Knoll Fabien, Lautenschlager Stephan, Valentin Xavier, Díez Díaz Verónica, Pereda Suberbiola Xabier, Garcia Géraldine
ARAID-Fundación Conjunto Paleontológico de Teruel-Dinópolis, Teruel, Spain.
Departamento de Paleobiología, Museo Nacional de Ciencias Naturales-CSIC, Madrid, Spain.
PeerJ. 2019 Nov 18;7:e7991. doi: 10.7717/peerj.7991. eCollection 2019.
Despite continuous improvements, our knowledge of the palaeoneurology of sauropod dinosaurs is still deficient. This holds true even for Titanosauria, which is a particularly speciose clade of sauropods with representatives known from numerous Cretaceous sites in many countries on all continents. The data currently available regarding the palaeoneurology of titanosaurs is strongly biased towards Gondwanan forms (Argentina above all, but also India, Malawi and Australia). In contrast, the palaeoneurology of Laurasian titanosaurs is known only from a few taxa from Spain and Uzbekistan, despite the discovery in other countries of Laurasia of a number of neurocranial remains that would lend themselves well to investigations of this kind. To fill in this gap in our knowledge, we subjected a titanosaurian braincase from the uppermost Upper Cretaceous of southern France to X-ray computed tomographic 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 reconstructions are used to clarify the phylogenetic position of the specimen from the Fox-Amphoux-Métisson site. A combination of characters, including the presence of two hypoglossal rami on the endocast, the average degree of development of the dorsal-head/caudal-middle-cerebral vein system and the relatively short and subequal lengths of the ipsilateral semicircular canals of the labyrinth, are particularly revealing in this respect. They suggest that, compared with the few other Laurasian titanosaurs for which in-depth palaeoneurological data are available, the French taxon is more derived than the distinctly more ancient, possibly non-lithostrotian titanosaur from the Uzbek site of Dzharakuduk but more basal than derived saltasaurids, such as the coeval or slightly more recent forms from the Spanish locality of Lo Hueco.
尽管有持续的进展，但我们对蜥脚类恐龙古神经学的了解仍然不足。对于泰坦龙类来说也是如此，泰坦龙类是蜥脚类恐龙中一个特别多样化的分支，在各大洲许多国家的众多白垩纪遗址都有其代表物种。目前关于泰坦龙古神经学的现有数据严重偏向冈瓦纳大陆的物种（尤其是阿根廷，但也包括印度、马拉维和澳大利亚）。相比之下，尽管在劳亚大陆的其他国家发现了一些适合进行此类研究的神经颅骨遗骸，但劳亚大陆泰坦龙的古神经学仅从西班牙和乌兹别克斯坦的少数分类群中得知。为了填补我们知识上的这一空白，我们对来自法国南部上白垩统最上部的一个泰坦龙脑壳进行了X射线计算机断层扫描，从而生成了包围大脑、颅神经和血管的颅内腔以及内耳迷路的三维渲染图。这些重建用于阐明来自福克斯 - 安富 - 梅蒂松遗址的标本的系统发育位置。在这方面，包括脑模上存在两个舌下支、背头/尾中脑静脉系统的平均发育程度以及迷路同侧半规管相对较短且大致相等的长度等特征组合尤其具有启发性。它们表明，与其他少数有深入古神经学数据的劳亚大陆泰坦龙相比，这个法国分类群比来自乌兹别克斯坦扎拉库德克遗址的明显更古老、可能非石颈泰坦龙更为进化，但比进化的萨尔塔龙类更为原始，比如来自西班牙洛韦科地区的同期或稍晚的物种。
