Spiclypeus shipporum is a chasmosaurine ceratopsian from the Campanian age of the Late Cretaceous. Like all ceratopsians, it was a four-legged herbivore with a frill on the back of its heads, a beaked mouth, and face horns, estimated to have been between 4.5 and 6 metres (14 - 19 feet) in length.
In 2005, a retired nuclear physicist called Bill Shipp, was interested in finding fossils, so he went out for a walk one day in the rocky part of his ranch land and found a femur in a hillside. Bill and some of his friends excavated the femur and other bones from the specimen over the next ten years (even building a road to the site for excavators to travel on), and in 2015 while on a trip to Ottawa he met with Jordan Mallon from the Canadian Museum of Nature. The museum agreed to purchase the fossil from Bill for the cost of the extraction over the last decade, around $350,000. Spiclypeus was described in 2016 by Jordan C. Mallon, Christopher J. Ott, Peter L. Larson, Edward M. Iuliano, and David C. Evans. The fossil site, known as Shipp's Ranch, is located in the Judith River Formation in the rural US state of Montana, about 8km West-southwest of a small town called Winifred, East of the Judith River. The formation is estimated to have been from 76.42 to 75.09 million years ago, judging by the age of the rock above and below the specimen.
The holotype consists of approximately half a skull (comparing to a typical ceratopsid skull), and about about six per cent (inferred from other ceratopsid skeletons) of the postcranium (the part of the skeleton beyond the skull) skeleton. The postcranium bones consist of vertebrae, ribs, the left humerus, partial left ilium, the partial left femur, partial left tibia, and the left fibula. The holotype is thought to have measured somewhere between 4.5 and 6 metres, and weighed between 3 and 4 tonnes. It was identified as a new species by the configuration of the spikes along its frill and over its eyes. Spiclypeus has frill spikes that curl forward, towards the snout, and spikes that just stick straight out. More basal ceratopsians had the straight-out configuration of frill spikes, whereas more advanced ceratopsians had forward-curling spikes along the frill. This implies that Spiclypeus was a missing link between the more basal and more advanced ceratopsians. Spiclypeus also had spikes over the eyes that stick out sideways; on other ceratopsians, the eye spikes point forward.
Bill Shipp had nicknamed the holotype Judith, after the Judith River near which it was found. Using skeletochronology, it has been estimated that Judith was between 7 and 10 years old. Judith was found to have had a number of issues before it died. There were fenestrae (skull holes) found in the skull with drainage tracts, implying that they were not naturally forming, and may have been caused by combat with other Spiclypeus. The humerus has rough regrowth and an abscess channel, implying that it suffered from a chronic infection. It seems to have suffered from some time, judging by he regrowth, and may have been caused by something like tuberculosis or a fungal infection.
As with other ceratopsians, Spiclypeus shipporum is an herbivore, as evidenced by its beak-shaped jaw and teeth.
Spiclypeus is a Latin portmanteau of the Latin words "spica" and "clypeus" "spike" and "shield", referring to the spikes around the outside of the frill. "Shipporum" refers to Bill Shipp and his family, the discoverer and original owner of the holotype's specimen.