Neurocranial Osteology and Neuroanatomy of a Late Cretaceous Titanosaurian Sauropod from Spain (<em>Ampelosaurus</em> sp.)

<div><p>Titanosaurians were a flourishing group of sauropod dinosaurs during Cretaceous times. Fossils of titanosaurians have been found on all continents and their remains are abundant in a number of Late Cretaceous sites. Nonetheless, the cranial anatomy of titanosaurians is still very poorly known. The Spanish latest Cretaceous locality of “Lo Hueco” yielded a relatively well preserved, titanosaurian braincase, which shares a number of phylogenetically restricted characters with <em>Ampelosaurus atacis</em> from France such as a flat occipital region. However, it appears to differ from <em>A. atacis</em> in some traits such as the greater degree of dorsoventral compression and the presence of proatlas facets. The specimen is, therefore, provisionally identified as <em>Ampelosaurus</em> sp. It was CT scanned, and 3D renderings of the cranial endocast and inner-ear system were generated. Our investigation highlights that, although titanosaurs were derived sauropods with a successful evolutionary history, they present a remarkably modest level of paleoneurological organization. Compared with the condition in the basal titanosauriform <em>Giraffatitan brancai</em>, the labyrinth of <em>Ampelosaurus</em> sp. shows a reduced morphology. The latter feature is possibly related to a restricted range of head-turning movements.</p>