From: throopw@sheol.UUCP (Wayne Throop)
Newsgroups: talk.origins
Subject: Holden and the superhumongoreallybigosaurs
Summary: Ted is basing his arguments on very scant evidence
Date: 14 Dec 92 05:42:17 GMT

:: From: swf@tools3.teradata.com (Stan Friesen)
:: Message-ID: <1590@tdat.teradata.COM>
::: Again, McGowan and others give out the weight for an ultrasaur as
::: 360,000 lbs,
:: What others?

: From: news@fedfil.UUCP (news)
: Message-ID: <169@fedfil.UUCP>
: Articles I've seen in newspaper and magazine accounts which, due to space
: limitations, I cannot always keep...  The Avon Field Guide to Dinosaurs.

It is always well to remember that McGowan and others give out the weight
for an ultrasaur as 180 or so tons based on the assumption that it is
close to 100 ft long.  But that is only the upper limit of a range of
guesses at its length.

:: In particular its accuracy is limited to the accuracy of the model. 
:: And just how accurate do you think a model based on *one* *leg* is going
:: to be? (At the time McGowan wrote his book, only one leg from the
:: ultrasaur has been exhumed, so that was all that was available for
:: analysis). 
: I remember reading that collar bones, ribs, and other bones were
: uncovered in the late 70's.  McGowan's book is dated 1991.  What exactly
: are you talking about?

Actually, the situation is worse than Stanley points out, though
Ted is right that more than "a single leg" is known of Ultrasaurus.
Sort of.

Let's look at a very recent book (published 1992), organized around the
major finds of currently active researchers, and containing interviews
with them.  The book is _The_Kings_of_Creation_, by Don Lessem.  Let's
see what there is to see about Ultrasaurus.  From the chapter on
sauropods, "Land of Giants", we have these points:

    In the summer of 1972, Jensen went to Dry Mesa on a headline-making
    hunt.  "I was an obsessed man.  I was going to find the oldest,
    biggest carnosaur [meat-eading dinosaur], the bigger the better,
    even though scientifically that means little."
    [...]
    He struck upon the shoulder blade of an enormous dinosaur [...]
    A little figuring, based on comparisons of this shoulder bone and
    vertebrae found nearby with those of other giant sauropods, put
    the length of the new animal at eighty-two to ninty-eight feet
    (or even 140 feet, if it proved to be related to the long-tailed
    Diplodocus, as Jensen believes) [...]

That was the discovery of Supersaurus.

    In 1979, Jensen was again digging around the Dry Mesa site, [...]
    when he and his crew came upon another shoulder blade.  This one
    was nearly nine feet long, and broader than that of Supersaurus.
    If not from an animal longer than Supersaurus, it certainly belonged
    to a far heavier animal.
    [...]

That was Ultrasaurus.  But...

    Jensen did not get around to formally dubbing Supersaurus and
    Ultrasaurus until October 1985 [...]
    Jensen didn't base his new genus on the intriguing giant shoulder
    blade evidence.  Ranterh he used one of several vertebrae found nearby
    as his holotype -- the distinctive bone upon which hangs new species
    or genus identification.
    [...]
    Jensen called his own diagnostic skills into question in a 1987
    paper.  There he took the unusual step of withdrawing his assignment
    of a neck vertebra to Ultrasaurus.  He redubbed it [..presumably this
    means the vertebra..] a diplodocid, in keeping with the backbone's
    forked spines.
    And Jensen noted, the biggest scapula from Dry Mesa should be the
    holotype for identifying Ultrasaurus.  Now, however, he has changed
    his mind again:  "That was wrong.  I was pressured to publish a lot
    quickly.  I assumed incorrectly it was Ultrasaurus."  Now Jensen
    believes the shoulder blade belongs to an unidentified brachiosaur, 
    but not Ultrasaurus.  By this latest analysis the quary at Dry Mesa
    would contain at least four different giant sauropods.
    Not surprisingly, Jensen's reconsiderations of Ultrasaurus left
    other paleontologists puzzled and displeased.  Several doubt that
    Ultrasaurus is an animal distinct from Brachiosaurus, and few think
    Jensen's description and naming will stand the test of time.  But
    The Dry Mesa quarry is still producing new fuel for the dispute.
    [.. a gargantual pelvis and other finds, some attributed to
    Ultrasaurus by some, but nothing definitive..]

