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RE: When carnivores kill other carnivores...



    Warning - pretty heavy waffling ahead. My supervisor made the
comment a couple of days ago that "Taxonomy seems to bring out the worst
in people"...
    With the proviso that I haven't seen Huene's original papers (and
that's a pretty big caveat - if there's one thing I've learnt in
taxonomy, it's that secondary sources are not to be trusted), I would
derive a different interpretation from this (which may lead to a similar
conclusion). The first paragraph Tim has transcribed indicates that
Huene explicitly established the name _Altispinax_ in 1923 for
_Megalosaurus dunkeri_ (which is then the type species by monotypy).
Despite the circumlocutious phrasing, this does not appear to have been
conditional. Huene explicitly states _'Megalosaurus' dunkeri_ Lydekker
to be distinguishable from _Megalosaurus_, and it is only in the 1926
publication that he introduces the 'if' factor (his use of the phrase
'gen. nov.' in 1926 must be regarded as erroneous, as must his 1936
reference to the name being proposed in 1926).
    This being the case, anything Huene may have said after 1923 is
effectively irrelevant. It is not generally possible to change the type
species or specimen of a taxon after publication, even if you were the
original author of said taxon. The relevant article of the Code is
61.1.3: "Once fixed, name-bearing types are stable and provide objective
continuity in the application of names. Thus the name-bearing type of
any nominal taxon, once fixed in conformity with the provisions of the
Code, is not subject to change except in the case of nominal genus-group
taxa as provided in Article 70.3.2 [snip]"
    However, Article 70.3 is directly relevant to this case: "70.3.
Misidentified type species. If an author discovers that a type species
was misidentified ... the author may select, and thereby fix as type
species, the species that will, in his or her judgment, best serve
stability and universality, either

70.3.1. the nominal species previously cited as type species [Arts. 68,
69], or

70.3.2. the taxonomic species actually involved in the
misidentification. If the latter choice is made, the author must refer
to this Article and cite together both the name previously cited as type
species and the name of the species selected."

    While not as explicit in the original 1923 publication as later,
Huene obviously established _Altispinax_ under the assumption that the
vertebrae were referrable to this species. This assumption no longer
holds water, and hence I feel that it effectively constitutes a
misidentification. What the ICZN states here is that it is the choice of
the reviewing author as to what exactly s/he wants to do about said
misidentification to best preserve stability of the name's usage. Either
_Megalosaurus dunkeri_ could be confirmed as type species (in which case
the name _Altispinax_ would be typified by the tooth that is type
specimen of _M. dunkeri_) or the type species could be transferred to
that actually described in the original genus description (in which case
_Altispinax_ would be typified by the three vertebrae, and the type
species would become _Acrocanthosaurus altispinax_). Offhand, the
example of this rule given in the ICZN indicates that it doesn't matter
if the new type species was not named until after the genus was
established (the example is a beetle genus established in 1829, whose
revised type species was named in 1832).
    For the latter possibility to be taken advantage of, it must be
validly published with an explicit statement of what is going on.
Huene's own later indications that _Altispinax_ was based on the
vertebrae would not be sufficient. _Altispinax_ is still nominally
attached to _Megalosaurus dunkeri_, but perhaps it is possible to
rectify the situation. The main consideration that comes to my mind,
however, is that maybe that ship has already sailed. If someone has
explicitly recognised the misidentification in print, but retained the
type species of _Altispinax_ as _Megalosaurus dunkeri_, their doing so
would take priority as establishing the type species of the genus under
Article 70.3 (note that maintaining the nominal type species does _not_
require an explicit reference to the Article). Has this actually
happened (for instance, did George Olshevsky do so when he established
the genus _Becklespinax_)?

    Cheers,

        Christopher Taylor

PS. Any poor phrasing in the above e-mail is to be entirely blamed on
the fact that it is now 12.30 at night.

-----Original Message-----
From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu] On Behalf
Of Tim Williams
Sent: Saturday, 11 March 2006 10:22 AM
To: dinosaur@usc.edu
Subject: Re: When carnivores kill other carnivores...

Mike Keesey wrote:

>I'm trying to figure out what ICZN rules
>(http://www.iczn.org/iczn/index.jsp) say and they're giving me a
>headache.

Me too - including the headache bit.

Here's what Rauhut says:

"Huene (1923: p. 453) referred to Lydekker's work, stating that "the
species 
described as _M. dunkeri_ by Lydekker (Dames) [sic], from the English
(and 
German) Early Wealden, is distinguished from _Megalosaurus_ by its 
enormously high neural spines in the dorsal region. I therefore propose
to 
establish a new genus, _Altispinax_, for it. [snip]

"However, Huene (1926a: pp. 482-483) stated: "There is another specimen
from 
the Wealden of Battle...consisting of three articulated middle dorsal 
vertebrae, with extremely high neural spines. ...if it were certain that

such dorsal vertebrae belong to _Megalosaurus dunkeri_, it would be 
necessary to put it into a distinct genus, for which the name
_Altispinax_, 
gen. nov., might be reserved.", and in 1932 (p. 235): "Three articulated

dorsal vertebrae with very elongated neural spines, figured by Owen
(202, 
Pl. 19), also seem to belong here; ...In 1926 ..., I based the genus 
_Altispinax_ on these specimens." (my translation). From this it is
clear 
firstly that the generic name _Altispinax_ was proposed for the three 
vertebrae, and secondly does not refer to the nomen dubium _Megalosaurus

dunkeri_. Since Huene (1926) did not propose a new specific name, the
first 
available species name given exclusively to the vertebrae is Paul's
(1988a) 
_Acrocanthosaurus altispinax_, the species thus becomes _Altispinax 
altispinax_ (PAUL, 1988a). _Becklespinax Olshevsky, 1991, is thus an 
objective junior synonym of _Altispinax_ Huene, 1923.

The gist of this nomenclatural saga would appear to be that when Huene
first 
coined the name "Altispinax_ in 1923 it may not have qualified as a
valid 
name under ICZN rules (this fits with what Mickey said about the 
"conditional" nature of the name).  However, Huene was more explicit in
his 
later publications, so by 1926 it is clear that he is basing
_Altispinax_ on 
the tall-spined vertebrae.  So although Huene was wishy-washy in the 
beginning about what he meant to attach the name "Altispinax" to, he
later 
cleared this up.

OK, time for an aspirin.

Cheers

Tim


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