of fact, we recorded a July episode in June. It’s September, and that podcast still hasn’t been posted. This isn’t really anybody’s fault: Scott is the audio editor but he’s always very busy, and I know nothing about audio editing and don’t especially want to learn how to do it. I do a gaming podcast, though, as you may have heard: the NWR Newscast, a biweekly, Nintendo-centric podcast about news, reviews, and off-track ranting. I’m also sometimes on Radio Trivia Podcast and rarely on Radio Free Nintendo. Actually, you’ll hear my nasally vocals on the upcoming episode of RFN, so stay tuned for that. Dino-Rama may continue in the future, but it will require a major overhaul and probably a fourth co-host who can also edit the audio.

In the coming months, you’ll probably see more irregularly-scheduled Figure Reviews and gaming news, maybe some more book reviews and paleo news coverage. I’ve got several art projects in the slow-cooker, including ceratopsids, Xenopermian critters, NWR avatars, and DinoNoir. None of these projects are on any kind of schedule (when you’re not paid for shit, there’s no incentive to get it done!) but I’ll post progress when I make it.

I’ll also post some updated contact information. A lot of people still use my Hotmail address, but I’m trying to move away from Hotmail for a variety of reasons. My standard email is now sillysaur (at) gmail (dot) com. You can also contact me on Facebook, and if you want to do some online PS3 gamin’ with me, my PSN Handle is Sillysaur.

Also, I’d like to point out that The Boneyard is back! Originally started by Brian Switek a few years ago as a monthly or bi-monthly collection of paleo-related posts, the project fell into disuse for over a year. David Orr, of Love in the Time of Chasmosaurs, has valiantly taken up the mantle. The first edition was just posted, so go check it out! David’s looking for volunteers for subsequent editions and, of course, more paleo posts to link to. All hail The Boneyard!

Excellent picture of Samus Aran by iwaisan, from Kotaku.

Symptom of a Larger Problem

This post is going to mention Toroceratops, but it's not actually about Toroceratops. I think the Toroceratops debate, and how it's going down in the paleo community, is a symptom of a larger problem in science generally: not waiting around. I'll use Toroceratops as an example: The paper describing the possibility that Triceratops and Toroceratops are synonymous just came out like two months ago, maybe less. What's more, this is the first time (AFAIK) that the idea has been broached in a scientific paper for all to see.

This idea is in its infancy. But what boggles my mind is that many people, including those working in the field and fans standing by the sidelines, have actually made up their minds about it. And many of these people may have access to additional information, specimens, or people that can give them a more accurate read on the situation. But the rest of us can't. In a case like this, the primarily literature itself must make the case. Word of mouth is not enough. I'm happy to see that SVP 2010 will feature a surprising number of talks regarding Toroceratops because the idea will be further explored. This needs to happen--it's how science works. I've spoken with more than a few people who have told me that Toroceratops is most likely correct based on things they've seen, specimens they've worked on, or people they've talked to. I've heard the opposite from other people. That's all heresay. It's not public record until it appears in a scientific publication.

I can't assess that information. All I can assess is what's been published. That's all anyone can assess. Inside information is inside baseball, and it's not something we can all see.

An example of how science should work can be seen with Balaur bondoc. The paper was just published, and the authors suggest that this strange dromaeosaur was a bizarre predator that attacked its prey with four sickle claws and a nonfunctional hand. Well, Andrea Cau has written several posts on his blog, Theropoda, about the interesting idea that Balaur used all four toes to support a bulky belly like a therizinosaur. Nobody's coming firmly down on either side--this is an idea in its infancy, and all possibilities should be explored. Andrea has not been attacked for suggesting that the authors are incorrect or that there might be another explaination. Maybe somebody out there has a third specimen of Balaur that's more complete that can prove one or the other, but it hasn't been published yet, so it's not assessable. This is the opposite of what's happening with Toroceratops.

My own posts regarding Toroceratops were simply explorations into the idea that it might be incorrect. I did not appreciate the surprising inflexibility of a few posters (in both Toroceratops posts) with regards to the idea that other explainations were possible. And again, even if those people have access to more information, it doesn't matter: I can only discuss what I have access to--what's been published.

The bottom line is that nobody should be making up their minds about Toroceratops or Balaur at this stage in both games. Wait a while. More information will be forthcoming, I'm sure, for both animals. Only when considerable evidence has been built up and published should anybody make up their minds about it. In science, extraordinary claims require extraordinary evidence, and that evidence will come...we just have to be willing to wait for it.

P.S. Anyone else miss the Dino-Riders?

Long Overdue Book Review: Dogs: Their Fossil Relatives & Evolutionary History

Dogs: Their Fossil Relatives & Evolutionary History is an aptly-titled book from Columbia University Press about the evolution of Man's Best Friend by Xiaoming Wang & Richard Tedford, with illustrations by the incomparable Mauricio Anton. First, I'll say this: if you're a paleo-artist, you need this book just for the illustrations. You will be continually inspired by Anton's photorealistic work. Along with Carl Buell, Mauricio is the most talented prehistoric mammal artist working today. His lavish pencil drawings dot almost every page, and the plates in the center of the book feature his full-color paintings which are a sight to behold.

Aside from the art, Dogs doubles as a handy and very educational reference guide for many aspects of canine evolutionary biology. The authors examine every aspects of dogs, including dog-like carnivorans that are not dogs, like creodonts and borhyaenas. They discuss what makes a dog a dog, and what makes a dog a carnivoran. These are things I never knew. I was especially fascinated to learn that one of the key distinctions between the dog (Canidae), bear (Arctoidea) and cat (Aeluroidea) branches of the Carnivora is the structure of the auditory bulla--the dome-shaped bones at the base of the skull that cover and protect the inner ear. Another interesting factoid is that the common ancestor of cats and dogs probably had retractable claws!

The authors dive into the evolutionary history of dogs and include discussions on just about every genus and species that popped up since the Eocene. The first dogs were fox-sized animals that were actually pretty dog-like, but with long tails and relatively short limbs. However, they quickly diversified and many dogs developed bone-crunching jaws and robust bodies while others stayed lean. It's clear that canids experienced a fast and impressive radiation early in their evolutionary history. The most impressive fossil dogs are perhaps the borophagines--big, short-skulled, tough-jawed bone-crunchers. With domed foreheads and short jaws, these big canids bear some resemblance to small dog breeds today. A less-derived borophagine, Aelurodon, had proportions more suited to a cat or bear than a dog.

