Archive for the 'Uncategorized' Category

Citations of lists – a small moan

I used to do this sort of thing a lot on this blog but with the posts generally slowing it has become rather more rare (for better or worse, most readers would likely go for better I imagine) but it’s time for a moan. This is something I have seen before but recently I’ve had a whole spate of papers to review that do this and it seemed something annoying and common enough to put out publicly so that a) hopefully people will agree with me and b) then some will stop doing it.

This is about points in papers were a big long list appears in the text but then all the citations come at the end. So you get something like ‘…as seen in Tyrannosaurus, Tarbosaurus, Daspletosaurus, Gorgosaurus, Albertasaurus and Zhuchengtyrannus (Smith et al., 1994; Jones, 2001; Smith and Jones, 2005, 2007; Smith and Smith, 2016, 2017).

At best this is annoying and at worst actively cryptic about information. In my example there are six taxa and six papers so you can assume that they realte to these taxa in order, but even if they do, it’s a slight pain to work out exactly which paper refers to which one. I’ve seen examples like this with a dozen papers and then you really do have to move your finger along and count to try and work out which is which. Even so, this assumption may not be true – are those papers certainly in the right order? The only way you can find out or to check is to go and read each to follow it through. The point of citations is a paper trail of what you did and where you got the information from and to credit it correctly. So this list in this format is actually making you redo the work of the author and is hardly something that actually helps communicate information.

Worse, I regularly see such lists have different numbers of points to the number of references given. That means that at least some points are covered by a single reference (if they are more numerous) or multiple points are covered in one reference (if there are more points), but again, it’s impossible to know which is which. You are back to having to reread each paper to check.

In short, for the apparent sake of making a list look slightly nicer on the page, the information the reader often wants, even needs (which paper does or does not directly refer to which of those things in the list, be they taxa, anatomical features, localities or whatever) is obscured. Now, I do get that this easier on the eye to read than say ‘Tyrannosaurus,(Smith et al., 1994),  Tarbosaurs (Jones, 2001),but personally I don’t find that an issue, I’ve read enough papers to skim over references while reading without a problem. More importantly, it is perfectly clear exactly which paper refers to which point and so is far superior to a big lump of papers are the end.

If it’s not immediately clear, it can’t immedaitely be verified and you may have to wade through a large number of references to check. This is hardly the end of times, but for me this really helps neither the author show that they have done what they set out to or the reader follow that up. And so really, please, please, cut out the lists followed by a list of references. Authors don’t do it and referees and editors, pick up on it and ask people to make specific points supported by specific references.

Flugsaurier 2018 deadline extended

The LA Flugsaurier meeting is creeping closer and we are working hard to get everything in place. However, as sure as night follows day, people are behind on their abstracts so we have decided to extend the abstract submission deadline by a week! The new deadline is April 9 (not 2nd!).

Keep up with new information and deadlines on the Facebook group or the conference website.

Flugsaurier 2018 Circular

This has been in the works for too long but we do now have a formal first cicular for Flugsaurier 2018. The abstract submission date is but 6 weeks away, but then you should have known about this conference from 3 years out… 🙂


Flugsaurier 2018: Los Angeles
The 6th International Symposium on Pterosaurs: First Circular

Welcome to Los Angeles

We invite all individuals working on, or interested in, pterosaur biology or associated geosciences to submit abstracts for the 2018 Flugsaurier meeting in Los Angeles, CA, USA. The meeting will be held August 10-14 at the University of Southern California and the Natural History Museum of Los Angeles County. Please mark your calendars for what we are sure will be an exciting meetinng!

Current  Calendar:

all events at USC, except Welcome Reception/Specimen Viewing and Field Trip

August 10th: Ice Breaker at USC (AM) and aRernoon technical sessions
August 11th: Technical Session; Welcome Recepion and Specimen Viewing at NHMLA
August 12th: Technical Session (AM); Workshops (PM); Paleoart Exhibition
August 13th: Technical Session (AM); Workshops (PM); Conference Dinner (PM)
August 14th: Field Trip (TBD)

Notes: The NHMLA is located adjacent to the main campus of USC. The Conference Dinner loca4on is TBD, but we expect to use a venue either on the USC campus or in nearby Downtown Los Angeles. The Field Trip costs will be included in the registraion. We hope to arrange a trip to the Moreno Formation of California.

