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Barosaurus neck vertebrae (free pdf)



From: Ben Creisler
bcreisler@gmail.com


A new paper in preprint:

Michael P Taylor & Mathew J Wedel (2013)
The neck of Barosaurus was not only longer but also wider than those
of Diplodocus and other diplodocines.
PeerJ PrePrints 1:e67v1
doi: http://dx.doi.org/10.7287/peerj.preprints.67v1
https://peerj.com/preprints/67/


Barosaurus is a diplodocid sauropod from the Upper Jurassic Morrison
Formation of the western United States, and is known for its very long
neck. It is related to the sympatric Diplodocus, and often thought of
as more or less identical except with a longer neck. The holotype YPM
429 includes three and a half posterior cervical vertebrae, somewhat
distorted and damaged, which are nevertheless very distinctive and
quite different from those of Diplodocus. The cervicals of the better
known and more complete referred Barosaurus specimen AMNH 6341 show
the same characteristic features as the holotype, though not to the
same extent: transversely broad but anteroposteriorly short
zygapophyseal facets; prezygapophyses carried on broad, squared-off
rami; zygapophyses shifted forward relative to the centrum;
diapophyses, parapophyses and neural spines shifted backwards; and
broad diapophyseal “wings”. These features form a single functional
complex, enabling great lateral flexibility, but restricting vertical
flexibility. This may indicate that Barosaurus used a different feeding
style from other sauropods perhaps sweeping out long arcs at ground
level. The Morrison Formation contains at least nine diplodocid
species in six to eight genera whose relationships are not yet fully
understood, but Barosaurus remains distinct from its relatives.