In a comment on the initial Shunosaurus tail-club post, Jaime Headden pointed out the passage in the Spinophorosaurus paper (Remes et al. 2009) that discusses the club of Shunosaurus (as justification for positioning the Spinophorosaurus osteoderms on the end of its tail):
With the holotypic skeleton, two closely associated dermal ossifications were found originating from contralateral sides (Fig. 4A–C). These elements have a subcircular base that is rugose and concave on its medial side, and bear a caudodorsally projecting bony spike with a rounded tip laterally. Although these elements were found in the pelvic region under the dislocated scapula, we regard it as most probable that they were placed on the distal tail in the living animal for the following reasons: First, the close association of the contralateral elements indicates they were originally placed near the (dorsal) midline of the body. Second, the stiffening of the distal tail by specialized chevrons is also found in other groups of dinosaurs that exhibit tail armor [42,43]. Third, osteoderms of similar shape are known from the closely related basal eusauropod Shunosaurus [26]. In the latter form, these elements cover the middle part of a tail club formed by coalesced distal vertebrae; however, the decreasing size of the distal-most caudal vertebrae of Spinophorosaurus indicate that such a club was not present in this genus. The right osteoderm is slightly larger and differs in proportions from the left element, indicating that, as in Shunosaurus [26], originally two pairs of tail spines were present (Fig. 5).
– Remes et al. (2009:6-8)
And this gives the reference that I needed for the Shunosaurus tail-spikes (as opposed to the club) — reference 26 is Zhang (1988), which, embarrassingly, we’ve featured here on SV-POW! in our first Shunosaurus post. Evidently I was so focussed on preparapophyses when I looked at that monograph that I completely failed to register the tail-club spikes — but then, which of us can truly say he has not made that mistake?
Anyway, here’s what Zhang has to show us:
And here’s that tail again, this time from the poorly reproduced photographic plate 12, part 1, and in right lateral view:
It’s apparent that this really is the other side of the distal tail (rather than a reversed image of the same side) because the osteoderms are in front of the club vertebrae in the left-lateral figure, but behind them in the right-lateral plate.
It would be great to say more about these, but the English language summary of Zhang’s monograph is understandably brief, constituting six pages of the 90. What’s not quite so understandable is that neither the diagnosis of the genus Shunosaurus nor that of the species S. lii mentions the tail-club or spikes, which are arguably the most distinctive features. The “revised diagnosis” on pp. 78-79 does, however — just:
Posterior caudals platycoelous, with small cylindrical centra; neural spines low, rod-like. In several last caudals swollen ralidly [sic] and forming “tail-mace”; in addition there are two pairs of little caudal spines, being analogous to that of stegosaurs.
Not much to go on, but something. That’s all, though — there is no further description, and crucially, no indication of whether the tail elements were found articulated or whether the spikes were found isolated and subsequently moved to the end of the tail. It may be that Remes at al. know something I don’t, of course — they might have a translation of Zhang (1988) — but if not, then it’s amusing to consider that the spikes on the tail of Shunosaurus may or may not be supported by evidence, and that the inference of tail-spikes on Spinophorosaurus might be based on dodgy premises.
The other thing that struck me forcibly, as I looked at the figure and plate above, is that the caudal vertebrae remain fairly complex all the way to the end: they retain distinct and prominent neural spines, unlike the distal caudal vertebrae of diplodocids and brachiosaurs. I notice that the distal caudals of Spinophorosaurus also seem to be complex, based on fig. 3H-I and also on the skeletal reconstruction that is fig. 5 — both of which we’ve reproduced before, in our old Spinophorosaurus article.
So what’s going on here? Are Shunosaurus and Spinophorosaurus unusual in having distal caudals that retain complex neural spines? If so, is this property correlated with the possession of a tail-club and/or spines? Is it causally related? Or could it be that this is normal for basal eusauropods, and my ideas of sauropod tails have been too coloured by extreme neosauropodocentricity? Clearly I ought to go and look at a lot more basal sauropods’ distal tails before publishing this post. And prosauropods’, theropods’, ornithischians’, pterosaurs’, crocadilians’ and lizards’ distal tails.
As it happens, the one non-neosauropod group of reptiles whose distal tails I do know something about is monitor lizards, thanks to my adventures with the corpse of “Charlie”. And those caudals do maintain astonishingly detailed structure right to the end of the tail, with even absolutely tiny caudals having distinct processes. Here are some photographs that show this.
First, one showing all 56 caudal vertebrae (the 1st is half in frame at top right, next to the sacrum; the rest read from left to right on successive rows, like words on a page).