Abstract Information
Abstracts have a limit of 500 words with up to 3 references (Harvard format) and 1 figure.
For details, or to determine if abstracts meet criteria, please contact Michael Habib: Abstracts can be submi]ed here. We will accept mul?ple submissions from authors but only one talk per lead author. Abstracts will be reviewed. We cannot guarantee speaker or poster slots. Abstracts submissions are due by midnight, Pacific Time, on March 26th. EDIT: Deadline extended – the new deadline is April 9th.

Host Committee:
Host committee will also be the review committee for all abstract submissions Michael Habib (Chair), Brent Breithaupt, Nathan Carroll, David Hone, Lu Junchang, Elizabeth Martin-Silverstone, Taissa Rodrigues.
Special Thanks goes to Luis Chiappe for hosting the NHMLA components of the program.

Travel Information

The closest hotel is the Radisson Hotel Los Angeles Midtown at USC. Rooms at this hotel
average 178 USD per night:
Less expensive options can be found in some parts of Downtown Los Angeles. The American Hotel often has rooms for 85 USD per night: The hotel is walking distance from a light rail sta?on, from which rail travel to USC and the NHMLA is approximately 10-12 minutes.

We are currently working with USC to secure some low-cost housing on campus. We expect this to be limited and available mostly to students. More informa?on about on-campus housing will follow as soon as it is confirmed.

Travel to Los Angeles:
The closest airport to the conference venue is Los Angeles International (LAX). However,
travelers can also fly into Hollywood Burbank Airport (BUR) or Long Beach Airport (LGB). LAX runs regular buses to Union Sta?on, from which light rail can be taken to Downtown Los Angeles and USC.
Note that travel to the United States for a conference typically requires a B Class Visitor Visa, unless the port of origin is part of the Visa Waiver Program. For details on Visitor Visa applications, and to determine if your country of origin is associated with a VWP, please check here:

Natural Histroy Museums of LA County:
The Natural History Museum of Los Angeles County is the largest natural and historical museum in the western United States. Its collections include nearly 35 million specimens and artifacts and cover 4.5 billion years of history. The NHMLA houses an extensive collection of specimens from the Niobrara Chalk and Pierre Shale, including a sizeable collection of Pteranodon specimens and one of the few partial skeletons of Nyctosaurus. In 2016, the NMHLA hosted Pterosaurs: Flight in the Age of Dinosaurs, from the AMNH.

Other Area Museums:
Alf Museum, Claremont CA: The Raymond M. Alf Museum of Paleontology, located on the
campus of The Webb Schools, houses extensive vertebrate fossil collections, including multiple excellent pterosaur specimens. It is the only nationally accredited museum in the USA on a high school campus. The Alf Museum provides a unique research program for Webb students where they study fossils they find on collec?ng trips and publish the results of their research in collaboration with museum staff, a unique program for secondary school students.
Tar Pits Museum, Los Angeles CA: Part of the LACM system of museums (along with the
NHMLA), the Tar Pits Museum in Los Angeles has one of the largest Pleistocene collections in the world. Active excavation continues throughout the year on the grounds of the museum, which is located in the Miracle Mile district.


The official website to keep an eye on is this one:


Sexual selection: patterns in the history of life

Longtime reads will know I have a huge interest in sexual selection and what that might mean for the evolution of all kinds of features (horns, crests, colours, feathers) in various archosaurs. In an effort to explore this further and help make new research connections, I have got together with Rob Knell and Doug Emlen to arrange a small meeting on this through the Royal Society. This will take place on the 9th and 10th of May next year jsut outside London.

The speaker list is fantastic and includes palaeontologists, modellers, theorists and people who link between those disciplines and with interests in dinosaurs, birds, insects, mammals and other clades. In short, this should least to a wide ranging discussion and opportunities for people to put some ideas out get and get collaborations and research going in major new directions.

Attendance is free (though there are costs for accommodation and food) but you will need to register and places may be limited. All of the details of the meeting are here including the speaker list. We hope to also run a poster session for non-speakers too.



Write me a review!

Calling all my fellow academics, I am the new Reviews Editor for the Journal of Zoology and as a result I’m on the lookout for review papers that cover any aspect of whole organism biology (behaviour, ecology, taxonomy, evolution, anatomy and many other aspects). The journal has a good track record of covering palaeo topics (including dinosaur combat, display, trilobite diversity) so it’s not all about fluffy mammals.

