As regular readers of this blog know, I have an extreme affinity for museums and always welcome the news of a long-lost specimen that was locked away in storage turning out to be something new and significant. In 2006 one such discovery occurred when Mike Taylor (seen left, holding the specimen) came across a sauropod vertebra named BMNH R2095, a fossil that would turn out to be something so entirely different that one year later it was assigned the name Xenoposeidon. Mike Taylor has done much more than bring Xenoposeidon to light, however, and I caught up with him to ask a few questions about sauropods, paleontology, and the ever controversial issue of religion vs. science.
- [Brian Switek] Do you recall how you first became interested in dinosaurs? What made you want to become a paleontologist?
[Mike Taylor] Before I answer that, I’d like to say what an honour it is to be interviewed for a series that so far has featured such iconic figures as Bakker and Horner and so very productive a worker as Jerry Harris. I can’t help thinking that you’ve made a tremendous mistake in asking me, and that you meant to ask the marine reptile specialist Michael A. Taylor. (I mean the reptiles are marine, not Taylor.)
Well, isn’t everyone interested in dinosaurs? Doesn’t everyone want to be a palaeontologist? At least, when they’re eight? That kid-level layman’s interest stayed with me as a sort of low-grade dormant infection as I went through school, university, a career in computers, marriage, mortgages and kids. It was when my first son was one year old, in 1999, that my interest suddenly awoke, largely thanks to the Dinosaur Mailing List (http://www.dinosaurmailinglist.org/), which was the first venue where I ever brushed up against primary literature. And I do mean “brushed up”, it’s not like I actually read it or anything, I just became aware that it was out there, and that there was more to dinosaur science than The Dinosaur Heresies. Actually, I should tip my hat to that book. I know a lot of people don’t like it, but I can’t help thinking that it was directly or indirectly responsible for a lot of palaeo careers getting started in the 80s and 90s, and it was an important incubator for me in my pre-DML days. (I tried to buy Bakker a beer when I briefly met him at SVP in 2007; turns out he doesn’t drink beer, so I had to buy him an orange juice instead. It’s not quite the same, is it?)
The turning point was an email I sent on 9 January 2001, to Matt Wedel asking for a copy of the then-new paper about the giant brachiosaurid Sauroposeidon that had appeared in Acta Palaeontologica Polonica. (The paper had appeared, I mean, not the giant brachiosaurid.) Matt sent me copies of the Sauroposeidon papers. The six-page initial description of Sauroposeidon was the first paper I ever read, struggling through all the technical terms and generally making heavy weather of it all. I wrote back to Matt, he wrote back to me, and before we knew it, *bam*, I had a friend who knew about dinosaurs. I don’t think Matt had any idea what he was taking on back then. I have 18 megabytes of archived email between us since then. In among talking about a lot of other stuff (Star Wars, Lord of the Rings, the nature of evil, Doctor Who – all the usual stuff), he taught me most of what I now know about dinosaurs.
To make a long story even longer, on a transatlantic flight on 25 September 2003, I read a paper that was so bad in so many ways that it made me think, “Hey, even I could do better than that”. It was an important moment – the first time it occurred to me that I could actually make a contribution to the field. My plan at first was to write a rebuttal to this terrible, terrible paper. Happily, that rather unambitious plan fell by the wayside as I rapidly started thinking of much more exciting things to write about. (Although my wife might query the description of diplodocoid phylogenetic nomenclature as “interesting”.)
Not long after that, I started casting about for an academic affiliation so that I could get access to journals. It turns out that the easiest way to get an affiliation (unless you’re already established, with a publishing track-record) is to do a Ph.D. Thanks to Darren Naish, who was at that time still at the University of Portsmouth, and who introduced me to Dave Martill, who is now my supervisor, I signed up with UoP in 2004 … and here I am.
I have no plans ever to get a job in palaeo, so in that sense I will never be a “professional”. But I do plan to keep doing research, and to do it to a good professional standard. I just won’t ever get paid for it. That’s because my day-job is too much fun, and too lucrative; and also because there’s something tremendously liberating about not intending to have a career in the field: I don’t need to think about grant proposals, or about making influential friends. or any of that stuff. I also don’t have to grade papers.
- [Switek] Much of your work has been focused on sauropod dinosaurs, and more specifically their vertebrae. What drew you to this area of research? What can a sauropod vertebra tell us about the animal it once belonged to?
