Neural spine bifurcation in sauropods, Part 6: more reasons why Haplocanthosaurus is not a juvenile of a known diplodocid
April 15, 2012
Last time, we saw why Haplocanthosaurus couldn’t be a juvenile of Apatosaurus or Diplodocus, based on osteology alone. But there’s more:
Ontogenetic status of Haplocanthosaurus
Here is where is gets really surreal. Woodruff and Fowler (2012) blithely assume that Haplocanthosaurus is a juvenile of something, but the type specimen of the type species — H. priscus CM 572 — is an adult. As Hatcher (1903:3) explains:
The type No. 572 of the present genus consists of the two posterior cervicals, ten dorsals, five sacrals, nineteen caudals, both ilia, ischia and pubes, two chevrons, a femur and a nearly complete series of ribs, all in an excellent state of preservation and pertaining to an individual fully adult as is shown by the coössified neural spines and centra.
So far as I can see, Woodruff and Fowler are confused because the second species that Hatcher describes, H. utterbacki, is based on the subadult specimen CM 879. Where possible in the previous post, I have used illustrations of the adult H. priscus, so that the comparisons are of adult with adult. The exceptions are the two anterior cervicals and the first dorsal, which are known only from H. utterbacki. And sure enough, if you look closely at the illustrations, you can see that in these vertebrae and only these vertebrae, Hatcher had the neurocentral junction illustrated — because it wasn’t yet fused.
Haplocanthosaurus posterior, mid and anterior cervical vertebrae, C14, C9 and C4, in right lateral view. C14 of adult H. priscus (from Hatcher 1903:plate I); C9 and C4 of H. utterbacki (from plate II). Red ellipses highlight neurocentral sutures.
As it happens, the difference in ontogenetic status between these two specimens is nicely illustrated by Wedel (2009), although he was only in it for the pneumaticity:
Neurocentral fusion in Haplocanthosaurus. A, B. Posterior cervical vertebra C?12 of sub-adult H. utterbacki holotype CM 879: A, X-ray in right lateral view; B, coronal CT slice showing separate ossificaton of centrum and neural arch. C, D. Mid-dorsal vertebra D6 of adult H. priscus holotype CM 572: X-rays in (A) right lateral and (B) anterior view, showing fully fused neural arch. Wedel (2009:fig. 6)
So H. utterbacki CM 879 certainly is an immature form of something; and that something is Haplocanthosaurus, most likely H. priscus. (The characters which Hatcher used to separate the two species are not particularly convincing.)
With that out the way, we can move on to …
Phylogenetic analysis
A simple way to evaluate the parsimony or otherwise of a synonymy is to use a phylogenetic analysis. In their abstract, Woodruff and Fowler claim that “On the basis of shallow bifurcation of its cervical and dorsal neural spines, the small diplodocid Suuwassea is more parsimoniously interpreted as an immature specimen of an already recognized diplodocid taxon”. Without getting into the subject of Suuwassea again — Matt pretty much wrapped that up in part 4 — the point here is that the word “parsimony” has a particular meaning in studies of evolution: it refers to minimising the number of character-state changes. And we have tools for measuring those.
So let’s use parsimony to evaluate the hypothesis that Haplocanthosaurus is one of the previously known diplodocids. Pretending for the moment that Haplocanthosaurus really was known only from subadults, how many additional steps would we need to account for if ontogeny were to change its position to make it group with one of the diplodocids?
You don’t need to be a cladistics wizard to do this. (Which is handy, since I am not one.) Here’s the method:
- Start with an existing matrix, add constraints, re-run it, and see how the tree-length changes. Since I am familiar with it, I started with the matrix from my 2009 paper on brachiosaurs.
- Re-run the matrix to verify that you get the same result as in the published paper based on it. This gives you confidence that you’re running it right. In this case, I got a minimum tree length of 791 steps, just as in Taylor (2009).
- Add extra instructions to the run-script defining and imposing constraints. Note that you do not have to mess with the characters, taxa or codings to do this.
- Run the matrix again, with the constraint in place, and see how the tree-length changes.
- Repeat as needed with other constraints to evaluate other phylogenetric hypotheses.
(This is how we produced the part of the Brontomerus paper (Taylor et al. 2011:89) where we said “One further step is sufficient to place Brontomerus as a brachiosaurid, a basal (non−camarasauromorph) macronarian, a basal (non−diplodocid) diplodocoid or even a non−neosauropod. Three further steps are required for Brontomerus to be recovered as a saltasaurid, specifically an opisthocoelicaudiine”. And that’s why we weren’t at all dogmatic about its position.)
