Archive for February, 2017
Tags: Dinosaurs, neurology, palaeontology
Tags: fossils, Pterosaurs, taxonomy
Immediately after the Munich pterosaur meeting ended in 2007, I moved to Beijing to take up a postdoctoral position at the IVPP. Perhaps the first bit of mail I has there was from the now late Wann Langston thanking me for setting up the Munich Flugsaurier (which he had attended) and sending me a photocopy of his notes and some old photographs he’d taken on a trip to China back in the 80s. This was of a superbly preserved pterosaur hindlimb, and one he wanted to know more about but which had since not been seen by any researcher he knew, or been in the literature.
This was a specimen of Noripterus, a small dsungaripterid from China found by, and then named by, C.C. Young back in 1973. The original description of this was both a bit sparsely described, and in Chinese which is a shame as Young mentions a number of specimens, and illustrates or measures only part of some of them. I asked around the curators at the IVPP but no one knew the location of the material and it was suggested to have been borrowed and not returned.
Fast forward a couple of years and while Paul Barrett was visiting the IVPP he had been directed by a colleague to a little used set of cabinets in the collection, where apparently some mislaid dinosaur material was residing. I happened to be looking over a specimen in the collections at the time so inevitably was keen to see what might turn up. On opening the case, Paul found his specimens, but one thing I spotted was immediately recognisable from Wann’s photos – the lost Noripterus foot. Accompanying it was quite a lot of other pterosaur specimens with similar specimen numbers – Noripterus was back.
Since then I’ve been working on and off on a number of projects on these specimens (hampered by my no longer being in China) and the first is finally out as part of the volume from the back of the 2015 Flugsaurier meeting in Portsmouth. A more full description is in the work but this is the first and important step because the taxonomy of the Asian dsungaripterids has been an issue that’s been problematic for quite a while, and much of it hinges on Noripterus.
Things have been difficult to resolve because as noted, the original description doesn’t give that much information on the material (and less if you don’t speak Chinese – I am indebted to my collaborators here as you may imagine). If you want to sort out how various other species and genera relate to it (or not) you really need to know what it actually is anatomically and taxonomically, and so having the specimens available means we can make some significant updates to Young’s identification and how other more recent discoveries might relate to it.
First off the bad news – what was originally designated as the holotype is mostly still missing. Only a fragment of the jaws remain and they are not in great condition. Still, they are diagnostic which helps us to define Noripterus better. On the good news side of things, there is a lot of nice associated material as Young collected multiple specimens from just a few sites and despite the lack of overlap in some areas, there’s some good reasons to think they are all the same thing. Noripterus is known from several superbly preserved specimens including a near complete set of limbs and girdles preserved in 3D. There will be more on this in the future, but obviously it’s very useful material to have.
Working out quite which specimen was which however actually took quite some time and detective work. The field numbers on the bones and the specimen numbers on the boxes they were in, did not always line up with the identities given in Young’s paper (either illustrations or the few measurements). Eventually though we got this sorted out and so one part of the paper gives some new specimen numbers and sorts out the various specimens into their (hopefully) correct sets.
The main issue though is the taxonomy itself of these animals. Noripterus was only the second dsungaripterid identified (you may not be shocked to learn Dsungaripterus was the first) and so it might not be a surprise that it’s considered a valid taxon. It is rather smaller than it’s more famous relative, and has straight rather than curved jaws, as well as rather more narrow teeth. That’s the easy bit.
Then we have ‘Phobetor’ from Mongolia, named from some very fragmentary material that has never been described in detail. More recently there’s more Mongolian stuff from 2009 called the ‘Tatal pterosaur’ that was used to link together that material, ‘Phobetor’ and Noripterus all under the latter name. On top of that we have the Chinese genus Longchognathosaurus known from little more than a few bits. Clearly lining these up and working out if there were one, two or three genera was going to prove difficult while 2 of these 4 sets of specimens were fragmentary and most had never been described or illustrated properly. In this context, getting to see Noripterus was clearly very useful in terms of making some meaningful comparisons of key characters.
