[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Bakker's Brontosaurus and Late Cretaceous populations

> Date: Tue, 02 Aug 2005 13:52:41 -0500
> From: Tim Williams <twilliams_alpha@hotmail.com>
>> Just to be picky --
> And just to be even pickier...  :-)

I take my hat off to you, sir.

>> _Cathetosaurus_ Jensen 1988 was indeed sunk into _Camarasaurus_ (as
>> the new species _C. lewisi_) by McIntosh et al. 1996,
> ...I think this synonymy was first done by Miller, McIntosh,
> Stadtman and Gillette (1992).

Ah, thanks for that correction.  I can't find the reference for this
-- do you have it?

> Anyways, there might be reason to quibble the referral of
> _Cathetosaurus lewisi_ to _Camarasaurus_ (as _Camarasaurus lewisi_)
> given that the ilium of _C. lewisi_ is reported to be angled
> somewhat upwards and forwards, as in brachiosaurids and other
> titanosauriforms.

I shouldn't really comment on this as I've not yet read the McIntosh
et al. osteology; but the Jensen 1988 paper does seem to make a strong
case for generic separation when read in isolation.  (It also contains
some bizarre assertions on the superiority of mammals' limbs to those
of sauropods for carrying great masses, but let's not go there.)

>> If it seems odd that the brachiosaur "Ultrasauros" should be sunk
>> into a diplodocid, that's because Jensen inexplicably nominated a
>> dorsal as the holotype of "U." instead of the indisputably
>> brachiosaurid scapula that is most associated with that name.
> And apparently, the "Ultrasaurus" scapula isn't really all that
> large...

Well, "not large" would be a bit harsh :-)  BYU 9462 is 2.5m long, or
a tad over eight feet -- for a scapulocoracoid, not a scapula alone.
That's better than a kick in the head.  Curtice et al. 1996 assert
that it's no larger than the largest of the Tendaguru
scapulocoracoids; but their own table in fact shows it in fact to be a
little longer than that of HMN Sa9, the longest, which comes in at
243cm.  The Tendaguru scap is, however, somwhat wider and 30% thicker
at the glenoid than BYU 9462.  At any rate, the "Ultrasaurus" scap
certainly does not represent a _much_ larger animal than is known from
Tendaguru, contra the widespread reports that it is 1/3 longer => 2.35
times as massive.

>> The others you mentioned are less emphatic, though.  The only
>> published attempt to synonymising _Seismosaurus_ Gilette 1991 with
>> _Diplodocus_ (so far as I know) is Lucas and Heckert (2000); and
>> all they have to say is "previously misrepresented as [...] a new
>> genus, _Seismosaurus_, but clearly not distinct from Diplodocus
>> (B. Curtice, pers.  comm., 2000)".  I'm not particularly convinced
>> by a pers. comm. for that,
> Nevertheless, Lucas and Heckert were convinced enough to cough up
> the new combination _Diplodocus hallorum_.

Yes ... with no actual justification whatsoever.  Anyone can make up
new combinations.  Look: _Triceratops rex_!  _Tyrannosaurus horridus_!
But I can't justify them, so they will be rightly ignored.

>> Curtice doesn't really commit himself one way or the other; and his
>> analysis has in any case now been superseded by McIntosh's (2005)
>> new _Barosaurus_ monograph, which reaffirms the genus _Supersaurus_
>> as distinct from _B._
> Yes, AFAIK the combination _Barosaurus vivianae_ has yet to be
> formally proposed.  I haven't seen or read McIntosh (2005), so
> thanks for the tip.

You definitely need to get Ken's sauropod volume!
(And so does everyone else!  C'mon people, what are you waiting for?
It's a volume full of sauropod papers!  It even has the looong awaited
follow-up to Stevens and Parrish 1999!)

 _/|_    ___________________________________________________________________
/o ) \/  Mike Taylor  <mike@miketaylor.org.uk>  http://www.miketaylor.org.uk
)_v__/\  "Debugging?  Klingons do not debug.  Our software does not coddle
         the weak." -- Klingon Programming Mantra

Listen to free demos of soundtrack music for film, TV and radio