The document discusses the International Code of Zoological Nomenclature (ICZN) and how it establishes rules for naming animal species to promote stability and universality. It explains that under the ICZN, each species should have a single agreed-upon name. Name changes can occur if new evidence shows species definitions or classifications need updating. The ICZN also has mechanisms for resolving issues like multiple names for one species or mistaken descriptions. The goal is to have a standardized system while maintaining the most accurate scientific understanding over time.

1. The ICZN, the rules and how they
result in name changes

2. Everyone loves a good noun
● Talking about things without giving them names
is hard
● Naming things is a natural part of language, as
is classification

3. Folk nomenclatures
● Collections of nouns for describing related
things
● Still widely used: common names
● Precedence given to useful things

4. An aside
● This happens elsewhere! The Roof Bed of the Bath
Stone was favoured by
quarrymen for the strength
it provided to the roof of
mines

5. An aside
● This happens elsewhere! Blue Lias uses
quarrymen's terms for
limestone layers:
Best
First Quick
Brick
Gumption

6. An issue
● One thing can have many folk names
● Regional variations
● Spelling variations (particularly when
transcribing oral traditions)

7. Zoological Nomenclature
Formalises this so that:
● One animal has one (correct) name

8. As we learnt more
Iris
Stinking Iris

9. Why we like Linnaeus
Iris foetidissima
Move from descriptions that would get ever
longer to binominals

10. That seems simple...
… why do we need a Commission on animal
names?
… why do they keep changing?
...hold on, what is a species?

11. An aside on species concepts
● Phenetic
● Biological/Reproductive
● Phylogenetic
● Ecological
● Cohesion

12. Classification
Implicit in a binominal name is a grouping of
related species
Carex divulsa
Carex pendula
Cyperus papyrus

13. So names change
● When we learn something that causes our definition
of a species to change
● When we learn something that means the grouping
(higher classification) of a species to change (only at
generic level)
● Or when someone did something wrong (almost
always accidental, and understandable)

14. Rules about name changes: priority
Generally (one animal, one name):
● If an animal has two names: the oldest wins
● If two animals have the same name: the first one to get it keeps it
● If the species name is an adjective, it describes the genus and if in a
language that uses gender must agree in gender.
*Lepidopterists by convention ignore the last rule, and many people
are keen for this to disappear.

15. Availability & Validity
● An available name has been correctly published
(has a type specimen, adequate description, etc). If
a name has not been correctly published it is
considered not to exist in relation to priority.
● A valid name is the currently correct name.
An animal may have many available names, but only
one is valid.

16. Change in species definition 1
Two species are found to be the same:
● The older name is valid (senior synonym)
● The younger name is a junior synonym
If both names were published in the same
publication the choice of which to use goes to
the 'First Reviser'.

17. Changes in species definition 2
A species is found to be two species
● The original species still exists, the name still
applies
● A new name is described with a new type
specimen

18. A note on types
There are two kinds:
● Primary types (Holotypes, Lectotypes Neotypes, Syntypes)
● Secondary types (Paratypes, Paralectotypes)
Primary types define a species, secondary types show within
species variation (in phasmids generally include opposite
sex to primary type, eggs, nymphs, etc)

19. Genus changes
Sometimes a species needs to be moved to a
different genus, this can cause name changes
● Every species must have a unique name, so if there
is a species with the same specific epithet in that
genus the name must change (junior homonym)
● If an adjective the name may need to change to
reflect the gender of the new genus

20. Mistakes
The same species is described twice:
● The second name becomes a junior synonym
A type specimen is lost/destroyed
● A neotype must be designated
A species is inadequately described
● It should be redescribed from the same primary types

21. Subspecies
When a species is split into subspecies
● The subspecies containing the original type is
nominotypical and the subspecific epithet is the
same as the specific epithet (Conocephalus
hastatus hastatus)
● The other species is given a unique subspecific
epithet (Conocephalus hastatus bodenheimeri)

22. Species group
So far we have discussed names in the
species-group

23. Some notes on the Genus group
Genera should have a type species the process of creating a
type species is called fixation
● Original designation: the author of the genus name sets the
type species explicitly
● Subsequent designation: a later author sets the type species
of an unfixed genus as First Reviser
● Indication: by original monotypy when a genus is originally
described with a single species. By absolute tautonymy when
a genus is described including a species with a specific
epithet identical to the genus name (Conocephalus
conocephalus)

24. Subgenera
Used to split genera into groups
● The subgenus containing the type-species of
the genus is nominotypical and takes the name
of the genus (analogous to subspecies)

25. The Family Group
Highest level controlled by ICZN:
● Covers Superfamily down to Tribe
● Names are based on a generic name
● All carry the authorship of the first person to
use that genus name as the root of a name in
the family group

26. Writing names
Conocephalus (conocephalus) hastatus hastatus (Charpentier, 1825)
Genus (subgenus) species subspecies Author, Date
● If the species is not in the original genus the name and date are placed in
parentheses (coordinate)
● Only the genus and author is capitalised
● Family-group names are not italicised

27. So far...
These things can be done by anybody publishing a
scientific paper following the International Code of
Zoological Nomenclature
The Code describes how species should be
described, types designates, and problems solved
Standards, Sense and Stability

28. Stability
The International Commission on Zoological Nomenclature has the plenary
power to suspend the rules of nomenclature in the case where not doing so
would lead to instability
●
An older available name is discovered for a well-known species (reversal of
precedence – name added to The Official List of Names and Works in
Zoology)
●
The type specimen of a species still exists but may be considered no longer
adequate (Archaeopteryx lithographica)
●
To suspend all priority for a group of organisms based on a List of Available
Names (new – currently in progress for Rotifera)

29. Process
● Authors prepare a Case for the Commission which is
published in the Bulletin of Zoological Nomenclature
● Others may comment via the BZN supporting (or
otherwise) the Case or proposing alternative solutions
The Commission votes on the Case and issue an Opinion
in the BZN.

30. Cases
● Generally relate to names or groups of names
of animals
● May relate to publications – making names in
some publications unavailable or making pre-
1758 names available

31. Further Notes 1
● Special rules for ichnotaxa
● Botanists have a separate code (as do
microbiologists and virologists)
● Also International Code of Nomenclature for
Cultivated Plants (cultivar, Group, grex)

32. Further Notes 2
● There are a lot more rules – but hopefully you
get the general idea
● A lot more has been written about
nomenclature, taxonomy and classification
● The history of nomenclature is quite interesting