I think reviews are important to science and provide a great platform for state-of-the-art updates, for people entering new fields (including students) and for steering debates or having new ideas put out there. They are also, I think, often a great paper to write as part of a PhD – they might not be REF-able, but give you a chance to get to grips with a subject and are often highly cited. In short, if you have an idea for a review you are likely to find me a sympathtic ear with a possible opening for you.

In particular I’m keen to reach out beyond the regular readers here, so do please pass on the gist of this message to people far and wide, especially in the biological / invertebrate divisions where I know far fewer people that the dinosaur / vertebrate community.

Tenth Anniversary Post

This blogpost is in fact a bit late since this date passed on the 7th of September, but I have now been blogging for a full decade. The archives here do not quite reach back that far, but very long time readers will know that I first started on the now defunct DinoBase pages (though these are available on some internet archive sites) hence the apparent gap.

I don’t want this post to turn into a long ramble about all of my posts and things I have got done, how I got blogging and so on, (this is after all covered in various places), but this seemed too big a milestone to ignore. I’m really not sure when I started all of this, how long I thought I might keep going for, but I doubt it would have included a guess of anything like ten years.

Back then I was still on my first postdoc with no guarantee of employment in another year or so, let alone an academic career and I was already running Ask A Biologist which was a massive outreach project in its own right. If I’d thought about it, I think I would have considered five years to be a big but achievable target and while I’m hardly going at the rate I once was, to still be going is something I’m rather proud of.

That really is it, just a post to mark the passing of the event. The blog will continue, slowly, as things progress and topics come up that I still want to talk about or are relevant. I doubt that I will still be going in 2027, but that in some ways doesn’t seem too far away or too unlikely. Time will clearly tell but I’m not stopping any time soon.

Some outreach

A couple of months ago I was lucky enough to be invited to give a second talk at the Royal Institution in London. It was, perhaps inevitably, on tyrannosaurs but if you want to hear an hour of me talking about them then the video is now up on YouTube here. As a bonus, they also filmed the Q&A afterwards so there’s an extra 20 mins of me droning on here.

If that’s still not enough of me for you (and it’s hard to imagine that it’s not actually too much for most people), I’m also doing some talks on the 29th of September as part of thy exhibition of Chinese dinosaurs in Nottingham. Keep your eyes peeled for details later. I’m also currently heavily involved in a secret dinosaur project which should be on your screens this Christmas (in the UK at least).

Dinosaur dimorphism, cryptic absence

Yes it’s new paper time and this is one I want to talk about in some detail, so here’s a longer than normal post on this. It’s an issue that has been in my brain for years but has taken time to mature with the right set of circumstances and quirks that make up the profile of a research paper possible. This one is returning again to the much investigated area of sexual selection in the extinct Dinosauria. I think it’s fair to say I’ve been a leading researcher in this field with a string of papers on various issues surrounding sexual selection and dimorphism in dinosaurs (and others), how we might detect sexually selected traits and what they may mean for behaviour, ecology and evolution.

The new paper is written with Jordan Mallon, and in it we tackle the issue of the apparent lack of dimorphism in dinosaurs and why there is still no good case for a dimorphic dinosaur. Despite numerous studies suggesting a split between male and female morphs (or similar robust and gracile ones) revisions have generally found the cases to be lacking and Jordan’s own recent paper in this area is relevant for several reasons. The story though starts quite a few years ago.

My own works on sexual selection mostly kicked off with a paper discussing mutual sexual selection and the idea that both sexes in many populations of dinosaurs may have borne ornaments for social and / or sexual dominance. In short, males had big ornaments (claws, horns, frills, crests etc.) to advertise their general good health and status to females for mating and other males in terms of competition, but females likewise advertised their general quality with the same signal. That meant that in something like a typical ceratopsian both males and females had a big frill and horns and hence an inability for us to identify and separate out the two populations.

