A new troodontid from the Upper Cretaceous Gobi Basin of inner Mongolia, China

A new troodontid dinosaur, Papiliovenator neimengguensis gen. et sp. nov., from the Upper Cretaceous (Campanian) Wulansuhai Formation at Bayan Manduhu, Inner Mongolia, China, is described here. The holotype (BNMNH-PV030) consists of a nearly complete cranium and fragmentary postcranial bones in semi-articulation and this specimen is inferred as a subadult based on the osteohistological information and the fusion of bones. Papiliovenator neimengguensis is distinguishable from other troodontids based on a suite of features such as the lateral groove of the dentary not posteriorly expanded, a deep surangular fossa anteroventral to the glenoid fossa and hosting the surangular foramen, the ventral ridge of the surangular fossa mainly on the surangular, and a unique anterolaterally broadened and butterfly-shaped neural arch of the anteriormost dorsal vertebrae in dorsal view. Our phylogenetic analysis recovered Papiliovenator neimengguensis at the earliest-diverging branch of a clade including all other Late Cretaceous troodontids except Almas . The discovery of Papiliovenator neimengguensis allows for an improved understanding of troodontid anatomy, as well as the regional variation of troodontids from the Upper Cretaceous of the Gobi Basin. • A new short-snouted troodontid from the Upper Cretaceous Gobi Basin showing novel osteological information. • Phylogenetic analysis recovering short-snouted troodontids as early-diverging branches of a Late Cretaceous troodontid clade. • Late Cretaceous troodontids from the Gobi Basin exhibiting wide variations of the cranium and the forelimb.