So, what did we find? Well, actually the Tatal material and the original ‘Phobetor’ are very similar based on the limited descriptions of each suggesting they are the same taxon. However, they have some consistent differences with the Noripterus material which suggests they represent a valid and separate genus and should not be synonymised with it. That also means that ‘Phobetor’ is still lacking a name (it’s preoccupied by a fish). Finally, Longchognathosaurus has at least a couple of the supposedly diagnostic characters present in the holotype of Noripterus and while it’s not necessarily the same thing, it is hard to justify it being unique at this point.
Clearly all of this is provisional, and lacking a good skull for Noripterus (or at least the rest of the holotype) would really help firm all of this up, not least when the Tatal specimens include a good skull and Longchognathosaurus is based mostly from cranial material. In fact given how much good Noripterus material there is, it is an oddity that there’s so little of the head, but hopefully more will turn up. In the meantime, this should help move things forwards and provide a better basis for sorting out these taxa and some curiosities about their relationships to other pterosaurs (in particular Germanodactylus which may or may not be an early dsungaripterid). Now we just need some more detailed descriptions of all the other Asian dsungaripterids (and yes, more on Noripterus too) but this is a start.
TLDR: We have a good amount of Noripterus back. ‘Phobetor’ is probably separate and valid and the same thing as the ‘Tatal pterosaur’ material. Longchognathosaurus is probably not valid.
I consider my 2008 paper “A critical re-appraisal of the obligate scavenging hypothesis for Tyrannosaurus rex and other tyrant dinosaurs” to have the highest “underappreciated:applicability” index. (The fact that it took 10 years for the paper to actually come out doesn’t help my appreciation for its unappreciatedness, too…)
It isn’t that other theropod workers ignore it; they do cite it. But since the topic of tyrannosaurid predation is studied by a larger spectrum of workers, many of whom do not have particular expertise in dinosaur morphology or even paleontology, many papers where it SHOULD have been cited do not do so. This is particularly frustrating because it is not a hard reference to find on a scholar.google search, and more importantly because it was specifically written to be accessible to a non-specialist audience. Of course I don’t think that they had to agree with every point in it, but I did collect and address all the major arguments for obligate scavenging in tyrannosaurs proposed up to that point, so it should at least be discussed.
Furthermore, when (often younger) paleontologists respond to the newer (and sometimes non-paleontologically-informed) studies on tyrannosaur predation, they wind up “re-inventing the wheel” (not being aware of my paper from so long ago…)
Holtz, T.R., Jr. 2008. A critical re-appraisal of the obligate scavenging hypothesis for Tyrannosaurus rex and other tyrant dinosaurs. Pp. 370-396, in P. Larson and K. Carpenter (eds.), Tyrannosaurus rex: The Tyrant King. Indiana University Press.
In my opinion, one of the least appreciated papers in dinosaur paleontology is
Janis & Carrano’s 1991 work comparing reproductive turnover in dinosaurs and mammals. The implications for this paper reach into nearly every aspect of dinosaurian ecology (size; evolutionary turnover rates; ontogenetic niche shifts; number of species per fauna; extinction sensitivity; etc.) in comparison to placental mammal ecology. And yet it seems (at least to me) to be underreported relative to its applicability.
Janis, C.M. & M. Carrano. Scaling of reproductive turnover in archosaurs and mammals: why are large terrestrial mammals so rare? Annales Zoologici Fennici 28: 201-216.
So kicking off the first in the series of favourite / underappreciated papers is Mike Taylor of SV-POW. Here’s his thoughts on one of his own works:
The paper I look on most fondly is Taylor and Wedel (2013) on “Why sauropods had long necks; and why giraffes have short necks”. I like the snarky title, of course — when I give talks about this subject, I just use the second half — and the subject matter is dear to my heart. But it’s how this paper came together that makes me love it the most.
It started out on a car journey in 2008. All three Wedels were staying with us that summer, as Vicki had a leprosy conference in Bradford. Matt and I visited several museums while they were around. I think it was as we were driving back from Oxford that we started listing the ways that sauropod necks didn’t make mechanical sense to us. Since I was the one driving, Matt took out his notepad and started making lists. “What the hell is going on?”, we asked — and so the embryonic project was dubbed WTH, for “what the hell”.
