Winton Formation

Winton Formation Stratigraphic range: Late Albian-Early Turonian ~104–92 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Unit of	Rolling Downs Group
Underlies	Unconformity with Quaternary Lake Eyre Basin sediments
Overlies	Mackunda Formation,[1]
Thickness	<100 m (330 ft) at the margin 1,200 m (3,900 ft) in the centre
Lithology
Primary	Sandstone, siltstone, claystone
Other	Conglomerate, coal
Location
Coordinates	22°18′S 143°06′E / 22.3°S 143.1°E / -22.3; 143.1Coordinates: 22°18′S 143°06′E / 22.3°S 143.1°E / -22.3; 143.1
Approximate paleocoordinates	51°48′S 134°06′E / 51.8°S 134.1°E / -51.8; 134.1
Region	Queensland
Country	Australia
Extent	Eromanga Basin
Type section
Named for	Winton, Queensland
Named by	Whitehouse
Location	Bores in and around Winton
Year defined	1955
Formation distribution within Australia

The Winton Formation is a Cretaceous geological formation in central-western Queensland, Australia. It is late Albian to early Turonian in age.^[2] The formation blankets large areas of central-western Queensland. It consists of sedimentary rocks such as sandstone, siltstone and claystone. The sediments that make up these rocks represent the remnants of the river plains that filled the basin left by the - an inland sea that covered large parts of Queensland and central Australia at least four times during the Early Cretaceous. Great meandering rivers, forest pools and swamps, creeks, lakes and coastal estuaries all left behind different types of sediment.

In some areas, the Winton Formation is over 400 metres thick. To bring with them such a huge amount of sediment, the rivers that flowed across these plains must have been comparable in size to the present-day Amazon or Mississippi rivers. As more and more sediment was brought in, the margins of the inland sea slowly contracted. By around 95 million years ago, the deposition was complete and the inland sea would never be seen again.

By virtue of its age and the environmental conditions under which the rocks it consists of were deposited, the Winton Formation represents one of the richest sources of dinosaur fossils anywhere in Australia.

Fauna[]

A fossil footprint-(ichnite), Wintonopus, found with two other dinosaur genera footprints at the Lark Quarry in Australia, c.f. Tyrannosauropus and Skartopus, have been found in the Winton Formation.

Dipnoi[]

Actinopterygii[]

Crocodyliformes[]

Crocodyliformes of the Winton Formation
Taxa	Species	Presence	Material	Notes	Images
Isisfordia	I. duncani		Nearly complete skeleton and partial skull, referred complete skull

Dinosaurs[]

