Spiclypeus shipporum was discovered in 2005 by Bill Shipp, and was described in 2016 by Jordan C. Mallon, Christopher J. Ott, Peter L. Larson, Edward M. Iuliano, and David C. Evans.
Bill Shipp, a retired nuclear physicist, purchased ranch land in 2000 in rural Montana, about 8km West-southwest of a small town called Winifred, East of the Judith River. Bill Shipp was interested in finding fossils, so he went out for a walk one day in the rocky part of his 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 shipporum is a chasmosaurine ceratopsian from the Judith River Formation. It is estimated to have been from 76.42 to 75.09 million years ago, judging by the age of the rock formation above and below the specimen. Ceratopsians are four-legged herbivorous dinosaurs with frills on the back of their heads, beaked mouths, and face horns. Chasmosaurines had no spikes on their frills, and their brow horns are generally longer than their nose horns.
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). 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.
The holotype 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.
The holotype was found to have had a number of issues before it died. There were fenestrae (skull holes) found in the holotype's 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 chanel, 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.
Bill Shipp has 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.
As with other ceratopsians, Spiclypeus shipporum is an herbivore, as evidenced by its 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.