[Taylor] Sauropod vertebrae are the most fantastically informative bones you could ever wish to meet. A well-preserved sauropod presacral can tell you more about the animal it came from than any other single bone. It’s hard to overstate just how delicious they can be, which is of course why Matt, Darren and I set up what may be one of the world’s most special-interest blogs, SV-POW! or Sauropod Vertebra Picture of the Week (http://svpow.wordpress.com/). It’s been a delight to write for, because there is just so much to say about sauropod vertebrae.
The thing about them is that they are enormously complex structurally. Your basic vertebra consists of a centrum, which is roughly cylindrical, pointing forward and backwards; and a neural arch above that, with a neural spine sticking up from it. (The arch and spine often mush in together and the terms are sometimes, imprecisely, used interchangeably.) The ends of consecutive centra articulate with each other. Most vertebrae also have extra articular surfaces at the front and back, above the centrum, called the prezygapophyses and postzygapophyses respectively. Then, sticking out the side of the vertebra, there are two pairs of facets for the ribs to attach to: the higher pair are the diapophyses and the lower are the parapophyses. That much is true of most tetrapods. Sauropods greatly improve on this plan in two important and related ways. First, they (in common with theropod dinosaurs, including birds) have air-filled, or “pneumatic”, vertebrae – a feature that shows up in lots of ways, including fossae (broad, shallow depressions) and foramina (narrow, deep depressions that penetrate the vertebral wall). Internal structure varies wildly between taxa, from a few huge spaces in, for example, Camarasaurus, to many small spaces in Saltasaurus. Secondly, sauropods have bony sheets and struts connecting the various parts of the vertebra. These are known as laminae (singular “lamina”) and are also found in a rather unimpressive form in other saurischians and even a little further back up the tree, but they come to full flower in sauropods. Laminae have complicated-sounding names such as the spinoprezygapophyseal lamina (or SPRL for short). But that’s an illusion: their names are actually very simple, and they’re just made by shoving together the names of the parts of the vertebrae that they join. If you want to sound more knowledgeble than you really are about osteology – say because you want to impress a girl at a party – the easiest way is to learn the system of lamina names.
Because the details of air-space and lamination vary so much between different sauropods, individual vertebrae can be tremendously diagnostic in a way that, say, a femur or an ulna can’t be. There’s a also a lot of interesting work to be done on the mechanical ramifications of all this structure – whether a few big spaces or many small spaces yield a stronger vertebra, for example.
Finally, sauropod vertebrae are just plain beautiful. From the elegance of brachiosaurid cervicals via the distinctive rearward bulge of titanosaur caudals to the finely constructed dorsals of diplodocids, sauropod vertebrae are a visual feast. (Except Camarasaurus dorsals. They are stupid and ugly.)
The wonder of sauropod vertebrae was first revealed to me thanks to, again, Matt Wedel, who himself had been obliged to become familiar with them because the only specimen of his taxon Sauroposeidon consisted of a sequence of four cervical vertebrae. It’s strange to think that, in theory, if I had come under someone else’s wing instead in my young and impressionable days, I might now be running Ornithopod Proximal Manual Phalanx Picture of the Week instead … yet somehow I just can’t make myself believe it. I think the essential superiority of sauropod vertebrae would have won through in the end.
- [Switek] Last year, along with Darren Naish, you published a paper about a new genus of sauropod dubbed Xenoposeidon proneneukos. From what I understand, this was one of the rare treasures that was left languishing in museum storage for quite some time and only later “rediscovered.” Can you fill me in on some of the details of the history of the specimen you described, as well as how Xenoposeidon fits in (or not) with other known sauropods?
[Taylor] Actually, it’s not so rare to find treasures that have been languishing in museum storage for quite some time! Museums seem to be full of them, so much so that I don’t feel the slightest desire ever to work in the field – there’s quite enough material in museums waiting to be worked on.
