   #copyright

Ceratopsidae

2007 Schools Wikipedia Selection. Related subjects: Dinosaurs

   iCeratopsids

                        Fossil range: Late Cretaceous

   Triceratops skull
   Triceratops skull

                             Conservation status

   Extinct (fossil)
               Scientific classification

   Kingdom:    Animalia
   Phylum:     Chordata
   Class:      Sauropsida
   Superorder: Dinosauria
   Order:      Ornithischia
   Suborder:   Marginocephalia
   Infraorder: Ceratopsia
   Family:     Ceratopsidae
               Marsh, 1890

                                   Genera

   See text.

   Ceratopsids, or members of the Ceratopsidae (or Ceratopidae), are a
   diverse group of marginocephalian dinosaurs like Triceratops and
   Styracosaurus. All known species were quadrupedal herbivores from the
   Upper Cretaceous of Western North America and are characterized by
   beaks, rows of shearing teeth in the back of the jaw, and elaborate
   horns and frills. The group is divided into two subfamilies. The
   Ceratopsinae or Chasmosaurinae are generally characterized by long,
   triangular frills and well-developed brow horns. The Centrosaurinae had
   well-developed nasal horns or nasal bosses, shorter and more
   rectangular frills, and elaborate spines on the back of the frill.

   These horns and frills show remarkable variation and are the principle
   means by which the various species have been recognized. Their purpose
   is not entirely clear. Defense against predators is one possible
   purpose - although the frills are comparatvely fragile in many species
   - but it is more likely that, as in modern ungulates, they may have
   been secondary sexual characteristics used in displays or for
   intraspecific combat. The massive bosses on the skulls of
   Pachyrhinosaurus and Achelosaurus resemble those formed by the base of
   the horns in modern musk oxen, suggesting that they may have butted
   heads. Centrosaurs have frequently been found in massive bone beds with
   few other species present, suggesting that the animals might have lived
   in large herds.

Taxonomy

     * Infraorder Ceratopsia
     * FAMILY CERATOPSIDAE
          + Subfamily Centrosaurinae
               o Avaceratops - ( Montana, USA)
               o Tribe Centrosaurini
                    # Monoclonius - ( Montana, USA & Alberta, Canada)
                    # Brachyceratops - ( Montana, USA & Alberta, Canada)
                    # Centrosaurus - ( Alberta, Canada)
                    # Styracosaurus - ( Alberta, Canada & Montana, USA)
               o Tribe Pachyrhinosaurini
                    # Einiosaurus - ( Montana, USA)
                    # Achelousaurus - ( Montana, USA)
                    # Pachyrhinosaurus- ( Alberta, Canada & Alaska)
          + Subfamily Ceratopsinae
               o  ? Ceratops - ( Montana, USA & Alberta, Canada)
               o Chasmosaurus - ( Alberta, Canada)
               o Agujaceratops - ( Texas, USA)
               o Pentaceratops - ( New Mexico, USA)
               o Anchiceratops - ( Alberta, Canada)
               o Arrhinoceratops - ( Alberta, Canada)
               o Torosaurus - ( Wyoming, Montana, South Dakota, North
                 Dakota, Utah & Saskatchewan)
               o Diceratops - ( Wyoming, USA)
               o Triceratops - Montana, Wyoming, USA & Saskatchewan,
                 Alberta, Canada.

   Retrieved from " http://en.wikipedia.org/wiki/Ceratopsidae"
   This reference article is mainly selected from the English Wikipedia
   with only minor checks and changes (see www.wikipedia.org for details
   of authors and sources) and is available under the GNU Free
   Documentation License. See also our Disclaimer.
