[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Plateosaurus gastralia (free pdf)



From: Ben Creisler
bcreisler@gmail.com


A new paper in open access:

Regina Fechner and Rainer Gößling (2014)
The gastralial apparatus of Plateosaurus engelhardti: morphological
description and soft-tissue reconstruction.
Palaeontologia Electronica  17 (1) 13A; 11p;
http://palaeo-electronica.org/content/2014/696-gastralia-of-plateosaurus


The fragmentary nature of the fossil record of the gastralial
apparatus of sauropodomorph dinosaurs has considerable impact on our
understanding its functional morphology and evolution in this group.
With the aim of increasing our knowledge on the functional morphology
of the gastralial apparatus of sauropodomorph dinosaurs, remains of
the gastralial apparatus of Plateosaurus engelhardti are described.
Soft-tissues and their function are reconstructed applying the Extant
Phylogenetic Bracket, in this instance comprising crocodiles and
birds. The gastralial apparatus of Plateosaurus consists of at least
18 gastralial rows. With exception of the 1st row, which has a
chevron-shaped medial and two lateral gastralia, the gastralial rows
consist of two medial and two lateral gastralia. The lateral gastralia
are 2.2-2.8 times longer than the associated medial gastralia. The
proximal ends of the medial gastralia overlap in a lattice-like
arrangement, forming a mid-ventral imbricating articulation.
Characteristic for Plateosaurus is the sigmoid form of the medial and
lateral gastralia, the increasing angle of the gastralial rows from
proximal to distal, as well as the increasing robustness of the
gastralia rows from proximal to distal. According to the Extant
Phylogenetic Bracket, the gastralial apparatus of Plateosaurus is
embedded into M. rectus abdominis, which attaches to the caudal aspect
of the sternum and indirectly to the distal end of the pubis. As in
extant archosaurs, m. rectus abdominis is closely related to the other
muscles of the hypaxial abdominal muscle group. The muscles of the
hypaxial abdominal muscle group are active during ventilation and
locomotion, which suggests that the functions of the gastralial
apparatus of Plateosaurus may be more complex than previously
suggested.