Re: Spinosaurus questions and the presence of air=.

[Dinogeorge@aol.com]

In a message dated 5/31/03 7:59:34 AM Pacific Daylight Time, 
mightyodinn@yahoo.com writes:

<< So _Altispinax_ would properly be cited as:
 _Altispinax_ Kuhn 1939
 = Altispinax von Huene 1923 [nomen nudum]
     _Altispinax dunkeri_ (Dames 1884) Kuhn 1939 [type]
     = _Megalosaurus dunkeri_ Dames 1884 >>

Yes, I suppose you could cite it this way, although Kuhn didn't create the 
name Altispinax, he merely fixed its type species explicitly. It was Huene who 
first used the combination Altispinax dunkeri, in his 1923 paper. This was most 
likely the basis for Kuhn's designation of dunkeri as the type species. It is 
the first species refered to Altispinax (by page priority), which is probably 
why Kuhn made it the type species.

Huene also referred Megalosaurus oweni to Altispinax (in 1923) and 
Megalosaurus parkeri to Altispinax (in 1932). The former I renamed Valdoraptor 
oweni, 
and the latter Walker renamed Metriacanthosaurus parkeri. As I've mentioned 
already, Altispinax is a nomen dubium to which no other species should be 
referred 
(unless they're also nomina dubia, in which case it doesn't really matter 
anyway, and it keeps the number of useless generic names down).

In the 1920s you could still get away with creating a generic name without 
designating a type species (this is how we once became stuck with 
Procheneosaurus, and also Crataeomus and a few other genera from the 1800s), 
but if a 
subsequent worker designated a type species for such a genus, that became the 
"official" type species and any material previously referred to the 
type-species-less genus would thereafter be referred to the type species or 
simply to the 
generic name with sp. This changed with the 1931 version of the Code, which 
required an explicit type species be designated when a new genus is created. 
(This 
is how we lost Tetragonosaurus to Procheneosaurus: the ICZN ruled its type 
species was not explicitly designated.)

The three vertebrae sat around in a nomenclatural limbo for a few decades, 
being provisionally referred to Altispinax dunkeri, until Greg Paul explicitly 
made them the type specimen of the new species Acrocanthosaurus altispinax in 
PDW. The original describers of Acrocanthosaurus (Stovall & Langston) gave some 
consideration to calling their new theropod a new species of Altispinax but 
finally decided the latter name had taxonomic problems that they were unwilling 
to address. They got addressed by Greg and me later: After examining the 
various illustrations and descriptions for the taxa in question, I decided the 
vertebrae could not be either Acrocanthosaurus or Altispinax, so I made 
Acrocanthosaurus altispinax the type species of the new genus Becklespinax.