Fig. 5

Phylogenetic relationships, chronostratigraphic, and paleoecological implications of M. intrepidus. a Graphic illustrating temporal range of North American tyrannosauroids including species-level range prior to the discovery of M. intrepidus, extension of current range, and hypothesized range based on isolated teeth¹². The current gap in the North American tyrannosauroid record spans from the Tithonian to the Aptian. Faunal composition of Late Cretaceous ecosystems was established between the Albian and Turonian, as recognized by the stratigraphic appearance of major clades (see refs. ^7,12 and references therein). b generalized phylogenetic relationships of Tyrannosauroidea, showing the appearance of select traits related to cursoriality in tyrannosaurs that are newly optimized as a result of the discovery of M. intrepidus. Tree topology follows this study using the modified dataset of Carr and colleagues²⁷. Coelurus and Tanycolagreus are grafted as basal tyrannosauroids following Brusatte and colleagues⁵. c Stratigraphic distribution of Allosauria in North America (incl. Megaraptora but see ref. ⁷⁰ for alternative hypotheses regarding this clade) documents overlap with M. intrepidus in early Late Cretaceous ecosystems leading to (d) refined calibration on the origin of late diverging tyrannosauroids and clade-level faunal turnover within apex predator roles throughout the Late Jurassic–Late Cretaceous of North America. Colored polygons are stylized call-outs and are not intended to reflect two-dimensional data. Temporal data corresponding to this figure are available in Supplementary Table 5