Leptoceratopsidae

Leptoceratopsidae was originally named by Franz Nopcsa von Felső-Szilvás in 1923 as a subfamily Leptoceratopsinae, and its type species is Leptoceratops gracilis. Leptocertops is derived from Ancient Greek, meaning "slender horned face." Mackovicky, in 2001, defined it as a stem-based taxon and a family consisting of Leptoceratops gracilis and all species closer to Leptoceratops than to Triceratops horridus. All previously published neoceratopsian phylogenetic analyses were incorporated into the analysis of Eric M. Morschhauser and colleagues in 2019, along with all previously published diagnostic species excluding the incomplete juvenile Archaeoceratops yujingziensis and the problematic genera Bainoceratops, Lamaceratops, Platyceratops and Gobiceratops that are very closely related to and potentially synonymous with Bagaceratops. While there were many unresolved areas of the strict consensus, including all of Leptoceratopsidae, a single most parsimonious tree was found that was most consistent with the relative ages of the taxa included, which is shown below. }} ==Palaeobiogeography==

Definitive leptoceratopsids lived in Asia and Western North America during the Late Cretaceous around 83-66 million years ago. However, material referred to leptoceratopsids from the early Campanian of North Carolina and Sweden possibly extends their geographic range into Eastern North America and Europe. A possible leptoceratopsid ulna named Serendipaceratops has been found in Australia, but this taxon is considered a nomen dubium due to the fragmentary holotype which cannot be confidently referred to any ornithischian group, though it might possibly belong to an ankylosaur instead. Leptoceratopsids range in age from Gryphoceratops, of the late Santonian, to Leptoceratops, right at the end of the Cretaceous in the late Maastrichtian. Gryphoceratops is the first definitive record of Santonian leptoceratopsid. It was named based on a partial left dentary from Alberta, Canada. Gryphoceratops represents the oldest known leptoceratopsid and probably the smallest adult ceratopsian known from North America. ==See also==