Anyway, going through this exercise with Haplocanthosaurus constrained in turn to be the sister taxon to Apatosaurus, Diplodocus, etc., yielded the following results:
- (no constraint) — 791 steps
- Apatosaurus — 817 (26 extra)
- Diplodocus — 825 (34 extra)
- Barosaurus — 815 (24 extra)
- Camarasaurus — 793 (2 extra)
- Brachiosaurus — 797 (6 extra)
(I threw in the other well-known Morrisson-Formation sauropods Camarasaurus and Brachiosaurus, even though Woodruff and Fowler don’t mention them, just because it was easy to do and I was interested to see what would happen. And when I say Brachiosaurus, I mean B. altithorax, not Giraffatitan.)
I hope you’re as shocked as I am to see that for Haplocanthosaurus to emerge as the sister taxon of any diplodocid needs a minimum of 24 additional steps — or an incredible 34 for it to be sister to Diplodocus. In other words, the hypothesis is grossly unparsimonious. Of course, that doesn’t in itself mean that it’s false: but it does render it an extraordinary claim, which means that it needs extraordinary evidence. And while “the simple spines of Haplocanthosaurus might bifurcate when it grows up” is extraordinary evidence, it’s not in the way that Carl Sagan meant it.
In short, running this simple exercise — it took me about a hour, mostly to remember how to do constraints in PAUP* — would have given Woodruff and Fowler pause for thought before dragging Haplocanthosaurus into their paper.
Oh, and it’s ironic that placing Haplo as sister to Brachiosaurus requires only a quarter as many steps as the closest diplodocid, and as sister to Camarasaurus requires only two steps. If you really want to synonymise Haplocanthosaurus, Camarasaurus is the place to start. (But don’t get excited, it’s not Camarasaurus either. It’s Haplocanthosaurus.)
[By the way, anyone who’d like to replicate this experiment for themselves is welcome: all the files are available on my web-site. You only really need the .nex file, which you can feed to PAUP*, but I threw in the log-file, the generated tree files and the summary file, too. Extra Credit: run this same exercise to evaluate the parsimony of Suuwassea as a subadult of one of these other genera. Report back here when you’re done to earn SV-POW! points.]
Conclusion
It’s a truism that we stand on the shoulders of giants. In the case of sauropod studies, those giants are people like J. B. Hatcher, Charles Gilmore, Osborn and Mook and — bringing it up to date — John McIntosh, Paul Upchurch, Jeff Wilson and Jerry Harris. When Hatcher described Haplocanthosaurus as a new genus rather than a subadult Diplodocus, he wasn’t naive. He recognised the effects of ontogeny, and he was aware that one of his two specimens was adult and the other subadult. He was also probably more familiar with Diplodocus osteology than anyone else has ever been before or since, having written the definitive monograph on that animal just two years previously (Hatcher 1901).
By the same token, people like Upchurch and Wilson have done us all a huge favour by making the hard yards in sauropod phylogenetics. If we’re going to go challenging the standard consensus phylogeny, it’s just good sense to go back to their work (or the more recent work of others, such as Whitlock 2011), re-run the analyses with our pet hypotheses encoded as constraints, and see what they tell us.
So in the end, my point is this: let’s not waste our giants. Let’s take the time to get up on their shoulders and survey the landscape from up there, rather than staying down at ground level and seeing how high we can jump from a standing start.
The rest of the series
Links to all of the posts in this series:
- Part 1: what we knew a month ago
- Part 2: why serial position matters
- Part 3: the evidence from ontogenetic series
- Part 4: is Suuwassea a juvenile of a known diplodocid?
- Part 5: is Haplocanthosaurus a juvenile of a known diplodocid?
- Part 6: more reasons why Haplocanthosaurus is not a juvenile of a known diplodocid
and the post that started it all:
References
- Hatcher, J.B. 1901. Diplodocus (Marsh): its osteology, taxonomy, and probable habits, with a restoration of the skeleton. Memoirs of the Carnegie Museum 1:1-63.
- Hatcher, J.B. 1903. Osteology of Haplocanthosaurus with description of a new species, and remarks on the probable habits of the Sauropoda and the age and origin of the Atlantosaurus beds; additional remarks on Diplodocus. Memoirs of the Carnegie Museum 2:1-75.
- Taylor, M.P. 2009. A re-evaluation of Brachiosaurus altithorax Riggs 1903 (Dinosauria, Sauropoda) and its generic separation from Giraffatitan brancai (Janensch 1914). Journal of Vertebrate Paleontology 29(3):787-806.
