Species Names in the PhyloCode

22nd February 2002

1. Introduction and Acknowledgements

With the exception of this introduction and the editorial asides in square brackets [like this], the text on this page is taken from the ``must read'' paper on PhyloCode species naming:

Philip D. Cantino, Harold N. Bryant, Kevin de Queiroz, Michael J. Donoghue, Torsten Eriksson, David M. Hillis & Michael S. Y. Lee: Species Names in Phylogenetic Nomenclature, Systematic Biology 48(4), 790-807 (1999)

It was retyped by David Marjanovic <david.marjanovic@gmx.at> and formatted as HTML by Mike Taylor <phylocode@miketaylor.org.uk> (that's me.) We've tried our best to make this page a fair and accurate representation of the original, but we cannot guarantee its accuracy. It is provided for convenience only: for definitive information, refer to the paper.

2. Table 1

Outline of the proposed methods for naming species in phylogenetic nomenclature, organized as a dichotomous key. A converted name is a name established under the PhyloCode and derived from a preexisting Linnaean binomial. A new name is a name established under the PhyloCode for a species that has no preexisting Linnaean binomial (i.e., a newly recognized species).

• 1. Converted names are based on the full preexisting binomial; new names may be binomial or uninomial in form, depending on the method.
  • 2. Names do not change with new knowledge of phylogeny.
    • 3. All names consist of two parts, although not necessarily two words (a word being a string of letters that means something by itself), separated by a space, hyphen, or dot.
      • 4. Names are capitalized, and their two parts are separated by a blank space, thus they are identical in form to Linnaean binomials. [Method A]
      • 4'. Names are distinguishable from Linnaean binomials, either by beginning with a lower-case letter or by separation of their two parts by a hyphen or dot.
        • 5. Genus names may not be established as clade names. [Method C]
        • 5'. Genus names may be established as clade names.
          • 6. New names must consist of two words. [Method B]
          • 6'. New names may consist of either two words connected by a dot or one word with a dot somewhere within it.
    • 3'. At least some names consist of a single unbroken string of letters.
      • 7. Converted names are binomial in form; new names are uninomial.
        • 8. Names are capitalized. [Method D]
        • 8'. Names are not capitalized. [Method E]
      • 7'. All names are uninomial in form; converted names are formed by the fusion of the two parts of the Linnaean binomial on which they are based.
        • 9. Names are capitalized. [Method G]
        • 9'. Names are not capitalized. [Method H]
  • 2'. Names sometimes change with new knowledge of phylogeny.
  • 10. Names are capitalized and their two parts are separated by a blank space, thus they are identical in form to Linnaean binomials. [Method I]
  • 10'. Names are distinguishable from Linnaean binomials, either by beginning with a lower-case letter or by separation of their two parts by a hyphen or dot. [Method J]
• 1'. Converted names are based on the epithet of the preexisting binomial; all names are uninomial in form.
  • 11. Names are unique and sometimes contain numbers.
    • 12. Names end in a sequential number (shorter than the registration number) if they are not unique without it. [Method K]
    • 12'. All names end in a registration number. [Method L]
  • 11'. Names do not contain numbers and are not necessarily unique (but the combination of name and registration number [or clade address, or author & year...] is unique). [Method M]

3. Table 2

Descriptions and examples of the proposed methods [...]. The person who proposed each method is indicated for the record, but it should not be assumed that the proposer prefers that option. [The annotation [L] is added for known list-members, but we don't know who else might be lurking.]

3.1. Group I. Stable, binomial-based names (methods A-H)

Converted species names are derived from preexisting binomials and are stable; that is, they do not change as a result of new information about phylogeny.

3.1.1. Methods A-C

(Griffiths, 1976; de Queiroz [L] and Gauthier [L], 1992)

All species names consist of two parts, separated by a space, hyphen, or dot. Converted species names are based on the accepted binomial under the preexisting code. In names of new species, the first part may be the name of a clade (except in method C), descriptive of the organism, or chosen in some other way.

