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Hadrosaur necks [was Re: A few species names if you please.]
Ann Schmidt wrote:
>Also what ever became of the "hadrosaur neck thickness/did they have a
>short fin or many spine-like structures along the back" Have scientist
>reached a consensus on the matter?
Which controversy? I know of three topics you could be referring to, and
non of them are really controversies per se:
1) Midline frills: there is evidence of rows of thick scales and segmented
soft frills down the backs of hadrosaurs. It has been suggested that
lambeosaurines had a soft frill extending from the "spike" at the back of
the crest down the neck. Czerkas as claimed that there is no evidence for
this, but his views have yet to be formally published. I would say that
there is a very reasobale possibility that such frills were present.
2) Sailbacks: It was recently suggested that the "sails" of high-spinned
dinosaurs actually supported buffallo-like humps. Sadly, although a paper
has been published on the subject, there has never been a formal reply.
The paper does a good job of showing that tall dorsal spines in dinosaurs
are morphologically dissimilar from those in "pelycosaurs." However, I am
personally not satisfied that the paper demonstrated that a "hump" is a
viable altenative hypothesis. However, rather than dismissing this paper
offhand, I will await a published rebuttal.
3) Nuchal ligaments: Czerkas has suggested that hadrosaurs had
"ungulate-like" nuchal ligaments extending from the "whithers" area above
the shoulders to the head (or the axis?). This suggestion has, to my
knowledge, NEVER been properly presented. Despite this, Greg Paul, for
whom I have the utmost repect, has adopted the suggestion wholesale,
including it on all of his reconstructions of hadrosaurs, as well as
I have, on this list, presented a sketch argument as to why such
an arrangement would be unprecedented in that the ligaments would have to
stretch over an extremely long distance. I have since recalculated and
determined that this is not necessarily true. However, I have
assembled mechanical, morphological, functional, taphonomic, and
phylogenetic evidence to suggest that a much more conventional and
conservative alternative, that of short ligaments connencting alternating
even-odd sets of cervical vertebrae (originally suggested by Alexander for
sauropods) is much more reasonable.
So far, however, the original hypothesis remains unpublished, and
thus the propriety of responding in print is in doubt. The fine art of
publication is being steadily replaced by abstract-mania (some recent
papers in JVP have had bibliographies with 30-50% abstract citations). I
wonder if Czerkas ever plans to publish it... maybe I'll ask.
So, anyway, nothing published, no controversy.
Hope this helps.