- Taylor, M.P., Wedel, M.J. and Cifelli, R.L. 2011. A new sauropod dinosaur from the Lower Cretaceous Cedar Mountain Formation, Utah, USA. Acta Palaeontologica Polonica 56(1):75-98. doi:10.4202/app.2010.0073
- Wedel, M.J. 2009. Evidence for bird-like air sacs in saurischian dinosaurs. Journal of Experimental Zoology 311A:611-628.
- Whitlock, J.A. 2011. A phylogenetic analysis of Diplodocoidea (Saurischia: Sauropoda). Zoological Journal of the Linnean Society 161(4):872-915. doi: 10.1111/j.1096-3642.2010.00665.x
- Woodruff, D.C, and Fowler, D.W. 2012. Ontogenetic influence on neural spine bifurcation in Diplodocoidea (Dinosauria: Sauropoda): a critical phylogenetic character. Journal of Morphology, online ahead of print.
Sauropod Vertebra Picture of the Week 
April 15, 2012 at 4:46 pm
Surely Jack McIntosh should have been included as a “giant”…
Mike and Matt, this series has been exceptional. Can’t wait to see it in paper-form!
April 15, 2012 at 5:15 pm
Yes, Jack McIntosh is definitely one of the giants: I have amended the list accordingly, thanks for pointing it out. We have only one more part to be posted in this series, and that’s one’s written and ready to go already. Once that’s done, we’ll be ready to think about what it will take to turn it into a paper, and where to send it. Thanks for your encouraging words!
April 15, 2012 at 6:49 pm
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April 15, 2012 at 6:54 pm
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April 15, 2012 at 6:54 pm
[…] Part 6: more reasons why Haplocanthosaurus is not a juvenile of a known diplodocid […]
April 15, 2012 at 6:55 pm
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April 15, 2012 at 6:56 pm
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April 15, 2012 at 10:53 pm
Suuwassea sister to Apatosaurus- 793 (2 extra)
Suuwassea sister to Diplodocus- 799 (8 extra)
Suuwassea sister to Barosaurus- 799 (8 extra)
Suuwassea sister to Brachiosaurus- 804 (13 extra)
– Brachiosaurus actually moves into Diplodocoidea.
Suuwassea sister to Camarasaurus- 812 (21 extra)
So I’d say based on this matrix, Suuwassea being a juvenile Apatosaurus is just fine, it being a juvenile diplodocine or brachiosaurid is less likely, and it being a juvenile Camarasaurus is probably untrue. Of course, checking it in Whitlock’s more diplodocoid-centered matrix would be preferrable, and this doesn’t take into account other factors.
April 15, 2012 at 11:06 pm
It’s not a huge shock that Mickey wins the SV-POW! points :-)
I am a bit surprised that Suuwassea makes a better Brachiosaurus than it does a Camarasaurus, but what really freaks me out is the idea of Brachiosaurus being pulled into Diplodocoidea.
“Suuwassea being a juvenile Apatosaurus is just fine” — well, no. Suuwassea being closely related to Apatosaurus is fine, but there’s no reason to think the type specimen is a juvenile anything.
Yes, I’ll probably run this in Whitlock’s matrix for the paper. For the blog post, I used mine just because I am already familiar with it and know that I know how to run it.
April 15, 2012 at 11:44 pm
Lets remember though that phylogenetic characters for phylogenetic analyses don’t really do a good job encapsulating ontogenetic variation, so its important to take the constraint analyses with a grain of salt.
April 16, 2012 at 2:43 am
I’ve only looked at the first post, and the first few lines of this, although I am told that you said that there are adults at the mother’s days site, and that we misidentify adult anterior cervs as juvie posterior. Hmm… I should take a closer look at that material if I were you…
Still, I can’t believe you wrote TWO blog postings on what is half a sentence in the paper that just says:
“Haplo.. (etc).. MIGHT be a known diplodocid”
You say we “blithely assume”; we actually said “MIGHT”. I already made a correction on my personal website iterating what we should have said, but even so, it is telling that you don’t use quotes when misrepresenting the paper. You seem to be getting terribly worked up about a nothing-statement in our paper.
Anyway, submit this as a comment to a proper journal and we will respond. As it stands, these blog-postings are a gross mischaracterisation of our paper that uses unfair and inaccurate language. You don’t have to agree with the research, and we may make some mistakes, but the attitude with which this blog is written is anything but professional.
