Saturday, December 10, 2016

Anchiceratops by atrox1 on DeviantArt

Anchiceratops is an genus of chasmosaurine ceratopsid dinosaur that lived approximately 72 to 71 million years ago during the latter part of the Cretaceous Period in what is now Alberta, Canada. Anchiceratops was a medium-sized, heavily built, ground-dwelling, quadrupedal herbivore that could grow up to an estimated 5 m (16.4 ft) long. Its skull featured two long brow horns and a short horn on the nose. The skull frill was elongated and rectangular, its edges adorned by coarse triangular projections. About a dozen skulls of the genus have been found.

NMC 8547 mounted at the Canadian Museum of Nature, completed with a skull cast of NMC 8535. NMC 8547 might represent a separate taxon.

Anchiceratops was a medium-sized ceratopsid. If specimen NMC 8547 is not taken into account, no very exact estimations of the body length of Anchiceratops can be given. Some popular science book state that it approached 20 feet (6 m) in length. In 2010 Gregory S. Paul, on the assumption that specimen NMC 8547 represented Anchiceratops, estimated its length at 4.3 metres, its weight at 1.2 tonnes.

The first remains of Anchiceratops were discovered along the Red Deer River in the Canadian province of Alberta in 1912 by an expedition led by Barnum Brown. The holotype, specimen AMNH 5251, is the back half of a skull, including the long frill, and two other partial skulls, specimens AMNH 5259 (the paratype) and AMNH 5273, were found at the same time, which are now stored in the American Museum of Natural History in New York City. A complete skull designated NMC 8535, was discovered by Charles M. Sternberg at Morrin in 1924, and was described as A. longirostris five years later, in 1929. but this species is widely considered a junior synonym of A. ornatus today. In total, at least ten incomplete skulls have been recovered. The skulls are different with respect to their proportions (e.g. size of the supraorbital horn cores, the dimensions of the frill) which had led researchers to conclude that the disparity is a result of interspecific differences or due to sexual dimorphism.

ROM 802, a skull in the Royal Ontario Museum by Daderot

The most distinctive features of this dinosaur are in its unusual neck frill. The frill is moderately long and rectangular with small, oval fenestrae (openings). The edge of the frill is thick just behind the brow horns. On the back of the frill are six large epoccipitals (bony knobs around the frill) that were expanded into short, triangular, backward-pointing spikes. Also on the frill are two short spikes that curve up and out.

Anchiceratops had a short nasal horn, a very long nose, and two moderate-size brow horns. Its skeleton shows it had a very short tail, but otherwise it looked much like other ceratopsids.

Anchiceratops lived at the same time as its close relative Arrhinoceratops. It was also closely related to TorosaurusChasmosaurusPentaceratops, and Triceratops.