Qantassaurus (/ˌkwɑːntəˈsɔːrəs/ KWAHN-tə-SOR-əs) is a genus of two-legged, plant-eating ornithischian dinosaur that lived in Australia about 115 million years ago, when the continent was still partly south of the Antarctic Circle. It was described by Patricia Vickers-Rich and her husband Tom Rich in 1999 after a find near Inverloch, and named after Qantas, the Australian airline.
|Skeletal reconstruction of Qantassaurus intrepidus at the Australian Museum, Sydney|
Rich & Vickers-Rich, 1999
- "The jaw is unique because it is short and stocky, whereas other jaws ... are long and slender"
Qantassaurus was probably about 1.8 meters (6 feet) long, and about one meter (3 feet) high. If it resembled its relatives, it had short thighs and long shins, and probably was a fast runner. Its feet had claws for traction, and a long tail probably helped with turning, stiffened by ossified tendons. One characteristic of the "Polar Victorian" euornithopods are distinctive spurs, or trochanters, on the upper surface of the thigh bone (or femur), where muscle was attached.
Qantassaurus is only known from jaw fragments. These are foreshortened compared to related species so its face was probably short and stubby. It had ten teeth in each lower jaw. It probably had a beak, and possessed leaf-shaped teeth back in its cheek, which were shed as they wore down, and replaced by new teeth growing up from the jaw. The teeth had eight distinctive vertical ridges on the outer side with a single larger primary ridge in the centre.
Qantassaurus lived 115 million years ago in Australia, during the late Aptian/early Albian age of the early Cretaceous period. At the time, Australia was part of the supercontinent of Gondwana, and partly within the Antarctic Circle, although the significance of polar conditions during the warm Cretaceous were greatly different from conditions in this region today. The average temperature of the region is contentious, with estimates ranging from -6 to well over 5 °C (21 to 37 °F). Conditions were likely to be at their coldest during the polar nights, which lasted up to three months.
One interpretation of the fossil material is that small ornithopods had adaptations to survive cooler conditions. Bone growth of presumed related taxa shows they were active all year round, so they did not hibernate through the winter. The structure of these bones also suggests warm-bloodedness, which would help maintain its body heat.
Qantassaurus is a basal iguanodont ornithopod that was originally assigned to the Hypsilophodontidae. Today, this is understood to be an unnatural (paraphyletic) group, and Qantassaurus was recently recovered as a basal iguanodont by Boyd (2015), and more specifically as a member of the iguanodontian clade Elasmaria by Rozadilla et al. (2016) and Madzia et al. (2017).
In this regard, it is one of four ornithischian species once considered hypsilophodontids from southeast Australia, along with Leaellynasaura amicagraphica, Atlascopcosaurus loadsi, and Fulgurotherium australe. The four taxa are mostly known from isolated bones and teeth; however the thigh bones of F. australe are very diverse and may belong to three genera.
Qantassaurus was discovered on 27 February 1996, during the third annual field season of the Dinosaur Dreaming project, a dig jointly run by Monash University and the National Museum of Victoria. The dig occurs on the beach of the Bunurong Marine Park at the intertidal site known as Flat Rocks, near Inverloch, in southeastern Victoria, Australia. The rock outcrops at this site are part of the Wonthaggi Formation of the Strzelecki Group, which during the Aptian stage were deposited in floodplains with braided river channels. The holotype specimen, NMV P199075, a fifty-six millimetres long single left dentary of the lower jaw, containing ten teeth (three unerupted), was found by Mrs Nicole Evered, a long time participant of the dig. Two other jaws, specimens NMV P198962, a left dentary, and NMV P199087, a right dentary, found at the same site the same year have also been tentatively associated with, or referred to, the species.
It was named Qantassaurus intrepidus by Patricia Vickers-Rich and Tom Rich, in honor of the Queensland and Northern Territory Air Service, which shipped fossils around the country as part of the Great Russian Dinosaurs Exhibit between 1993 and 1996, and sponsored expeditions to South America and Eastern Europe. QANTAS is an acronym, which is why a u does not follow the q in Qantassaurus. The specific name means "intrepid" in Latin, referring to the climatic challenges the small dinosaur had to face.
The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous epoch/series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± 0.9 Ma (million years ago). The Albian is preceded by the Aptian and followed by the Cenomanian.Aptian
The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous epoch or series and encompasses the time from 125.0 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ago), approximately. The Aptian succeeds the Barremian and precedes the Albian, all part of the Lower/Early Cretaceous.The Aptian partly overlaps the upper part of the regionally used (in Western Europe) stage Urgonian.