• Method A: All species names are identical in form to Linnaean binomials and thus indistinguishable from species names governed by the preexisting codes.

  Example: The preexisting name of the Common Starling, Sturnus vulgaris, remains Sturnus vulgaris under the PhyloCode, but Sturnus may or may not be the name of a clade to which the species belongs. A new species must take the same form (e.g., Sturnus phalacrocephalus).

• Method B (Cain 1959; Michener 1963, 1964; Cantino [L] 1998): All species names are nearly identical to Linnaean binomials, differing only in a convention that makes them distinguishable from names governed by the preexisting codes (e.g., noncapitalization or separation of the first and second parts by a hyphen or dot).

  Example: [...] becomes sturnus vulgaris or Sturnus-vulgaris or Sturnus.vulgaris, depending on which convention is adopted, but Sturnus may or may not be the name of a clade to which the species belongs. A new species name must take the same form (e.g. sturnus phalacrocephalus or Sturnus-phalacrocephalus or Sturnus.phalacrocephalus).

• Method C (proposed by H[arold] Bryant [L]): Method C is identical to method B except that genus names cannot be used as clade names, and new species names must not incorporate a clade name as their first part. (Note: These restrictions could equally well be combined with the features of method A.)

  Example: [...] but no clade may be named Sturnus. [...]

3.1.2. Methods D and E

(Proposed by P[hilip] Cantino [L])

Converted species names consist of the two parts of the preexisting binomial, separated by a hyphen or dot, but new species names may be any unique, Latinized [or not] word containing only letters (i.e., no hyphen or dot).

• Method D: Species names are capitalized, thus new species names are indistinguishable from clade names.

  Example: [...] becomes Sturnus-vulgaris or Sturnus.vulgaris, depending on which convention is adopted, but Sturnus may or may not be the name of a clade to which the species belongs. A new species name might take the form Phalacrocephalus or Sturnusphalacrocephalus.

• Method E: Species names begin with a lower-case letter; thus all species names are distinguishable from clade names.

  Example: [...] becomes sturnus-vulgaris or sturnus.vulgaris [...] phalacrocepthalus or sturnusphalacrocephalus.

• Method F (proposed by M. Donoghue [L IIRC!]) Converted species names consist of the two parts of the preexisting binomial separated by a dot. New species names may be any unique, Latinized [or not], nonhyphenated string of letters (representing one word or two), with a dot placed somewhere within the name, but not immediately following the first or second letter and not at the beginning or end of the name.

  Example: [...] becomes Sturnus.vulgaris, but Sturnus may or may not [...]. A new species name might take the form Phalacro.cephalus (providing that this name, or one differing only in the presence or position of the dot, has not previously been established) or Sturnus.phalacrocephalus.

3.1.3. Methods G and H

(Michener, 1963)

Converted species names consist of one word, formed by the fusion of the two parts of the preexisting binomial. New species names may be any unique, Latinized word containing only letters.

• Method G: Species names are capitalized and thus are undistinguishable from clade names.

  Example: [...] becomes Sturnusvulgaris, but Sturnus may or may not [...]. A new species might take the form Phalacrocephalus or Sturnusphalacrocephalus.

• Method H: Species names begin with a lower-case letter and thus are distinguishable from clade names.

  Example: [...] becomes sturnusvulgaris [...] phalacrocephalus or sturnusphalacrocephalus.

3.2. Group II. Binomial-based names with limited stability (methods I and J)

(Proposed by P. Cantino)

Converted species names are derived from preexisting binomials. The first part of a species name must be changed if it is the established (under the PhyloCode) name of a clade to which the species does not belong.

• Method I: Method I is identical to method A except that the first part of the species name must be changed if it is the name of a clade to which the species does not belong.