Now here are five representative caudals from different regions on the tail — the last ones from each row in the picture above, as it happens: caudals 1, 10, 21, 30, 42 and 56. They are in more or less dorsal view, though caudal 1 has fallen forward onto its anterior face. In this and subsequent pictures, caudal 10 (the second shown) is for some reason back to front.
Now here are the same vertebrae, in the same order and orientation, but now in left dorsolateral aspect (except caudal 10 which is of course in right dorsolateral):
Finally, here are the three smallest of these vertebrae (numbers 30, 42 and 56) in close-up, again in left dorsolateral view, so you can more easily see how much structure even the distalmost caudal has:
That last caudal is about 2.5 mm long.
(It’s interesting that caudals 30 and 42 have those cute fused chevrons.)
So anyway: we know that caudal vertebrae retain distinct structure all the way down to the tip of the tail in monitor lizards at least some basal eusauropods: could it be that this is the primitive state, and that degenerate caudals are found only in neosauropods and mammals? Gotta prep out some more animals’ skeletons and find out!
References
- Remes, Kristian, Francisco Ortega, Ignacio Fierro, Ulrich Joger, Ralf Kosma, Jose Manuel Marin Ferrer, for the Project PALDES, for the Niger Project SNHM, Oumarou Amadou Ide, and Abdoulaye Maga. 2009. A new basal sauropod dinosaur from the Middle Jurassic of Niger and the early evolution of Sauropoda. PLoS ONE 4(9):e6924. doi:10.1371/journal.pone.0006924
- Zhang Yihong. 1988. The Middle Jurassic dinosaur fauna from Dashanpu, Zigong, Sichuam, vol. 1: sauropod dinosaur (I): Shunosaurus. Sichuan Publishing House of Science and Technology, Chengdu, China.
Well, not really really.
Appendicular skeleton of savannah monitor lizard Varanus exanthematicus, "Charlie", in dorsal view.
What we have here is of course the bones of all four feet of a lizard (plus the limb bones): “sauropod” means “lizard foot”, so lizard-foot skeletons are sauropod skeletons — right?
(Note that the hind limbs are arranged in a weird posture here, with the knees bent forward. Also that the left pes is missing one digit — possibly IV — which was presumably lost some time ago and healed.)
These are the bones of “Charlie”, a mature savannah monitor lizard Varanus exanthematicus, estimated as fourteen or fifteen years old at the time of death. I have his whole skeleton — cranial, axial and limb-girdles — in various states of preparation, and no doubt they will all appear here sooner or later. I was fortunate enough to encounter Charlie in the reptile house of a local kids’ activity centre with the boys, and he was not in a good way. Luckily, his keepers happened to come in as I was looking at him, we got talking, and I popped the question as tactfully as I could — would it be OK to take his body away when the sad day comes?
The sad day came, and I found a message on my answering machine. For one reason and another, it was a couple of days before I was able to drive out and pick up his mortal remains, but it was a proud day when I brought him home:
Savannah monitor lizard Varanus exanthematicus, "Charlie", recently expired, in left dorsolateral view. Scale bar for, uh, scale.
Charlie was a good-sized beast: 111 cm in length from snout to tail, and massing 3.4 kg. I tell you, it was quite a challenge getting him into that pot that you see top right.
Savannah monitor lizard Varanus exanthematicus, "Charlie", recently expired, in right anterodorsolateral view. Juvenile Homo sapiens "Jonno Taylor" for scale.
To prepare Charlie for the pan, I had to remove his tail — much, much harder than I’d been prepared for, as it was so difficult to locate the sacrocaudal intervertebral joint — and gut him. Unfortunately, by the time I opened him up, internal decomposition had set in, and he was not in a pleasant state:
Savannah monitor lizard Varanus exanthematicus, "Charlie", recently expired, in the unpopular right posteroventrolateral view.
(I have much more disgusting photos than this one, but it wouldn’t be tasteful to show them.) Anyway, I abandoned my initial plan of dissecting the organs out, and basically just removed and discarded them. I’ve actually had shamefully little experience with dead animals, so I don’t know how much the horrible state of Charlie’s guts is due to his final illness and how much to post-mortem decomposition.
Once I’d managed — just — to get him into the pot, Charlie was lightly simmered for a couple of hours (to Fiona’s delight), then dismembered, and the individual parts reboiled before I started picking the bones out of the various parts. There’s more to say, but that will have to wait for another time.
I have a much less realised view of the digital future than Matt does, so I won’t be making a lot of predictions here. But I do have some questions to ask, and — predictably — some whining to do.