Xenoposeidon is based on (guess!) a single dorsal vertebra; it’s a small one, too, as it goes – small enough to hold comfortably in one hand, and evidently to be overlooked for a long time. It was found by Philip James Rufford, who was best known for his fossil plant collections, and we know it was from somewhere near Hastings, so we concluded that it was probably from the same Hastings Beds Group area where he collected most of his plants – Ecclesbourne Glen or nearby. The vertebra was briefly described by Lydekker in 1893, but you have to realise that in those days sauropod classification was still very, very primitive, and Lydekker had no way really of knowing what it was. He put it down as Morosaurus brevis, then thought to be the best name for the material originally named by Owen in 1842 as Cetiosaurus brevis (and which is also known as Pelorosaurus conybeari, which in turn is not at all closely related to the specimen known as “Pelorosaurus” becklesii. Get used to this sort of thing if you’re going to work on old English fossils.) Of course, Morosaurus is now recognised as a synonym of Camarasaurus, and there is no justification whatsoever for assigning the Cetiosaurus brevis material to Camarasaurus. (Also, Cetiosaurus brevis is not closely related to to Cetiosaurus oxoniensis, which is the animal we all think about when we think about Cetiosaurus. Like I said, best get used to it. Or just don’t think about it.)
Why did Lydekker think that The Vertebra Now Known As Xenoposeidon was the same thing as Cetiosaurus brevis? Because the fossil was the same colour. Seriously: “Now, all these bones are characterized by their ochreous colour, and are thereby very different from those of Hoplosaurus from the Isle of Wight, which are blackish.” By “Hoplosaurus“, which by the way should be spelled “Oplosaurus“, he meant the genus which is usually called either Ornithopsis or Eucamerotus. And with that, I think I will abandon the historical taxonomy (not before time), although there is a lot more that could be said.
The point is that for various reasons, some good and some … not so good, Lydekker completely failed to recognise how weird this bone is. What’s more, everyone who saw it between 1893 and 2006 (if anyone did) also overlooked its significance. I can only put that down to the vastness of the NHM collections – I have no doubt there are plenty more sauropod treasures in there that I’ve yet to notice. For whatever reason, five or six generations of palaeontologists overlooked it, or maybe just had other things to work on that they cared about more: so far as Darren and I were able to determine, it’s not once been mentioned in the literature between 1893 and 2007. So there is very little “history” of the specimen, really – it just sat there for 113 years.
Now I’m not sure if I’m secure enough to admit this in a public venue, but I may as well come out with it: at first, I wasn’t sure which was round the bone went. That’s because backward-sloping neural arches are pretty common in sauropods, but forward sloping is much more unusual – and no other sauropod vertebra neural arch slopes forwards anywhere near as strongly as that of Xeno (which is why we chose the species name proneneukos, which means “inclined forward”.) Also, its laminae are all over the place, and the landmarks that they attach to are mostly missing: the neural spine, the diapophyses and the pre- and postzygapophyses are all smashed off. So it took a bit of detective work to figure out where the preserved laminae are headed as the make their way off the top of the preserved chunk of bone. Well, we got there in the end, and our interpretation is in figure 5 of the paper. (Did I mention that you can download the paper from http://www.miketaylor.org.uk/dino/pubs/taylor-and-naish2007/TaylorNaish2007-xenoposeidon.pdf? You can. There is also a whole bunch of extra information at http://www.miketaylor.org.uk/dino/xeno/.)
So the Xeno vertebra is a nice illustration of what I was saying earlier about how diagnostic sauropod verts are. Even though it’s only about one half of one bone, we can say a lot about its systematic position. To paraphrase from Taylor and Naish (2007:1554): first, we know it’s a sauropod because of the concave articular surface at the back, the lateral fossae in the sides, all those laminae, and, well, just that it’s too big to be pretty much anything else. (Xeno is small for a sauropod, but that still leaves it elephant-sized.) Second, we know it’s in or close to the sauropod clade Eusauropoda because of the height of the preserved part of the neural arch and the deep concavity on the front of the arch. Within that group, we know it’s in or close to Neosauropoda because of the deep lateral foramen and the large pneumatic chambers that we can see inside the centrum through the broken-off part at the front. And the anterior centroparapophyseal lamina shows that it is actually a neosauropod. So we’ve worked our way quite some distance down the tree.
But what kind of neosauropod is it? A diplodocid, like Diplodocus or Apatosaurus? A dicraeosaurid, like Dicraeosaurus or Amargasaurus? A rebbachisaurid, like Limaysaurus or Nigersaurus? A camarasaurid, like Camarasaurus or … er, another species of Camarasaurus? Or maybe a brachiosaurid? Or a titanosaur? The answer seems to be “none of the above”, and that is what’s so exciting about Xeno. Although we have about 0.2% of the skeleton, that’s enough to show pretty convincingly that it doesn’t fit neatly into any of those well-known and established groups. For each group, it has features that are wrong; and it has other features that are totally unique across all sauropods. Its neural arch covers the whole of the top of the centrum, it slopes steeply forward as I mentioned earlier, it has this weird flat area on the side of the neural arch where there are no laminae, fossae or foramina, it has these odd “accessory laminae” below the parapophysis and postzygapophysis, forming a “V”, it has a funny neural canal that is huge and teardrop-shaped at the front but small and round at the back, and finally it has supporting laminae that form a vaulted arch over the front of the neural canal. All very strange, none of it seen elsewhere in sauropods (with the exception of the vaulted anterior laminae, which I’ve not seen described for any other sauropod, but which do exist in a couple more Wealden specimens that have not yet been properly studied).
