Wintonotitan

Live reconstruction of Wintonotitan wattsi. From zero Hock and colleagues, 2009.

• Queensland, Australia ( Winton Formation)

• Wintonotitan wattsi

Wintonotitan is a genus of sauropod dinosaur and an original representative of Titanosauriformes from the Lower Cretaceous of Australia. This species was first scientifically described by the single species, Wintonotitan wattsi 2009. Wintonotitan is known by a skull loose, fragmentary skeleton consists of bones of the front legs, the shoulder girdle, some vertebrae, fragmentary pelvic bone and parts of the tail spine. Parts of this skeleton have been discovered in 1974 and provisionally described as a kind of Austrosaurus. More bones of this skeleton were first uncovered during excavations between 2006 and 2009.

The Titanosauriformes are a group living mainly in the Cretaceous sauropod, which Brachiosaurus and related species (also known as Brachiosauridae ) and the Titanosauria, which include Saltasaurus, Opisthocoelicaudia and Argentinosaurus are include. Some shared derived characteristics ( synapomorphies ) suggest that it could actually act in Wintonotitan a Titanosauria.

Features

Wintonotitan can be estimated to have a length of about 16 meters. From other genera can this genus are distinguished by a unique combination of features: So showed the vertebrae in the upper third of air-filled ( pneumatic ) chambers. Overall had Wintonotitan about 35 caudal vertebrae. While the anterior and middle caudal vertebrae were flat at both ends ( amphiplatisch ), the posterior caudal vertebrae were cylindrical and convex on both ends - the latter feature is considered unique for this genus ( autapomorphy ). The front leg was a total gracefully, humerus (humerus ) had divided lower condyles on.

Various features allow classification within the Titanosauriformes. For example, the vertebrae showed a complex, sponge-like internal structure of numerous chambers. Iliac ( ilium ) was in the front ( präacetabularen ) half an enlarged and upwardly lobe-like ridge, which led to the iliac its highest point in the front half shown and not directly on the socket ( acetabulum ), as primitive sauropod. The front (anterior ) projection on the bottom of the iliac bone ( pubic peduncle ) was perpendicular to the axis of the sacrum ( sacrum ).

Some characteristics are shared derived characteristics ( synapomorphies ) of the Titanosauria, which could mean that Wintonotitan this group is to be assigned. So the vertebrae showed eye-shaped lateral cavities ( Pleurocoele ). Furthermore showed the ulna ( ulna ) a distinct olecranon - a bone spur at the upper end which extends through the articular surface of the ulna. In addition, the ischium ( ischium ) was plate-like.

Research History and naming

The skeleton was discovered in 1974 by Keith Watts. The site ( QML 313 "Triangle Paddock " ) is located about 60 km north- west of the city Winton in Queensland. Stratigraphy of the locality belonging to the lower Winton Formation. More bones of the same skeleton were recovered Museum between 2006 and 2009 excavations of the Australian Age of Dinosaurs Museum of Natural History and the Queensland. The same excavation team found in the vicinity of another occurrence of the Winton Formation, the " Matilda - reference ", the remains of a new Titanosauriers, Diamantinasaurus, as well as a new allosauroiden theropods, Australovenator. Originally, the skeleton described as a new species of the genus Austrosaurus ( Austrosaurus sp.), The then only known Cretaceous sauropods from Australia. Austrosaurus (or the holotype material of the type species Austrosaurus mckillopi ) based only from about eight heavily weathered vertebrae that few reveal for the classification of useful features, which is why this type of Hock zero and colleagues ( 2009) as a noun dubium ( dubious name) is performed. Only one bone of Wintonotitan skeleton - a fragmentary vertebrae Center - overlaps with the type material of Austrosaurus. However significant differences can be seen between the two bones, as in the lateral cavity Wintonotitan is eye-shaped and much greater than Austrosaurus, confirming that both finds among different genera.

The skeleton ( holotype, specimen number QMF 7292 ) consists of the shoulder blade, arm bones, metacarpal bones, fragmentary dorsal and sacral vertebrae, ribs, parts of the ilium, ischium, and parts of the tail spine. Another find ( copy number QMF 10916 ) has also been attributed to this genus and consists of isolated middle and posterior caudal vertebrae.

Wintonotitan is named after the town of Winton in Queensland, the ending titan has the Titans of Greek mythology. The Artepitheth wattsi honors Keith Watts, who in 1974 first discovered bones of the skeleton and she offered to the Queensland Museum.