What counts, what doesn’t, and why?
Assuming you have made some science (e.g. a description of fossil, a palaeobiological hypothesis supported by evidence, a taxonomic revision), there are plenty of different ways you can present it to the world. I may have missed some, but here are the ones I’ve thought of, in roughly descending order of respectability/citability/prestige:
- Peer-reviewed paper/book chapter
- Unreviewed paper/book chapter
- Peer-reviewed electronic-only paper
- Published abstract (e.g. for SVP)
- Conference talk
- Conference poster
- Dissertation
- Online supplementary information
- Blog post
- Blog comment
- Email to the DML (which is archived on the web)
- Personal email
- Chat over a beer
How many of these are Science? Where is the line? Is the line hard or fuzzy? Why is it OK to cite SVP abstracts but not so much SVPCA abstracts? And other such questions. I think a very good case can be made that dissertations — provided they are made available — are better sources than conference talks, posters and abstracts; and a pretty good case can be made that blog posts are (especially when webcitation’ed — see below). Both dissertations and (good) blog posts have the advantage over talks and posters that they have a permanent existence, and over abstracts the simple fact that they are substantial: a 200-word abtract cannot, by its very nature, say anything much.
Zoological nomenclature
Unfortunately, for nomenclatural purposes, the ICZN’s Article 8 currently says that only publications on paper count, period, which counts out dissertations. I say unfortunately because were it not for this rule, then at least part of Aetogate would never have happened: the ramifications of Bill Parker’s case would not have been so awful if the perfectly good description of Heliocanthus in his (2003) dissertation had been allowed priority over Lucas et al.’s (2006) rush-job which attached the name Rioarribasuchus to the same specimen. Happily, the ICZN is as we write this considering an amendment to recognise nomenclatural acts in electronic-only publications. There has already been some published discussion of the pros and cons of this amendment, and the Commission is actively soliciting further comments, so those of you with strong feelings should put them in writing and send them to the Executive Secretary. (I will certainly be doing so.)
Self-scooping
We all know that blog entries are Not Sufficiently Published to be citable, at least in most journals; but are they Too Published to let you re-use the same material? When you submit to most journals, they ask you to formally state “this material has not previously been published” — is that true if we’ve blogged it? I am guessing different editors would answer that differently. For what it’s worth, we’ve been reasonably careful up till now not to blog anything that we’re planning to make into a paper — which is why we were so mysteriously silent on the obviously important topic of sauropod neck posture during the first 19 months of SV-POW!. We’ve not been 100% pure on this: for example, I have a paper on Brachiosaurus in press that mentions in passing the spinoparapophyseal laminae, absence of an infradiapophyseal laminae and perforate anterior centroparapophyseal laminae of the 8th dorsal vertebra of the Brachiosaurus brancai specimen HMN SII — the features that I have blogged here in detail, with illustrations that would certainly never have been given journal-space. Since the relevant passage in my paper accounted for half a manuscript page (of a total of 75 pages), I’m assuming no-one’s bothered about that. In a case like this, I guess the SV-POW! posts are best thought of as pre-emptive and unofficial online supplementary information.
Counts for what purpose?
We’ve already mentioned that dissertations, blog entries and suchlike don’t count for nomenclatural purposes. Whether they count in the sense of being citable in published works is up for debate right now (and again, see below on webcitation). It seems pretty clear that these forms of “grey publication” do count in establishing people’s reputations among their peers — dissertations are obviously important in this regard, and Darren’s ridiculously broad knowledge of tetrapods extant and extinct is near-universally recognised largely because of his blogging efforts (although you could argue — and Matt and I often have argued — that he might have been able to enhance his reputation even more if he’d taken some of that blogging time and invested it in formal publications). Conversely, it’s clear that blogs, however rigorous and scientific, count for squat when it comes to committees. The world of dinosaur palaeontology is probably just as aware of Matt’s series of Aerosteon response articles here on SV-POW! as it would be if he’d put those together into a paper that was published in PLoS ONE; but when his tenure committee comes to count up the impact factors of the journals he’s published in, those articles will count for nothing. One day that might change, but not while impact factors still exert their baleful influence.
Deciding what to blog and what to write up as a “proper paper”
Matt posted his response to the Aerosteon paper as a sequence of three blog entries even though he knew that what he had to say was substantial enough to make a paper. Why throw away a potential publication that would look good on the CV? Because he wanted to get it out there ASAP, and didn’t want to wait until all the media dust had settled. So he fought people off when they pestered him to publish it as a paper. He doesn’t really need to do it now, and he doesn’t really have time (especially since I keep badgering him about all the papers we’re supposed to be collaborating on). If we were starving for publications, we could turn a lot of SV-POW! posts into LPUs — but we’re not starving.