So what we have seems to be a new “family” of sauropods. I’m using the scare-quotes because I don’t really believe in Linnaean ranks, but since Xeno is a long way morphologically from any other known sauropod, we have to assume that it has a clade of stuff around it that approaches its condition – which means there are lots of juicy new sauropods waiting to be discovered. Now in fact, although as I said above Xeno doesn’t fit any of the well-known neosauropod groups, it pretty much has to be inside one of them, because between them they nearly partition up Neosauropoda. n particular, it has to be either a diplodocoid of some kind (if it’s more closely related to Diplodocus than to Saltasaurus), or a macronarian (if vice versa). But whatever part of the tree it’s from, it’s diverged a long way from the members of the group that we know now. So my hope is that in the next few decades we might find more complete remains of sauropods related to Xeno, (and my guess is that if we do, someone will find it necessary to define a named clade for those animals).
Well, I hope so, anyway! I can’t think of anything more exciting than that someone might find a complete skeleton of a Xeno-like sauropod. I guess it’s bound to happen – we now know that those babies were out there – I just hope it’s in my lifetime.
By the way, some of the TV spots about Xenoposeidon are now up at YouTube. If you have a hankering to see how Xeno comes across on TV, my recommendations are the Channel 4 News interview and one or other of the Meridian spots: the shorter of the two is more graphics-heavy and the longer one has more talking.
- [Switek] Last year you also published a paper about PhyloCode. What is PhyloCode, and how might it potentially change dinosaur taxonomy and systematics?
[Taylor] Well, I have a slightly different view on the Phylocode to most people. (By the way, although current document spells it bicapitalised as “PhyloCode”, I believe the committee has agreed to change the spelling to “Phylocode”, which I think is much nicer.)
The Phylocode is (or will be – read on) a formal code governing the definition of clade names using phylogenetic nomenclature, just as the ICZN (International Code of Zoological Nomenclature) governs the definition of rank-based names for animals: species, genera, families and all the variations thereof (subspecies, superfamily, and so on). The ICZN has been around for quite a while now, and has proven its worth in enforcing a much higher quality in species- and genus-level taxonomy. In order to establish a new taxon to the satisfaction of the ICZN, you have to do a specific set of things: nominate a holotype specimen, state its specimen number, give locality and horizon information, figure the specimen, give a diagnosis that can be used to recognise other specimens, etc. Older acts of taxonomy often didn’t do any or all of these things – for example, the Wealden sauropod genus Eucamerotus was raised and dismissed by Hulke (1872) in a single paragraph: he named it and immediately synonymised it with Streptospondylus, Ornithopsis and Cetiosaurus without even hinting at a diagnosis along the way. Thanks to the ICZN, that sort of cavalier behaviour is no longer tolerated, and now even the very perfunctory new-taxon descriptions that appear in extended-abstract publications like Science and Nature have at least some scientific value.
So, the ICZN governs species and genus-level taxonomy (and families, if you care, although for some reason not higher-level ranks, such as order and class). But at the moment, there is no equivalent code for defining clades using phylogenetic nomenclature (PN). [Before I go on, I should take a moment to say what a clade is, and what phylogenetic nomenclature is. A clade is a “natural” taxon consisting of an ancestor together with all its descendants. For example, Archosauria is a clade, consisting of the most recent common ancestor of crocodiles and birds plus all its descendants – including the dinosaurs. By contrast, Reptilia (as traditionally understood) is not a clade, because the common ancestor of crocs, lizards including snakes, and turtles is also the ancestor of birds, but birds are not considered reptiles. It’s useful to be able to formally define clades by nailing down a common ancestor, as I just did with Archosauria. Doing this is called phylogenetic nomenclature (or sometimes, in older papers, phylogenetic taxonomy). To pick a more exciting example, in 2005 I and Darren gave the old name Apatosaurinae a phylogenetic definition, as the clade of all organisms more closely related to Apatosaurus than to Diplodocus. The new Wyoming Dinosaur Center specimen of Supersaurus shows Supes to be closer to Apatosaurus than to Diplodocus, so it is therefore an apatosaurine.]
