Pentaceratops

Skeletal reconstruction of Pentaceratops Sternbergii. From Samson et al. (2010)

• Canada

• P. Sternbergii Osborn, 1923

Pentaceratops ( "Five - horn face" ) is a genus of bird Beck dinosaurs from the group of Ceratopsidae within the ceratopsians. Fossil evidence of the genus are from the Late Cretaceous of western North America.

Features

Pentaceratops reached a body length of 7 to 7.5 meters, a height of about 2.5 meters and an estimated weight of up to 5 tons. He was one of the greatest representatives of Ceratopsidae. He had a massive body, which was carried by four strong legs, like other members of this group. The hind legs were much longer than the front legs, these dinosaurs moved like all Ceratopsiden quadruped ( four legged ) away. His cock was shorter than in related genera.

The skull of Pentaceratops was bulky and massive, he reached including the neck plate has a length of about 2 meters, which is one of the longest known skull of all land-dwelling animals. The muzzle was pointed, it was formed from the Rostralknochen ( in front of the upper jaw ) and the Praedentale ( in front of the lower jaw). The dentition consisted of tooth batteries, which are arranged in rows of teeth that are replaced by the following tooth when worn. The occlusal surfaces of the teeth were almost perpendicular.

On the nose sat a little horn, two horns were located above the eyes. The cheek region was expansive and wide, so that the skull together with the pointed snout had an approximately triangular shape from above. The Epijugale, a skull bone, formed on either side of a prominent cheeks horn. The typical for Ceratopsidae neck shield was formed from the parietal and squamosal. He was provided with very long and large, paired openings. The outer edge of the shield was covered with knob-shaped ossification, called Epoccipitalia.

Paleobiology

In contrast to related species no bone beds ( " bone stock " ) were found by Pentaceratops in which the fossils of many animals lay together. Conclusions on the social behavior and a possible life in herds are therefore not possible from the fossil record.

Horns and neck shields of Ceratopsidae are often associated with the defense against predators. However, the small plate edge horns and cheek horns should not have been very well suited for defense purposes. Also the neck shield was too thin to be a protection against neck bites. After today's perspective, the headdress was primarily the identification of the individual species as well as the interaction with other dogs - either by exhibition, threatening gestures or in fighting. It may be decreased by territorial boundaries or mating privileges.

The tooth batteries of Pentaceratops with the vertical occlusal surfaces were aligned for overlapping but not be ground movement. The pointed snout is evidence of ability to selectively food intake, the construction of the lower jaw indicates a high bite force. It is probable that this dinosaur fed on hard, fibrous plants.

Discovery and designation

The fossil remains of Pentaceratops were found in the U.S. state of New Mexico and first described by Henry Fairfield Osborn in 1923. The genus name is derived from the Greek words penta / πέντα ( = "five" ), keras / κέρας ( = " horn " ) and -ops/ωψ ( = "face" ) from and alludes to the nose horn, the two supraorbital horns and the two horns on cheeks.

Type species P. was Sternbergii, a second, described 1930 species ( P. fenestratus ) is now regarded as a synonym of P. Sternbergii. The specific epithet honors Charles H. Sternberg, an important amateur paleontologists and explorers in the fossil deposits in western North America. A total of nine at least partially preserved skull and a complete and several partial skeletons have been preserved. The finds are dated to the Late Cretaceous (late Campanian to early Maastrichtian ) in age 76-69 million years.

System

Pentaceratops is classified within the Ceratopsidae in the Chasmosaurinae, which were characterized by a usually long neck shield and long over eyes horns. Its closest relatives are Chasmosaurus and Agujaceratops, with whom he forms a clade basal Chasmosaurinae.