ISPN

[tmkeesey]

The order which clade names are listed in in the Companion Volume will be of some importance, since some may turn out to be heterodefinitional synonyms under certain phylogenetic hypotheses, and page priority will presumably be used to determine the senior synonym. Thus, it seems to me that a good rule of thumb would be to list all names in chronological order of their first coining.

For example, suppose that Mammalia Linnaeus 1758 were defined in the Companion Volume as the node-based clade specified internally by Didelphis marsupialis, Homo sapiens, and Ornithorhynchus anatinus, and Theria Parker and Haswell 1897 were defined as the node-based clade specified internally by D. marsupialis and H. sapiens. Under a phylogenetic hypothesis wherein D. marsupialis and O. anatinus share a closer common ancestor with each other than with H. sapiens*, these clade names would be heterodefinitionally synonymous. If listed chronologically, Mammalia would have clear precedence over Theria.

One potential problem with this idea is that, as I understand it, the Companion Volume is going to be split into several sectors of the Tree of Life, somewhat like the boards in this forum. Thus, strict adherence to page precedence would make any name in one sector "senior" over any name in another sector, even if it was coined later. One way to get around this would be to state that seniority in the Companion Volume is not determined primarily by page precedence, but primarily by original publication date of the clade name (and perhaps secondarily by page precedence, e.g., for new clade names in the Companion Volume).

But are there any situations where people think precedence by date of original name publication would be a bad idea?

* An unlikely hypothesis, I know, but this is just for the sake of argument.
_________________
T. Michael Keesey
Director of Technology, Exopolis, Inc.

[David Marjanović]

(Priority will be determined by the registration number, but that will surely be the same as page priority.)

(The "Marsupionta hypothesis" is as unlikely as you say, but several molecular analyses found such a clade in the 1990s, and their authors were usually naïve enough to believe it! )

I can't think of an example right now where priority by original publication date wouldn't be a good idea , but I bet there are some!

[tmkeesey]