More than any of our other papers, this one went through really significant revisions. The earliest “complete” version was rather formless: it contained a lot of good stuff, but there was no structure to it. We revised it into an unconventional form with three main sections: “Facts”, “Interpretation” and “Speculation”. At this point, the title was still “What the hell is wrong with you? Mechanical design flaws in the necks of sauropod dinosaurs”.
This was also the basic shape of the version we finally submitted to a journal, though by then it had the more sober (and boring) title “Vertebral morphology and the evolution of long necks in sauropod dinosaurs”. We had a very bad review experience at that journal, which I won’t go over here; but suffice to say that the result was that, having thoroughly reworked it into a form resembling the one we know today, we sent it to a different journal rather than back to the first one. We were bullish about this submission, and pleased to think we were giving a good paper to a journal that could probably use it. So we were rather shocked to find it rejected with reviews that we couldn’t sympathise with — especially one that said “The manuscript reads as a long “story” instead of a scientific manuscript”, which we feel is praise though it was intended as criticism.
We made some revisions in response to those reviews, but by the time we’d done that PeerJ was on the horizon so we sent it there — and after very quick and genuinely helpful reviews, it was published as part of that journal’s first batch: https://peerj.com/articles/36/
We’re really happy with the “story-like” final form of the paper. Our goal was to make something that was not only informative but also fun to read. I hope the progression of the argument makes sense — Introduction, Long Necks in Different Taxa (finishing with sauropods), Factors Enabling Long Necks, Architecture of Sauropod Necks — and that readers always have a solid sense of where they are in the progressing argument. We’re also really happy with the illustrations in this paper: PeerJ, being an online-only open-access journal, imposes no limits, so this is a lavishly illustrated paper with some comparative illustrations (Figs 1, 3 and 7 particularly) that we’re really proud of: https://peerj.com/articles/36/#fig-3
Finally, I won’t deny it’s satisfying that a paper which was (wrongly, we feel) rejected by two palaeo journals has gone on to be viewed 23,000 times by 17,000 different visitors, and has been downloaded 3,000 times. We very much hoped that that paper would reach a non-specialist audience as well as other researchers, and those numbers suggest that’s happening.
Finally, Mike has a pick for an underappreciated paper by someone else is:
Hokkanen, J. E. I. 1986. The size of the largest land animal. Journal of Theoretical Biology 188: 491-499.
The Musings has been too quiet of late what with mad work commitments, and my ongoing responsibilities for blogging etc. elsewhere means I have too little time. The old days of a post nearly every day are, I suspect, never coming back but I do want to keep producing material on here. Happily I have a cunning plan (insert your own favourite Blackadder response here) and more happily still, a number of colleagues could be persuaded to write something for me that I can put up here.
Anyone who has read or written a fair amount of scientific papers will know that there are lots of hidden gems out there. Yes, there are tons of celebrated great papers, and tons that all but deserve to be overlooked, but it’s also true that there are many great papers, or even important bits of papers that are glossed over, or simply never spotted. There’s numerous examples of major discoveries turning out to have been already found or worked out years or decades before and even in the modern digital age, people cannot find, let alone read, everything. Important bits of papers, or whole manuscripts will fall by the wayside and key points missed or underappreciated.
With this in mind comes the new series – Buried Treasure (and thanks to Paul Barrett for coming up with the name) where authors talk about papers of theirs or bits of papers which deserve a second (or even a first) reading. Obviously academics are sensitive about their paper and do get annoyed when things are missed or bypassed, so while this isn’t supposed to be a place for axe grinding, (or tooth grinding) it does hopefully provide a platform for people to showcase their work and talk about how papers came about and why they think something is important and might benefit people to revisit it.
The whole thing is supposed to be a bit of fun and rather free from constraints, so people have already suggested they might write about papers that are not their own, but simply one they think needs some more recognition, or just want to write about a paper that has a strong significance for them, or they simply enjoyed writing. Hopefully it’ll be interesting and readers will discover (or rediscover) some nice ideas and see how others look at their own works.
I’ll kick this off with a first entry tomorrow and then it will build up as posts come in, so it is likely to be fairly irregular and I have no idea how long this will run. However, I do already have a small set ready to go, so it won’t die immediately at least and with luck there will be quite a few to come.