Checklist for new zoological genus and species names
February 25, 2026
This checklist applies only to the establishment of new genera and species. It is not intended to guide the assignment of replacement names, nor for judging the availability of existing names, nor to guide the establishment of names of other ranks (e.g. families, subgenera). For simplicity, in some places its requirements are more stringent than those of the Code. This version of the Checklist is based on the 4th Edition (2000) of the Code (including its electronic-publication amendment). For further information, see the ICZN’s official FAQ.
Requirements
- The new name must be published in a work issued for the purpose of providing a permanent, public scientific record.
- The work must either printed or electronic. A printed work must be produced in an edition containing numerous simultaneously obtainable identical and durable copies. Numerous copies that are not simultaneously obtainable (e.g., print on demand, paper reprints, etc.) do not constitute published works. For the purposes of priority, the Code defines the date of publication as the date on which the numerous identical durable copies were made simultaneously obtainable. [The Code does not specify how many copies must be printed, but 50 or more is typical.] An electronic work must be registered in ZooBank before publication, and must state the date of publication and contain evidence that registration has occurred. The ZooBank registration must specify an electronic archive intended to preserve the work and the ISSN or ISBN associated with the work.
- The newly named animal must not already have a name that can be used for it.
- A new genus name must not have previously been used for a different genus or subgenus; a new species name must not have previously been used in the same genus for a different species or subspecies.
- The new name must be spelled using only the 26 letters of the English-language alphabet, without diacritics or punctuation.
- New scientific names must consist of “words” (not merely initialisms or arbitrary combination of letters), i.e. the name, or each part of a binomial, must in some language be pronounceable as a single word.
- The new name must be explicitly stated to be new and the rank of the new taxon must be given. This may be done by appending “sp. nov.” to the first use of a new species name, and “gen. nov.” to a new genus name.
- The new name must be accompanied by the explicit designation of a type. For a species, this must be a holotype specimen or syntype series. If the holotype or syntypes are not lost or destroyed, state that they are (or will be) deposited in a collection, and indicate the name and location of that collection and the specimen number within the collection. For new genera, a type species must be designated.
- The new name must be accompanied by a description or definition that states in words characters that differentiate the taxon, or be accompanied by a bibliographic reference to such a published statement.
- If a species name (i.e., the second part of a genus+species combination) is, or ends in, a Latin or latinized adjective or participle in the nominative singular, it must agree in gender with the name of the genus that contains it.
Best practice
- The Code does not state exactly what constitutes “a permanent, public scientific record”. To avoid controversy, recognised academic journals should be used, and newsletters and popular magazines avoided. While peer-review is not required, names published in reviewed literature may be more widely recognised.
- Publish new taxon descriptions in a widely understood language where possible; otherwise, provide a summary in a widely understood language.
- The date of publication should be stated within the published work itself. Sometimes only the year is given, but more precision (month and day) is preferable in case a priority dispute arises.
- When establishing a new species, avoid species names already established within closely related genera, to avoid the creation of secondary homonyms if the genera are later synonymized.
- Avoid creating new names that have been represented as misspellings of existing names.
- Avoid creating zoological names that are already established under other Codes of scientific nomenclature (e.g., the botanical code or the bacteriological code). These are not forbidden by the Code, but may cause confusion.
- Avoid spellings that are likely to be misspelled by subsequent users, and take care to spell the new name consistently throughout the work.
- Species can be named after people by casting those people’s names into a Latin genitive: when doing this, observe gender and number distinctions. The default method is: add -i to the name of a single male, -ae for a single female, -arum for several females, and -orum for any group with at least one male.
- If at all uncertain about the formation of the new name, consult a linguist.
- State the etymology of the new name.
- State the gender of a new genus name.
- Illustrate the type material, showing the diagnostic features of the taxon where possible.
- Register the new name at ZooBank.
Contributors (in chronological order)
- Mike Taylor
- Wolfgang Wuster
- Francisco Welter-Schultes
- David Patterson
- Paul van Rijckevorsel
- Brad McFeeters
- William Miller
- Christopher Taylor
- David Marjanović
- Bill Eschmeyer
- Frank Krell
- Richard Pyle
- Mark Robinson
- Matt Wedel
- Stephen Thorpe
- Tony Rees
- Gunnar Kvifte
- Miguel Alonso-Zarazaga
Note that this page has no official standing with the ICZN, and for that matter neither do I. (If the Commission were to want to adopt this document, they would be welcome.)
Belatedly … here’s DRAFT v4 of the checklist for new zoological genus and species names
January 20, 2026
Long-term readers will remember that waaay back in 2011, we started the process of putting together a checklist for people naming new zoological genera and species, distilling the relevant portions of the long and complex International Code of Zoological Nomenclature (ICZN). Across twelve days of intense discussion, we got as far as DRAFT v3 of the checklist, and then I … sort of forgot about it for fifteen years.
Six months into those fifteen fallow years, of course, the ICZN introduced the electronic publication amendment, which means that the checklist has spent twenty-nine 30ths of its life outdated in a critical respect. So now I am doing what I should have done fourteen and a half years ago, and finalizing the checklist.
So I present DRAFT v4 of the checklist, which quietly went up on the site last night. I’ve tweaked the wording here and there, and adjusted whitespace, but the only substantive change is in clause 2 of the Requirements section, on what constitutes published work. Here’s what it now says:
2. The work must either printed or electronic. A printed work must be produced in an edition containing numerous simultaneously obtainable identical and durable copies. Numerous copies that are not simultaneously obtainable (e.g., print on demand, paper reprints, etc.) do not constitute published works. For the purposes of priority, the Code defines the date of publication as the date on which the numerous identical durable copies were made simultaneously obtainable. [The Code does not specify how many copies must be printed, but 50 or more is typical.] An electronic work must be registered in ZooBank before publication, and must state the date of publication and contain evidence that registration has occurred. The ZooBank registration must specify an electronic archive intended to preserve the work, and the ISSN or ISBN associated with the work.
