[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Rigid dinosaurs?
I wasn't there for Horner's presentation on his "microscopic analysis
of the dinosaur's vertebrae", but I assume he was referring to the
interspinalis ligament? Having dissected a few ratites, I was already
convinced by the gross morphological similarity, not to mention that
it's a level one EPB inference AND you can track the character's
homology through the fossil record to early birds.
I'm sure the interspinalis ligaments made T. rex necks just as "stiff"
as it does modern theropods, like ostriches. Of course tyrannosaurs
have fewer cervicals than extant birds, and they are less elongate, but
really, this is stupid; the ligament was likely elastic, as it is in
extant theropods, and was there to reduce the load the dorsal axial
musculature had to support when the head and neck were in a fairl
neutral pose. It wouldn't have constrained T. rex neck mobility any
more than the osteological articular range of movement allows. If he
was interested in a range of movemment study, Jack should have asked
Kent Stevens to help him out...of course Kent might not have comeup
with the answer Jack wanted.
And now I can look forward to 5 more years of kids asking "Is it true
that T. rex was just a scavenger?"
Wyoming Dinosaur Center
110 Carter Ranch Rd.
Thermopolis, WY 82443
(800) 455-3466 ext. 230
Cell: (307) 921-8333
From: W. F. Zimmerman, wfzimmerman.com <email@example.com>
Sent: Fri, 17 Feb 2006 09:37:02 -0500
Subject: Rigid dinosaurs?
Dr Horner and colleagues carried out microscopic analysis of the
vertebrae. They found tissue remnants related to the animal's nuchal
ligament, which provides passive support for the head and neck.
Since the amount found in the vertebrae is proportional to how stiff the
ligament would have been, the researchers determined it would have been
rigid in their T. rex.
"We think this applied to all dinosaurs, certainly all saurischians -
the meat-eating dinosaurs and all the sauropods," Dr Horner said.
"I think we need to re-model dinosaurs and think of them as being very
rigid. They're just not as fluid as we thought."
They would have needed lots of space to turn in order to avoid falling
--They sound like my son's plastic dino figurines.
--This sounds like a lot of extrapolation based on a small number of
--My gut reaction is that rigidity isn't very adaptive. It's hard to
imagine millions of predators tottering around in straight lines for
millions of years...
From: firstname.lastname@example.org [mailto:email@example.com] On Behalf
Sent: Friday, February 17, 2006 8:22 AM
Thanks very much to all that send me the papers.
Curador y Técnico Preparador
Fundación de Historia Natural Félix de Azara.
Departamento de Ciencias Naturales y Antropología.
CEBBAD - Universidad Maimónides.
Valentín Virasoro 732 (C1405BDB) Ciudad Autónoma de Buenos Aires,
Argentina. Teléfono/fax: 4905-1100 (int. 1228).
Página web: www.fundacionazara.org.ar
Internet gratis. Siempre.