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Archaeopteryx skull redescribed and reconstructed



From: Ben Creisler
bcreisler@gmail.com

A new online paper:

Oliver W. M. Rauhut (2013)
New observations on the skull of Archaeopteryx.
Paläontologische Zeitschrift (advance online publication)
DOI: 10.1007/s12542-013-0186-0
http://link.springer.com/article/10.1007/s12542-013-0186-0

Although skeletal remains of the iconic oldest known avialian
Archaeopteryx have been known for almost 150 years, several aspects of
the cranial anatomy of this taxon have remained enigmatic, mainly
because of the strongly flattened and often fractured and incomplete
nature of available skull materials. New investigation of the skulls
of the recently described, excellently preserved tenth (Thermopolis)
and the seventh (Munich) specimens revealed several previously
unrecognized characters and helps to resolve some problematic issues.
Thus, the nasal of Archaeopteryx shows a lateral notch for the
lacrimal, as is found in many other saurischian dinosaurs, the maxilla
clearly participates in the margin of the external nares, and there
seems to be a pneumatic foramen in the lacrimal, comparable to the
lacrimal fenestra found in many non-avian theropods. In the braincase,
Archaeopteryx shows pneumatic features reminiscent of non-avian
theropods, including a ventral basisphenoid recess and an anterior
tympanic recess that is laterally incised into the
basisphenoid/prootic. Most importantly, however, the postorbital
process of the jugal shows a facet for the suture with the
postorbital, thus resolving the question of whether Archaeopteryx had
a closed postorbital bar. A new reconstruction of the skull of
Archaeopteryx is presented, making the skull of this taxon even more
theropod-like than previously recognized. Furthermore, the closed
postorbital bar and the configuration of the bones of the skull roof
cast serious doubt on claims that an avian-style cranial kinesis was
present in this taxon.