I welcome comments on this clause — especially regarding any factual errors that might have crept in, but also on infelicities in the wording. Please hop over to DRAFT v4 to comment. (Comments on this post are closed, to avoid splitting discussion across two places.)
Never name a new species of an existing dinosaur genus
January 16, 2026
I’m still making my way through Brian Curtice’s excellent and detailed post on Greg Paul’s (2025) recent erection of a new titanosaur genus (Curtice 2025), but I just want to comment on this one passing thought of Brian’s:
The species tells me where it was found if named by “Old Timers,” the genus almost can do that if named by “New Kids on the Block” as they almost never add species names to existing genera (recent tyrannosaur excepted :-)).
The new kids are right.
You should never[1] name a new species of an existing dinosaur genus. Here’s why. Suppose you have two genera, A and B, which are sister taxa in your phylogeny:
Genus A
/
\
Genus B
Now you discover a new specimen, X, which your phylogenetic analysis says is more closely related to Genus A than than to any other named genus:
Genus A
/
/\
/ Specimen X
\
\
\
Genus B
The smart play is to name it genus X. But suppose you say “Oh, but it’s really quite similar to genus A, it can’t be separated at the genus level”, and you instead name it as a new species, A. x. You go merrily on your way congratulating yourself on not being one of those filthy splitters, and all is well until someone else runs a different phylogenetic analysis with more characters, better taxon sampling, a better weighting algorithm, whatever. And it comes out like this:
Genus A
/
/
/
\ Specimen X
\/
\
Genus B
Now the new author has to say something like “The species x is hereby removed into the genus B yielding the new combination B. x.”
And now your taxon’s name has changed. That’s really bad. The whole purpose of a name is to be a fixed, permanent label that consistently refers to the same thing. But Linnaeus’s terrible mistake, the Linnean binomial, is a “name” that encodes a specific phylogenetic hypothesis, and which implodes when that hypothesis is considered false.
Naming a new species x of a genus A is a nomenclatural enshrining of your phylogenetic hypothethesis that specimen X is more closely related to the genoholotype of genus A than to that of any other genus. It’s a bet that has no upside if you turn out to be right, but makes you look like a dummy if you’re wrong. There is absolutely no need to make such a bet.
Names are for naming things. Phylogenetic analyses are for analysing things. Don’t confuse them. And don’t reify that confusion in nomenclature.,
Note 1. As so often when one writes “never”, we really mean “hardly ever”. I don’t discount the possibility that there may be some very special circumstances when a new species within an existing genus is warranted, but I bet that your example of such a very special circumstance doesn’t qualify.
References
- Curtice, Brian. 2025. Et Tu Ut Te (Titan)? Thoughts on Alamosaurus and more. Fossil Crates, 5. https://www.fossilcrates.com/blogs/news/alamosaurus
- Paul, Gregory S. 2025. Stratigraphic and anatomical evidence for multiple titanosaurid dinosaur taxa in the Late Cretaceous (Campanian-Maastrichtian) of southwestern North America. Geology of the Intermountain West 12:201-220., doi: 10.31711/giw.v12.pp201-220.
The world is full of wonderful animals, both extant and extinct, and they all have names. As a result, it’s fairly common for newly named animals to be given names already in use — as for example with the giant Miocene sperm whale “Leviathan“ (now Livyatan). BUt there are ways to avoid walking into this problem, and in a helpful post on the Dinosaur Mailing Group, Ben Creisler recently posted a summary. I’m reproducing it here, with his permission, for posterity.
The Journal of Vertebrate Paleontology website recently posted an article that describes a new taxon. Unfortunately, the new generic name was preoccupied and I contacted the lead author. As a reminder, there are a number of ways that authors, reviewers, and editors can check online if a proposed new name has been used before in zoological literature. Even if a generic name is not in current use (it’s a junior synonym), it still counts for zoological nomenclature if it was published in a way that makes it an available name according to ICZN requirements.
A good first place to check a name is: Index to Organism Names (ION). This database is kept up-to-date with the Zoological Record. Queries can be exact letter-for-letter or end in * to bring up partial matches after the first letters. The * query feature will not work at the beginning of a name, however. So cerat* works as a query but not *ceratops.
The queries will bring up a name or the first part of a name (when a * is used) that has been used for a species and for a genus (which may require scrolling through the names because of species matches).
If a queried name does not show up as a generic name in the ION, it is not a guarantee that a name has not been used before, and a good policy would be to double-check a number of other online resources.
The Interim Register of Marine and Nonmarine Genera (IRMNG) has the advantage of being limited to generic names, but is not exhaustive. Still worth checking.
GBIF | Global Biodiversity Information Facility
The recent problem with the preoccupied dinosaur name Jingia (replaced with Jingiella) highlights some of the content issues with each of these databases. Jingia Chen, 1983 (a moth) shows up in the GBIF and the Tree of Life, but not in the ION or the IRMNG. It’s a good idea to check all of them.
Note that I will happily check new names for people for preoccupied status or for questions on meaning or formation.
… And in a followup comment, Tyler Greenfield also recommended the Nomenclator Zoologicus and Index Animalium as great resources for checking historical names.
So now you know! No more excuses: check your new names for preoccupation.
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 [email protected]. (But it’s best also to copy your email to [email protected], 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 