Leptoceratopsidae

The family Leptoceratopsidae, its name derived from the type genus Leptoceratops, is a group of several small neoceratopsian genera which appear not to belong to the clade

Clade

A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...

 Protoceratopsidae. They resembled, and were closely related to, other ceratopsids, but all discovered species are generally smaller and more primitive. Leptoceratopsids have so far been found exclusively in the Late Cretaceous of Asia and Western North America. A possible leptoceratopsid ulna, named Serendipaceratops

Serendipaceratops

Serendipaceratops is a dubious genus of ornithischian dinosaur from the early Cretaceous Period of Australia.The type species, S. arthurcclarkei, was named after Arthur C...

, has been found in Victoria

Victoria (Australia)

Victoria is the second most populous state in Australia. Geographically the smallest mainland state, Victoria is bordered by New South Wales, South Australia, and Tasmania on Boundary Islet to the north, west and south respectively....

, Australia.

Leptoceratopsids range in age from Udanoceratops

Udanoceratops

Udanoceratops is a genus of ceratopsian dinosaur. It lived during the Late Cretaceous Period in the late Santonian or early Campanian faunal stages...

, of the late Santonian

Santonian

The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous epoch or Upper Cretaceous series. It spans the time between 85.8 ± 0.7 mya and 83.5 ± 0.7 mya...

 or early Campanian

Campanian

The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch . The Campanian spans the time from 83.5 ± 0.7 Ma to 70.6 ± 0.6 Ma ...

, to Leptoceratops

Leptoceratops

Leptoceratops , was a primitive ceratopsian dinosaur genus from the Late Cretaceous Period of what is now Western North America, at the same time as its giant...

, right at the end of the Cretaceous

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 in the late Maastrichtian

Maastrichtian

The Maastrichtian is, in the ICS' geologic timescale, the latest age or upper stage of the Late Cretaceous epoch or Upper Cretaceous series, the Cretaceous period or system, and of the Mesozoic era or erathem. It spanned from 70.6 ± 0.6 Ma to 65.5 ± 0.3 Ma...

.

The family, implicitly named by the naming of subfamily Leptoceratopsinae by Nopsca in 1923, was explicitly named by Mackovicky in 2001, when defining a clade Leptoceratopsidae as the group consisting of Leptoceratops gracilis and all species closer to Leptoceratops than to Triceratops horridus.