10.5061/DRYAD.DG027
Knoll, Fabien
University of Bristol
University of Manchester
Museo Nacional de Ciencias Naturales
Witmer, Lawrence M.
Ohio University
Ridgely, Ryan C.
Ohio University
Ortega, Francisco
National University of Distance Education
Sanz, Jose Luis
Autonomous University of Madrid
Data from: A new titanosaurian braincase from the Cretaceous “Lo Hueco”
locality in Spain sheds light on neuroanatomical evolution within
Titanosauria
Dryad
dataset
2016
endocast
Sauropod
Sauropoda
braincase
titanosaur
Dinosauria
Titanosauria
2016-09-03T00:00:00Z
2016-09-03T00:00:00Z
en
https://doi.org/10.1371/journal.pone.0138233
101965360 bytes
1
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Despite continuous improvements, our knowledge of the neurocranial anatomy
of sauropod dinosaurs as a whole is still poor, which is especially true
for titanosaurians even though their postcranial remains are common in
many Upper Cretaceous sites worldwide. Here we describe a braincase from
the uppermost Cretaceous locality of ‘‘Lo Hueco” in Spain that is one of
the most complete titanosaurian braincases found so far in Europe.
Although the titanosaurian Ampelosaurus sp. is known from the same
locality, this specimen is clearly a distinct taxon and presents a number
of occipital characters found in Antarctosaurus and Jainosaurus, which are
approximately coeval taxa from southern Gondwana. The specimen was
subjected to X-ray computed tomographic (CT) scanning, allowing the
generation of 3D renderings of the endocranial cavity enclosing the brain,
cranial nerves, and blood vessels, as well as the labyrinth of the inner
ear. These findings add considerable knowledge to the field of sauropod
paleoneuroanatomy in general and titanosaurian endocast diversity in
particular. Compared with that of many sauropodomorphs, the endocast
appears only slightly flexed in lateral view and bears similarities (e.g.,
reduction of the rostral dural expansion) with Gondwanan titanosaurians
such as Jainosaurus, Bonatitan, and Antarctosaurus. The vestibular system
of the inner ear is somewhat contracted (i.e., the radius of the
semicircular canals is small), but less so than expected in derived
titanosaurians. However, as far as the new specimen and Jainosaurus can be
contrasted, and with the necessary caution due to the small sample of
comparative data currently available, the two taxa appear more similar to
one another in endocast morphology than to other titanosaurians. Recent
phylogenetic analyses of titanosaurians have not included virtually any of
the taxa under consideration here, and thus the phylogenetic position of
the new Spanish titanosaurian—even its generic, let alone specific,
identification—is not possible at the moment. Nevertheless, both the
braincase osteology and the endocast morphology suggest that the specimen
represents a derived titanosaurian that presumably branched further from
the base of Lithostrotia, potentially even near Saltasauridae, comparable
in evolutionary terms with Jainosaurus.
CT scan data (DICOM) for Spanish titanosaur braincase (MCCM-HUE-1667)CT
scan data (DICOM) for Spanish titanosaur braincase (MCCM-HUE-1667). This
specimen was collected from the Villalba de la Sierra Formation at a
locality named “Lo Hueco,” near the village of Fuentes, Castile-La Mancha,
Spain. Cretaceous (late Campanian-early Maastrichtian). The specimen was
scanned on an Yxlon CT Compact (Yxlon International, Hamburg, Germany)
with a voltage of 180 kV and a current of 2.8 mA. The in-plane pixel size
was 0.18 mm, with an inter-slice spacing of 0.20
mm.Spanish_titanosaur_MCCM-HUE-1667_DICOM.zip
Europe
Spain