The Selli Event, also known as OAE1a, was one of two oceanic Anoxic events in the Cretaceous period, which occurred around 120 Ma and lasted approximately 1 to 1.3 million years. The Aptian extinction was a minor extinction event hypothesized to have occurred around 116 to 117 Ma.Aralosaurini
Aralosaurini is a tribe of basal lambeosaurine hadrosaurs endemic to Eurasia. It currently contains Aralosaurus (from the Aral sea of Kazakhstan) and Canardia (from Toulouse, Southern France).Atlascopcosaurus
Atlascopcosaurus (meaning "Atlas Copco lizard") is a genus of herbivorous basal iguanodont dinosaur from the Early Cretaceous of the present Australia.Canardia
Canardia is an extinct genus of aralosaurin lambeosaurine dinosaur known from the Late Cretaceous Marnes d’Auzas Formation (late Maastrichtian stage) of Toulouse, Haute-Garonne Department, southern France. The type species Canardia garonnensis was first described and named by Albert Prieto-Márquez, Fabio M. Dalla Vecchia, Rodrigo Gaete and Àngel Galobart in 2013.Elasmaria
Elasmaria is a clade of iguanodont ornithopods known from Cretaceous deposits in South America, Antarctica, and Australia.Galleonosaurus
Galleonosaurus (meaning "galleon lizard" as the upper jaw bone resembles an upturned galleon) is a genus of basal ornithopod dinosaur from the Wonthaggi Formation of the Gippsland region of Victoria, Australia. The type and only species is Galleonosaurus dorisae.Huxleysaurus
Huxleysaurus (meaning "Huxley's lizard") is a genus of herbivorous styracosternan ornithopod dinosaur.Iguanodontia
Iguanodontia (the iguanodonts) is a clade of herbivorous dinosaurs that lived from the Middle Jurassic to Late Cretaceous. Some members include Camptosaurus, Dryosaurus, Iguanodon, Tenontosaurus, and the hadrosaurids or "duck-billed dinosaurs". Iguanodontians were one of the first groups of dinosaurs to be found. They are among the best known of the dinosaurs, and were among the most diverse and widespread herbivorous dinosaur groups of the Cretaceous period.Jaxartosaurus
Jaxartosaurus is a genus of hadrosaurid dinosaur similar to Corythosaurus which lived during the Late Cretaceous. Its fossils were found in Kazakhstan.Laiyangosaurus
Laiyangosaurus ("Laiyang lizard") is a genus of saurolophine hadrosaurid from the Late Cretaceous of China. It is known from one species, L.youngi, found in the Laiyang Basin within the province of Shandong.Lapampasaurus
Lapampasaurus is an extinct genus of hadrosaurid known from the Late Cretaceous Allen Formation (late Campanian or early Maastrichtian stage) of La Pampa Province, Argentina. It contains a single species, Lapampasaurus cholinoi.The generic name refers to the Argentine province of La Pampa. The specific name honours the late collector José Cholino. The material includes cervical, dorsal, sacral and caudal vertebrae, the forelimb girdle, and the partial hindlimb.Osmakasaurus
Osmakasaurus is a genus of herbivorous iguanodontian dinosaur. It is a basal iguanodontian which lived during the lower Cretaceous period (Valanginian age) in what is now Buffalo Gap of South Dakota, United States. It is known from the Chilson Member of the Lakota Formation. This genus was named by Andrew T. McDonald in 2011 and the type species is Osmakasaurus depressus. O. depressus was previously referred to as Camptosaurus depressus, and was first described in 1909 by Charles W. Gilmore.Pareisactus
Pareisactus (from the Greek "pareisaktos", meaning "intruder", referring to being represented as a single element among hundreds of hadrosaurid bones) is a genus of rhabdodontid ornithopod dinosaur from the Late Cretaceous Conquès Member of the Tremp Formation in the Southern Pyrenees of Spain. The type and only species is P. evrostos, known only from a single scapula.Plesiohadros
Plesiohadros is an extinct genus of hadrosauroid dinosaur. It is known from a partial skeleton including the skull collected at Alag Teg locality, from the Campanian Djadochta Formation of southern Mongolia. The type species is Plesiohadros djadokhtaensis.Sahaliyania
Sahaliyania (from "black" in Manchu, a reference to the Amur/Heilongjiang River) is a genus of lambeosaurine hadrosaurid dinosaur (crested duckbilled dinosaur) from the Late Cretaceous of Heilongjiang, China.Tsintaosaurini
Tsintaosaurini is a tribe of basal lambeosaurine hadrosaurs native to Eurasia. It currently contains only Tsintaosaurus (from China) and Pararhabdodon (from Spain ).Koutalisaurus, also known from late Cretaceous Spain and formerly referred to Pararhabdodon
, may also be a tsintaosaurin because of its association with the latter genus; some recent work also suggests it may indeed be referrable to Pararhabdodon.Wonthaggi Formation
The Wonthaggi Formation is a geological formation in Victoria, Australia whose strata date back to the Early Cretaceous. It is part of the Strzelecki Group. Dinosaur remains are among the fossils that have been recovered from the formation. It is equivalent to the Eumeralla Formation.Xuwulong
Xuwulong is a genus of hadrosauroid dinosaur from the Early Cretaceous period. It lived during the early Cretaceous period (Aptian-Albian age) in what is now Yujingzi Basin in the Jiuquan area, Gansu Province of northwestern China. It is known from the holotype – GSGM F00001, an articulated specimen including a complete cranium, almost complete axial skeleton, and complete left pelvic girdle from Xinminpu Group. Xuwulong was named by You Hailu, Li Daqing and Liu Weichang in 2011 and the type species is Xuwulong yueluni.