Oh, and get your own research ideas. Investigating bifurcation is (in part) Cary’s MS project. You’re not acting much better than your characterisation of Spencer Lucas in your “aetogate” stories.
April 16, 2012 at 3:48 am
I’m having a difficult time understanding how scientific criticism of a *published* paper using *published* specimens (not just published, but monographed over 50 years ago!) is the same as scooping unpublished theses.
I’m not sure how Denver can get on his high horse when he hasn’t even bothered to read all the posts. I’d be interested to know what he thinks is “unfair and inaccurate”? I actually think Matt and Mike, although maybe using casual language, stick to the science quite well, perhaps with the exception of ‘blithly assume.’ Oh, and that comment was about Haplo. being a juvenile, NOT as Denver seggests, about Haplo. being a diplodocid.
P.S., they’ve already stated that they’re planning to submit to a peer-reviewed journal. There’s nothing wrong with trying to get constructive feed-back from the community before publishing.
April 16, 2012 at 6:39 am
Randy cautions:
Of course. That’s why I used the wording:
April 16, 2012 at 6:46 am
Mike – sorry; I wasn’t clear. I was mainly replying to Mickey’s evaluation of the Suuwassea constraint analyses about likelihood of being another taxon; as in, I’m not really sure what 2 extra steps to be sister to Apatosaurus really tells you. In retrospect my comment probably wasn’t necessary, but we all get the picture I think.
April 16, 2012 at 7:22 am
I’ve only looked at the first post, and the first few lines of this, although I am told that you said that there are adults at the mother’s days site, and that we misidentify adult anterior cervs as juvie posterior. Hmm… I should take a closer look at that material if I were you…
Well, as you are fond of saying, falsify the hypothesis. But do read the post first, and see what I actually wrote, and why I wrote it.
As it stands, these blog-postings are a gross mischaracterisation of our paper that uses unfair and inaccurate language.
Wait–how can you say that when by your own admission you haven’t read them yet? Also, where is the unfair and inaccurate language? Please point me to it.
You don’t have to agree with the research, and we may make some mistakes, but the attitude with which this blog is written is anything but professional.
Really? We started with what has been in the published literature for ages, to try to get a handle on the problem. Then we went through the evidence in your paper as carefully and thoughtfully as we could. Where we disagreed with your interpretations, we documented why that was so, with illustrations, direct quotes from other papers, and copious citations. Throughout, we tried to avoid editorializing or unfairly criticizing your work. I may be biased here, but I think that we have been about as professional as possible.
Unless you are making the mistake of interpreting “professional” as “only says nice things even when confronted with gross factual inaccuracies”, in which case I think we are working in different professions.
Oh, and get your own research ideas. Investigating bifurcation is (in part) Cary’s MS project. You’re not acting much better than your characterisation of Spencer Lucas in your “aetogate” stories.
Wait, now I’m completely lost. If someone publishes on a topic, and we disagree with their treatment and rebut some of their points, after the paper is published and citing that work at every step, that counts as scooping!? I wonder, would you be accusing us of stealing other people’s research ideas if our coverage of the paper had been more positive?
April 16, 2012 at 7:27 am
Oh, sorry Randy, misread your comment.
April 16, 2012 at 7:40 am
Hi, Denver, thanks for chipping in.
If we were mistaken in our assessment of that material, we’d appreciate being corrected before we submit for publication. Matt’s argument in laid out in this post (skip down to the What is MOR 790 8-10-96-204? section if you don’t have time to read it all). It looks solid to me — where is the mistake?
That’s the plan. It’s here out in the open so that anyone who sees mistakes in it can let us know before we submit. Obviously that includes Cary and you, the people who best know the paper we’re critiquing.
Just for the record: I don’t accept that. If you want to make the accusation stick we’ll need details of the alleged unprofessionalism. What we set out to do is respond scientifically to a scientific paper.
I’m sure I’m misunderstanding you here: you seem to be saying that no-one but Cary should be allowed to work on bifid spines, but that can’t be right, especially in response to a published paper. So what do you mean?
Finally, and most seriously: having chewed this over a fair bit, I can’t begin to understand what you mean by comparing our public scientific response to a published scientific paper with the documented instances of plagiarising unpublished work that were Aetogate. I think you had better either substantiate or withdraw that allegation. (While you’re at it, it would be nice if you’d withdraw your earlier unsubstantiated allegation of bullying as well.)
April 16, 2012 at 7:50 am
Oops — Matt and I crossed in the post, writing essentially the same things in response to Denver. Sorry for the duplication.
