Data from: A new ankylosaurine dinosaur from the Judith River Formation of Montana, USA, based on an exceptional skeleton with soft tissue preservation

The terrestrial Judith River Formation of northern Montana was deposited over an approximately 5 million year interval during the Late Campanian (Late Cretaceous). Despite having been prospected and collected continuously by paleontologists for over a century, few relatively complete dinosaur skeletons have been recovered to date. Here we describe a new genus and species of ankylosaurid dinosaur, Zuul cruravastator gen. et sp. nov., from the Coal Ridge Member of the Judith River Formation, based on an exceptionally complete and well-preserved skeleton (ROM 75860). This is the first ankylosaurin skeleton known with a complete skull and tail club, and it is the most complete ankylosaurid ever found in North America. The presence of abundant soft tissue preservation across the skeleton, including in situ osteoderms, skin impressions, and dark films that likely represent preserved keratin, make this exceptional skeleton an important reference for understanding the evolution of dermal and epidermal structures in this clade. Phylogenetic analysis recovers Zuul an ankylosaurin ankylosaurid within a clade of Dyoplosaurus and Scolosaurus, with Euoplocephalus being more distantly related within Ankylosaurini. The occurrence of Zuul cruravastator from the upper Judith River Formation fills a gap in the ankylosaurine stratigraphic and geographic record in North America, and further highlights that Campanian ankylosaurines were undergoing rapid evolutionary rates and stratigraphic succession of taxa as observed for Laramidian ceratopsians, hadrosaurs, pachycephalosaurs, and tyrannosaurs.