Identification of the ontogenetic status of an extinct organism is complex, and yet this
underpins major areas of research, from taxonomy and systematics to ecology and …

Cranial ornamentation is widespread throughout the extinct non-avialian Ornithodira, being
present throughout Pterosauria, Ornithischia and Saurischia. Ornaments take many forms …

The well-sampled Late Cretaceous fossil record of North America remains the only high-
resolution dataset for evaluating patterns of dinosaur diversity leading up to the terminal …

Background In horned dinosaurs, taxonomy is complicated by the fact that the cranial
ornament that distinguishes species changes with age. Based on this observation, it has …

The placement of over 50 skulls of the well-known horned dinosaur Triceratops within a
stratigraphic framework for the Upper Cretaceous Hell Creek Formation (HCF) of Montana …

ABSTRACT An articulated, 1.5 m long skeleton of a juvenile Chasmosaurus, lacking only the
front limbs, pectoral girdles, and terminal caudal vertebrae, was collected from the Dinosaur …

The end-Cretaceous (K/Pg) mass extinction event is the most recent and well-understood of
the “big five” and triggered establishment of modern terrestrial ecosystem structure. Despite …

The horned dinosaurs (Ceratopsidae) were a diverse family of herbivorous dinosaurs
originating in the Late Cretaceous in western North America (Laramidia). As one of the most …

Ceratopsian dinosaurs arguably show some of the most extravagant external cranial
morphology across all Dinosauria. For over a century, ceratopsian dinosaurs have inspired …

Background Recent assessments of morphological changes in the frill during ontogeny
hypothesized that the late Maastrichtian horned dinosaur Torosaurus represents the “old …