The only "mistake" I see is that Wang & Tedford constantly discuss a direct line of decent between any one species or genus and another, as if dog evolution has been essentially anagenetic throughout its history, but that can't be true. This is a common complaint I have with books discussing the evolutionary history of mammals generally, but it's very noticable here.

The authors then discuss, in impressive detail, how dogs work in comparison to other modern carnivores like bears, cats, and hyaenas. Differences in the teeth, the skulls, the senses, and the musculature of the head and neck are are gloriously discussed and illustrated, which gives great insight into how all of these different carnivores can operate in their own spheres without competition. Unfortunately, the authors don't really look at postcranial anatomy (that could probably be its own book).

Happily, the book does look generally at dog behavior and society. Sexual dimorphism, scavenging, and pack hunting are all discussed and compared to cats and hyaenas. It's a relatively brief look, but it's appreciated nonetheless. Better, perhaps, is the discussion on how canids filled their environmental niches throughout their evolution as the world changed. Canids didn't reach their peak of diversity until the late Oligocene, for example, an event which may have contributed to or benefitted from the decline of more archaic predators like hyaenodonts. Basal hesperocyonine dogs began to dwindle in number by the middle of the Miocene but were readily replaced by borophagines, which exploded in diversity and dominated until the late Miocene/early Pliocene, at which point the world was changing, and modern canines took their turn.

Interestingly, modern canids (including wolves) did not really diversify until the Pleistocene Ice Age. The largest (but exinct) modern canine, Canis dirus, was the top predator among Ice Age megafauna. Modern dogs may have rose to dominance because of their flexible diet. While most dogs are "strictly" carnivorous, none will turn down tasty vegetable matter (just ask my corgi) or, in one case (Cerdocyon), crabs. Wang & Tedford wrap things up with a lively discussion of the history and debate of dog domestication, noting that dogs were the first animals to be domesticated by humans. But were dogs domesticated by humans, or did they domesticate themselves? This final chapter doesn't necessarily answer that question, but it does offer intruiging insight.

Dogs: Their Fossil Relatives & Evolutionary History was originally published in hardback in 2008, but came out in paperback earlier this year. It's a fantastic read, and as I said, worth the price of admission purely for the incredible art. But hey, you might learn something too, and this book of course provides an excellent companion piece to The Big Cats. They're sitting next to each other on my shelf, though I wish I had a hardcover copy of that feline book...

Apologies to Meredith Howard for not doing this sooner!

Last Thing on Toroceratops

Okay, look, it's clear that I'm not the BEST guy to go to when it comes to this subject. I don't have the same access to primary literature that many of you do, I certainly haven't seen many actual specimens of Triceratops OR Torosaurus, my knowledge of stratigraphy is poor, and bone histeology is still very new to me.

I'm not trying to overturn anybody or make a serious case against Scannella and/or Horner. I'm not trying to bogart anybody's future or current research. I'm sorry if I've hit any nerves or didn't read the right papers...well enough.

That said, on morphological grounds alone, I think that known specimens of Torosaurus differ significantly from known specimens of Triceratops, either T. prorsus or T. horridus (although T. horridus looks a bit more like Torosaurus). Several things lack decent explaination. Among them:

Why don't any specimens of Torosaurs have "adult" nasal horn morphology of Triceratops? What other ceratopsid goes through such a radical late-stage morphological change?
How do we know that a solid frill is a juvenile trait, and not a derived trait?
Why aren't there any (AFAIK) Triceratops skulls with small fenestrae besides Nedoceratops, which itself is a contentious specimen?

I liked Haikaru's example in the comments for the 2nd Toroceratops post: if you found a humpback whale and a blue whale as fossils, you might assume that the latter is the adult of the former. Again, I'm not saying that Scannella and/or Horner are WRONG, I'm saying that their conclusion is not completely solid based on that paper alone. And you know what? Few papers are. Further research into post-cranial anatomy, histeology, stratigraphy, and morphology will doubtlessly illuminate this topic further, and I welcome that research.

I didn't mean to step on any toes or insult anybody. My posts were meant to suggest that further research was needed, and that alternatives to Toroceratops are possible.

And that's the last I'll say on the subject...at least until more data is published.

Torosaurus latus is not Triceratops sp.

Earlier this year, Scannella & Horner hypothesized that skulls attributed to the large chamosaurine Torosaurus latus represented a “fully adult” ontogenetic stage of Triceratops, thus invalidating Marsh’s pierced lizard as a distinct taxon. This theory was based in part on a growth series for Triceratops published by Horner & Goodwin in 2006. In neither paper do the authors consider Triceratops at the species level. Prior to 1996, as many as sixteen separate species of Triceratops had been considered valid, but in that year Catherine Forster published a revision of the genus which greatly reduced that number to just two: Triceratops horridus and Triceratops prorsus. Actually, in 1986, Ostrom & Wellnhofer went as far as suggesting that only Triceratops horridus is the only valid species. Neither Scannella & Horner nor Horner & Goodwin address the issue of species-level ontogenetic change in Triceratops. Is the Horner & Goodwin growth series for T. horridus or T. prorsus? Is Torosaurus latus the “fully adult” form of T. horridus, T. prorsus, or both? While not stated outright, the Horner & Goodwin growth series implies that features used by Forster to distinguish T. prorsus from T. horridus may simply be ontogenetic markers, including size and shape of epioccipitals, size and shape of the nasal horn, and curvature of the postorbital horns. Certain abstracts that I’ve read but don’t know if I can actually divulge have suggested stratigraphic or anagenetic reasons for the changes between Triceratops species.

