Bagaceratopidae is a family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 of neoceratopsian dinosaur

Dinosaur

Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

s. It was named by Alifanov in 2003 but no definition has been proposed. Because of lacking of the definition, Bagaceratopidae was considered inactive by Paul Sereno

Paul Sereno

Paul Callistus Sereno is an American paleontologist from the University of Chicago who discovered several new dinosaur species on several continents. He has conducted excavations at sites as varied as Inner Mongolia, Argentina, Morocco, and Niger...

 in 2005. Alifanov in 2003 classified to this family four genera

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

: Bagaceratops

Bagaceratops

Bagaceratops, meaning "small-horned face" , is a genus of ceratopsian dinosaur that lived in what is now Mongolia around 80 million years ago, during the Late Cretaceous...

, Breviceratops

Breviceratops

Breviceratops was a ceratopsian dinosaur from Late Cretaceous Mongolia. It was related to Protoceratops. The fossils originally described by Maryanska and Osmolska in 1975 and placed in Protoceratops, were moved to the new genus by Kurzanov in 1990.The type species is Breviceratops...

, Lamaceratops

Lamaceratops

Lamaceratops,"Lama Horned Face", is a dinosaur from the Late Cretaceous period. It is classified as a ceratopsian, a herbivorous "frilled" or armored dinosaur similar to, but smaller than, Bagaceratops. It had a horn on the front of its face, much like most of the later Ceratopsids.The fossils of...

and Platyceratops

Platyceratops

Platyceratops is a dinosaur from the Late Cretaceous, during the Campanian Age, about 75-72 million years ago. Its fossils have been found in Mongolia. Its skull is larger than Bagaceratops; it has been referred to Bagaceratopidae or the Neoceratopsia...

and in a publication from 2008 he included in Bagaceratopidae also Magnirostris

Magnirostris

Magnirostris, from the Latin "magnus" 'large' and "rostrum" 'beak', is the name given to a genus of dinosaur from the Late Campanian epoch in the Late Cretaceous. It was a ceratopsian which lived in Inner Mongolia in China...

and newly described genus Gobiceratops

Gobiceratops

Gobiceratops is a genus of ceratopsian dinosaur from the Upper Cretaceous of Mongolia. It is based on a skull that is 3.5 centimeters long, from the Khermin Tsav locality in the Barun Goyot Formation of southern Mongolia; the type individual was young. Gobiceratops is thought to have been...

. Alifanov suggested also that Bagaceratopidae, unlike other neoceratopsian families, is of Paleoasiatic origin.

Bagaceratopsids existed during the late Cretaceous period, between about 85.8 and 70.6 million years ago.