Sonidosaurus

Sonidosaurus (meaning "Sonid lizard", after Sonid, the large geographical area that includes the type locality) is a genus of sauropod dinosaur from the Late Cretaceous. It was a titanosaur which lived in what is now Inner Mongolia. The type species, Sonidosaurus saihangaobiensis, was described by Xu, Zhang, Tan, Zhao, and Tan in 2006. It was a small titanosaur, about 9 meters (30 ft) long. It was first discovered in the Saihangaobi, Iren Dabasu (Erlian) Formation, in 2001 in a quarry which would later yield the remains of Gigantoraptor.

== Classification == Sonidosaurus exhibits a combination of derived characteristics of titanosaurs and plesiomorphic features suggesting a more basal position. It shares several similarities with some other Asian titanosaurs, such as Opisthocoelicaudia, suggesting possible close affinities. In a 2017 review of Asian titanosaurs, Sonidosaurus was considered a lithostrotian titanosaur, with possible saltasaurid affinities. In particular, it shared with saltasaurids and the Bor Guve titanosaur a posterior centrodiapophyseal lamina on its dorsal vertebrae.