The buffalo dinosaur

  • Name: Einiosaurus
  • Diet: Herbivore
  • Weight: 1,3 tons
  • Period: Cretaceous
  • Found In: Montana, USA

In this article, we will discuss extensive information related to one more representative of the popular ceratopsian family. Read on to learn more about them.

What does the name Einiosaurus mean?

The name Einiosaurus means “buffalo lizard”, meaning an American Indian term and a Greek term. Einio means ‘bison or buffalo’ and’saurus’ means lizard.

The name of the species E. procurvicornis, for its part, means ‘forward curved horn‘.

History of the discovery of the Einiosaurus

In 1985 a team led by Jack Horner found several ceratopsian bones in Montana. These remains were partially excavated between 1986 and 1989.

One of them, the Canyon Bone Bed, was located in Glacier County.

The remains in all these layers were originally thought to belong to the genus Styracosaurus and informally referred to as ‘Styracosaurus makeli’, whose species name honors Robert Makela, who died during excavations in 1987 as a result of a car accident.

This name was published in 1990 as nomen nudum in a caption in a book by Stephen Czerkas. Horner, meanwhile, had already changed his mind; he now thought that the different specimens belonged to three different taxa that he had provisionally designated as Type A, Type B, and Type C.

These three specimens would form, as he explained in a 1992 article, a series of direct descendants.

In 1994/1995 Scott Sampson gave type B and type C names of his own species.

He called Einiosaurus procurvicornis type B. The name of sex is derived from Eini which means “bison” in the language of the Black Footfoot Indians.

Since the discovery site is located on your reservation. The species designation is a combination of the Latin procurvus, “bent forward”, and the cornu, “horn”.

Type C would be called Achelousaurus, described in the same article. Material Type A would then be assigned to Rubeosaurus.

The holotype consists of a skull. Two other skulls and numerous fragments of skulls and post-cranial skeletons have been assigned to the species.

Einiosaurus Classification

Einiosaurus is representative of the Ceratopsidae family (distant relative genus Triceratops), a group of large herbivorous dinosaurs that lived during the Cretaceous period in what is now North America and Asia.

Within this group (the Ceratopsia series) is included in the Centrosaurinae subfamily.


The affinity with the members of this subfamily is not clear, so the relatives can be considered very close to the Centrosaurus, Styracosaurus, Pachyrhinosaurus, and Achelousaurus.

When did the Einiosaurus live?

The Einiosaurus fossils were found in what would be the top layer of the Montana Two-Medicine Formation, which is estimated to date from the Campanian, more accurately from the late Cretaceous period, approximately 74.5 million years ago.

The climate of this region was characteristically warm and semi-arid.

What did the Einiosaurus eat?

Like all ceratopsians this animal was fed on grass and some low fruits. They usually moved in packs and protected each other.

Einiosaurus Characteristics

Einiosaurus is a relatively small ceratopid. It was calculated that the height of this dinosaur could be approximately 5 meters, with a weight of 1.3 tons.

The skull of Einiosaurus is quite low. The muzzle is very narrow and pointed.Einiosaurus-picture

A short knob on the back of the head protrudes almost directly to the back.

In the nasal bone is a horn bent forward. The base of the horn is particularly long, measured from back to front. In the transverse direction, the horn is very narrow.

The base of the horn immediately begins to curve forward strongly, with the result that at 23 centimetres the horn forms an angle of almost 30°, inclined downwards.

The trumpet shaft must have extended before the top peak. Above each cavity of the large eye are two bone thicknesses.

The anterior forms a protrusion in the upper part of the forehead bone.

The second can be seen as an eyebrow horn in the posthorbital part and forms a triangular element that protrudes laterally and backwards at the tip.

The post-cranial skeletal parts are not well known. The body was carried by strong legs.