Now, here’s the problem: since there’s no code governing how to do PN, we’re still stuck at the stage that Hulke and his buddies were with their species-and-genus taxonomy. Published papers can and do contain some pretty vague and otherwise poor definitions, and it’s not even clear what is and isn’t a definition: for example, Thulborne (1984:124), in a paper on birds, mentioned “the crown-group (Neornithes)” in passing. Is that a PN definition of Neornithes as the most recent common ancestor of all extant birds together with all its ancestors? Right now, it’s up to individual authors to judge the validity of such names. (My 2007 paper tried to establish some guidelines for interpreting this kind of thing, but it carries no authority – it’s just suggestions.)
The Phylocode is the solution to this problem. It’s a relatively short and comprehensible document – at 97 pages including a long, discursive preface and an index, it’s a fraction the size of the ICZN – which says what you have to do to define a clade name. For example, you have to specify the anchor taxa either as species or as specimens which are the types of their species. It seems clear that this is a great leap forward: even die-hard Linnaeists like Mike Benton are defining clades in their work these days, and it seems obvious to me that it’s better to do this under the governance of a code than not. And so far as codes governing PN go, the Phylocode is the only game in town. So as far as I am concerned, every biologist should be firmly behind it.
Unfortunately, quite a lot of traditionalists, notably Benton himself, are dead set against the Phylocode. So far as I can tell, this is mostly because they perceive it as an alternative, and therefore a threat, to the traditional rank-based codes (ICZN for animals, ICBN for plants, etc.) It ain’t so: although earlier drafts of the Phylocode did give the impression of intending to replace the old codes, that language is, quite properly, absent from the current draft, and the Phylocode is now best seen as a complement to the rank-based codes. In fact, I would argue that the Phylocode actually needs the rank-based codes, so they can define the species that it needs as clade specifiers: when Apatosaurinae is defined as everything closer to Apatosaurus ajax than to Diplodocus longus, what exactly do we mean by Diplodocus longus? For an answer to that, we need to go to the rank-based code. Bottom line, clades and rank-based named are completely different kinds of thing, and neither code is a threat to the other.
(A few years ago, I wrote a manuscript called Why Can’t We All Just Get Along? which argued for this separation-of-church-and-state between the codes. The first and second versions of it that I submitted were quite rightly rejected – it needed work – but while I was making the changes suggested by the second set of reviewers, the new Phylocode draft came out and disclaimed all intention of taking over species nomenclature, which rendered my poor manuscript almost completely redundant. Darn.)
So to come back to the actual question you asked, how will the Phylocode change dinosaur phylogeny and systematics? It won’t change anything that’s happening now in regard to species and genus names; and it will give a sound framework to the definition of clades that have so far been defined in an ad-hoc way. Everyone wins.
The key word here, though, is “will”. The Phylocode has not yet been implemented, so while new papers including PN are free to follow its recommendations, the definitions that they form will have no priority when the code finally is implemented. Why the delay in implementing? What’s the hold-up? The code itself has been through several iterations and is ready to go. It seems that the wait is for the “companion volume” to be ready – a big book of Phylocode-compliant PN definitions that is to be launched simultaneously with the code. But since this book is a compendium of many short articles by many authors, it’s a bit of an editors’ nightmare, and it’s anyone’s guess when it’ll be ready. Personally, I think the committee should just go ahead and launch the code ASAP, and let the volume follow when it may.
- [Switek] You have also been involved with the controversy known as “Aetogate,” paleontologists Bill Parker and Jeff Martz accusing New Mexico Museum of Natural History and Science paleontologist Spencer Lucas (and others) of unethical conduct in naming & describing aetosaurs (an extinct group of armored archosaurs). The case has polarized some scientists, but why is it important to see this case through? Regardless of the outcome, how might it affect the careers of professional paleontologists as a group?