This general concept had been completely overlooked in the literature in sexual selection and dimorphism in dinosaurs and it’s worth repeating that this can totally confound some ideas and tests for sexual selection and it needs to be borne in mind when discussing these kinds of traits. While later papers have built on this issue and surrounding ones for the function of crests and the like, in my mind it has always been an unsatisfying explanation for things. Sure, it’s a big issue and to ignore it is incorrect, but while we are finding more and more examples of mutually sexually selected species, it seems unlikely that so many dinosaurs (huge numbers of hadrosaurs and ceratopsians, various theropods and other lineages) all had equal ornaments. Sexual dimorphism, be it in body size or crest size and shape (or of course, presence / absence) surely was present in a few of these lineages?

One issue is of course that for a lot of species we have very few specimens (often only one) and certainly don’t have lots of adults in good condition from a single site for many. As I noted in a paper on social behaviour in dinosaurs, lots of large terrestrial mammals at least show different fundamental patterns in group behaviours between the sexes so even if we do have 50 animals from a mass mortality site, there’s no guarantee it is not a group of 50 males or 50 females. Identifying different sexes is also problematic of course but it would help if in a few cases we *knew* we had both present in a sample size.

Even so, where was the dimorphism? Was it really absent or merely for some reason, hard to detect? After quite some thought I realised that what might be a major factor is the growth patterns of dinosaurs. Where large mammals and birds rather race to adult size and then stick there, dinosaurs (at least the larger ones) took a longer and more reptilian growth pattern with an extended growth phase (even if they were sexually mature during much of this). That means that much of the reproducing population isn’t full size and that even if say males were much bigger than females, you’d struggle to tell apart and old female from a young male which might be comparably sized. Right, now I had a hypothesis and a mechanism to test it by getting a dataset on dimorphic animals with differential growth and see how they looked depending on how things were sampled.

And then I got stuck. Datasets like this, (especially with reptiles and birds) simply didn’t seem to exist in the literature. Over perhaps 5 years I sent out dozens of e-mails and spoke to various people about data, including biologists, palaeontologists, conservation and zoo workers – anyone I thought might have or know of a dataset of mass for lots of individuals of known sex and age. I got nowhere. Even trying to compile sets from lots of individual measurements didn’t get me anywhere and I was resigned to having a good idea I couldn’t test, until Jordan got in touch.

He sent me a draft of his now published paper re-examining analyses that had looked for dimorphism and found them wanting. Reading it through I was annoyed to see that he seemed to be leaning the same way and that the elongate growth might be a decisive factor, but while the paper discussed some issues around detection it didn’t go there. I was relieved that my idea seemed to still be mine to work on, but as Jordan had asked for any comments to help improve things, it also seemed a bit mean to withhold an idea that might provide a nice extra aspect of the paper.

Happily, as these things often do, a quick chat via Skype helped revolve things. Jordan liked the idea but agreed we could try and combine forces, as he thought he had a good lead on some data we could finally use and importantly also knew how to run the analyses. So with new impetus, the idea was resurrected and the final output of this collaboration is now out.

So, what did we find? Well it looks like my thoughts were generally correct but far more so that either of us suspected. We used alligators as the reptile model since they form a part of the dinosaur phylogenetic bracket and have large dimorphism (at full size, males are 30% and up longer than females), with rheas on the other side (also show major dimorphism and are large birds). Doing various subsamples of each it is clear that it’s much easier to detect dimorphism in the birds because you are tending to sample animals that are at full size. You can use a much smaller sample size to detect dimorphism in birds than reptiles. You typically need around 30 animals of *each* sex to get a statistically significant difference in alligators, even though that have one of the highest levels of dimorphism recorded.

Given how few dinosaurs even have a dataset of 60 animals (and then the issues of making sure you can measure them all accurately, and of course the fact that you’ll be lucky if even a few are sexed, and you may have all of one sex, and there is often variations between populations) and then it becomes little surprise we have picked up no good signals for dimorphism in dinosaurs to date. This does become a little better when we sample from larger individuals (as there are several biases against juveniles in the fossil record) but still well below what we can do for almost any dinosaur.

One other aspect that we look at is the range of dimorphism appearing in extant reptiles. There’s a surprising (to me) level of variation in populations with major variations in terms of just how dimorphic one population is versus another and these can also change over time. Some populations of single species even show males being larger with others having larger females. That’s also potentially an issue given our tendency to have to lump together specimens from multiple different sites to get to a decent number of animals to measure and while it might not be common, it’s clearly a potentially confounding signal.

