Open Paleo

Sonidosaurus

Xu et al., 2006 soh-nid-oh-sore-us

Named after Sonid, the large geographical area in Inner Mongolia that includes the type locality, combined with Greek sauros, "lizard" — means "Sonid lizard"

89.8–66.0 million years ago Coniacian–Maastrichtian, Late Cretaceous
Late Cretaceous stages

Sonidosaurus 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.

Under dispute

Sonidosaurus was described as a relatively derived titanosaur whose position within Titanosauria is ambiguous (Xu and colleagues, 2006). Ksepka and Norell (2010) recover it in a polytomy at the base of Titanosauria, outside Lithostrotia, while Averianov and Sues (2016) regard it as a non-saltasaurid lithostrotian with possible saltasaurid affinities.

Diagnosis

  1. Thick ridge extending ventrally from postzygapophysis on lateral surface of neural arch of posterior dorsal vertebrae
  2. Transversely oriented accessory lamina between anterior centroparapophyseal lamina and lateral centroprezygapophyseal lamina of posterior dorsal vertebrae
  3. Long, anteroventrally directed caudal rib with two distinctive fossae on posterior margin on anterior caudal vertebrae
  4. Prominent vertical ridge above pubic peduncle on medial surface of ilium

Species

Sonidosaurus saihangaobiensis Xu et al., 2006

Type species

Named for Saihangaobi, the locality in Inner Mongolia, China, where the fossils were first discovered in 2001.

Holotype
LH V 0010 , Long Hao Institute of Geology and Palaeontology
Material
Five dorsal vertebrae, the last sacral vertebra, one anterior caudal vertebra, several dorsal ribs, one anterior chevron, partial left and right ilia, partial left pubis, and both ischia
Horizon
Iren Dabasu Formation, Coniacian–Maastrichtian, Late Cretaceous , 89.8–66.0 million years ago
Locality
Saihangaobi, Inner Mongolia, China

References

  1. Xu, X.; Zhang, X.; Tan, Q.; Zhao, X.; Tan, L. (2006). A new titanosaurian sauropod from Late Cretaceous of Nei Mongol, China. Acta Geologica Sinica (English Edition) 80(1): 20-26. Wiley. doi:10.1111/j.1755-6724.2006.tb00790.x

    Named Sonidosaurus as a derived titanosaur.

    xu2006c
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

    Reports the lithostrotian reading of Averianov and Sues (2016).

    jones2026b
  3. Ksepka, D. T.; Norell, M. A. (2010). The illusory evidence for Asian Brachiosauridae: new material of Erketu ellisoni and a phylogenetic reappraisal of basal Titanosauriformes. American Museum Novitates 3700: 1-27. American Museum of Natural History. doi:10.1206/3700.2

    Recovered Sonidosaurus in a polytomy at the base of Titanosauria, outside Lithostrotia.

    ksepka2010a
  4. Averianov, A. O.; Sues, H. D. (2016). Review of Cretaceous sauropod dinosaurs from Central Asia. Cretaceous Research 69: 184-197. doi:10.1016/j.cretres.2016.09.006

    Regard Sonidosaurus as a non-saltasaurid lithostrotian with possible saltasaurid affinities.

    averianov2016b
  5. Averianov, A. O.; Lopatin, A. V. (2020). An unusual new sauropod dinosaur from the Late Cretaceous of Mongolia. Journal of Systematic Palaeontology 18(12): 1009-1032. Informa UK Limited. doi:10.1080/14772019.2020.1716402

    Call Sonidosaurus a lithostrotian, but its position unclear.

    averianov2020a