In Scannella & Horner’s “Toroceratops” hypothesis, the authors suggest that, very late in life, Triceratops goes through radical morphological change: the length and shape of the frill increases, and the parietal becomes rapidly fenestrated as bone is reabsorbed on either side of the parietal bar. The authors point to a number of Triceratops skulls with extremely thin areas of the parietal where fenestrae would be expected to appear. However, none of the specimens investigated by the authors have even incipient parietal perforations (except Nedoceratops, but we’ll get into that in a minute). All investigated Triceratops skulls retain a solid frill. That is, the authors cannot point to any Triceratops skulls that would form a transition between the "no fenestrae" condition and the "big fenestrae" condition of Torosaurus. With the often-stated abundance of Triceratops material, I believe this is an important consideration.

According to the Horner & Goodwin growth series for Triceratops, specimen MOR 004 is regarded as an “adult” form. It has thick, forwardly-curved postorbital horns; elongate, highly reabsorbed epiparietals; a large, thick, forwardly-directed nasal horn; and a relatively short, deep rostrum below and anterior to the nasal horn. If MOR 004 is the model adult form of Triceratops, then no currently recognized specimen of Torosaurus latus conforms to the Horner & Goodwin growth series. All currently recognized specimens of Torosaurus latus (ANSP 15192, MOR 1122, YPM 1830, and YPM 1831) have short, upwardly-directed nasal horns with an elongate, shallow rostrum anterior to the nasal horn. Additionally, the snout has a distinctive “stepped-up” morphology wherein the dorsal margin of the rostrum anterior to the nasal horn is lower than the dorsal margin of the rostrum behind the nasal horn. This feature is similar to the “large juvenile” and “subadult” examples of Triceratops in Horner & Goodwin’s growth series. However, even those Triceratops specimens lack the elongate, shallow rostrum anterior to the nasal horn.

Diagonally from top to bottom, the proposed Horner & Goodwin growth series for Triceratops showing overall trends in morphology. To the lower left, Torosaurus latus.

The overall shape of the frill is quite distinct in both taxa. In MOR 004, the frill more or less frames the rest of the skull in anterior view: the parietal bar forms the apex of the frill, and the left and right halves of the frill slope down and out from there. This is especially obvious in two other specimens of Triceratops: YPM 1822 (Forster 1996) and YUM 1822 (Hatcher 1903). In lateral view, the frill attains a distinctive upward curve. Additionally, the squamosals of Triceratops are D-shaped, or perhaps axeblade-shaped. In many individuals, the squamosal-parietal suture is not visible for most of its posterior length. In contrast, Torosaurus’ frill is broad and largely flat, and does not frame the face in anterior view. Rather, it grows away from the rest of the skull and does not retain a distinct upward curve. Additionally, the squamosals in all recognized specimens of Torosaurus have a distinct shape reminiscent of a chef’s onion or paring knife, and the suture between the parietal and the squamosals is surprisingly clear along its entire length.



The largely complete frill of Torosaurus latus, after Hatcher 1903.

According to Scannella & Horner, the underlying geometry of the frill of MOR 004 would have been significantly altered—and quickly—to produce a frill attributable to Torosaurus latus. This sort of morphological change is wholly unknown in other ceratopsians where juveniles are known. In centrosaurines, for instance, the adult frill is, by and large, simply a larger version of the juvenile skull with the addition of unique spikes on the parietal margin or parietal bar (Pachyrhinosaurus lakusai and Centrosaurus apertus is particularly illustrative of this). In addition, the morphology of the snout and nasal horn would essentially reverse from the adult condition to a subadult form. These sorts of radical morphological changes have no basis in close relatives of “Toroceratops.”

Because all of the known specimens of Torosaurus latus share certain morphological features regardless of size or, presumably, age, we are forced to conclude that they are taxonomically valid characters that differentiate it from its closest relatives. For reference, its closest relatives have been consistently shown to be Triceratops and Nedoceratops. Whereas skulls attributed to Triceratops are far more numerous and individualized, those recognized as Torosaurus are much more uniform (ANSP 15192 does differ significantly in the length of the frill and size of the postorbital horns, but this may be an age-related character). While there is obviously a sampling bias at work here, it is instructive to list characters shared by the best-known specimens of Torosaurus latus—ANSP 15192, MOR 1122, YPM 1830, and YPM 1831:

1) Relatively small, upwardly-directed nasal horn that is triangular and develops about halfway up the snout. The horn never grows into the impressive forward-pointing thick horn you see in many Triceratops skulls.

2) An elongate, shallow rostrum anterior to the nasal horn. There is a clear height differentiation between this region and the dorsal margin of the skull behind the nasal horn in the adult stage. This may be termed a “stepped-up” condition.

3) An elongate nasal passage retained into the adult stage. In Torosaurus, the extent of the nasal system resembles the juvenile condition in Triceratops. In that taxon, however, the nasal passage compresses and rounds out as the subadult and adult stages are reached. Torosaurus, by contrast, retains an elongate nasal passage.

4) Blade-like squamosals which remain distinct from the parietal even in the adult stage.

5) An elongate frill that is “swept back” rather than “swept up,” is relatively flat and broad, and contains large parietal fenestrae. In adults, the margins of the frill may be almost completely smooth due to the absorption of the epioccipitals.

Before we go too much farther into Torosaurus, let’s turn our attention to Triceratops. In fact, let’s go back to Forster’s paper regarding species diversity in that genus. She references two individual specimens as models for the two species of Triceratops: YPM 1822 for T. prorsus and SDSM 2760 for T. horridus. I note that the latter displays several features in common with Torosaurus, including the structure of the snout and nasal horn (though not to the same extent), and possibly the structure of the squamosals. It also seems to lack distinct epioccipitals, and the frill is broader than its sister species, T. prorsus. That species, represented by YPM 1822, shows very different features: the nasal horn is large and directed forward, the rostrum in front of the nasal horn is short and deep, and the nasal area is rounded. The epoccipitals are fairly large and triangular.

Neither skull displays a singular suite of ontologic characters consistent with any one growth stage according to Horner & Goodwin. In SDSM 2760, the morphology of the snout and nasal horn are juvenile characters according to the suggested growth series, whereas the thickness and orientation of the brow horns, as well as the loss of epioccipitals, are indicative of adult status. By contrast, YPM 1822 shows a clearly adult snout and nasal horn, but the ends of the brow horns point a bit upwards (a subadult trait) and the frill retains distinct, fairly large epioccipitals (a juvenile or subadult trait). Are these isolated incidents? I’m afraid not. Just ask John Hatcher. In 1903, he included several beautiful illustrations of skulls attributed to Triceratops in his wonderful monograph on the horned dinosaurs. Exactly none of them conform to the Horner & Goodwin growth series to a "T." Going forward, where I reference "juvenile," "subadult," and "adult" features, I'm talking about those ontogenetic stages as defined in Horner & Goodwin 2006.