[Taylor] At the moment, the Society of Vertebrate Paleontology’s Ethics Committee is considering the evidence in this case: our allegations, Lucas’s defence, our response to that, and Lucas’s response to that. The process is, understandably, taking a while, and I want to be very careful not to say anything that could be seen as attempting to influence that process. I’ll say just two things: first, that all the information, presented as objectively as we can, is freely available at http://www.miketaylor.org.uk/dino/nm/ and interested readers should check it out and make up their own minds. The second is the answer to your question of why we’re pursuing this – and, specifically, why I, a disinterested English worker on a quite different group of animals, am involved. At the risk of sounding grandiose, I can’t explain it better than by quoting Martin Luther King:
“Cowardice asks the question, ‘Is it safe?’ Expediency asks the question, ‘Is it politic?’ Vanity asks the question, ‘Is it popular?’ But, conscience asks the question, ‘Is it right?’ And there comes a time when one must take a position that is neither safe, nor politic, nor popular, but one must take it because one’s conscience tells one that it is right.”
That’s all. If the evidence really does say what we think it says, then what’s been happening in New Mexico is a big deal, and not something that we as a community should sweep under the carpet. If we’ve been mistaken, then Lucas and his colleagues deserve to have that clearly stated and widely known. So we wait to see what conclusion the Ethics Committee reaches. I don’t think it’s overstating matters to say this is just about the most important decision the SVP has ever had to make.
- [Switek] You recently gave a lecture at the Dinosaurs: A Historical Perspective 2008 conference called “The evolution of sauropod dinosaurs from 1841 to 2008.” How has our understanding of sauropods changed during that time? Is the public perception of sauropods in step with our scientific understanding of them?
[Taylor] That’s a pretty big question. I was hoping for something more along the lines of “what’s your favourite colour?” It’s blue, by the way. No, yellow.
To get an idea of how things have changed through time, I recommend the abstract for my talk, which is up at http://www.miketaylor.org.uk/dino/pubs/dahp2008/abstract.html along with a nice figure of the first ever sauropod skeletal reconstruction. The good news is that there will be a conference volume, and I will be writing up my talk as a paper for that volume (I’ve already started, in fact) so interested readers can get the full scoop on sauropod history from there.
Regarding public perception: probably it’s swung too far in the dinosaur-renaissance direction, with Jurassic Park’s gratuitously rearing Brachiosaurus being the worst offender: sauropods made more athletic, and readier to display that athleticism, than we have any right to think realistic. But I don’t mind that too much: I think it’s a good counterbalance to the decades-long dark ages in which sauropods were seen as obligate swamp-dwellers, slow and stupid, unable even to stand up on land. We may have swung too far in the other direction, but my best guess is that we’re closer to the truth now than we were fifty years ago.
- [Switek] One aspect of sauropod paleobiology I’ve always been curious about is the hypothesis that they could stand up on their back legs to reach higher levels of vegetation or (in the case of the AMNH Barosaurus mount) defend themselves from predatory dinosaurs. What is the current status of this hypothesis? Are there any clues in the vertebrae of sauropods that might tell us how blood flow was controlled in animals with such extraordinarily long necks?
[Taylor] I’m glad you asked me that! The current status of this hypothesis is: totally untested! It’s been asserted many times, but only with the barest minimum of quantitative evidence (I have in mind Alexander’s (1985) calculation of centres of mass, and his observation that a Diplodocus would have to shift its hind-feet forward only a little in order to get its CoM above the feet, a precondition for rearing.) On the other hand I do like a reply attributed to Bakker when asked whether sauropods ever reared: “At least males did, sometimes.”
Back in 2000, Matt Bonnan (the king of sauropod appendicular functional anatomy) wrote a classic message to Dinosaur Mailing List which I always have a heck of a time finding. It laid out some of the specific issues that would need to be addressed by a half-decent study into sauropod rearing, and to the best of my knowledge no-one has taken up that challenge yet. Ah, here it is: http://dml.cmnh.org/2000Jul/msg00256.html
To quote the main questions: “how much rotation is possible of the femur in the hip socket of a sauropod? what muscles are involved and what landmarks can be used to verify that these muscle groups are indeed doing what we suggest? what effect does the large tail muscle (caudofemoralis longus) that pulls the femur back have on a rearing sauropod? did sauropods bend their knees when rearing, and if so, what sort of strain and stress did this send through their pelvis, hindlimb, and foot? sauropods have an open hip socket and a cylindrical femoral head: how was force transmitted through this during normal weight bearing, and could the pelvis and hindlimb handle rearing up?” So far as I can tell, that email is still the state of the art on sauropod rearing, and possibly the most important thing that anyone has ever written on the subject. (Matt B., if you’re out there, can’t you find a promising Ph.D student to do it?)