Dinosaurs of the Winton Formation
Taxa	Species	Presence	Material	Notes	Images
Australotitan[5]	A. cooperensis		A partial scapula, humeri, ulna, pubes, ischia, femora, presacral vertebral centrum fragments, and rib fragments.	A large diamantinasaurian sauropod that possesses a mosaic of features shared with titanosaurians with similar geographical and temporal range.
Australovenator [6]	A. wintonensis		Dentaries, dorsal ribs and rib fragments, gastralial ribs and fragments, partial ilium, ulnae, radius, manus metacarpals, unguals, femur, tibiae, fibula, astragalus, metatarsals, pedal phalanges, humeri, radiale, distal carpal, and manual phalanxes.	A megaraptoran theropod known from postcranial and cranial material.
Wintonotitan [6]	W. wattsi[6]		A scapula, both humeri, both ulnae, both radii, near complete metacarpus preserving complete metacarpals II–V with proximal half of metacarpal I, fragmentary dorsal and sacral vertebrae and ribs, partial ilium, ischium, caudal vertebral series including anterior caudals, middle caudals, posterior caudals, proximal chevrons, and numerous unidentifiable fragments.	A titanosaur that is likely to be closely related to Australotitan, Diamantinasaurus and Savannasaurus.
Diamantinasaurus [6]	D. matildae[6]		A squamosal, quadrates, braincase, surangular, atlas intercentrum axis, cervical vertebrae, middle cervical neural arch, co-ossified sacral centra, cervical ribs, dorsal vertebrae, numerous dorsal ribs, fragmentary gastralia, coalesced sacral vertebrae, isolated sacral processes, scapula, coracoid, partial sternal plate, humeri, ulnae, radius, metacarpals I–V, manual phalanges, ilium, pubes, both ischia, femur, tibia, fibula, astragalus, and numerous fragments.	A diamantinasaurian sauropod known from partial cranial material.
Savannasaurus [7]	S. elliotorum[7]		Posterior cervical vertebrae, cervical ribs, dorsal vertebrae, dorsal ribs, sacral vertebrae with processes, partial caudal vertebrae, fragmentary scapula, coracoid, sternal plates, incomplete humeri, shattered ulna, radius, metacarpals I–V, metacarpal IV, manual phalanges, fragments of ilia, pubes, ischia, astragalus, metatarsal III, and associated fragments.	A wide-bodied sauropod that was well adapted to the wet, temperate floodplain environment it inhabited.
Ornithopoda	Undescribed		A nearly complete skull and mandible and at least three partial postcranial skeletons.[8]	Small-bodied, recovered as part of "a diverse clade of Gondwanan ornithopods that includes taxa from Australia, South America, and Antarctica"
Titanosauriformes	Undescribed		Partial skull, consisting of a braincase, quadrates, quadratojugals, a left squamosal, postorbitals, and several unprepared elements. associated with a hind limb[9]
Neornithischia	Indeteriminate		Tooth[10]
Ankylosauria[11]	Indeterminate		Three isolated teeth from left and right dentary and right maxilla

Pterosaurs[]

Pterosaurs of the Winton Formation
Taxa	Species	Presence	Material	Notes	Images
Ferrodraco[12]	F. lentoni		A partial premaxillae, maxillae and dentaries, partial frontal, mandibular articular region comprising the surangular, angular and articular, partial cervical vertebrae, partial scapulocoracoid, partial ulna, partial radius, proximal and distal carpals, metacarpal IV, proximal end of metacarpal IV, fragmentary non-wing manual phalanges, partial first wing phalanx (IV-1), and associated fragments.	The most complete pterosaur from Australia and the youngest known anhanguerian.

Flora[]

Flora of the Winton Formation[13]
Taxa	Species	Presence	Material	Notes	Images
	M. marguerita			Liverwort
Equisetites	Indeterminate		Axes	Horsetail
Aff. Lygodium?	Indeterminate		Fern pinna
	P. macclymontae		Numerous pinnule impressions	A fern belonging to the family Osmundaceae
	cf. M. gleichenoides		Frond fragment impression	A fern belonging to the family Gleicheniaceae
Tempskya	T. judithae		Permineralized false trunks	A tree fern
Otozamites	cf. O. bengalensis		Leaves	Member of Bennettitales
Ptilophyllum	Indeterminate
	Indeterminate			A possible cycad
Ginkgo	G. wintonensis, four other possible species		Leaf impressions (G. wintonensis) Dispersed cuticle	A gingophyte, genus extant.
	Indeterminate		Leaf impression	A member of Pentoxylales, youngest record of the group in Australia
	E. microcarpa		Seed cones	A member of Araucariaceae, more closely related to Agathis and Wollemia than Araucaria.[14]
	A. wintonensis		Cones and leaved axes	A member of Cupressaceae
Araucariaceae	Indeterminate		Leaves
Cheirolepidiaceae	Four taxa		Dispersed cuticle
	L. wintonensis		Permineralised flower	A member of Laurales
Angiospermae	Indeterminate		Leaf impressions, cuticle fragments	At least ten distinct types, belonging to both monocots and dicotyledons

See also[]

• Lark Quarry Conservation Park
• List of dinosaur-bearing rock formations
• South Polar region of the Cretaceous

References[]