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Saltasaurine titanosaur presacral vertebrae

From: Ben Creisler

A new online paper:

V.L. Zurriaguz & A. Álvarez (2013)
Shape variation in presacral vertebrae of saltasaurine titanosaurs
(Dinosauria, Sauropoda).
Historical Biology (advance online publication)

Shape variation in presacral vertebrae of saltasaurine titanosaurs
(Dinosauria, Sauropoda).
Titanosaurs were small- to giant-sized sauropods, highly derived and
highly pneumatic. Using morphometric analyses, we studied differences
in shape of the presacral vertebral centra in some of these sauropods,
especially in saltasaurines, and compared asymmetry patterns in
lateral pneumatic foramina (LPF) between these titanosaurs and avian
and non-avian theropods. Geometric morphometric analyses showed that
the cervical centra tend to be elongated and dorsoventrally short,
with an elliptical LPF located in the middle of the centrum; dorsal
centra tend to be short and higher than the cervical centra, with the
LPF slightly displaced to the anterior region. Shape variation can be
described as a result of the ordering of the vertebrae within both the
cervical and dorsal sequences, and therefore these methods can be
applied to predict the position of isolated vertebrae. A persistent
pattern of asymmetry among LPF was observed when length–height indexes
were plotted. The right LPF are usually larger than those on the left
side in the cervical vertebrae (except in Saltasaurus loricatus) but
variable in the dorsal vertebrae. We propose an explanation of this
asymmetry based on the asymmetric arrangement of viscera and late
development of the respiratory (and air sacs) system.