This is USNM 2100, identified by Hatcher as Triceratops prorsus(?). Although the anterior portion of the snout is missing, one may notice the underdeveloped nasal horn (juvenile-subadult), low-angled brow horns (adult) with sloped tips (subadult), and small but distinctive epioccipitals (subadult). The parietal bar is interesting in that it’s quite bumpy. Where would USNM 2100 fit on Horner & Goodwin’s growth series?




This is Triceratops brevicornus, ”YPM” 1834. It also shows a curious mix of characters: the nasal horn is distinct and forwardly-directed (adult), but the anterior portion of the snout is quite long (subadult). The brow horns are directed forward (adult) and are unusually short. The parietal-squamosal suture appears to be lost (adult), but the epoccipitals are reasonably distinct and not entirely rounded (subadult). Where would YPM 1834 fit on Horner & Goodwin’s growth series?




This is Triceratops elatus, USNM 1201. It also displays some curious features. The nasal horn’s growth seems to have stalled: the underlying nasal is indeed reaching forward (subadult), but the epinasal is still apparent (juvenile). The brow horns are large and directed forward (adult). The frill’s margins are bumpy—the epoccipitals have largely been absorbed (adult). Notice the distinct upward bend to the squamosals. While it gives the bones a superficially onion-knife appearance, the parietal curves distinctly upward rather than being directed back. Where would USNM 1201 fit on Horner & Goodwin’s growth curve?




Then there’s this famously odd duck: USNM 2412, Nedoceratops hatcheri. The nasal horn isn’t really a horn so much as a bump in the road, giving the snout a very pronounced “stepped-up” profile. The brow horns are quite large and directed almost straight upward. The frill is riddled with accessory fenestrae, some of which are probably the result of pathologic or natural re-absorption. The skull retains distinct epioccipitals, and the squamosal has a bizarre shape. Nedoceratops may be too much of a wildcard to include in this analysis, but Scannella & Horner consider it to be a transitional form that would exist between MOR 004 and Torosaurus latus. But what happened to the nasal and brow horns? Where did all these accessory fenestrae come from? Surely, Nedoceratops is either an incredibly abarrant individual or a distinct taxon, and will not be considered further here.




This is where things start getting interesting. This is Triceratops calicornis, USNM 4928, and it displays a lot of features that I listed for Torosaurus latus, above. In other words, its morphology conforms nicely to known morphologies that are consistent across currently-recognized specimens of Torosaurus. These include: a small, upwardly-directed nasal horn that is roughly halfway down the snout; a stepped-up snout profile with an elongate anterior portion; an elongate nasal passage; and squamosals that are onion-knife shaped. Most of the epoccipitals are completely re-absorbed. There is one distinct epoccipital capping the parietal-squamosal contact, and half of one above it. The parietal was not preserved in USNM 4928—it may have been fenestrated.



AMNH 5116 (top) compared to YPM 1830 (bottom). The overall similarities are striking.

Based on these proposed characters, I could make an argument that the most famous, well-known specimen of Triceratops in the world—AMNH 5116—is actually a Torosaurus. It has a short, upwardly-directed nasal horn, an elongate rostrum anterior to the nasal horn, an elongate nasal passage, onion-knife shaped squamosals, and a lack of epioccipitals. Like USNM 4928, it was also missing portions of its parietal, although major portions were apparently recovered and plastered back on. The beast was restored with a solid frill (maybe it had one), the assumption being that this is Triceratops. However, when you take the parietal out of the equation, AMNH 5116 is strikingly similar to Torosaurus skulls, particularly YPM 1830. Sorry about the lack of fenestrae in the illustration for YPM 1830—I just now noticed that they’re not there. *facepalm*
MNHN 1912.20, housed in Paris, is strikingly similar to USNM 4928, although its “Torosaurus” features are even more obvious: the snout has a more pronounced “step-up,” the nasal horn is small and retains the epinasal. The anterior portion of the snout is elongate, as is the nasal passage. The frill is elongate and broad. Epoccipitals are nearly absent, and the squamosals are onion-knife shaped. Like AMNH 5116, the frill of MNHN 1912.20 has been heavily restored, although exactly how much of the parietal was “touched up” is not specified in this skull’s description (Goussard, 2006). It may very well be that MNHN 1912.20 is a Torosaurus skull.



AMNH 5116 (top) compared to MNHN 1912.20. Again, note the many similarities.

Go back and look at the growth series picture at the top of the post. Diagonally from top to bottom, this is Horner & Goodwin’s proposal for ontogenetic change in Triceratops from small juvenile (MOR 1199) to adult (MOR 004). If Torosaurus latus were to follow MOR 004, the underlying geometry of the frill would have to change radically, the snout would significantly elongate, and the nasal horn would regress to an earlier developmental stage. Additionally, two giant holes would suddenly open up in the parietal! Scannella & Horner expect us to believe that all of these large-scale changes would happen in the dinosaur’s final years, and in stark contrast to the direction of growth that Triceratops had been experiencing up to that point. No other ceratopsian goes through this sort of late-stage transformation, and there is no reason to think that Triceratops is any different. Additionally, as pointed out by many readers, the rarity of “fully adult” individuals of Triceratops (Torosaurus) compared to the incredible abundance of earlier growth stages is a bizarre and unrealistic preservation bias that does not occur in other fossil animals. If anything, the opposite tends to be true: juvenile and subadults are rare while adults and “full adults” are more common. That is certainly the case in other ceratopsids, even among bonebeds. The bottom line is this: assuming the Horner & Goodwin growth series is generally accurate, YPM 1830 and MOR 1122 would NOT follow MOR 004. It really is that simple.

