Achelousaurus is a genus of ceratopsid dinosaur that lived during the Late Cretaceous Period of what is now North America, about 74.2 million years ago. The first fossils of Achelousaurus were collected in Montana in 1987, by a team led by Jack Horner, with more finds made in 1989. In 1994, Achelousaurus horneri was described and named by Scott D. Sampson; the generic name means “Achelous lizard“, in reference to a Greek mythological figure, and the specific name refers to Horner. The genus is known from a few specimens consisting mainly of skull material from individuals, ranging from juveniles to adults.
- Lived: 83.6 million years ago – 70.6 million years ago (Campanian)
- Scientific name: Achelousaurus (Achelous lizard)
- Mass: 3,000 kg
- Kingdom: Animalia
- Phylum: Chordata
- Clade: Dinosauria
- Order: Ornithischia
- Family: Ceratopsidae
- Subfamily: Centrosaurinae
- Genus: Achelousaurus Sampson, 1994
- Species: A. horneri
- Binomial name: Achelousaurus horneri
Introduction Achelousaurus dinosaur
The Achelousaurus is dinosaur that existed on the earth in the late Cretaceous Period. The time range of its existence is judged to be between 79 and 60 million years ago. It was a ceratopsid, the same group that includes the better known Triceratops. Like other ceratopsids, it was quadrupedal, i.e. it walked on all four legs. The distinguishing characteristic of the Achelousaurus is the structure if its skull and jaws. Its snout is beak like and the nasal bone bears a thick ridge. It also has two horns situated behind its orbital cavity. Such special structures are seen in all ceratopsids.
The Achelousaurus was medium sized dinosaur. It weighed about two to three tons and its length is expected to be about 6 meters. Its diet was herbivorous and it was likely predated upon by other larger carnivorous theropods.
Achelousaurus dinosaur Lived
Achelousaurus was a herbivore. It lived in the Late Cretaceous period and inhabited North America. Its fossils have been found in places such as Montana.
Achelousaurus dinosaur Classification
In 1995, Sampson formally placed Achelousaurus in the Ceratopsidae, more precisely the Centrosaurinae. In all analyses, Einiosaurus and Achelousaurus are part of the clade Pachyrhinosaurini. By definition, Achelousaurus is a member of the clade Pachyrostra (or “thick-snouts”), in which it is united with Pachyrhinosaurus. In 2010, Gregory S. Paul assigned A. horneri to the genus Centrosaurus, as C. horneri. This has found no acceptance among other researchers, with subsequent taxonomic assessments invariably keeping the generic name Achelousaurus
Horned dinosaurs mainly differ from each other in their horns, which are located on the snout and above the eyes, and in the large skull frill, which covers the neck like a shield. Achelousaurus exhibited the build of derived (“advanced”) centrosaurines, which are typified by short brow horns or bosses, combined with elaborate frill spikes.
The general frill proportions are typically centrosaurine, with a wide rounded squamosal bone at the side, which expanded towards the rear. It also shares the typical frill curvature with a top surface that is convex from side to side and concave from front to rear.
Characteristics and lifestyle of an Achelousaurus
Commonly known as a medium sized dinosaur, an average achelousaurusweighed about 2000 to 4000 kilos and grew about 20 feet in height. This was definetly not as big of a size when compared to its peers.
The most significant and distinguished feature of an achelousaurus is its head. The head a small but a very prominent nasal bone that resembles a broken horn.
It also possess a fan like frill on the hind side of its head along with two large horns.
Habits and habitat
The Achelousaurus was herbivorous dinosaur and obtained its nourishment from low lying bushes and shrubs. It is unknown whether it could charge at high speeds like the modern day rhinoceros. Ceratopsids are believed to be dinosaurs that lived in herds.
But there is no concrete proof backing these claims. Furthermore, some scientists believe that ceratopsids displayed sexual dimorphism. Again, there isn’t enough data to say this with certainty, and the fossils of the Achelousaurus do not show the presence of gender differentiation. If the Achelousaurus used its posterior horns for attack, it would need to lower its head so low that it would cease to see its predator. This is unlikely, yet not impossible.
Achelousaurus dinosaur Facts
- A genus of dinosaur.
- lived between about 83 million years ago and 74 million years ago, during the late Cretaceous period.
- lived in North America.
- Achelousaurus was a herbivore (plant-eater).
- about 20 feet (6 meters) long.
- weighed about 6 tons.
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