Mongolostegus

Mongolostegus (meaning "Mongolian roof") is a genus of stegosaur from the Early Cretaceous (Aptian-Albian) Dzunbain Formation of Mongolia. The type and only species is M. exspectabilis, known from a single specimen previously under the nomen nudum Wuerhosaurus mongoliensis.

Mongolostegus is one of the youngest known stegosaurs, along with Stegosaurus, Yanbeilong, and an unnamed species from the Dzunbain Formation.

Discovery and description
The holotype is PIN 3779-15, which consists of posterior dorsal and anterior caudal vertebrae as well as pelvic material. It was discovered in a layer of the Dzunbain Formation at Chamrin-Us, Mongolia.

Mongolostegus was first reported by Alifanov et al. (2005) and Alifanov (2012) as an indeterminate stegosaur.

Ulansky (2014) informally dubbed the material Wuerhosaurus mongoliensis, but Galton and Carpenter (2016) found W. mongoliensis to be invalid. It was formally named as Mongolostegus by Tumanova and Alifanov in 2018.

Classification
Tumanova and Alifanov (2018) found Mongolostegus to belong to Stegosauridae.