with Pentaceratops. In 2014 Nicholas Longrich named a new species: Pentaceratops aquilonius, "the northern one," based on fragmentary fossils discovered during the 1930s near Manyberries in Alberta, Canada. The species has been described as having a first epiparietal pointing upwards instead of forwards. In 2016, Mallon et al. found P. aquilonius to be morphologically similar to Spiclypeus shipporum, with it possibly being the same species, and considered P. aquilonius a nomen dubium. Description Pentaceratops was a large ceratopsid; Dodson estimated the body length at . The skull length of AMNH 1624 is while PMU R.200 has a length of . In 2016 Paul estimated its length at 5.5 meters (18 ft) and its weight at 2.5 metric tons (2.75 short tons). The nose horn of Pentaceratops is small and pointing upward and backward. The brow horns are very long and curving strongly forward. The somewhat upward tilted frill of Pentaceratops is considerably longer than that of Triceratops, with two large holes (parietal fenestrae) in it. It is rectangular, adorned by large triangular osteoderms: up to twelve episquamosals at the squamosal and three epiparietals at the parietal bone. These are largest at the rear corners of the frill, and are separated by a large U-shaped notch at the midline, a feature not recognized until 1981 when specimen UKVP 16100 was described. Within the notch the first epiparietals point forwards. The very thick jugal and the squamosal do not touch each other, a possible autapomorphy. The torso of Pentaceratops is tall and wide. The rear dorsal vertebrae bear long spines from which ligaments possibly ran to the front, to balance the high frill. The prepubis is long. The ischium is long and strongly curves forward. In smaller specimens the thigh bone bows outwards. Classification Osborn originally assigned Pentaceratops to Ceratopsia. Within this group Pentaceratops belonged to the Ceratopsinae or Chasmosaurinae. It appears to be most closely related to Utahceratops. Their clade was perhaps more derived than the earlier genus Chasmosaurus but more basal than Anchiceratops, the latter representing a line of which Triceratops was a member, which lived a few million years later, right at the end of the Cretaceous period, when all ceratopsians died out. The cladogram of the phylogeny of Pentaceratops according to a study by Scott Sampson et al. in 2010 found that the genus was most closely related to Utahceratops, from a similar age and region. The below