However, Torosaurus material might not be nearly as rare as everyone seems to think. I believe that the genus can be distinguished based on more than just the presence or absence of parietal fenestrae. It’s possible that specimens once referred to as Triceratops are, in fact, Torosaurus. If nothing else, I hope this post has convinced some of you out there in Readerland that the Scannella & Horner paper presents interesting ideas but serious flaws as well, and needs to be given a second look.

I offer an enormous, Pentaceratops-skull-sized thanks to Andrew Farke for taking the time to double-check my claims and correct others. Readers, notice that I don’t really talk about histeology or stratigraphy. This is largely because I am ill-informed to do so intelligently. I do think that Torosaurus is morphologically distinct from Triceratops based on skull anatomy alone, however, so those factors may not necessarily play a part. On the point of stratigraphy, however, I do wonder whether T. prorsus or T. horridus is older, and whether the similarities between the latter and Torosaurus may represent a close relationship. That is, perhaps T. horridus is closer to the common ancestor of Triceratops and Torosaurus, and that Triceratops prorsus is derived, anagenetically or otherwise, from T. horridus?

Breaking: Mosasaurs Are Awesome

This is Platecarpus tympaniticus, and yes, it has a caudal fluke. Confused? I recommend clicking this link for the answers to all your questions.

Tracy Responds

Hey, remember that critique I did on Ford & Martin's semi-aquatic Psittacosaurus paper awhile back? Seriously, just scroll down if you haven't seen it. Tracy was good enough to write a rebuttal, but it was too long to be in that post's comments, so I offered to post it as a separate post. I'm rather star-struck that he bothered to write a rebuttal at all, actually! Ah, people do read my humble blog! At any rate, here's how this is going down: Tracy basically wrote a response to me, point-by-point, referencing specific sections of my post. I'm going to reproduce that here, then add MY OWN commentary after each of his points in a different color. So, to be clear, his stuff is in black, mine is in...uh...red. So here we go! The next words you read will be from the pen of Tracy Ford.

First off I have to say that I am the principle writer, not Martin. If anyone has a problem understanding it, it rests on my shoulders, not Larry’s. I’m going to quote Ricky from I love Lucy: “Lucy, you have some ‘splaining to do.”

I won’t go into how the idea for the article came about, for that you can see the recent issue of Prehistoric Times. The editor/peer reviewer didn’t think it was relevant. In fact several things I wanted to put in the article he told me to take out (including some illustrations). I will be addressing Zach’s comments with a Z for Zach and a TLF for me.

Z) Ford, T. L. & Martin, L. D. (2010). A Semi-Aquatic Life Habit for Psittacosaurus.

TLF) Hey, somebody read the article!

Of course I did! It was lovely, really. Despite what I considered shortfalls, I did enjoy it.

Z) The fact that Larry Martin's name was attached to the paper instantly sent multiple red flags up in my mind. His moniker is the kind of warning label one usually associates with "Dougal Dixon" and "Alan Fedducia" (who, I'm told, can't even get ornithology right). Still, I tried to repress my angst and read on, determined to see this theory through. Larry can't get bird origins right to save his life, but maybe he's on the ball when it comes to ceratopsians. Maybe they'll make a slam-dunk case.

TLF) I like Larry. I’ve known him for a few decades now and he’s always been on the up and up with me and he’s the kind of person who will tell you how it is, and will correct anything that he’s said before.

I would hope so. He seems pretty dead-set on this whole BAND thing, but that's another post for another day. I should launch into a giant argument about rhetoric, inductive reasoning, and Aristotle's concept of ethos, but that's yet another post for another day (I am schooled in the art of rhetorical argument, after all).

Z) Readers, they do not.

TLF) Hopefully I can rectify that.

Avast, ye!

Z) The authors draw on six features of Psittacosaurus to make the case for a semi-aquatic lifestyle.

TLF) Yes, but Zach neglects to comment that even though we site 6 reasons, we aren’t the first to comment on an aquatic life style for Psittacosaurus, which is important. Rozhdestvensky (1955), Suslov, 1983, Currie (pers.com. 1997), and Averianov et al. (pers. com. 2006). This will become important as I continue to comment on his comments.

I should mention here that, when writing the original post, I did not cite the Ford & Martin's citations, mainly because I'm incredibly lazy, but also because I believe that if you cite an authors' work in the affirmative, you are basically advocating that position. Therefore, their position becomes your position, too. Just sayin'.

Z) First thing's first, though: I should point out that a modern analogue doesn't really exist, and the authors don't point to one. They never say something like, "Psittacosaurs were Mesozoic hippos!" or "Psittacosaurus lived like a crocodile!"

TLF) AH, DUHH!!! They don’t look like hippos or crocodiles. And we do compare them to beaver-like lifestyle, so this statement is false.

I'm gonna stick to my guns here. Psittacosaurus exists as a sort of mash-up of various semi-aquatic vertebrates in the paper, and even the final beaver analogue is more a comparison of its choice of environment than behavior.

Z) No, instead, their vision of everyone's favorite parrot lizard is a polytomy of various semi (or fully) aquatic modern animals as the authors struggle to come up with "semi-aquatic" reasons for Psittacosaurus' anatomy. Let's dive right in, shall we?

TLF) Again, we aren’t the first.

That's not an argument. Bad Tracy! Argumentum ad...uh...something! Something Greek.

Z) The first point the authors make is that Psittacosaurus is often found lying on its belly, hindlimbs akimbo in a "sprawling" position, and sometimes hyperflexed. This is apparently evidence of a semi-aquatic lifestyle. That seems like a non-starter to me, though. I can name plenty of modern animals with sprawling limbs that are NOT semi-aquatic, and even some fossil animals with sprawling limbs that have never been considered semi-aquatic. It's also worth noting that many modern semi-aquatic animals have parasagittal postures. The authors also do a poor job of explaining how an offset femur head (which Psittacosaurus apparently has) equals semi-aquatic lifestyle. They suggest it has something to do with a "swimmer's kick," because from what I gather, no animal can swim without splaying its hindlimbs and using a scissor, or breast-stroke, kick. Frogs do, after all. Crocodiles don't (they swim with their tail). Birds don't. Mammals don't. But one branch of Lissamphibia does.

