Atlascopcosaurus (/ˌætləsˌkɒpkəˈsɔːrəs/) is a genus of herbivorous basal iguanodont dinosaur from the Early Cretaceous Eumeralla Formation of Australia.[1]
| Atlascopcosaurus Temporal range: Early Cretaceous
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| NMV P157390, a referred maxilla of A. loadsi (top), and NMV P166409, a cast of the holotype maxilla of A. loadsi (bottom) | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | †Ornithischia |
| Clade: | †Neornithischia |
| Clade: | †Ornithopoda |
| Genus: | †Atlascopcosaurus Rich & Vickers-Rich, 1989 |
| Species: | †A. loadsi
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| Binomial name | |
| †Atlascopcosaurus loadsi Rich & Vickers-Rich, 1989
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Discovery and naming
editThe type specimen, NMV P166409, was found in 1984 at the Dinosaur Cove East site at the coast of Victoria, in layers of the Eumeralla Formation dating from the early Cretaceous, Aptian-Albian. The holotype consists of a piece of the upper jaw, a partial maxilla with teeth, and referred specimens include teeth, another maxilla, and dentaries.[1] Although the rest of the skeleton is unknown it can be inferred from closely related species that the genus represents a small bipedal herbivore.
The type species, Atlascopcosaurus loadsi, was named and described by Tom Rich and Patricia Vickers-Rich in 1989. The generic name refers to the Atlas Copco Company who had provided equipment for the dig that discovered this dinosaur in 1984. The project revealed 85 fossil bone fragments of various species. 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, loadsi, honours William Loads, the state manager for Atlas Copco at the time, who assisted during the dig.[1]
Description
editBy extrapolation it has been estimated that Atlascopcosaurus loadsi was about two to three metres (6.5–10 ft) long and weighed approximately 125 kg.[2]
Classification
editDespite being assigned to Hypsilophodontidae by its describers, the original classification of Atlascoposaurus was considered untenable given that Hypsilophodontidae has been recovered as paraphyletic in subsequent cladistic studies and Atlascopcosaurus was tabulated as a basal member of Ornithopoda in the second edition of the Dinosauria.[2] Because the teeth are not species-specific and the maxilla fragment is little informative, Agnolin et al. (2010) treated it as a nomen dubium, even though they noted similarities with the elasmarians Anabisetia and Gasparinisaura from Patagonia.[3] However, Boyd (2015) considered the genus valid and recovered it at the base of Iguanodontia in a clade with Anabisetia, Gasparinisaura, and Qantassaurus.[4]
References
edit- ^ a b c Rich, T. and Rich, P., (1989), "Polar dinosaurs and biotas of the Early Cretaceous of southeastern Australia", National Geographic Research 5(1): 15-53
- ^ a b 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.
- ^ Agnolin, Federico L.; Ezcurra, Martín D.; Pais, Diego F.; Salisbury, Steven W. (2010-05-21). "A reappraisal of the Cretaceous non-avian dinosaur faunas from Australia and New Zealand: evidence for their Gondwanan affinities". Journal of Systematic Palaeontology. 8 (2): 257–300. Bibcode:2010JSPal...8..257A. doi:10.1080/14772011003594870. ISSN 1477-2019.
- ^ Boyd, Clint A. (2015-12-22). "The systematic relationships and biogeographic history of ornithischian dinosaurs". PeerJ. 3: e1523. doi:10.7717/peerj.1523. ISSN 2167-8359. PMC 4690359. PMID 26713260.