Re: Superfamilies

["Jaime A. Headden" <qilongia@yahoo.com>]

Steven Mahon (floridamahon@yahoo.com) wrote:

<I was told several times that I should change names ending in -oidea in
accordance with ICZN. (e.g. Oviraptoroidea to Caenagnathoidea, &
Spinosauroidea to Megalosauroidea). I have only one problem with this: how
do I know what that group should contain, (I know of course the
family-level of the name). How do I know what other families belong in the
super-family?>

  According to the ICZN, any family level taxon name, including the
superfamily in reptiles/birds which end in -oidea by convention, must be
based on the earliest included and _valid_ family name. Since Sereno's
Oviraptoroidea (1999) was a "superfamily" (not by his designation, though,
but because it ended in -oidea and including immediately two -idae clades
referred to as family-ranked taxa) that included Caenagnathidae, named in
1940, as well as Oviraptoridae, named in 1976, the earliest name available
is the former, and in 2000 Sereno changed the name to Caenagnathoidea to
reflect this. The same is true for Spinosauroidea vs. Megalosauroidea,
however Megalosauroidea, being based on Megalosauridae, is in turn based
on *Megalosaurus* which may be a nomen dubium and not very diagnostic,
must less very comparable to other referred taxa, unless you assume the
rest of the Stonesfield Quarry bones belong to the same taxon (hardly
provable right now). This nature as a nomen dubium is the one condition
the ICZN offers that Megalosauridae can be treated as a dubious
designation. The next available name is Torvosauridae for the same
inferred content, and this is younger than Spinosauridae. Sereno
designated the Torvosauroidea in 1994, and similarly used Spinosauroidea
later as a redesignation of the same clade. Technically, all names are
available under phylogenetic taxonomy only, as the ICZN reflects, the
nominotypic taxon is valid. Above that, any other name can be used at any
"level."

  Potentially, the original senses of names apply, and under phylogenetic
nomenclature, Oviraptoroidea would be used as Caenagnathoidea is an
"unneccessary" usage. After all, Oviraptoroidea includes an included
"-idae" taxa based on a valid genus. Also based on the oldest valid genus
included in that Oviraptoroidea (not to mention the Oviraptorosauria).
Megalosauroidea wins by this extension, except it may not be valid, in
which case Sereno's original Torvosauroidea would have priority over the
younger synonym of Spinosauroidea. It all depends on how you define names,
however.

  Cheers,

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

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