TLF) Ah, this is totally mine. Now I take it he accepts the resting life pose that I propose then? Good, but I’d like to say that I’ve seen several different dinosaurs that have been found in a resting pose. Not just dromaeosaurs, and psittacosaurs, Coelophysis, other theropods, ornithischians, and even sauropods! Yes, there are several modern animals that sprawl. But 98% of dinosaurs couldn’t--they physically could not. And if I’m saying that they do (I’ll be using me from now on since I did write it), then I have to explain why they could.

Ah, I see. Other dinosaurs are found in resting postures that are NOT sprawling (like Mei or Saurornitholestes or Coelophysis), so the fact that Psittacosaurus is found in a sprawling posture is reason for pause. I agree!

Z) So, according to Ford & Martin, the animal most closely resembling the alleged swimming mode of Psittacosaurus is a non-amniote. Real good. It's not the only amphibian analogue the authors will make.

TLF) Not sure I understand this statement.

The language of the paper makes it sound like you're suggesting a swimming kick that's analogous to a frog, with splayed limbs making a scissor kick. If that's not actually the point you're trying to make, it's poorly worded in the paper itself.

Z) The femur thing is also inconsistent because in Figure 23.3 of their paper (on page 332), they show a rousing series of genasaur femora. The first two are psittacosaurs. Figure A (P. xinjiangensis) does seem to have an offset femur head. Figure B (P. sibiricus) really doesn't. Figure F (P. xinjiangensis) is a picture of P. xinjiangensis' femur abducted to a comical degree, without any consideration for muscle and cartilage. It's worth noting that plenty of non-aquatic animals with parasagittal hindlimbs have somewhat offset femur heads. I have a sheep femur with an offset head. Tyrannosaurus rex has a somewhat offset head. Animals with truly sprawling postures have very offset femur heads. No living animal can move between a completely sprawling and completely parasagittal posture. But I guess Psittacosaurus could.

TLF) Ah, I couldn’t illustrate a lot of femur heads and did the few I could. Dinosaurs for the most part could not sprawl, like I said before. The femur would not allow it. Dozens of Psittacosaurs have been found in a sprawling position. If it is a life position like I purposes then I have to explain why they could. I’ve heard the argument that there’re muscles, tendons, whatever but we do not know for the most part whether or not the muscles would allow it without having a living animal. Maybe they could (which I believe) and maybe they couldn’t. But for argument sake, I say they could. Now an offset femur would allow a broader range of movement. Since the top of the femur has a cartilgouse cap, I contend the femur could be moved even more into the acetabulum, as can be seen in figure 23.3 (F). Crocodiles walk in a sprawling and completely parasagittal posture. Ever see a crocodile run? So yes, animals do.

A little YouTube research shows that when crocodiles are walking quickly, they still rotate the shoulders and femurs out and around. At no point are the legs directly underneath the body. When they "gallop," it's a different motion: the hind limbs act in unison, pushing the body up and forward, and the fall is caught by the forelimbs, which also act in unison. Still not parasagittal, though. In order for Psittacosaurus to fully sprawl its hindlimbs, we're talking about essentially a cartilage cap that would separate the bone of the femur from the acetabulum...right?

Z) Let's move on the foot. The authors suggest that the foot was broad, and that large attachment scars existed on the shafts of metatarsals 1-4, suggesting that the foot was used for "more than just walking."

TLF) This is Rozhdestvensky (1955), he said this and I followed it. The phalanges and unguals are dorosal/ventrally flattened, making the foot ‘wider/flatter’ than any other dinosaur.

I know, I just didn't have the energy to flip through the citations index. I seem to recall hadrosaurs and ankylosaurs having pretty flattened unguals. Do Psittacosaurus' unguals have lateral "shelves" that would suggest webbing as in modern otters and beavers?

Z) Perhaps running, or jumping, or simply being active.

TLF) Ok, but I can’t see it jumping.

I can't see it swimming. :-P

Z) Where, exactly, can I find a rubrik telling me how much muscle is required for walking, and how much is excessive? Strong feet do not necessarily equal a "swimming kick."

TLF) Actually it was Sereno (1987) who said the foot had more muscle attachment, meaning a stronger ‘foot’ stroke. And I can see how this would work for a strong swimming stroke.

Yeah, but even that's an ambiguous statement. "Foot stroke," I mean. I'm betting that Sereno took it to mean a powerful push-off step, but...eh. It's just vague language. That's not your fault, and you're certainly free to interpret that however you want, I just wish...Sereno used more precise terms there.

Z) Also, again I say, very few habitually semi-aquatic animals use a scissor kick. Frogs use that same motion for jumping. Maybe Psittacosaurus was also an excellent leaper, and all that padding and muscle was used for shock absorbtion.

TLF) Are you serious? What morphology of the animal leads to this?

I was being facetious. I admit that it's hard to tell sometimes.

Z) Also, you don't need a lot of muscle in the foot itself for swimming. You need a lot of muscle in the part of the leg that provides propulsion--the thigh. Look at moose. Moose are perfectly capable swimmers (go figure). They have hooves. But they do have enormous thigh muscles.

TLF) So are Elephants.

You mean elephants are good swimmers? Sure, but my point is that, ultimately, if a moose can swim across Turnagain Arm, foot morphology is not the biggest factor what it comes to being a good swimmer--a powerful thigh muscle is. How powerful was Psittacosaurus' thigh?

Z) How about the forelimb? According to the authors, Psittacosaurus couldn't pronate or supinate, so the palms faced medially, sort of like theropods.

TLF) This is Senter (2007).

I know it is. I've read most of his "arm bone ranges of motion" papers. They're quite good, though I do have some problems with them--just because specific joint has a certain range of motion does not mean that the living animal could access such a range. Look at your elbow or knee, for example. The osteological range of motion is greater than the living range because soft tissue gets in the way. If anything, his maximum ranges of motion are too forgiving! But the main point here--that Psittacosaurus' arms had a similar range of motion to theropods--is quite valid.

Z) It had a tiny little hand with three main digits and a vestigal Digit IV. The proportions of the fingers bring to mind basal theropods Eoraptor and Herrerasaurus, but shorter and stockier and probably stiffer. Ford & Martin suggest that the fingers were webbed, and that flexion of the first digit (which is very small) may have folded the web during the return stroke. So now we're talking about a doggy-paddle. A very bad doggy-paddle, because the palms face medially. Not even frogs doggy-paddle. So you've got a frog kick combined with a horrible forelimb doggy-paddle.

