Wintonotitan wattsi

Wintonotitan wattsi was a genus of somphospondylan sauropod, found in the earliest late Cretaceous (Cenomanian) period in the Winton Formation of north eastern Australia.

ETYMOLOGY: (Keith) Watts’ Winton Giant (Win-ton-oh-tie-tan what-sigh)
GEOLOGY: Winton Formation, central western Queensland
AGE: Earliest Late Cretaceous (Cenomanian) 98–95 million years ago

DISCOVERY

In 1974, Keith Watts, owner of Elderslie Sheep Station (located northwest of Winton in Queensland, Australia), notified the Queensland Museum of a dinosaur discovery on his property. Dr Mary Wade and Andrew Elliot (both Queensland Museum staff) collected several bones from the site, which were designated the fossil numbers QM F7292. The bones were first described in 1981 and tentatively referred to Austrosaurus sp., the only Cretaceous sauropod known from Australia at the time, despite the absence of anatomical overlap between QM F7292 and the Austrosaurus holotype. In 2004, the current owners of Elderslie Sheep Station rediscovered the site, which was excavated by a combined Queensland Museum/Australian Age of Dinosaurs team in June 2006. More remains were discovered, and it was determined that the bones belonged to a new species of sauropod. In 2009, QM F7292 (now nicknamed "Clancy") was made the holotype of W. wattsi. The generic name refers to the Winton Shire, whereas the specific name honours Keith Watts. The nickname "Clancy" refers to the Andrew Barton "Banjo" Paterson poem "Clancy of the Overflow".

SKELETAL REMAINS

The holotype specimen of W. wattsi, QM F7292, comprises several fragmentary dorsal vertebrae, two conjoined sacral vertebrae, at least twenty-five caudal vertebrae, five chevrons, the left scapula, both humeri, both ulnae, both radii, left metacarpals I–V, the left ilium, and the left ischium. Several bones were misidentified in the original description: the left and right ulna were switched; metacarpal IV was described as metacarpal V, and vice versa; the manus was interpreted as the right, when it is in fact the left; and the ilium was misinterpreted. The remains of W. wattsi were recovered from the mid-Cretaceous Winton Formation, which has also yielded the remains of Diamantinasaurus matildae and Australovenator wintonensis. The W. wattsi type site (QM L313, the "Triangle Paddock site") was originally interpreted to date to the upper Albian. However, subsequent zircon dating of the D. matildae and A. wintonensis type site (AODL 85), located approximately 3 km from QM L313, has demonstrated that it is in fact much more likely to be Cenomanian in age, since both sites lie west of the Cork Fault.

 

Several anatomical features of the limb, pectoral and pelvic girdle bones of W. wattsi show that it was distinct from D. matildae. The forelimbs of W. wattsi are less robustly constructed than those of D. matildae, despite the slightly larger size of W. wattsi (16–20 metres long, 3 metres tall at the hips).The proportions of the forelimbs are also different, with the metacarpals of W. wattsi 53% the length of the radius, compared with 61% in D. matildae. The other forelimb elements show several differences between the two taxa, and the ischium of W. wattsi has a pronounced ridge for muscle attachment which is reduced in D.matildae. Like all sauropods, W. wattsi would have been entirely herbivorous. Its coexistence with D. matildae in the mid-Cretaceous of north-eastern Australia suggests that these sauropods would have had different dietary preferences to prevent interspecific competition. However, the absence of the hind limb of W. wattsi, and the absence of cranial or cervical remains of either taxon, precludes assessment of their specific dietary habits or relative body shapes.

RELATIONSHIPS

The remains of W. wattsi were first included in a phylogenetic analysis in 2004, as part of Austrosaurus. In this analysis, it was resolved as a basal titanosaur. When QM F7292 was made the holotype of W. wattsi, it was included in two phylogenetic analyses and in both was recovered in a position within Somphospondyli but outside Titanosauria. 
In many recent analyses (with some notable exceptions), this interpretation has been upheld; most recently, it was included in two analyses and recovered in both as a non-titanosaurian somphospondylan. Therefore, W. wattsi represents a more primitive sauropod than its contemporary D. matildae, which is a lithostrotian titanosaur.

FOR MORE INFORMATION WE RECOMMEND READING... 

Scientific papers, Wintonotitan wattsi (Clancy). 

Wikipedia, Wintonotitan wattsi.

Australian Museum, Wintonotitan wattsi.

For more information read an excerpt from "Waltzing the Billabong" by Robyn Molan found in AAOD Journal, Issue 7 

 

Top Scientific papers | Next - Savannasaurus