Re: [dinosaur] Procheneosaurus

[David Marjanovic <david.marjanovic@gmx.at>]

>>
This would have been true, if Procheneosaurus Matthew 1920 was not a nomen 
nudum. This paper, a lay article on Canadian dinosaurs, lacks an adequate 
enough definition of what Procheneosaurus is, among other inadequacies. He 
literally only states: "(5) Procheneosaurus, â a small kind with a little 
bill and short round head. A fine skeleton is on exhibition in the American 
Musuem.". This appears inadequate as any diagnosis would go, and the text 
should not be taken as a diagnosis just to tick off on a taxonomic checkbox.
<<

Yes, that _is_ sufficient as a diagnosis for ICZN purposes. Below are the 
complete texts of Articles 12.1 and 13.1; 12.1 applies, but the explanation of 
what a "description or definition" is is in 13.1.1, so I cite that too. 
"Diagnosis" only appears in Recommendations 13A and arguably 13B and in the 
glossary, so the glossary entry is below; it is clearly understood as a synonym 
of the badly chosen term "description or definition".

========================

12.1. Requirements

To be available, every new name published before 1931 must satisfy the 
provisions of Article 11 and must be accompanied by a description or a 
definition of the taxon that it denotes, or by an indication.

13.1. Requirements

To be available, every new name published after 1930 must satisfy the 
provisions of Article 11 and must

13.1.1. be accompanied by a description or definition that states in words 
characters that are purported to differentiate the taxon, or

13.1.2. be accompanied by a bibliographic reference to such a published 
statement, even if the statement is contained in a work published before 1758, 
or in one that is not consistently binominal, or in one that has been 
suppressed by the Commission (unless the Commission has ruled that the work is 
to be treated as not having been published [Art. 8.7]), or

13.1.3. be proposed expressly as a new replacement name (nomen novum) for an 
available name, whether required by any provision of the Code or not.

Recommendation 13A. Intent to differentiate. When describing a new nominal 
taxon, an author should make clear his or her purpose to differentiate the 
taxon by including with it a diagnosis, that is to say, a summary of the 
characters that differentiate the new nominal taxon from related or similar 
taxa.

Recommendation 13B. Language. Authors should publish diagnoses of new taxa in 
languages widely used internationally in zoology. The diagnoses should also be 
given in languages used in the regions relevant to the taxa diagnosed.

=======================

diagnosis, n.
    A statement in words that purports to give those characters which 
differentiate the taxon from other taxa with which it is likely to be confused.