TLF) I never said doggy-paddle! Read Senter (2007) and the movement of the forelimb in basal neoceratopsians and tell me what you think the forelimbs were for. Chinnery, Sereno said they were able to walk on the forelimbs and bring food to their mouths. Senter (2007) showed that they could do neither. But his research does make for a beautiful swimming stroke.

Well, a doggy-paddle is what you get when the forelimbs are moved through the water in an arc parallel to the body. I doubt the thumb was big enough or strong enough to facilitate any kind of propulsive catch on the return stroke. If Psittacosaurus wanted to use its forelimbs to swim, it would've had to wave them to the side of the body like plesiosaurs or use an ineffective doggy paddle. Now, if it really did have sea turtle flippers, it might be able to pull of that first one...

Z) And then, the best part: "...the manus of psittacosaurs may have been held together by thickened skin (e.g., sea turtles)."

TLF) Again, Rozhdestvensky (1955), said not only the pes but the manus unguals and phalanges were dorsally flattened. Why not have a webbed hand. Oh, and by the way it was also Rozhdestvensky (1955) who said the hind feet may have been webbed.

I'm really just making fun of the choice of example. I immediately got a Mock Turtle vibe. A "mit" of skin, like a duckbill, is very different from a sea turtle's flipper. Gotta admit, it's a funny image!

Z) They even handily show a picture of a sea turtle's FLIPPER on page 334, compared to a psittacosaur paw. They look NOTHING ALIKE. Their other examples look even less like Psittacosaurus: a whale, a sea lion, and a penguin. Did you guys even look at your other figures?

TLF) Yes, the manus in Psittacosaurus is more of an inverted sea turtle’s flipper.

I mean...com'on, that's being kind. I'd also like to note here that all the animals in the example are fully marine. Wouldn't a better analogue be an otter or a freshwater turtle?

Z) Furthermore, the authors muse that the limited range of motion of the forelimb could not be used for digging or food gathering, so they must have been used for swimming. Interestingly, they cite a study by Phil Senter who played around with psittacosaur limbs to figure this out. He's come to similar conclusions about dromaeosaur arms, so maybe dromaeosaurs used their feathered arms for swimming, too and that, below all those feathers was a meat-encased flipper. So now we've got an animal who uses a frog kick and a doggy-paddle with sea turtle FLIPPERS

TLF) What, you don’t agree with Senter’s psittacosaur arm movements? But you’re okay with his dromaeosaur? What other conclusion can you come up with for the psittacosaur arm movement? They couldn’t walk on their forelegs or gather foot to their beak. You have a problem with this, talk to Senter.

No, I'm saying that if you label psittacosaurs as being semi-aquatic because of its range of motion in the arms, you COULD say the same about dromaeosaurs, but that would be silly in raptors, because they have big feathers on their arms. I have no idea why psittacosaurs would have arm movements similar to dromaeosaurs (apart from the shoulder), but I don't know if you can pin psittacosaurs as being semi-aquatic when dromaeosaurs clearly weren't, but they have the same range of motion in the (non-shoulder) arms.

Z) Now, they do raise interesting point: many psittacosaur specimens are found with gastroliths. Why use gastroliths for breaking down food when you're already doing that with your teeth self-sharpening, leaf-slicing teeth? Perhaps the gastroliths were used for ballast, as they are in crocodiles. It is unusual that Psittacosaurus used gastroliths--the only other dinosaurs with gastroliths (to my knowledge) are sauropods and ornithomimids, neither of whom chewed their food, so gastroliths would help with digestion in this case. It's also possible that Psittacosaurus ate a wide variety of foodstuffs, some of which were not sufficiently broken down by chewing alone, and so needed further gastrolith processing. They could have also been used to achieve negative bouyancy while submerged.

TLF) Did you actually read the article? Did you miss the part where I said it was Phil Currie who came up with this? No, I guess you forgot that. In fact I contacted Phil just to make sure. He said the teeth are sharp enough that they didn’t need gastroliths and HE is the one who said they used them for ballast. Have a problem with that, take it up with Phil.

I...have no response. I'm just saying that there are other explainations for gastroliths in Psittacosaurus. Sinraptor and Caudipteryx have gastroliths, too. I can see their use in the oviraptoroid, but Sinraptor? Go figure.

Z) Next, we move to the tail. The authors consider the tail to be ""long"" (their word is actually in quotes, as if admitting that, no, it's not really all that long). They also argue that the tail is quite deep. It is not. Hadrosaur tails are deep. Stegosaur tails are deep. Psittacosaur tails are not. The authors similarly note: "The neural spines are proportionately tall in all species and are particularly tall in P. sinensis. In P. mongoliensis and P. sinensis distal neural spines are flattened side-to-side, and fan-shaped.... Thus the tail may have been laterally compressed, which would help in swimming as in some modern lizards.... (or crocodiles)" Help me out here, folks: what's the ossified tendon situation in psittacosaurs? I'm not sure myself. But here's what I do know: it's just as likely that Psittacosaurus used its tail for swimming as any other dinosaur with a tail unhindered by ossified tendons.

TLF) Ossified tendons are over rated and I did an article (or at least I think I did) for Prehistoric Times. Tendons don’t stiffen they strengthen. Ok, you’ve made my argument then. Yes, Hadrosaur tails are deep which is why they were thought they swam, and maybe they did.

But if they were ossified, isn't there a risk of breakage? As for duckbills, they're not considered semi-aquatic. If anything, they just happened to be good swimmers. My point is that if hadrosaurs and stegosaurs are not considered semi-aquatic with tails like those, how can you say it about Psittacosaurus' pretty average caudal series?

Z) This is after spending the previous paragraph comparing the tail to that of a crocodile. So, just so we're all keeping track, we've got a frog-kicking, flipper-handed doggy-paddler with the deep tail of a crocodile but the compressed tail of a lizard. Clearly, Psittacosaurus was the ultimate semi-aquatic vertebrate.

TLF) Yep.

