Endocasts of some sauropod taxa discussed in the text, displayed on a cladogram.

<p>From left: <i>Camarasaurus lentus</i> (CM 11338), indeterminate titanosaurian from Uzbekistan (CCMGE 628/12457), <i>Ampelosaurus</i> sp. from Spain (MCCM-HUE-8741, right side mirrored), indeterminate titanosaurian from Spain (MCCM-HUE-1667), and <i>Jainosaurus septentrionalis</i> (composite). In left lateral view. Dorsal is to the top. All but E digital endocasts; <i>Jainosaurus septentrionalis</i> is a montage of a photograph of the physical endocast (incomplete rostrally) made from the lectotypic braincase (GSI K27/497 ([<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0138233#pone.0138233.ref028" target="_blank">28</a>]: fig. 7A), right side mirrored and colorized) combined with the digital reconstruction of the endosseous labyrinth from a different specimen referred to the same species (ISI R162). CCMGE 628/12457 ([<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0138233#pone.0138233.ref010" target="_blank">10</a>]: fig. 3A, B) is depicted in a more basal phylogenetic position than either <i>Ampelosaurus</i> sp., MCCM-HUE-1667 or <i>Jainosaurus septentrionalis</i> based on its well-developed “middle cerebral vein” system. Scale bar equals 5 cm.