April 16, 2012 at 12:39 pm
Wow, I am deeply flattered at being included in that list of “greats,” though I really don’t agree with it! I’ve really just dabbled in sauropods a bit, whereas that others you list made systematic, career-long contributions to these amazing animals. They definitely deserve all the accolades!
April 16, 2012 at 12:50 pm
Well, Jerry, you’re on there because your series of four papers on Suuwassea (cranial, axial and appendicular anatomy, and phylogeny), at 15, 31, 22 and 14 pages, together constitute an 82-page monographic description that is (in the best sense) a throwback to the work of people like Hatcher. Your baby is, by some distance, the best-described new sauropod since at least 1936 (depending on whether you count Apatosaurus as having been new back then, which is at best tenuous).
April 16, 2012 at 2:29 pm
Thanks Mike…I myself am a huge fan of monographic descriptions that don’t skimp on details! I had a few complaints that having the description dissected and scattered across several journals made “assembling” an ad hoc “monograph” more painful than it ought to have been, but given that the places that produce monographs these days (well, last decade) don’t have the distribution or visibility of other sources, and given that I couldn’t find a journal that would publish the papers serially in a single issue or two (they all seem to have policies against that), it was the only real solution at the time. Too bad I wasn’t keyed into PLoS back then!
April 16, 2012 at 2:33 pm
Actually Jerry I quite like it like that. While monographs are great, something like this that is carefully dissected does mean it’s relatively easy to sit and read say the phylogeny bit or check a detail on a femur without having to backtrack and cross reference across a whole massive paper.
April 16, 2012 at 2:47 pm
“I couldn’t find a journal that would publish the papers serially in a single issue or two (they all seem to have policies against that).”
That has to be one of the most stupid things I have ever heard.
You are dead right, though, that PLoS is the way to go now. When I come to think of the other sauropods that have been given the proper treatment post-Gilmore, all I can think of is three Asian-produced monographs: Upchurch et al. (2005) on the Tokyo Apatosaurus, Ouyang and Ye (2002) on Mamenchisaurus youngi and He et al. (1988) on Omeisaurus tianfuensis. (There are some good, comprehensive sauropod descriptions in PLoS ONE, but none of them is badsed on an at all complete specimen.)
April 16, 2012 at 4:04 pm
Jerry, are costs also a limitation of publishing monographs in paleontological journals? In my own field, Wildlife Monographs costs ~ $12,000-$14,000 to publish a manuscript, which is well out of the range of a manageable cost without a decent research budget behind you.
If PLoS were to add a section that allows for review papers (I’m currently working on a review of within-Carnivore interspecific killing on and by the world’s felid species that, even while its associated database is unfinished, has over 320 references of dietary and observed mortality interactions), I’d publish there without a second thought. As it is, the most likely solution is for me to use a journal’s supplementary information for the copious numbers of references that I’ve collected (at the project’s completion, I suspect that I’ll have 450-500 compiled), which is a less than optimal way of going about a project like this.
April 16, 2012 at 4:06 pm
Er, that should read ‘within-Carnivora.’
April 16, 2012 at 4:27 pm
Tor, I have spoken to Pete Binfield a couple of times about the desperate need for a PLoS-like journal that accepts review papers — either extending PLoS ONE’s remit to include reviews, or adding a new PLoS Reviews journal. I know that the idea is floating around at PLoS Towers. Whether anything will come of it or not, I don’t know — nor whether, if it does happen, it will be in time for your paper — but it’s something.
In your position I would write to PloS, and particularly PLoS ONE, outlining the situation you’re and making them aware that your case is not an isolated one. It can only help to make them aware of the need.
I know of a recentish review paper that was turned away from PLoS ONE and eventually had to be brutally cut to fit the length limits of the barrier-based journal that it ended up in. So the paper is less useful than it would have been even for those lucky few who can get it at all. How does that help to accelerate progress in science and medicine?
April 16, 2012 at 5:38 pm
Tor–yes, almost certainly costs are the primary reason most journals don’t do monographs, at least in paleontology. Most paleo monographs today–and, come to think of it, in the past–are/were published in in-house journals that presumably have internally funded budgets to cover such things. But those monographs are/were also dominated by, if not exclusive to, employees of the same institutions–for someone outside to try to get in is difficult and often expensive.
April 16, 2012 at 7:52 pm
“When I come to think of the other sauropods that have been given the proper treatment post-Gilmore, all I can think of is three Asian-produced monographs …”
Oh, and of course McIntosh et al. (1996) on the Gunma Museum Camarasaurus. Silly me.