Let me explain this by taking a digression though the economics of file-sharing and the way labels persistently — maybe deliberately — misunderstand them. Let’s imagine for the sake of an example that a while back, I sent Matt the MP3s that make up Blue Oyster Cult’s awesome Fire Of Unknown Origin album. Now anyone with their brain switched on can see that the net effect of this on his music-buying pattern would be positive: if he really liked Fire, there is a fair chance that he would then have gone and bought a BOC album or two, or three — just as I’ve been buying Dar Williams albums like crazy since someone slipped me MP3s of Mortal City. The labels’ perception, however, is that instead I would have denied them a sale: that if I’d not sent the Fire of Unknown Origin MP3s, Matt would of course have bought his own legitimate copy, and so I’ve stiffed them out of $6.99 less whatever tiny slice they pass on to the artist. The misunderstanding here is that they think — or would like to think, who knows if they really believe this themselves? — that people’s music consumption is limited by the time we have available to listen to music, and that one way or another we will obtain enough music to fulfil that need: for free if possible, but by paying for it if necessary. But the truth is completely different: there would be zero chance of Matt’s ever buying any BOC album, since he’d never even heard of them (beyond Don’t Fear The Reaper, I guess) whereas in the hypothetical universe where I sent him the Fire MP3s, there is a non-zero chance. And the labels’ failure to understand that is because of a wholly incorrect model of what factor limits music listening.
Digression ends. Its relevance is this: in the same way, we are used to thinking that our ability to get papers published is limited by the number of publication-worthy ideas we have — so that every paper idea we “waste” on a blog entry is a net loss. In truth, ideas are cheap, and our ability to get papers published is actually limited by our throughput — our ability to find time to actually write those ideas up with sufficient rigour, prepare high-resolution figures, format the manuscripts for journals, wait through the review period, deal with the reviews, revise, resubmit, handle editorial requests, and so on and on. (That is especially true when the journal takes six months to come up with a rejection.) This is why Matt and I, like everyone else I know in palaeo who I’ve discussed this with, have huge stacks of POOP that we’ve not yet found time to convert into papers. So when we spend a paper-worthy idea on a blog entry, we’re not wasting it: we’re putting it out there (in an admittedly inferior format) when otherwise it would never have made it out there at all. The remaining issue is whether the time we spend on blogging an idea would have been better spent on moving a paper further towards publication. Maybe, sometimes. But you have to stop and smell the roses every now and again. So the real cost of SV-POW! for us is not the “waste” of paperable ideas, but the time we spend on writing it. I am guessing that in the time I’ve put into SV-POW! so far, I could have got two more papers out — certainly one. Has it been worth it? I think so, but it’s not a no-brainer. On the other hand, SV-POW! probably acts as a reader-funnel, so that when I do get a paper out, more people read it than otherwise would. How big that effect is, I don’t know, and I can’t think of a way to measure it.
How to cite blog entries: WebCite
One of the great things about writing for SV-POW! is that you can learn some really useful stuff from the comments; and the most useful comment I’ve seen so far is the one in which Cameron Neylon pointed us at WebCite (http://webcitation.org/). This is a superbly straightforward site that makes permanent archive copies of web-pages, and mirrors them around the world. In doing so, it deals with the problems of web pages being vulnerable to disappearance and prone to change. (In off-list emails with Matt, I had suggested that I might build something like this myself, as I am software engineer in my day job; I am delighted that these guys have done it properly instead.) So if you ever want to cite Matt’s second Aerosteon post in a journal, use the archive URL http://webcitation.org/5hPYTmWpW — and if you want to cite any other SV-POW! article, just submit its URL to WebCite yourself, and get back an archive URL which you can use. And tell all your friends about WebCite!
Oh, and by the way …
Here’s that photo of a monitor lizard getting its arse kicked by an elephant that you ordered:
Monitor lizard postcranium, aerial, strongly inclined. Photograph by Hira Punjabi, downloaded from National Geographic
References
- Lucas, S. G., Hunt, A. P. and Spielmann, J. A. 2006. Rioarribasuchus, a new name for an aetosaur from the Upper Triassic of north-central New Mexico. New Mexico Museum of Natural History and Science, Bulletin 37: 581-582.
- Parker, W. G. 2003a. Description of a new specimen of Desmatosuchus haplocerus from the Late Triassic of Northern Arizona. Unpublished MS thesis. Northern Arizona University, Flagstaff. 315 pp.