  Example: [...] remains Sturnus vulgaris [...]. A new species name must take the same form (e.g., Sturnus phalacrocephalus). If Sturnus is the established name of a clade to which this species does not belong, the word Sturnus within the species name must be formally changed to the name of a clade to which this species belongs or to some other Latinized word that is not the name of a clade.

• Method J: Method J is identical to method B except that the first part of the species name must be changed if it is the name of a clade to which the species does not belong.

3.3. Group III. Epithet-based names (methods K-M)

(Graybeal 1995; Schander and Thollesson 1995; Schander 1998b)

Converted species names are derived from the epithets of preexisting binomials and are stable; that is, they do not change as a result of new information about phylogeny. To provide a reference to the preexisting binomial, the name of the genus to which the species belongs under the preexisting code may (but need not) be cited as a taxonomic address; it is recommended that this be done if the species name alone might be confusing (proposed by M. Lee and T. Eriksson).

• Method K (proposed by K. de Queiroz): Species names are terminated by a number (which is part of the name) if the rest of the name has previously been established for a different species under the PhyloCode. The number must be the lowest integer >1 that has not previously been used as part of a name that is otherwise spelled the same. The number may be dropped after the first use of the name in a particular publication. When a species name is converted, the nonnumerical portion of the name is the epithet of the accepted binomial under the preexisting code. When a species name is new, the nonnumerical portion of the name may be any Latinized word. If a taxonomic address is cited, the combination of address and species name may or may not be distinguishable from a Linnaean binomial, depending on whether the two names are separated by a delimiter of some sort (e.g., a slash or parentheses). If a delimiter is not used, the combination of taxonomic address and species name will be identical in form to a binomial if the name does not contain any numbers (i.e., if it is the first name established under the PhyloCode based on this epithet) or if the number is omitted subsequent to its first use in a publication.

  Example: [...] becomes vulgaris. If vulgaris has already been established for another species, the name vulgaris2 is used (or vulgaris.2 or vulgaris [2] [brackets in the original], depending on which convention is adopted). If vulgaris2 has already been established for another species, vulgaris3 is used, and so forth. If the name vulgaris2 by itself might be confusing to readers, it is recommended that Sturnus be cited as a taxonomic address; this would take the form Sturnus vulgaris2 or Sturnus/vulgaris2 or (Sturnus) vulgaris2 or vulgaris2 (Sturnus or Sturnus:vulgaris2, depending on which convention is adopted.

• Method L (proposed by T. Eriksson): Species names are terminated by a unique registration number (which is part of the name). The number may be dropped after the first use of the name in a particular publication. When a species name is converted, the nonnumerical portion of the name is the epithet of the accepted binomial under the preexisting code. When a species name is new, the nonnumerical portion of the name may be any Latinized word. If a taxonomic address is cited, the combination of address and species name may or may not be distinguishable from a Linnaean binomial, depending on whether the two names are separated by a delimiter of some sort (e.g., a slash or parentheses). If a delimiter is not used, the combination of taxonomic address and species name will be identical in form to a binomial if the number is omitted subsequent to its first use in a publication.

  Example: [...] becomes vulgaris### (or vulgaris.### or vulgaris [###] [brackets in the original], depending on which convention is adopted). If the name vulgaris### by itself might be confusing to readers, it is recommended [...]

• Method M (proposed by D[avid] Hillis [L] and K. de Queiroz): Species names do not contain numbers, but it is recommend that the unique registration number be cited at least once within any publication in which the name is used. When a species name is converted, the name is the epithet of the accepted binomial under the preexisting code. When a species name is new, the name may be any Latinized word. If a taxonomic address is cited, the combination of address and species name may or may not be distinguishable from a Linnaean binomial, depending on whether the two names are separated by a delimiter [...]. If a delimiter is not used, the combination of taxonomic address and species name will be identical in form to a binomial.

  Example: [...] becomes vulgaris. [...] The species name with its taxonomic address could take the form Sturnus vulgaris 2[...] [or with delimiter, see above].