What is the nature and purpose of a type specimen?
September 13, 2016
It’s been interesting seeing the response to my comment on the ICZN petition to establish Diplodocus carnegii as the replacement type species of the genus Diplodocus. In particular, Mickey Mortimer’s opposition to the petition seems to be based primarily on this argument:
The dinosaur community has recently lost sight of the fact that the type concept was never meant to indicate the most well preserved or described specimen/species.
I find this unconvincing, on the basis that the ICZN was never designed with dinosaurs in mind in the first place. For the great majority of the species that have been named under its rules, the selection of the obvious holotype has been perfectly adequate, because extant animals — by far the majority — are nearly all represented by complete and well-preserved specimens.
Alphina nigrosignata (type specimen; photo courtesy Geert Goemans, Department of Ecology and Evolutionary Biology, The University of Connecticut; specimen loaned from Herbert Zettel from The Museum of Natural History Vienna (NHMV). From University of Delaware, College of Agriculture & Natural Resources.
Dinosaurs — which in many cases are represented by eroded and distorted fossils of a tiny part of the animal — are already an aberration from the perspective of the ICZN, and that is why they sometimes need special treatment.
What are type specimens for, after all? The Code itself says “The fixation of the name-bearing type of a nominal taxon provides the objective standard of reference for the application of the name it bears” (Article 61.1); and comments that type specimens “are the international standards of reference that provide objectivity in zoological nomenclature” (Article 72.10). That is a role that YPM 1920 is simply not capable of fulfilling — and, more to the point, a role that it is not filling. The Diplodocus carnegii holotype CM 84 is the international standard of reference that provides objectivity in Diplodocus nomenclature. Slavishly following the usual provisions of the Code to retain the fiction that YPM 1920 fulfils this role simply does not reflect reality.
Some people occasionally object to the nomination of neotype specimens or replacement type species on the grounds that the Code does not require this. Of course it doesn’t: if it did, there would be no need for petitions. The fact that the Code allows for petitions constitutes explicit recognition that its usual provisions do not always suffice to produce the “sense and stability for animal names” that the Commission’s web-site used to have as its banner before the last redesign. Petitions exist precisely to allow the setting aside of the usual rules when sense and stability is served by doing do.
My comment in support of the Diplodocus carnegii ICZN petition
September 8, 2016
If you keep an eye on the wacky world of zoological nomenclature, you’ll know that earlier this year Emanuel Tschopp and Octávio Mateus published a petition to the International Commission on Zoological Nomemclature, asking them to establish Diplodocus carnegii, represented by the ubiquitous and nearly complete skeleton CM 84, as the type species of Diplodocus.
That is because Marsh’s (1878) type species, YPM 1920, is a pair of non-diagnostic mid-caudals which no-one has paid any attention to since 1901:
Tschopp and Mateus (2016: fig. 1). More anterior of the only two reasonably complete caudal vertebrae of the type specimen of Diplodocus longus (YPM 1920) in dorsal (A), anterior (B), left (C), posterior (D), right (E), and ventral (F) views. The neural spine is lost. The estimated position within the caudal column is caudal vertebra 17â24. Note the transverse ridge between the prezygapophyses shared with AMNH 223 (1).
I have now submitted a formal comment to the ICZN in support of the petition, in which I argue:
In its use as the definitive exemplar of the genus Diplodocus, as the foundation for numerous palaeobiological studies of the genus, and as the specifier for numerous important clades, the species D. carnegii is already effectively functioning as the type species of Diplodocus. Therefore the petition of Tschopp and Mateus (2016) requests only that the commission recognises de jure what is already the case de facto.
Anyone else who has strong feelings either in favour of or against the establishment of D. carnegii as a replacement type species for Diplodocus is welcome to submit their own comment to the ICZN. (I know of at least one person who has submitted a comment opposing the petition.)
The procedure is straightforward: just write your comment and email it to the Commision at iczn@nhm.ac.uk. (But it’s best also to copy your email to iczn@nus.edu.sg, as that seems to be where the ICZN is operating out of now: it took the NHM address four days to reply to my initial inquiry, but the Singaporean address responds quickly.)
References
- Marsh, O.C. 1878. Principal characters of American Jurassic dinosaurs, Part I. American Journal of Science (series 3) 16:411–416.
- Tschopp, Emanuel, and Octávio Mateus. 2016. Case 3700: Diplodocus Marsh, 1878 (Dinosauria, Sauropoda): proposed designation of D. carnegii Hatcher, 1901 as the type species. Bulletin of Zoological Nomenclature 73(1):17-24.
It was ten years ago today: my first published paper
September 15, 2015
Ten years ago today — on 15 September 2005 — my first palaeo paper was published: Taylor and Naish (2005) on the phylogenetic nomenclature of diplodocoids. It’s strange to think how fast the time has gone, but I hope you’ll forgive me if I get a bit self-indulgent and nostalgic.
