Qantassaurus
Encyclopedia
Qantassaurus 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.
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 trochanter
s, 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 to 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 euornithopods 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 was probably a browser, who grabbed fern
s and other vegetation with its hands, and ran away from predators like a modern gazelle
.
that was originally assigned to the Hypsilophodontidae. Today this is understood to be an unnatural (paraphyletic) group.
In this regard, it is one of four 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.
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.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of two-legged, plant-eating ornithischian dinosaur that lived in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
about 115 million years ago, when the continent was still partly south of the Antarctic Circle
Antarctic Circle
The Antarctic Circle is one of the five major circles of latitude that mark maps of the Earth. For 2011, it is the parallel of latitude that runs south of the Equator.-Description:...
. It was described by Patricia Vickers-Rich and her husband Tom Rich in 1999 after a find near Inverloch
Inverloch, Victoria
Inverloch is a seaside village in Victoria, Australia. It is located on the Bass Highway 143 kilometres southeast of Melbourne, at the mouth of Anderson Inlet, in the Bass Coast Shire and is located close to Australia’s southernmost stand of mangroves...
, and named after Qantas
Qantas
Qantas Airways Limited is the flag carrier of Australia. The name was originally "QANTAS", an initialism for "Queensland and Northern Territory Aerial Services". Nicknamed "The Flying Kangaroo", the airline is based in Sydney, with its main hub at Sydney Airport...
, the Australian airline.
Stub-nosed runner
- "The jawJawThe jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term jaws is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it and is part of the body plan of...
is unique because it is short and stocky, whereas other jaws ... are long and slender"- — Patricia Vickers-Rich
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 trochanter
Trochanter
In human anatomy, the trochanter is a part of the thigh bone. It can refer to:* Greater trochanter* Lesser trochanter* Third trochanter-See also:* Intertrochanteric crest* Intertrochanteric line...
s, on the upper surface of the thigh bone (or femur
Femur
The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...
), 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
Mandible
The mandible pronunciation or inferior maxillary bone forms the lower jaw and holds the lower teeth in place...
. It probably had a beak
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
, 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.
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, during the late Aptian/early Albian age
Faunal stage
In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by convention have the same name, and the same boundaries.Rock...
of the early Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
period. At the time, Australia was part of the supercontinent
Supercontinent
In geology, a supercontinent is a landmass comprising more than one continental core, or craton. The assembly of cratons and accreted terranes that form Eurasia qualifies as a supercontinent today.-History:...
of Gondwana
Gondwana
In paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...
, and partly within the Antarctic Circle
Antarctic Circle
The Antarctic Circle is one of the five major circles of latitude that mark maps of the Earth. For 2011, it is the parallel of latitude that runs south of the Equator.-Description:...
, although the significance of polar conditions during the warm Cretaceous were greatly different to 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 euornithopods had adaptations to survive cooler conditions. Bone
Bone
Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...
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
Thermoregulation
Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different...
.
Qantassaurus was probably a browser, who grabbed fern
Fern
A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...
s and other vegetation with its hands, and ran away from predators like a modern gazelle
Gazelle
A gazelle is any of many antelope species in the genus Gazella, or formerly considered to belong to it. Six species are included in two genera, Eudorcas and Nanger, which were formerly considered subgenera...
.
Classification
Qantassaurus is a basal euornithopod or ornithopodOrnithopod
Ornithopods or members of the clade Ornithopoda are a group of ornithischian dinosaurs 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, and dominated the North American...
that was originally assigned to the Hypsilophodontidae. Today this is understood to be an unnatural (paraphyletic) group.
In this regard, it is one of four species once considered hypsilophodontids from southeast Australia, along with Leaellynasaura
Leaellynasaura
Leaellynasaura is a genus of small herbivorous ornithischian dinosaur from the Albian stage of the Early Cretaceous, first discovered in Dinosaur Cove, Australia. The type species is Leaellynasaura amicagraphica...
amicagraphica, Atlascopcosaurus
Atlascopcosaurus
Atlascopcosaurus is a genus of herbivorous basal euornithopod dinosaur from the Early Cretaceous of the present Australia....
loadsi, and Fulgurotherium
Fulgurotherium
Fulgurotherium is the name given to a genus of dinosaur from the Early Cretaceous . It lived in what is now Australia.The type species, Fulgurotherium australe, was named by Friedrich von Huene in 1932...
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.
History
Qantassaurus was discovered on 27 February 1996, during the third annual field season of the Dinosaur Dreaming project, a dig jointly run by Monash UniversityMonash University
Monash University is a public university based in Melbourne, Victoria. It was founded in 1958 and is the second oldest university in the state. Monash is a member of Australia's Group of Eight and the ASAIHL....
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
Victoria (Australia)
Victoria is the second most populous state in Australia. Geographically the smallest mainland state, Victoria is bordered by New South Wales, South Australia, and Tasmania on Boundary Islet to the north, west and south respectively....
, Australia. The rock outcrops at this site are part of the Wonthaggi Formation
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....
of the Strzelecki Group, which during the Aptian
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 112.0 ± 1.0 Ma , approximately...
stage were deposited in floodplains with braided river channels. The holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as 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
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
and Eastern Europe
Eastern Europe
Eastern Europe is the eastern part of Europe. The term has widely disparate geopolitical, geographical, cultural and socioeconomic readings, which makes it highly context-dependent and even volatile, and there are "almost as many definitions of Eastern Europe as there are scholars of the region"...
. 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.
Further reading
- "The Hypsilophodontidae from southeastern Australia", by Tom H. Rich, and Patricia Vickers-Rich. October, 1999. In Proceedings of the Second Gondwana Dinosaur Symposium, edited by Y. Tomada, Tom H. Rich. and Patricia Vickers-Rich. National Science Museum Monographs, number 15, pages 167 to 180. (the technical paper naming the species)
External links
- Qantassaurus intrepidus, from Dann's Dinosaurs.
- Qantassaurus at DinoData