''Atlascopcosaurus'' () is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of herbivorous basal

iguanodont Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (). They represent one of the most successful groups of herbivore, herbivorous dinosaurs during the Cretaceous. The most primitive members of the group were bipedal and rel ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

from the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...

Eumeralla Formation The Eumeralla Formation is a geological formation in Victoria, Australia whose strata date back to the Early Cretaceous. It is Aptian to Albian in age. Dinosaur remains are among the fossils that have been recovered from the formation, particul ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

Discovery and naming

The

type specimen In biology, a type is a particular wikt:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to ancho ...

, NMV P166409, was found in 1984 at the Dinosaur Cove East site on the coast of

Victoria Victoria most commonly refers to: * Queen Victoria (1819–1901), Queen of the United Kingdom and Empress of India * Victoria (state), a state of Australia * Victoria, British Columbia, Canada, a provincial capital * Victoria, Seychelles, the capi ...

, in layers of the

dating from the early

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

Aptian The Aptian is an age (geology), age in the geologic timescale or a stage (stratigraphy), stage in the stratigraphic column. It is a subdivision of the Early Cretaceous, Early or Lower Cretaceous epoch (geology), Epoch or series (stratigraphy), S ...

Albian The Albian is both an age (geology), age of the geologic timescale and a stage (stratigraphy), stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early Cretaceous, Early/Lower Cretaceous epoch (geology), Epoch/s ...

. The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

consists of a piece of the upper jaw, a partial

maxilla In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...

with teeth, and referred specimens include teeth, another maxilla, and dentaries. Although the rest of the skeleton is unknown it can be inferred from closely related species that the genus represents a small bipedal

herbivore A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...

. The

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

, ''Atlascopcosaurus loadsi'', was named and described by Tom Rich and

Patricia Vickers-Rich Patricia Arlene Vickers-Rich (born 11 July 1944), also known as Patricia Rich, is an Australian Professor of Palaeontology and Palaeobiology, who researches the environmental changes that have impacted Australia (including the ancient super ...

in 1989. The generic name refers to the

Atlas Copco Atlas Copco (''Copco'' from Compagnie Pneumatique Commerciale) is a Swedish multinational industrial company that was founded in 1873. It manufactures industrial tools and equipment. The Atlas Copco Group is an industrial corpration with headq ...

Company which had provided equipment for the dig that discovered this dinosaur in 1984. The project revealed 85 fossil bone fragments of various

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

. This opened the door for more excavation and, along with other companies, Atlas Copco helped over ten years excavate about sixty metres of tunnel in a cliff wall at the sea shore. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

, ''loadsi'', honours William Loads, the state manager for Atlas Copco at the time, who assisted during the dig.Rich, T. and Rich, P., (1989), "Polar dinosaurs and biotas of the Early Cretaceous of southeastern Australia", ''National Geographic Research'' 5(1): 15-53

Description

By extrapolation it has been estimated that ''Atlascopcosaurus loadsi'' was about two to three metres (6.5–10 ft) long and weighed approximately 125 kg.

Classification

Despite being assigned to

Hypsilophodontidae Hypsilophodontidae (or Hypsilophodontia) is a traditionally used family (biology), family of ornithopod dinosaurs, generally considered invalid today. It historically included many small bodied bipedal neornithischian taxa from around the world, ...

by its describers, the original classification of ''Atlascoposaurus'' was considered untenable given that Hypsilophodontidae has been recovered as

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

in subsequent cladistic studies and ''Atlascopcosaurus'' was tabulated as a basal member of

Ornithopoda Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (). They represent one of the most successful groups of herbivorous dinosaurs during the Cretaceous. The most primitive members of the group were bipedal and relatively sm ...

in the second edition of the ''Dinosauria''.Norman DB, Sues H-D, Witmer LM, Coria RA (2004). Basal Ornithopoda. In: Weishampel DB, Dodson P, Osmólska H, editors. The Dinosauria. Second edition. Berkeley: University of California Press; 2004. pp. 393–412. Because the teeth are not species-specific and the maxilla fragment is little informative, Agnolin ''et al.'' (2010) treated it as a ''

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium,'' it may be impossible to determine whether a ...

'', even though they noted similarities with the

elasmaria Elasmaria is a clade of Ornithopoda, ornithopods known from Cretaceous deposits in the former Gondwana (South America, Antarctica, Australia, and possibly Africa) that contains many bipedal ornithopods that were previously considered Hypsilophodo ...

ns ''

Anabisetia ''Anabisetia'' ( ) is a genus of ornithopod dinosaur from the Late Cretaceous Period of Patagonia, South America. It was a small bipedal herbivore, around long. Discovery Argentine paleontologists Rodolfo Coria and Jorge Orlando Calvo name ...

'' and ''

Gasparinisaura ''Gasparinisaura'' (meaning "Gasparini's lizard") is a genus of herbivorous ornithopod dinosaur from the Late Cretaceous. The first fossils of ''Gasparinisaura'' were found in 1992 near Cinco Saltos in Río Negro Province, Argentina. The type spe ...

'' from

Patagonia Patagonia () is a geographical region that includes parts of Argentina and Chile at the southern end of South America. The region includes the southern section of the Andes mountain chain with lakes, fjords, temperate rainforests, and glaciers ...

. However, Boyd (2015) considered the genus valid and recovered it at the base of

Iguanodontia Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (). They represent one of the most successful groups of herbivorous dinosaurs during the Cretaceous. The most primitive members of the group were bipedal and relatively sm ...

in a clade with ''Anabisetia'', ''Gasparinisaura'', and '' Qantassaurus''.

References

{{Taxonbar, from=Q131399 Elasmaria Dinosaur genera Albian dinosaurs Dinosaurs of Australia Fossil taxa described in 1989 Taxa named by Patricia Vickers-Rich Taxa named by Tom Rich