This is of course not the final word on any of this. There are other aspects to both growth and dimorphism and how we measure it in both living and extinct animals. Certainly I think it’s possible to make a good case for dimorphism with only a limited sample (as has been looked at for example with oviraptorosaur tails, or indeed for some pterosaurs) but the apparent lack of dimorphism for dinosaurs in the fossil record is not as alarming as it might seem. Yes we might expect numerous species to have been dimorphic but it appears that our sample sizes are simply too small. Through in the unknown age and sex of most specimens, and the potentially confounding effects of mutual sexual selection and it becomes perfectly possible that many species (even those represented by large numbers of good specimens) were strongly dimorphic but we are simply unable to identify it.

For years I’d been puzzled by the apparent lack of dimorphism, and Jordan’s paper confirmed that we really have yet to show it clearly in any dinosaur. Mutual sexual selection is a major issue but it probably doesn’t explain all the cases we know about, but I think this paper adds a pretty substantial concept to our understanding of dinosaur dimorphism. Or rather, that we don’t understand it that well but that the apparent absence could well be a classic absence of evidence problem. As with a number of issues in behaviour and ecology, I rather suspect we don’t know as much as we think we do, but understanding what we do and don’t know with confidence is a major step forwards to getting to grips with the problem, so this hopefully is progress even if we can’t find much right now.


Hone, D.W.E., & Mallon, J. [joint first authors]. In press. Protracted growth impedes the detection of sexual dimorphism in non-avian dinosaurs. Palaeontology.


The Tyrannosaur Chronicles – now in paperback

So nearly a year has passed since the book launched and that now means that the paperback is due. I’ve been fielding a few questions about it (and of course I want to promote the new release – due on April 20th) so this seemed like a good opportunity to do a quick blogpost on it.

As you can see the paperback has a switched-up colour scheme from the original purple hardback but that’s one of the biggest changes. The book has really not been updated and while there are some corrected typos (and the annoyingly switched around phylogenies in Chapter 4) these are the only real alterations. There are some more notes in the introduction, but that’s it – I didn’t have the opportunity to revise and update the book as a whole and I’m not sure I’d have taken it if I had, so please don’t invest thinking this is a new version, it is not. The paper quality is good on the paperback and the Hartman figures and drawings do not suffer at all, and the glossy photos are all still there in the middle.

One year on is a decent time to reflect on things and I’ve been amazed at the positive response to the book. I always expected it would go down well with dinosaur aficionados but it has sold in numbers that show it has gone well beyond any fanbase I might have, and even that tyrannosaurs might have, and there’s been loads of responses and reviews from more ‘normal’ people who simply enjoyed it as a book on popular science. is especially good averaging 4.6 from 28 reviews, but is hardly bad (4.0 from 7 reviews) and it’s done well on Goodreads as well (3.93 from 114 ratings with 34 reviews). I’ve yet to see a review below 3/5 (though I’ve hardly been hunting down bad ones!) and that is really nice since it’s impossible to appeal to everyone, but clearly it’s coming across well generally.

That’s it really. I’m obviously delighted with how things have gone and hope it continues to do well. It naturally is already dated (damned new species being named!) but the fundamentals I hope will be relevant for many years to come and continue to be enjoyed by readers.

Buried Treasure – Dave Hone

I could hardly expect everyone else to write about their own papers without taking a turn myself at some point. In may case it’s a fairly recent paper that I’d like to cover, my paper in the Journal of Zoology on sorting out hypotheses for behaviour when dealing with fossil species. OK, so it’s only a few years old and things take time to accrue citations, but it does seem to have had very little impact given the raft of papers I have seen that (I think) would really benefit from taking a look at what I and my coauthor Chris Faulkes proposed.

Over the last few years I’ve become increasingly invested in looking at definitions and how they are used. When you are trying to look at multiple species and compare them, or get a sense of something of the state of play for an issue like the ratio of different life stages of animals, it’s enormously helpful if everyone is using the same definitions. Unfortunately the opposite is true, people use different words to mean broadly the same thing (without ever clarifying it), or the same word to mean very different things depending on context (again, without ever providing an explicit definition) and the whole situation becomes a bit of a mess. My paper on defining juveniles and adults for dinosaurs is a case in point and similarly, there’s lots of unhelpful use of the term ‘social’ with out reference to other works (especially on living taxa) as covered in my paper on Protoceratops and what it means to be ‘social’.

