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Re: Greg Paul is right (again); or "Archie's not a birdy"



Tim Williams <tijawi@gmail.com> wrote:

> Well, it doesn't go against *all* historical usage.  Neornithes was
> originally erected to include _Hesperornis_!   (And _Ichthyornis_ too,
> as well as modern birds.)

But only because _Hesperornis_ and _Ichthyornis_ were believed to be
modern birds when Gadow coined the name. _Ichthyornis_ was classified
as a charadriiform and _Hesperornis_ as a relative of extant "ratites"
(Newton 1884), penguins (Beddard 1898), or loons and grebes
(Fürbringer 1888). Would you be willing to extend Charadriiformes to
the _Ichthyornis_ node and _Ratitae_, _Sphenisciformes_, or
Gaviomorphae to the _Hesperornis_ node as well? The logic behind this
decision would be the same one that you use in the case of
_Neornithes_.

> So if we were to drag Neornithes down a few nodes... no big deal.

It would just contradict the way the name has been applied for the
last 30 years. Really, no big deal :o)

> I don't see any problem with using _Hesperornis_ as specifier.  Some
> node-based definitions of Ornithurae have already incorporated
> _Hesperornis_ (Chiappe, 1995; Padian et al., 1999).  As for
> Gaviomorphae... I don't understand its relevance to
> Hesperornithes/_Hesperornis_.

I agree with Mike Keesey that it is no longer relevant, but there was
a hypothesis that _Hesperornithes_ are deeply nested in the crown
clade as a sister-group to a clade consisting of grebes
(Podicipedidae) and loons (Gaviidae). Cracraft (1982) even
corroborated it by a cladistic analysis, where "Hesperornithiformes"
and Gaviiformes (Gaviidae + Podicipedidae) constituted a clade named
Gaviomorphae. If names resting on _H. regalis_ were applied to
Cracraft's topology, _Ornithurae_ would be a subclade of _Neornithes_
(it is hard to be more specific, because there is no particular
"species" mentioned as the other specifier in the node-based
definition of _Ornithurae_ -- just _Neornithes_ as a whole) and
_Hesperornithes_ (> _H. regalis_ ~ _P. domesticus_) would be
equivalent to some kind of "waterbird assemblage", including at least
"gaviomorphs", penguins, pelecaniforms, and procellariiforms.


References:

Beddard FE 1898 Structure and classification of birds. London:
Longmans, Green. 548 p

Cracraft J 1982 Phylogenetic relationships and monophyly of loons,
grebes, and hesperornithiform birds, with comments on the early
history of birds. Syst Zool 31(1): 35–56

Fürbringer M 1888 Untersuchungen zur Morphologie und Systematik der
Vögel, zugleich ein Beitrag zur Anatomie der Stütz- und
Bewegungsorgane, vol. 1–2. Amsterdam: Von Holkema. 1751 p

Newton A 1884 Ornithology. Encyclopædia Britannica 9th ed, vol. 18: 2–50
-- 
David Černý