As to blood circulation: there are two main schools of thought on this and other sauropod biology questions. One school, of which Matt Wedel is a strong proponent, is that sauropods were just like extant critters, but bigger. In other words, they did all the same things in the same ways, but with the numbers tweaked a bit. The other school assumes a priori that sauropods were too big to do things the usual way, and must have had anatomical novelties. There have been a lot of these: to list a few off the top of my head, there is the ventral compression-member neck bracing of Martin et al. (1998), the neck elevation by inflated air-sacs of Schwarz et al. (2007), the gill slits in the body proposed by an Irish gentleman whose name eludes me for the moment, the multiple accessory hearts of Choy and Altman (1992) and the closed-loop circulatory siphon of Badeer and Hicks (1996). No doubt I’ve missed some. Now I admit that I am naturally drawn to some (not all!) of these ideas: some make perfect sense from a design-a-better-sauropod perspective. But we need to realise that, for now at least, all of these are totally speculative. At best. (Some are flat-out nonsense; which ones is left as an exercise for the reader.) These hypotheses are badly in need of some quantitative modelling to determine whether they are necessary and/or possible.
So my best guess for sauropod circulation is that it was pretty much like ours but more so. If elevating the head in order to feed induced anoxia, well, so what? Whales deal with it in their hour-long dives, so why shouldn’t sauropods deal with it, too? Lower the heart periodically to get the brain re-oxygenated, then off you go.
I’d love to spend more time on this question, but all my replies are way too long already, so I won’t. One day I will publish on this stuff. For now, though, I have a shedload of alpha taxonomy and cladistics to get through for my dissertation, so all this sexy biomechanical stuff will have to wait for another day.
- [Switek] Are there any paleontologists, past or present, who have been an inspiration to you as you pursue your own career?
[Taylor] Oh, heck, yes, where to start?
I guess Matt Wedel comes in first for me, because without his example, encouragement, collaboration and creative abuse I would still be just another dino-ligger. That I am now some kind of scientist is largely his doing. I love his work, and aspire to match and surpass it. In particular, Wedel et al. (2000) was as comprehensive as possible a paper on Sauroposeidon, and it was explicitly my model in writing the Xenoposeidon paper: the goal with that paper was to say everything there is to say about the specimen, as Matt did with his own -poseidon.
I would then say Darren Naish, but the sheer breadth of his knowledge is more by way of being terrifying than inspiring. Recognising that he knows forty or fifty different tetrapod groups as well as I know sauropods is pretty scary.
Randy Irmis is another one who, were he not such a nice guy, would frighten me. His productivity is astonishing: not just a lot of papers, which some other people also achieve, but a lot of good papers.
Paul Upchurch and Jeff Wilson impress me with the sheer comprehensiveness of their work. I think it’s very typical of Wilson that his 2002 cladistic analysis of sauropods included appendices listing the synapomorphies at every internal node and the autapomorphies at every leaf, while the Sauropoda chapter of Dinosauria II that Upchurch lead-authored (2004) is the definitive survey of sauropods. Paul is also a nice guy who gives the impression of really wanting others’ work to succeed. (Jeff might be, too, but I don’t really know him.)
These people are all in some sense my peers – at least, they are working during the same period of history as I am, though they are all far, far ahead of me. And, by the way, they are only a sampling of the currently active dinosaur palaeontologists that I admire – if I listed them all, we really would be here all night. But looking back half a generation or so, Jack McIntosh has been, and continues to be, a huge inspiration to me – not just because of the quality and importance of his work on sauropods, but also because he did it all in his spare time, being a physicist by vocation. Since I am computer programmer in my day-job and work on sauropods only what I laughably call my spare time, his example is one that I aspire to. He is proof by example that it can be done.
Looking back further, I greatly admire Werner Janensch. He was in Tendaguru (Tanzania) before the First World War, leading the expeditions that excavated, among many other things, Brachiosaurus brancai. And he had the sticking-power to keep working on on that Tendaguru material, through two world wars, for basically the rest of his life. Nearly fifty years after the expeditions, he was still cranking out monographs like his 1961 epic on the appendicular material of the Tendaguru sauropods. His reward is that fifty years on his work is still in constant use: and it still will be in another fifty years.
- [Switek] In the first interview in this series, Robert Bakker stated that the real threat to science education were not creationists but “…the loud, strident, elitist anti-creationists. The likes of Richard Dawkins and his colleagues.” This comment stirred a fair number of rebuttals here and elsewhere on the web, and the question of whether books like The God Delusion are helping or hurting the public’s perception of science is ever-controversial. What are your thoughts on the current debate about the conflict of religion and science (especially when it comes to paleontology & evolution)?