In short, we need to be careful about how things are defined because that’s important for making data comparable, but it’s also an issue for testing hypotheses. If it’s not clear what you mean by ‘juvenile’ then it’s very hard to say whether or not this is the correct assignment, or using it to assess a growth pattern etc. The other side of this, is whether or not a hypothesis is really credible in the first place. I think with palaeontology we are so used to dealing with incomplete specimens and limited data generally that hypotheses based on little evidence is the norm, but it does seem that when it comes to behaviour (and / or ecology) these can get erected based on almost nothing at all, and really only add to a long list of vague statements that don’t really add anything to our understanding of how animals lived. I won’t pick on any specific examples, but it’s not hard to find hypotheses like ‘this animal may have been a piscivore / scavenger / hunted in packs / migrated long distances’ and so on based on the flimsiest of lines of evidence. Statements about the sociality of whole clades of taxa based on a set of footprints of two individuals together is not something that should be taken seriously, but too often it’s not only published but then picked up and carried forwards.

So my paper on establishing hypotheses was designed to be something that could help provide guidance towards making hypotheses stronger. What lines of evidence would likely be useful to support a case, which would be weaker, how can that evidence be best integrated with available data or our understanding of the behaviour of living animals? Taken together, is an idea even supported by enough data to make it worth evoking as a formal hypothesis and if so, how can this best be formalised to the species or specimen in hand in a way that is supported by the evidence and is most amenable to further support or even formal testing later on?

I think this is really important. We as a field have become so much better at being rigorous when it comes to assessing ideas about descent, relationships, ages, functional morphology, evolutionary patterns and many more, but I do think that behaviour really lags here. Too many vague and unsupported hypotheses are not just in the literature, but are entering the literature and I do hope that the ideas in this paper will help slow up some of this and get people (authors, referees and editors) to take a more critical look at terms and how they are used, and in particular the support for hypotheses about behaviour.

Hone, D.W.E. & Faulkes, C.J. 2014. A proposed framework for establishing and evaluating hypotheses about the behaviour of extinct organism. Journal of Zoology.

Buried Treasure – Andy Farke

Sometimes, even research that gets a fair bit of press can get overlooked–particularly for little tidbits in the paper that might get obscured by the “big picture” stuff.

One of the coolest fossils I’ve ever worked on is a “baby” Parasaurolophus from southern Utah. The fossil–the smallest, youngest, and most complete of this kind of duck-billed dinosaur (hadrosaur) ever discovered–was found in 2009 by one of my high school students. The resulting 2013 paper received international press and has racked up a decent number of citations since. The fossil was even invited to travel to Japan as part of the 2016 Dinosaur Expo, where it was viewed by nearly a million people!

I am incredibly proud of the work, a collaborative effort with high school students, myself, and bone expert Sarah Werning, and consider it one of the best pieces of research I have ever published. Yet, there is one tiny angle that seems to get overlooked by a lot of people: the beak.

The skull on our baby Parasaurolophus is accompanied by an impression of the horny beak that lined the front bones of the upper jaw. Notably, it shows that the skull was not a terribly accurate representation of life appearance–the beak itself extended far beyond the bony anatomy.

Importantly, the baby Parasaurolophus was not the first hadrosaur to show this, either. Fossils of Edmontosaurus, reported as far back as the 1920s, revealed a similar structure, and strongly indicate that an elongated horny beak was pretty typical across “duck-bills”. In fact, they weren’t really duck-bills at all, but more like “shovel-beaks” (Brian Switek has a great post on this topic). The beak extension created a big scoop that was perfect for mowing off vegetation!

Long-beaked sauropod by Panzarin

Long-beaked hadrosaur by Lukas Panzarin

Despite a long history of knowledge about the beaks in these animals, very few artists include the structure in their reconstructions. I’m not sure why this is, but even very recent reconstructions by many talented artists simply follow the bony outline of the jaws. It is just a tiny blow to my ego that this tidbit from our Parasaurolophus paper (and work by others) gets overlooked!

Hadrosaurs looked quite a bit different than usually pictured. So, if you are an artist, or advising artists, give hadrosaur beaks an extra little bit of love!


