Centrosaurinae

Styracosaurus, live reconstruction

  • West North America

The Centrosaurinae are a taxon ( a systematic group) of the dinosaurs. Together with the Chasmosaurinae they form the group of Ceratopsidae within the ceratopsians.

Features

The Centrosaurinae have the usual physique of Ceratopsidae. There were rather unwieldy animals with stocky limbs, the quadruped continue moving ( on all fours ). The hind legs were much longer than the front legs.

The skull was large and bulky and had a pointed snout. This was made ​​like all ceratopsians from the Rostralknochen ( in front of the upper jaw ) and the Praedentale ( in front of the lower jaw). The Rostralknochen was (side considered ) at the Centrosaurinae laterally approximately triangular. The dentition was like all Ceratopsidae from dental batteries that are in rows spaced teeth that are replaced by the following tooth when worn.

The most striking differences to the Chasmosaurinae existed in the horns and neck plate. The nasal horn was prolonged ( it was at Styracosaurus up to 50 centimeters ) introduces the supraorbital horns, however, were reduced or even completely absent. The neck shield, which was formed as in all higher ceratopsians from the parietal and squamosal, was relatively short - its length is at most 70 % of the length of the actual skull. ( However, there are also at the Chasmosaurinae representatives ( subsequently) a shortened neck shield as Triceratops. ) The outer edge of the shield is covered with wavy ossification, called Epoccipitalia. In some species, the Epoccipitalia developed to spine- like structures could also be directed to the front.

Distribution and systematics

Like all Ceratopsidae the Centrosaurinae were restricted to western North America, which was separated in the Cretaceous through a sea from the rest of the continent. Fossil remains of this dinosaur group known only from the Upper Cretaceous ( Campanian to Maastrichtian ) and thus 83-66 million years old.

The following genera are included among the Centrosaurinae:

A possible cladogram of Centrosaurinae looks like this:

Chasmosaurinae

Diabloceratops

Avaceratops

Nasutoceratops

Albertaceratops

Rubeosaurus

Styracosaurus

Spinops

Centrosaurus

Coronosaurus

Xenoceratops

Sinoceratops

Einiosaurus

Achelousaurus

Pachyrhinosaurus

Mya (unit) Cerapoda Lawrence Lambe Rostral bone Digital Object Identifier
172783
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