[Taylor] First of all, I make no secret of the fact that I am a Christian. Second, and it really bothers me that I even have to say this, that does not mean I am a creationist – I am absolutely not, and in that respect I am like 90% of Christians. Unfortunately for all of us, of those other 10%, 0.1% are very, very loud, and shout about creationism a lot, tarring the rest of us with the same brush in the eyes of the world and giving the wholly unwarranted impression that Christianity is an unthinking religion. (I am reminded of a quote that I’ve seen attributed to Annie Lennox: “Christianity must have something in it, because it’s survived 2000 years of Christians.”)
In point of fact, there is no conflict whatsoever between Christianity, as it has been historically understood and as it is mostly practised today, and science: many denominations, including Catholicism, explicitly support evolution; the Clergy Letter project at http://www.butler.edu/clergyproject/rel_evol_sun.htm has gathered 11,000 signatures from Christian leaders in support of evolution; many of them teach evolution in their churches. The problem is that fundamentalists on both sides shout so loud that it’s easy to be browbeaten into believing their rhetoric: whether it’s Ken Ham saying that if you believe in evolution you can’t be a Christian, or Richard Dawkins saying that if you believe in any religion you’re not merely mistaken but deeply stupid. It’s for this reason that most of the other Christians I know in palaeo (and, yes, there are quite a few, including some well-known names) keep quiet about it: not because they are ashamed of Christianity per se, but because they are ashamed to be wrongly tarred with the same brush as your Ken Hams, by your Richard Dawkinses. (As an evangelist for the science of evolution, Dawkins used to be superb; but since he’s abandoned that calling in favour of full-time religion-bashing, he’s pretty much thrown away the chance he had of demonstrating to creationists the error of their ways, because he now explicitly sets himself up as their enemy. Not so bright.)
I think most problems of the science-vs.-religion kind come about from fuzzy thinking. We’d probably all agree that science is the best available tool for figuring out what happens in the universe and how it happens. Religion, properly understood, doesn’t really involve itself with those questions at all, but with why things are as they are, and with who is ultimately responsible for it all. This distinction is of course is what Gould (1997) was referring to in his concept of Non-Overlapping Magisteria (NOMA). Gould himself was an atheist, or at least agnostic; but he understood what kind of a thing religion is, and respected it on its own terms rather than holding it in contempt because it’s not science. You know, a lot of things are not science: literature, music, relationships, the visual arts – and religion. Those things should certainly not be dismissed because of their not being science, which is a mistake that a lot of scientists have a propensity to make. Yes, it’s true that science can and does inform all of those areas; but it is not at the heart of them.
So while I don’t have the slightest expectation of persuading anyone who reads this interview that Christianity is true, I do hope at least to open up a little understanding between two camps that are not so much opposed to each other as they are at right angles to each other. From scientists who are not sympathetic to religion, we could stand a little less of the “sky fairy” stuff; and from any Christians who hang around this blog supporting creationism: guys, give it a rest. Religion is not science; neither the Bible nor historical Christianity teaches creationism, and it has not the slightest scientific foundation. Creationists who think they’ve come up with a slam-dunk argument when they say “Ah, but what about the eye?” sound just as foolish to evolutionary scientists as atheists who say “Ah, but who made God?” sound to Christians. Both groups could usefully assume that the other has thought through basic issues.
Well, it’s a shame to end this interview on a controversial note that, probably, everyone will hate equally but from opposite directions. It would have been nice to end with a sauropod vertebra … something that we can all agree on! So let me just close by reminding everyone that, down in the basement of the Natural History Museum, just a few rows across from the Xeno holotype, are the many elements of Migeod’s (1931) Tendaguru sauropod: at least five cervicals, two complete dorsals, two more dorsal centra and a neural spine, plus some appendicular bits and pieces and a shedload of as-yet unopened jackets left over from 1930. Like Xeno, that specimen has been overlooked for far too long – ever since it arrived, in fact – but also as with Xeno, that’s set to change! The paper won’t be out for a little while yet (because, er, I’ve not actually written it yet), but I promise you some nice surprises when it arrives.
Finally, many thanks to Brian for inviting me to do this. Sorry to have gone on for so very long – it’s about three times as long as even I’d expected, but then Brian does ask such darned interesting questions.
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