If I have to pick an underappreciated historical paper, I would say it has to be the classic monograph on the anatomy of Protoceratops by Barnum Brown and Eric Schlaikjer. It’s got a ton of careful anatomical description and some really brilliant thoughts on ontogeny (changes during growth). There is unfortunately a bit of a misconception arising that long-ago paleontologists didn’t think about ontogeny in any serious way–Brown and Schlaikjer show this isn’t true. Peter Dodson’s 1975 paper on ontogeny in hadrosaurs is another great one–he was one of the first people to show that what had been split into multiple species of duckbilled dinosaurs were in fact young and old individuals of a single species. This work by Brown, Schlaikjer, Dodson, and others paved the way for ongoing investigations of ontogeny today, many of which are using methods like histology to add another layer of data to the questions.


Brown, B., and E. M. Schlaikjer. 1940. The structure and relationships of Protoceratops. Annals of the New York Academy of Sciences 40:133–266.

Dodson, P. 1975. Taxonomic implications of relative growth in lambeosaurine hadrosaurs. Systematic Zoology 24:37–54.

Farke, A. A., D. J. Chok, A. Herrero, B. Scolieri, and S. Werning. 2013. Ontogeny in the tube-crested dinosaur Parasaurolophus (Hadrosauridae) and heterochrony in hadrosaurids. PeerJ 1:e182.

Morris, W. J. 1970. Hadrosaurian dinosaurs bills–morphology and function. Los Angeles County Museum Contributions in Science 193:1–14.

Versluys, J. 1923. Der Schädel des Skelettes von Trachodon annectens im Senckenberg-Museum. Abhandlungen Der Senckenbergischen Naturforschenden Gesellschaft 38:1–19.

Buried Treasure – Jordan Mallon

What is my least appreciated paper? That’s an easy one:

Mallon, J. C., and Evans, D. C. 2014. Taphonomy and habitat preference of North American pachycephalosaurids (Dinosauria, Ornithischia). Lethaia 47:567–578.

This is a paper that I co-wrote with my good friend and colleague, Dave Evans. It’s been published for nearly three years now, and has garnered only two citations—both of which are from Dave and me! Despite this, the paper effectively debunks a widely held meme that North American pachycephalosaurs were mountain dwellers, à la big-horned sheep. This is an idea that gets a lot of play in both the popular media and textbooks (including some that have come out even after our paper was published).


See what I mean? The belief that North American pachycephalosaurs lived in the mountains is all over the place!

 The idea for the project came to mind shortly after I started my postdoc at the Canadian Museum of Nature in 2013. I was reading some papers by my predecessor here, Charlie Sternberg, and repeatedly came across this notion of his that North American pachycephalosaur skull domes tend to be well worn, “as if they had been rolled down a stream” (C. M. Sternberg. 1970. Comments on dinosaurian preservation in the Cretaceous of Alberta and Wyoming. National Museums of Canada Publications in Palaeontology 4:1–9). For Charlie, the implication was that these pachycephalosaurs must have lifted in upland—even intermontaine—environments, and not in the ancient coastal plain environments where their skull domes are typically found. Others have run with the idea since then.

But was Charlie right? Are these pachycephalosaur domes typically water-worn? No one had done the hard work of looking over the original fossil material to find out. Fortunately, most of the domes that Charlie collected were available for examination at the Canadian Museum of Nature. Dave and I further supplemented our dataset with domes from the Royal Ontario Museum and the Royal Tyrrell Museum of Palaeontology. In all, we had a respectable dataset of 187 domes, which is nothing to sneeze at (particularly if you’re a dinosaur palaeontologist). Without going into the nitty gritty of how we assessed dome wear (you can read the paper for that), suffice it to say that we found that domes were not typically worn. We also found that dome wear does not correlate with distance from their presumed origin in the Rocky Mountains, nor are pachycephalosaur remains relatively more abundant in intermontaine deposits, which we could expect if the critters lived there.


North American pachycephalosaurs almost certainly lived in the ancient coastal flood plains where we find their skull domes today. Image credit: Brett Booth.

Dave and I took this to mean that pachycephalosaurs must’ve been living where we find their remains: in the low-lying coastal floodplains, alongside the more common hadrosaurids and ceratopsids. It’s an important first step in understanding things like dinosaur community ecology and beta diversity. It’s also a good reminder that taphonomic processes like erosion can actually inform our understanding of the habits of fossil organisms, and are not simply information-destroying by nature.

If anyone wants a copy of the paper (which is behind a paywall), please fire me off an email at jmallon AT


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