I’d applied to join Portsmouth University on a Masters course back in April 2004 — not because I had any great desire to earn a Masters but because back in the bad old days, being affiliated to a university was about the only way to get hold of copies of academic papers. My research proposal, hilariously, was all about the ways the DinoMorph results are misleading — something that I am still working on eleven years later.
In May of that year, I started a Dinosaur Mailing List thread on the names and definitions of the various diplodocoid clades. As that discussion progressed, it became clear that there was a lot of ambiguity, and for my own reference I started to make notes. I got into an off-list email discussion about this with Darren Naish (who was then finishing up his Ph.D at Portsmouth). By June we thought it might be worth making this into a little paper, so that others wouldn’t need to do the same literature trawl we’d done.
In September of 2004, I committed to the Portsmouth course, sending my tuition fees in a letter that ended:
On the way to SVPCA that year, in Leicester, I met Darren on the train, and together we worked through a printed copy of the in-progress manuscript that I’d brought with me. He was pretty happy with it, which meant a lot to me. It was the first time I’d had a legitimate palaeontologist critique my work.
At one of the evening events of that SVPCA, I fell into conversation with micro-vertebrate screening wizard Steve Sweetman, then on the Portsmouth Ph.D course, and he persuaded me to switch to the Ph.D. (It was my second SVPCA, and the first one where I gave a talk.) Hilariously, the heart of the Ph.D project was to be a description of the Archbishop, something that I have still not got done a decade later, but definitely will this year. Definitely.
On 7th October 2004, we submitted the manuscript to the Journal of Paleontology, and got an acknowledge of receipt<sarcasm>after just 18 short days</sarcasm>. But three months later (21st January 2005) it was rejected on the advice of two reviewers. As I summarised the verdict to Darren at the time:
It’s a rejection. Both reviewers (an anonymous one and [redacted]) say that the science is pretty much fine, but that there just isn’t that much to say to make the paper worthwhile. [The handling editor] concurs in quite a nice covering letter […] Although I think the bit about “I respect both of you a great deal” is another case of Wrong Mike Taylor Syndrome :-)
This was my first encounter with “not significant enough for our journal” — a game that I no longer play. It was to be very far from my last experience of Wrong Mike Taylor Syndrome.
At this point, Darren and I spent a while discussing what to do: revise and resubmit (though one of the reviewers said not to)? Try to subsume the paper into another more substantial one (as one reviewer suggested)? Invite the reviewers to collaborate with us on an improved version (as the editor suggested)? Or just revise according to the reviewers’ more helpful recommendations and send it elsewhere? I discussed this with Matt as well. The upshot was that on 20th February Darren and I decided to send the revised version to PaleoBios, the journal of the University of California Museum of Paleontology (UCMP) — partly because Matt had had good experiences there with two of his earlier papers.
[Side-note: I am delighted to see that, since I last checked, PaleoBios has now made the leap to open access, though as of yet it says nothing about the licence it uses.]
Anyway, we submitted the revised manuscript on 26th May; and we got back an Accept With Minor Revisions six weeks later, having received genuinely useful reviews from Jerry Harris and Matt. (This of course was long before I’d co-authored anything with Matt. No handling editor would assign him to review one of my papers now.) It took us two days to turn the manuscript around with the necessary minor changes made, and another nine days of back and forth with the editor before we reached acceptance. A week later I got the proof PDF to check.
Back in 2005, publication was a very different process, because it involved paper. I remember the thrill of several distinct phases in the publication process — particularly sharp the first time:
- Seeing the page proof — evidence that I really had written a legitimate scholarly paper. It looked real.
- The moment of being told that the paper was published: “The issue just went to the printer, so I will send the new reprints […] when I get them, probably sometime next week.”
- Getting my copy of the final PDF.
- The day that the physical reprints arrived — funny to think that they used to be a thing. (They’re so Ten Years Ago now that even the SVPCA auction didn’t have many available for bid.)
- The tedious but somehow exhilarating process of sending out physical reprints to 30 or 40 people.
- Getting a physical copy of the relevant issue of the journal — in this case, PaleoBios 25(2).
I suppose it’s one of the sadder side-effect of ubiquitous open access that many of these stages don’t happen any more. Now you get your proof, then the paper appears online, and that’s it. Bam, done.
I’m kind of glad to have lived through the tail end of the old days, even though the new days are better.
To finish, there’s a nice little happy ending for this paper. Despite being in a relatively unregarded journal, it’s turned out to be among my most cited works. According to Google Scholar, this humble little taxonomic note has racked up 28 citations: only two fewer than the Xenoposeidon description. It’s handily outperforming other papers that I’d have considered much more substantial, and which appeared in more recognised journals. It just goes to show, you can never tell what papers will do well in the citation game, and which will sink without trace.
Sauropod Vertebra Picture of the Week 