Sorting out Cetiosaurus nomenclature

March 31, 2009

Today saw the publication of the most startlingly dull paper I’ve ever been involved in (Upchurch et al. 2009) — and remember, I write this as co-author of a paper on the phylogenetic taxonomy of Diplodocoidea.  Not only that, but one time when I was practising a conference talk with my wife Fiona as audience, she fell asleep actually while I was speaking.  Actually asleep.  And yet the new paper beats them all hands-down for boredom.  If you don’t believe me, feast your eyes, gloat your soul, on the accursed ugliness of the very title of the new paper: “Case 3472: Cetiosaurus Owen, 1841 (Dinosauria, Sauropoda): proposed conservation of usage by designation of Cetiosaurus oxoniensis Phillips, 1871 as the type species.”  What is it all about?

Well, take a look at the type material of Cetiosaurus:

Upchurch and Martin (2003: fig. 2) -- type material of Cetiosaurus medius

Type material of Cetiosaurus medius, from Upchurch and Martin (2003: fig. 2). Scale bars 50 mm.

Yes indeed — the most historically important of all sauropods is based on a set of non-diagnostic uninformative eroded partial mid-to-distal caudal centra.  That is because this is the type material of the species which, for complex technical reasons, is the type species of the genus Cetiosaurus.  We tend to ignore this fact because the material is clearly rubbish: the taxon C. medius is not valid.  Sadly, however, the name C. medius is valid — nomenclaturally valid, even though it’s not taxonomically valid.  But the International Code of Zoological Nomenclature (ICZN), which governs all zoological nomenclature, is purely a code of nomenclature, and does not take taxonomic considerations such as diagnosability into account.  (It can’t, after all: how could the code contain rigorous rules that let you determine whether material is diagnostic, or whether a description is adequate?)

Anyway, the material of C. brevis, C. brachyurus, C. medius and C. longus, all published together (Owen 1842) is all pretty useless; but Phillips (1871) described in detail the much better material of a new species C. oxoniensis, and this is what everyone has meant by the name Cetiosaurus ever since.  Upchurch and Martin (2003:215) even explicitly stated that they were provisionally using C. oxoniensis as the de facto type speces, pending a petition to the ICZN to overrule strict priority.  And no wonder: the C. oxoniensis material really is way better.  For example, check out this dorsal vertebra (which is by no means the best one — just one that I have a convenient photo of):

Cetiosaurus oxoniensis referred partial dorsal vertebra OUMNH J13648, right lateral view

Cetiosaurus oxoniensis partial dorsal vertebra OUMNH J13648 (part of the lectotype series), right lateral view

Today’s new paper is that long-promised petition: in it, we recount the nomenclatural history of the name Cetiosaurus and its species, explain with a big list of references that C. oxoniensis has been overwhemingly used historically and is overwhelmingly used today, and ask the Commission to legitimise this universal behaviour.

Will they do it?  We actually don’t know, although I can’t think of any reason why they shouldn’t.  The process now is that interested workers can send their comments, either in favour of or against our proposal, to the Executive Secretary of the ICZN (address at the end of the PDF), and these comments are weighed before a decision is returned.  From my informal sampling of previous petitions, the process seems to take between one and two years.  So we’re probably stuck in type-species limbo until 2011.  Oh well — at least the main step has been taken.

So.  I’m not exactly as excited about this paper as I was of Xenoposeidon — don’t worry, we won’t be launching a nine-post Cetiosaurus Type Species Redesignation Week — nor as pleased with it as I am with a certain in-press paper that all three of us SV-POW!sketeers are very much looking forward to because REDACTED.  But it’s a dirty job that someone had to do.


  • Owen, Richard.  1841.  A description of a portion of the skeleton of the Cetiosaurus, a gigantic extinct saurian reptile occurring in the oolitic formations of different portions of England.  Proceedings of the Geological Society of London 3: 457-462.
  • Owen, Richard.  1842b.  Report on British fossil reptiles, Part II. Reports of the British Association for the Advancement of Science 11: 60-204.
  • Phillips, John.  1871.  Geology of Oxford and the valley of the Thames.  Clarendon Press, Oxford.
  • Upchurch, Paul, and John Martin.  2003.  The anatomy and taxonomy of Cetiosaurus (Saurischia, Sauropoda) from the Middle Jurassic of England.  Journal of Vertebrate Paleontology 23: 208-231.
  • Upchurch, Paul, John Martin, and Michael P. Taylor.  2009.  Case 3472: Cetiosaurus Owen, 1841 (Dinosauria, Sauropoda): proposed conservation of usage by designation of Cetiosaurus oxoniensis Phillips, 1871 as the type species. Bulletin of Zoological Nomenclature 66 (1): 51-55.