April 16, 2012 at 8:23 pm
AND the other McIntosh et al. (1996), on Camarasaurus lewisi. And we should probably include McIntosh (2005) on Barosaurus, too, although I would kill for a set of gatefold plates of the Barosaurus material to match the plates in Hatcher and Gilmore.
Still, the general point is sound: that in sheer exhaustive detail, Jerry’s Suuwassea papers are a high-water mark for sauropod descriptions. We should all aspire to do as well.
April 16, 2012 at 8:34 pm
Sorry, dude — I respect McIntosh as much as the next man, but the C. lewisi description and 2005 Barosaurus revision are really not the same kind of thing as the classic descriptive monographs.
Agreed on Jerry, though.
If I could live my life all over again, I would make more of an effort to have illustrated the various Brontomerus elements from more angles, as we did for that nice caudal.
April 16, 2012 at 9:28 pm
>>>blush<<<
April 22, 2012 at 4:13 am
So I sat and read the other posts. You make fair points (although I do not agree with them all); it saddens me that we didn’t make things clear enough in the paper such that some issues would not have arisen, and that we included some sloppy phrasing (for which I will take the blame). I trust Cary’s follow-up will include more of the required details; with better detailed descriptions it will become more clear that bifurcation is indeed ontogenetic.
I appreciated your approach in the review of a previous MS, so I apologise if my comments have seemed unreasonable. I am not apologizing unreservedly because I did find terms like “ontogeny fairy”, “tarred with the hornerite brush” (etc.) to be unnecessary. Maybe these were meant in good humor, but they were not received as such. If you’re writing a rebuttal to another’s work it would be better to stick to the printed matter (as in replies 1-5 of this series, which I thought were well done).
We look forward to further discussion in print.
April 22, 2012 at 9:12 pm
Hi, Denver, thanks for this — good to read.
Good, too, to know that Cary has more work coming up on sauropod vertebral ontogeny. I’ll admit up front that, having looked into the claims of the first paper, I am skeptical that he’ll be able to show that bifurcation is primarily ontogenetic, but I’m always open to new data or insights. We’ll see what happens.
On “I apologise if my comments have seemed unreasonable. I am not apologizing unreservedly” — can I assume that the parts you are apologising for are the accusations of bullying and plagiarism? I won’t deny that those rankle, and it’ll be good to put them to bed.
On “ontogeny fairy” — I have to admit that I laughed when I saw that (it’s one of Matt’s). You can certainly rest assured that we won’t be expressing our thoughts in those terms in the paper! On “tarred with the Hornerite brush” — I can’t find that phrase anywhere on SV-POW!. Matt says “tarred as a Hornerite” in a comment, which might be what you’re talking about, but that was in response to a comment of yours where you introduced the term “Hornerite”, so I’m not sure you have grounds for complaining at Matt’s use of the same term. At any rate, Matt’s often been called a Padianite and more than once referred to himself as such, so I’m not sure “Hornerite” is anything to get too worried about. (Just don’t call me a Martillite! :-) )
April 28, 2012 at 11:35 pm
Mickey Mortimer wrote:
I ran the same analysis myself, since I’ll be putting numbers for Suuwassea in the paper. Mickey, I got exactly the same results for you except in the case of Camarasaurus, where I was getting trees of length 811 (20 extra steps) rather than your 812. Not only that, I am getting 12 such trees, so it’s not that there’s just one hiding somewhere in the search space that I happened to land on and you didn’t.
Any idea why the difference? I am using these PAUP* commands:
April 29, 2012 at 8:11 pm
[…] arising from our response to Woodruff and Fowler (2012) [part 1, part 2, part 3, part 4, part 5, part 6]. Here is an oddity. Sacra of Haplocanthosaurus. Top, H. utterbacki holotype CM 879 in right […]
June 27, 2012 at 9:21 pm
good series guys. I don’t agree with the Horner-school of minimalist taxonomy (which my doctor friend says is because geologists are dabbling in biology).
Still, I do think raising controversy is good for paleontology (such as the Woodruff and Fowler article) because it causes a deeper and more thorough look at the data/specimens (as it prompted you to do). Therefore, I will defend the oppositions right to be wrong. Science benefits in the end.
Long live Suuwassea!
Ken
June 27, 2012 at 9:33 pm
Thanks, Ken, I’d agree with all that. If nothing else, it provoked Matt and me to write a paper (based heavily on this series of blog posts) that is now in review.
October 2, 2017 at 7:42 am
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