Styracosaurus albertensis stih-RAK-oh-SOR-us

"Spiked lizard"

Styracosaurus silhouette — silhouette · Matthew Dempsey (CC-BY) via PhyloPic

Length: 5.5 m (18 ft) — About 5.5 m long, ~2 tonnes — famous for the giant spikes ringing its neck frill.
Period: Late Cretaceous (76–75 Mya)
Place: North America · Alberta, Canada · Montana
Food: Herbivore — Tough low-growing plants — beak and tooth batteries similar to Triceratops.
Clade: Ceratopsidae Dinosauria Ornithischia Cerapoda Marginocephalia Big horned ceratopsians of the Late Cretaceous.

A spike-frilled plant-eater whose neck crown bristled with four to six long horns.

Styracosaurus reconstruction by Connor Ashbridge — Reconstruction · Connor Ashbridge (CC-BY)

Styracosaurus had the most dramatic frill of any ceratopsian — a ring of long forward-curving spikes sprouted from the back edge of the bony neck shield, with a single long horn rising from the nose. The frill was probably for display rather than defense, though it certainly looked intimidating. Bonebeds suggest Styracosaurus traveled in large herds.

More about Styracosaurus

Discovery

Named by Lawrence Lambe (who named and described it); the first fossil was found by Charles H. Sternberg · 1913 · the southwest bank of the Red Deer River, below the mouth of Berry Creek, in what was then the Belly River Formation (now within Dinosaur Provincial Park, Alberta)

Charles H. Sternberg found the skull in the summer of 1913 on a Geological Survey of Canada expedition; it lay embedded horizontally, largely complete but missing the lower jaw and the rest of the skeleton. Lambe described this skull the same year as the holotype of Styracosaurus albertensis.

The name means "spiked lizard," from Ancient Greek: a word for the spike at the butt-end of a spear-shaft, plus "lizard."

Lawrence Lambe. A Canadian palaeontologist who described the skull in 1913 and named the new ceratopsian Styracosaurus albertensis.

What were the horns and frills actually for?

The text says the function or functions of the horns and frills have been debated for many years. The powerful shoulders may have been useful in fights between members of the same species, but no single purpose is stated as settled.

Could some specimens be males and females of the same animal?

Centrosaurine species vary a lot, even between individuals, so which genera are valid is debated. In 1996 Peter Dodson suggested Monoclonius nasicornis might be a female Styracosaurus, but most other researchers rejected this, and the text notes there is no firm evidence for sexual dimorphism in any ceratopsid.

What we know

Single long nose horn — up to 60 cm.
Ring of six long spikes around the back of the neck frill.
Bonebeds preserve dozens of individuals — strong evidence of herd life.
Lived alongside Gorgosaurus, Corythosaurus, and Lambeosaurus.

What we guess

Whether the frill and spikes were primarily for species recognition, mate attraction, or defense.
Whether the horn and spikes were colorful in life.
Whether Styracosaurus and other centrosaurines competed or specialized in different plants.