But some of those swimming modes are contradictory and wouldn't have evolved in concert with each-other!

Z) What about the nose and orbit? They are "dorsally high" and favorably compared to those of crocodilians, hippos, and capybaras.

TLF) And the problem? I did this kick-ass illustrations of different Psittacosaur skulls and compared it to a Capybara but the editor took it out due to space. Also some Psittacosaurs have a more foreword facing orbits than Tyrannosaurus rex! Reminds me of a dicynodont.

Brother, you have post those skulls on Facebook. I must see! I've noticed the dicynodont resemblence before, especially in the bulky-headed guys like P. sinensis.

Z) What about the skin? It's thick...and strong! So it probably strengthened the limbs and tail for swimming. You need thick skin to swim! Just ask any amphibian! Or lizard! Or semi-aquatic mammal like the capybara! You know what kinds of animals DO have thick skin? Fully aquatic animals. Ichthyosaurs and whales.

TLF) And you know Psittacosaurs didn’t have thick skin?

I'm saying that thick skin doesn't really scream "semi-aquatic." It may scream "fully aquatic" or "semi-aquatic in very cold waters," but otters and martins and muskrats and capybaras and beavers don't have particularly thick skin. They have insulation. Some more than others.

Z) My big long bristle rant.

TLF) This is something that I will admit is a stretch (maybe). The reason why the whole article came to place is explained in the PT article.

I look forward to reading that. I agree that you agree that the bristle-fin thing is a bit odd.

Z) Finally, the authors suggest that psittacosaurs "may have fed in lakes or rivers, perhaps crawling in the mud in search of aquatic plants...

TLF) This is Suslov. Did you really read the article?

My gripe here is with the choice of verbage. "Crawling" makes it sound like an herbivorous protorosaur or something.

Z) However, a variety of forelimb to hindlimb relative lengths suggest that some psittacosaurs were likely more terrestrial than others...." Nice save, guys.

TLF) What, I’m wrong? Did you check that cool figure of the different Psittacosaurs? Oh, right, I was wrong and they have the same limb lengths.

Not at all, your illustration is top-notch! I just felt like it was a cop-out statement.

Z) Their final comparison is with a beaver, who I guess lives in the same kind of environment that psittacosaurs are found.

TLF) Hey, I thought you said we didn’t compare them to a living animal?

The comparison was more in terms of choice of environment.

Z) So here we have a frog-kicking, flipper-handed doggy-paddler with the tail of both a crocodile and a lizard, the skin of an ichthyosaur, the tail of a salamander, and the environmental preference of a beaver. No other animal has evolved so many different, sometimes contradictory, strategies for semi-aquatic life. Psittacosaurus really wanted to get it right. Clearly, had its reign not been cut short at the end of the Mesozoic, we might well see this creature swimming the post-Cretaceous seas.

TLF) Nice, I like it. The Editor took out my illustration of this, that sucks!

Was it similar? Can we agree that the fin looks a little wonky?

Look, all kidding aside, the problem(s) with Ford & Martin's idea is that almost every argument they make is an example of false conclusion. This is the same kind of argument you see Horner making in regards to Tyrannosaurus rex being a scavenger. "It's got tiny little arm" does NOT mean it had to, therefore, be a scavenger. Plenty of hunting animals don't use their arms to hunt. "It couldn't run fast" does NOT mean it had to scavenge because it's prey was running slower than it was. By the same token, having dorsally high eyes does NOT mean you spend a lot of time underwater. Crocodiles and hippos actually have somewhat telescopic eyes (that is, the eyes are above the skull table). This is not the case in Psittacosaurus, and in fact the eyes of many dinosaurs are proportionately as high or higher on the skull than Psittacosaurus.

TLF) Then why the high eyes and nose? You don’t need telescoping eyes for a swimming animal.

Well, no, but my point is that Psittacosaurus' orbits aren't any higher than in many clearly-terrestrial theropods, or some sauropods. There are a few dinosaurs with proportionately higher orbits that haven't been accused of a semi-aquatic lifestyle.

Z) Broad feet does not necessarily imply a semi-aquatic lifestyle, either. Plenty of animals without broad feet swim (dogs, hippos, moose) and plenty of dinosaurs had strong, broad feet and are not thought of as semi-aquatic (tyrannosaurs, duckbills, ankylosaurs).

TLF) Again you have a problem with the feet see Rozhdevensky. No other, NO OTHER dinosaur has the dorsally flattened unguals and phalanges, NONE! Hadrosaurs and Ankylosaurs have broad phalanges but not fattened ones.

Awright, I'll roll with it.

Z) *rants about Larry Martin*

TLF) I did not think that was funny. You have no idea on how much time I’ve spent, read, researched, etc on this. You neglected to state that there were several other paleontologist who came up with this idea and made it look like it was us and that we are idiots.

I totally understand and apologize. Just out of curiosity, why put Larry's name on the paper at all? This could've been all you, man! Whether I think it's wrong or not, just getting published is pretty pimp.

TLF) You also didn’t mention the article that said large ceratopsians may have been semi aquatic. Description of a Complete and Fully Articulated Chasmosaurine Postcranium Previously Assigned to Anchiceratops (Dinosauria: Ceratopsia) JORDAN C. MALLON AND ROBERT HOLMES, P 189-202.

No, I did see that paper. I'm not really against the idea, but the thrust of the argument comes from paleoenvironmental association. I wouldn't say that ceratopsids exhibit any really convincing habitually semi-aquatic features. Waders, maybe, but hippo-like waders? Color me skeptical.

Z) Anyway, my opinion is that it's a poorly-researched bit of speculation on the part of the authors, and is nowhere NEAR a slam-dunk. Just my opinion, of course. Maybe you readers out there in Readerland have something different to say about it.

TLF) What, you forgot to mention the part about them being found more in a lacustrine environment then Aeolian. Must believe that part!

See above. :-)

Thanks for Tracy for providing this well-thought and well-written response to my rambling critique! You are a scholar and a gentleman, sir, though we may still get in a fist-fight someday about that whole BCF thing. I shall endeavor to make your acquaintance at SVP, perhaps in Vegas? Now, I demand you post your rejected Psittacosaurus pictures on Facebook or some similar website.