DINOREVIEWS

[GSP1954 <GSP1954@aol.com>]

In the April 10 Science Ruben reviewed the Encyclopedia of Dinosaurs. He cites
as an example of dubious science my observation (in the book's reproduction
section) that some dinosaur babies' bones were so poorly ossified that they
should have been altricial (so immobile they could not leave the nest). 

Here is the situation. Ten years ago in Nature Horner & Weishampel published a
paper claiming that the poorly ossified limb joints of hadrosaur chicks
prevented them from leaving the nest. I did not believe that, the limb joints
of fully grown but not yet fully mature ostriches are very poorly ossified,
yet those big spring chickens can run as fast as when the joints fully ossify
a few months later. When the Oregon State group in 96 published a Science
paper saying that bone ossification in the same babies favored their being
precocial, I was also skeptical. In part because the trampled eggshells and
fairly large skeletons found in hadrosaur nests implied they did remain
nestbound. What does make sense is Horner's recent work showing that the
pattern of deeper bone ossification in hadrosaur chicks is more like that of
altricial than precocial bird chicks.  I could have ignored that work in that
it was/is only in abstract form, but that would have left the argument badly
incomplete. So in it went into the repro section. 

So much for that specific issue. In a broader sense, Ruben seems to be using a
review of the Encyclopedia as a platform to take the field of dinosaur
paleobiology to task for not being sufficiently rigorous. There are indeed
problems of that nature in dinosaur paleontology, as the just finished
Dinofest attests. Some of them were a mite peculiar. One of my own talks
directly addressed some of those problems. 

Problem is, that the Oregon State group is part of the problem.  Ruben seems
to set high standards - but for others, not his own work. 

After all, he published a radical hypothesis concerning theropod respiration
based upon photographes (generally of poor quality) of supposed soft tissues
associated with a specimen he and his group had never seen. This is just not
done in paleontology. The danger of misinterpreting a two dimensional phot of
a two dimensional specimen of what was once a 3-D animal is just too great.
Same with the stuff about the integument. They think they see the body outline
outside the fibers. Their ideas end up, with accompanying photograph, in an
unreviewed article in Science. 

When new investigation of the specimens shows that the septum and body
outlines are really just post excavation artifacts - rather than acknowledging
the possibility of error - the Oregon group actually argues that their
hypotheses are conservative views that need to be refuted. Not only that, they
then assert that the liver of Scipionyx is croc-like, again only on the basis
of photographes of a specimen they have not seen, and in contradiction to the
reviewed paper. 

Personally, I do not think I have ever seen a situation in which such weak
hypotheses have been presented, and so unambiguously refuted by direct
examination of specimens. Yet Ruben and company continue to believe the rest
of the community should take the liver pump and collagon fiber hypotheses
seriously. 

Think about it this way. If I presented evidence for the preservation of air-
sacs and feathers in a dinosaur based on photographes, and without examining
the specimen.

Would it get published in Science? 

Dream on. 

Would the Oregon state group take my conclusions seriously? 

Ha, ha, hee, hee. 

Ruben has made other substantial errors. In 1991 he asserted that
Archaeopteryx lacked pnuematic vertebrae, which is not true. In 1995 he
calculated that the estimated growth rate of Troodon was similar to that of
alligators, when no wild gator has been observed to grow to 50 kg in the 3-5
years the dinosaur seems to have. He also argued that growth rates should be
compared using age of sexual maturity. Not only is this incorrect (growth can
only be compared over the majority of juvenile growth), he neglecting that
sexual maturity is not generally observable in fossils. He has stated that
birds must have ossified uncinate processes in order to help ventilate their
air-sacs, when some lack the processes. He argues that ossified sterna and
sternal ribs are also crucial, ignoring those active and energetic precocial
bird chicks in which these bones remain cartilagenous. The Oregon group has
repeatedly published a figure showing a short nasal airway in Dromaeosaurus,
when the skull is much too incomplete to restore the passage, and more
complete dromaeosaur skulls show a much longer airway. 

Now, we all make mistakes. I know I have. Ruben as a physiologist knows more
about metabolics than most of us. Why I even sometimes agree with him - Ruben
has shown that the notion that dinosaurs could haved switched from being
tachymetabolic juveniles to bradymetabolic adults is implauisible at the
cellular level. But he does not appear to understand how to make the switch
from living systems to fossils. This can be seen in his tendency to use out of
date sources (such as quarter century old figures of dromaeosaur skeletons).
At this point I have thrown my hands up and assume  what the Oregon state
group says about fossils and certain other matters is probably in error unless
proven otherwise. 

There is that line about those who live in glass houses not throwing stones.
If the Oregon State group wants to see the level of science in dinosaurology
rise, and critize those that do not meet high standards, then they should
first set an appropriate example. As it is, they are not raising the rigor of
the field, instead there is a danger of their helping lower it. This is why
the reaction against some of their work has been so vigorous in some quarters.

GSPaul 

(PS - In his review, Ruben cites the recent SVP presentation by dinosculptor
Dave Thomas [which included an attempt to use musical timing to demonstrate
the co-timing of a theropod and sauropod footfall sequence] as an example of
bad science. Dave is much too nice a fellow to respond - and he does not have
access to Science - so I will. First, Dave was trying to use musical timing in
an innovative manner, in order to show how the theropod was steeping in
sequence with the sauropod in a manner typical of attacking predators. Nothing
wrong with that whether he is right or wrong in the end. Second, it is because
of Dave's meticulous work that it is now known that the famous Paluxy
theropod-sauropod trackway very probably records an actual attack by a giant
dinosaur upon an even bigger dinosaur [presented in a recent SciAmer article].
In doing his research Dave bothered to travel in order to directly examine the
actual trackways in Texas and NY, as well as Bird's original descriptions and
notes. Dave not only never did anything wrong, his standards of science were
well above those of the Oregon State group. Yet his fine work ends up
inappropriately disparaged in the most widely read science forum. Not fair.)