''Weewarrasaurus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

ornithopod Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (), that started out as small, bipedal running grazers and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous world ...

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

from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...

of the

Griman Creek Formation The Griman Creek Formation is a geological formation in northern New South Wales and southern Queensland, Australia whose strata date back to the Albian-Cenomanian of the Early-Late Cretaceous.Bell et al., 2019 It is most notable being a major so ...

near

Lightning Ridge Lightning Ridge is a small outback town in north-western New South Wales, Australia. Part of Walgett Shire, Lightning Ridge is situated near the southern border of Queensland, about east of the Castlereagh Highway. The Lightning Ridge area is ...

, in

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. The type and only species is ''W. pobeni'', known from the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

, an isolated preserved in

opal Opal is a hydrated amorphous form of silica (SiO2·''n''H2O); its water content may range from 3 to 21% by weight, but is usually between 6 and 10%. Due to its amorphous property, it is classified as a mineraloid, unlike crystalline forms ...

, as well as a secondary referred dentary. It is thought to have co-existed with multiple other ornithopods of different sizes and lineages.

Discovery and naming

The type specimen (the specimen on which the species was first recognised), specimen number LRF 3067, consists of two sections of a jawbone with

teeth A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

. It was first discovered in 2013 by miners. They found the specimen in a mine at the Wee Warra geologic locality of the

, near the town of

during a routine mining run, and it was broken during excavation.

Opal Opal is a hydrated amorphous form of silica (SiO2·''n''H2O); its water content may range from 3 to 21% by weight, but is usually between 6 and 10%. Due to its amorphous property, it is classified as a mineraloid, unlike crystalline forms ...

dealer Mike Poben, from

Adelaide Adelaide ( ) is the capital city of South Australia, the state's largest city and the fifth-most populous city in Australia. "Adelaide" may refer to either Greater Adelaide (including the Adelaide Hills) or the Adelaide city centre. The dem ...

, first recognised it as a

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

, after acquiring it in a bag of rough opals received from the miners. The specimen was noted for being preserved in green-blue opal, a

gemstone A gemstone (also called a fine gem, jewel, precious stone, or semiprecious stone) is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks (such as lapis lazuli, opal, ...

for which the region is well known.

Palaeontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

Phil Bell was shown the specimen in 2014 and remarked upon its significance, and so Poben donated it to the Australian Opal Centre, which has the world's largest collection of opal fossils. Bell and colleagues later named it as a new genus and species in a study published on December 4, 2018, which reviewed the

fossil record for the

, which includes the mine. The generic name ''Weewarrasaurus'' refers to the Wee Warra fossil locality where the fossils were found, and the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

word ''saurus'', meaning lizard. The specific name, ''W. pobeni'', honours Poben. The opal banding on the fossil was used to confirm that both parts of the dentary, which do not form a continuous sequence, were from the same individual. These bands also allowed investigation of how far apart in the jawbone the two sections were originally. In addition to the opal type specimen, or holotype, the researchers assigned a second partial jawbone, specimen LRF 766, to the new species, due to the similar tooth morphology. It was found in the Holden's locality on the Three Mile opal field, also near Lightning Ridge and part of the Griman Creek Formation.

References

{{Taxonbar, from=Q59456759 Ornithopods Cenomanian life Cretaceous dinosaurs of Australia Paleontology in New South Wales Fossil taxa described in 2018 Ornithischian genera