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

Turtle ligament homology in temporal skull region (free pdf)

From: Ben Creisler

A new paper that may be of interest. The paper is open access.

Ingmar Werneburg (2013)
The Tendinous Framework in the Temporal Skull Region of Turtles and
Considerations About Its Morphological Implications in Amniotes: A
Zoological Science 30(3):141-153. 2013
doi: http://dx.doi.org/10.2108/zsj.30.141

In 1926, Tage Lakjer hypothesized a replacement of the infratemporal
bar in diapsids by a ligament spanning between quadrate and the upper
jaw. As a similar ligament is also present in turtles, he argued for a
diapsid origin of this group. Based on recent advances in the
homologization of the tendinous framework in the reptile jaw adductor
chamber — reviewed in this paper — one could argue for independent
origins of the cheek ligaments in sauropsids. The quadratomaxillar
ligament of turtles could, with reservation, be homologized with the
quadrate aponeurosis of other sauropsids, as well as to the
superficial tendon of m. masseter in mammals. These structures have a
strong morphogenetic influence to cranial anatomy. Given such an
identity, the hypothesis of a structural replacement of the lower
temporal arcade in lizards would be refuted. Moreover, such a homology
could be correlated to the evolution of the middle ear and to the
origin of the chewing mechanism in mammals, which contributed to the
evolutionary success of that group. The homologization presented
herein is critically discussed and is open for revision. Nevertheless,
the value of tendinous structures for fundamental homologisations in
the vertebrate head is highlighted.