Update (3 April 2009)

Here’s that photograph of a leopard seal pulling the head right off a penguin you ordered:

Leopard seal PULLING THE HEAD RIGHT OFF a penguin

Leopard seal PULLING THE HEAD RIGHT OFF a penguin

Acknowledgement: I got this photo from  Thanks to “Paul A.” (see comment below) I now know that it is the work of Paul Nicklen who has a stellar collection of photographs on his own site.  This picture is entitled The Death Shake, and is the 10th of the 29 pictures in his leopard seal gallery.

Relevant Update (31 August 2010)

I should have noted this long ago, but back in July 2009 (more than a year ago!) Paul Barrett and Pete Galton both published comments in the BZN that were supportive of our petition.

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18 Responses to “Sorting out Cetiosaurus nomenclature”

  1. David Hone Says:

    Least. Diagnostic. Ever.

  2. William Miller Says:

    Dang, I was looking forward to Cetiosaurus Type Species Redesignation Week…

    On the serious side, I didn’t think it was too boring. Where could I find more information on the specimens of C. brevis, brachyurus, and longus and why they aren’t valid?

  3. Mike Taylor Says:

    William, the remains of the various Cetiosaurus species are described in some detail in Upchurch and Martin 2003, which you can download FOR A SHORT TIME ONLY at:

    In fact, I simplified a bit for this article: Upchurch and Martin wrongly concluded that C. brevis was the correct type species under ICZN rules, because they conflated taxonomic and nomenclatural validity. The fact that C. brevis is potentially diagnostic whereas C. medius is not (and neither are C. longus and C. brachyurus) does NOT affect the availability of those names for nomenclatural purposes, as they then thought — a very common misapprehension. That it turns out to be C. medius (the details are in the paper) is actually a blessing, because it meant that we were able to cut out a lot more history and argumentation from the paper on the subject of C. brevis also being a senior synonym (whether objective or subjective is hard to say!) of Pelorosaurus — for a little more on that, see and Taylor and Naish (2007:1559-1560).

  4. Adam Yates Says:


    This is a very common problem in Dinosauria. Loads of well known taxa are actually based on shitty non diagnostic types: Allosaurus, Archaeopteryx, Massospondylus, Plateosaurus (well maybe, just barely)to name a few. I’m involved with a similar plan to re-designate the holotype of Massospondylus. I’m told that the more correspondance a petition receives the more quickly the council responds, so get writing. The Archaeopteryx (shifting the holotype from the isolated feather to the London skeleton) case is also current at the moment and could also do with favourable comment.

  5. Mike from Ottawa Says:

    Ceitosaurus? Looks like what you got yerself there is one o’ them Chunkosauruses.

  6. [...] 17, 2009 Because of my work on the recent Cetiosaurus petition, I’m on the ICZN mailing list.  Apart from the brutally technical threads on specific [...]

  7. Matt Wedel Says:

    Ceitosaurus? Looks like what you got yerself there is one o’ them Chunkosauruses.

    As a long time commenter, you should know that sauropod bits of questionable utility are nevertheless referred to as shards of excellence, or in taxonomic form, as Shardasaurus excellensis. This is your only warning; next time you have to go in the Hole.

  8. Damn, that top picture looks like a pliosaur cervical…

  9. DDeden Says:

    Do you have any photos of orcas popping off the heads of leopard seals?

  10. DDeden Says:

    nvm. Stumbled on to something somewhat similar though, headless sea otter on the beach:

  11. [...] conscientious, insightful and diplomatic.  We’ve already collaborated on a few short papers (Upchurch et al. 2009 and a couple of Phylocode companion-volume chapters that are in press), and I hope there will be [...]

  12. [...] things, the new issue 66(2) of the Bulletin of Zoological Nomenclature contains two comments on our petition to the ICZN to fix Cetiosaurus oxoniensis as the type species of the historically impor… (Upchurch et al. 2009) — both of them supporting the proposal  (Barrett 2009 and Galton [...]

  13. Paul A. Says:

    That incredible photo is by Paul Nicklen:

    He does a lot of work for National Geographic and he has at least one magnificent book out.

  14. Mike Taylor Says:

    Thanks for that, Paul A. I’ve updated the article accordingly.

  15. [...] around at the end of the slideshow).  By the way, this is the very talk that my wife, Fiona, fell asleep in the middle of while I was rehearsing it at [...]

  16. [...] them the shortest and most boring manuscript I’ve ever written (and it is up against some pretty stiff competition in the “most boring” category).  And that manuscript was published today (Taylor [...]

  17. [...] 3. leopard seal (12,797) — this explains why “Sorting out Cetiosaurus nomenclature”, which even Mike admits is the most boring topic we’ve ever covered here, is the 11th most popular post of all time on this blog! [...]

  18. […] “Leopard seal” is due to the inclusion of a single sensational (but off-topic) photo in a post on Cetiosaurus nomenclature. “Basement” is another one-hit wonder, thanks to a poorly located Mamenchisaurus cast. […]

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