| Leptoceratopsids Temporal range: Late Cretaceous, 83.5–65.5 Ma |
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|---|---|
| Skull and mandible of Zhuchengoceratops | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Superorder: | Dinosauria |
| Order: | †Ornithischia |
| Suborder: | †Ceratopsia |
| Node: | †Coronosauria |
| Family: | †Leptoceratopsidae Nopcsa, 1923 |
| Type species | |
| †Leptoceratops gracilis Brown, 1914 |
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| Genera | |
Leptoceratopsidae is an extinct family of neoceratopsian dinosaurs from the of Asia and North America. They resembled, and were closely related to, other neoceratopsians, such as the families Protoceratopsidae and Ceratopsidae, but they are more primitive and generally smaller. Leptoceratopsids have so far been found exclusively in the Late Cretaceous period (late Santonian - late Maastrichtian stages) of Asia and Western North America.[1] A possible leptoceratopsid ulna, named Serendipaceratops, has been found in Victoria, Australia. However, a 2010 study showed that it could not be confidently referred to any ornithischian family, and is considered a nomen dubium.[2]
Leptoceratopsids range in age from Gryphognathus, of the late Santonian, to Leptoceratops, right at the end of the Cretaceous in the late Maastrichtian. Gryphognathus is the first definitive record of Santonian leptoceratopsid. It was named based on a partial left dentary from Alberta, Canada. Gryphognathus represents the oldest known leptoceratopsid and probably the smallest adult-sized ceratopsian known from North America.[1]
Leptoceratopsidae was originally named by Franz Nopcsa von Felső-Szilvás in 1923 as a subfamily Leptoceratopsinae, and its type species is Leptoceratops gracilis. 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.[3] The cladogram below follows the topology from a 2012 analysis by Michael J. Ryan, David C. Evans, Philip J. Currie, Caleb M. Brown and Don Brinkman.[1]
| Ceratopsia |
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