So.  We see that the size was guessed based on a shoulder blade, and a
mismatched vertebra.  Further, 100 feet long is only the longest of a
range of guesses, just as for Supersaurus.  (It is typical of Ted to
take the longest of a broad and speculative range as definitive. 
Perhaps this is because he is viewing things through accounts in the
popular press, which are in turn trying to make things sound as big and
amazing as possible.)

So, let's see what the best expert in the biz (after whom the
Ultrasaurus species, "Ultrasaurus macintoshi" was named) has to say.

    McIntosh has examined all the bones in question.  He was one
    of the first outsiders at Dry Mesa after the giant pelvis was
    found.  He has worked with Gillette and has long been convinced
    of the worthiness of Gillette's claim that Seismosaurus is a new
    and singularly long animal.  Of Ultrasaurus, he says, "It's known
    from so few bones.  I'm skeptical."  McIntosh is not convinced that
    Ultrasaurus is something new.  Like other researchers, he thinks it
    might be just a big Brachiosaurus.  Its huge vertebra with a high
    spike, used to name the animal, might belong to the rear end
    of a diplodocid.  Nor did the shoulder bones excavated at Dry Mesa
    provide clear evidence for Ultrasaurus or Supersaurus in McIntosh's
    mind.  "But I thought all three were different."  Still, it's
    possible, says McIntosh, that "Supersaurus and Ultrasaurus might be
    the same animal."  As for Supersaurus, McIntosh is more confident
    as to its identity, but not utterly convinced.  "I'd say it's a
    diplodocid with a two-thirds' chance of being new.  But I hate
    to speculate. [...]"

Of the Seismosaurus site, Lessem has this to say:

    Unlike Jensen's Dry Mesa site, this one was not a jumble of bones
    from many species, but rather the largely intact remains of one
    animal.

Of the seismosaur, there is no doubt: it is a diplodocid sauropod
of 140 to 150 feet in length.  It is by far the largest sauropod
for which complete a complete skeleton is available (and even it
isn't completely excavated, let alone prepared or mounted).

:: Try reading some actual journal articles on dinosaur weight estimates,
:: and you will see that they are generally considered to have about a 30%
:: (or higher) confidence bound.  This is *very* crude, little more than
:: order of magnitude. 

: 30% Off from 180 tones is still 120 tons and more.  He still can't
: make it.  Bill Kazmaier at that size would be able to lift less than
: half his weight off the ground, and Kaz is the most powerful creature
: his size or larger, lb. for lb. imaginable.  

Ted has a limited imagination indeed.  And, as I've already pointed out,
sauropods didn't have to be stronger "lb. for lb." (though Ted probably
means square cube scaled strength instead of lb.  for lb.  as he
actually says).  But the main thing to note here is that Ted is missing
the ponit.  The point is, WITH A SKELETON the weight estimates can be
off 30%.  That's the best case, when a volumetric model made with full
information, and only guessing at the density.  With no skeleton, as in
the case of Ultrasaurus, one is even guessing at the length.  And the
guesses of length span 20%, corresponding to masses from under 100 tons
to 180 tons.

As more information is known about Ultrasaurus, the estimates are
tending towards the low end of the original range of guesses.  Ted has
claimed that this re-evaluation was based on trying to get the weights
down under 132 tons, given by Guiness as a limit.  But from above we can
clearly see that this is not the case.  The re-evaluations are based on
featues of the bones themselves.  So, far from interpreting the bones in
light of an attempt to get a known result, new results are being arrived
at because of newly noted features of the bones, or because of new finds
altogether. 

: Archimedes' technique could not be improved upon, assuming you have a
: good idea as to the general shape and size of the creature involved,
: which we do. 

No, we do not, as I've amply demonstrated above.

The bottom line is, the largest example for which a full skeleton
is known is under 100 tons.  Even the Ultrasaurus is plausibly
under 100 tons, based on the 20% range of sizes in the original
identification.  Ted is basing his argument for masses over 100 tons
on very poor evidence indeed.

And, of course, Ted's unmodified square-cube scaling is invalid.
--
Wayne Throop  ...!mcnc!dg-rtp!sheol!throopw
Newsgroups: talk.origins