Xenovenator

Xenovenator (lit. 'strange hunter') is an extinct genus of troodontid theropod dinosaurs known from the Late Cretaceous (Campanian age) of North America. The type species of the genus, Xenovenator espinosai, is known from fragmentary skull bones found in the Cerro del Pueblo Formation of Mexico. It is characterized by an unusually expanded and rugose skull roof, somewhat comparable to that seen in pachycephalosaurs. This may imply Xenovenator individuals engaged in combat with other members of their species, a behavior for which adaptations had not been previously observed in non-avian paravians.

"Saurornitholestes" robustus, known from the Kirtland Formation of New Mexico, United States, was tentatively placed in this genus by Rivera-Sylva and colleagues in their 2026 description of Xenovenator, although it lacks the characteristic domed skull roof of X. espinosai. Later that year, Jasinski & Sullivan placed X.? robustus in a new genus, Dinevenator.

Discovery and naming

During fieldwork in the Cerro del Pueblo Formation (La Parrita locality) in Coahuila, Mexico, in the summer of 2000, Martha C. Aguillón-Martinez collected the partial skull of a theropod dinosaur. This specimen, comprising a partial skull roof (frontals, parietals) and braincase (orbitosphenoids, laterosphenoids, exoccipitals, prootics, basisphenoid, and basioccipital) was accessioned at the Museo del Desierto as specimen CPC 2973. In 2023, Aguillón-Martínez described CPC 2973 in collaboration with Héctor E. Rivera-Sylva.