The Winton Formation is a Cretaceous geological formation in central-western Queensland, Australia. It is late Albian to early Turonian in age. 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 Eromanga Sea - an inland sea that covered large parts of Queensland and central Australia at least four times during the Early Cretaceous period. 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.

Mollusca

Mollusca of the Winton Formation
TaxaSpeciesPresenceMaterialNotesImages
MelanoidesIndeterminate
HyridellaH (Protohyridella). goodiwindiensis
H. macmichaeli
MegalovirgusM.wintonensis
PledgiaP. eyrensis

Arthropods

Arthropods of the Winton Formation
TaxaSpeciesPresenceMaterialNotesImages
Oribatida?Indeterminate
OdonataIndeterminate
MecopteraIndeterminate
ColeopteraIndeterminate

Chondrichthyes

Chondrichthyes of the Winton Formation
TaxaSpeciesPresenceMaterialNotesImages
SelachiiIndeterminateA shark

Dipnoi

Dipnoi of the Winton Formation
TaxaSpeciesPresenceMaterialNotesImages
MetaceratodusM. boneiIsolated tooth platesLungfish belonging to the extinct family Ceratodontidae
M. ellioti
M. wollastoni

Actinopterygii

Actinopterygii of the Winton Formation
TaxaSpeciesPresenceMaterialNotesImages
CladocyclusC. geddesiNearly complete skull and partial skeleton

Squamates

Squamates of the Winton Formation
TaxaSpeciesPresenceMaterialNotesImages
VaranoideaIndeterminateA damaged posterior trunk vertebraOriginally considered as dolichosaurid (cf. Coniasaurus), but reassigned

Chelidae

Chelidae of the Winton Formation
TaxaSpeciesPresenceMaterialNotesImages
ChelidaeIndeterminate

Sauropterygia

Sauropterygia of the Winton Formation
TaxaSpeciesPresenceMaterialNotesImages
PlesiosauriaIndeterminate

Crocodyliformes

Crocodyliformes of the Winton Formation
TaxaSpeciesPresenceMaterialNotesImages
ConfractosuchusC. sauroktonosNearly complete skeleton preserving a juvenile ornithopod in its abdomen
IsisfordiaI. duncaniNearly complete skeleton and partial skull, referred complete skull

Dinosaurs

Ornithischians

Ornithischians of the Winton Formation
TaxaSpeciesPresenceMaterialNotesImages
AmblydactylusA. gethingiLark Quarry.Multiple footprints.
AnkylosauriaIndeterminateThree isolated teeth from left and right dentary and right maxilla
NeornithischiaIndeterminateTooth
OrnithopodaIndeterminateDigested remains associated with the holotype of Confractosuchus
OrnithopodaUndescribedA nearly complete skull and mandible and at least three partial postcranial skeletons.Small-bodied, recovered as part of "Elasmaria"
WintonopusW. latomorumSnake Creek and Lark Quarry track site.Footprints.An ornithopod.

Sauropods

Sauropods of the Winton Formation
TaxaSpeciesPresenceMaterialNotesImages
AustralotitanA. cooperensisA 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. Possibly a junior synonym of Diamantinasaurus.
DiamantinasaurusD. matildaeA 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.
SavannasaurusS. elliottorumPosterior 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.
SauropodaIndeterminatePoorly preserved remains associated with the holotype of Confractosuchus
TitanosauriformesUndescribedPartial skull, consisting of a braincase, quadrates, quadratojugals, a left squamosal, postorbitals, and several unprepared elements. associated with a hind limb
WintonotitanW. wattsiA 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.

Theropods

Theropods of the Winton Formation
TaxaSpeciesPresenceMaterialNotesImages
AustralovenatorA. wintonensisDentaries, 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.
MegaraptoridaeIndeterminateA partial skeleton, consisting of caudal vertebrae, metatarsals, a phalanx, and numerous unidentifiable fragments. Stated to be larger than Australovenator.

Pterosaurs

Pterosaurs of the Winton Formation
TaxaSpeciesPresenceMaterialNotesImages
FerrodracoF. lentoniA 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.

Therapsida

Therapsida of the Winton Formation
TaxaSpeciesPresenceMaterialNotesImages
CynodontIndeterminate

Flora

Flora of the Winton Formation
TaxaSpeciesPresenceMaterialNotesImages
AngiospermaeIndeterminateLeaf impressions, cuticle fragmentsAt least ten distinct types, belonging to both monocots and dicotyledons
AraucariaA. cf. mesozoicaLeavesA member of Araucariaceae
AraucariaceaeIndeterminateLeavesConifer
AustrosequoiaA. wintonensisCones and leaved axesA member of Cupressaceae
CarnoconitesIndeterminateFemale ovulate fruiting organA member of the extinct seed plant order Pentoxylales, youngest record of the group in Australia
CheirolepidiaceaeFour taxaDispersed cuticleConifer
EmwadeaE. microcarpaSeed conesA member of Araucariaceae, more closely related to Agathis and Wollemia than Araucaria.
EquisetitesIndeterminateAxesHorsetail
GinkgoG. wintonensis, four other possible speciesLeaf impressions (G. wintonensis) Dispersed cuticleA gingophyte, genus extant.
LovelleaL. wintonensisPermineralised flowerA member of Laurales
Aff. Lygodium?IndeterminateFern pinnaFern
MarchantitesM. margueritaLiverwort
Microphyllopteriscf. M. gleichenoidesFrond fragment impressionA fern belonging to the family Gleicheniaceae
Otozamitescf. O. bengalensisLeavesMember of Bennettitales
PhyllopteroidesP. macclymontaeNumerous pinnule impressionsA fern belonging to the family Osmundaceae
PterostomaIndeterminateLeavesA possible cycad
PtilophyllumIndeterminateLeavesMember of Bennettitales
SphenopterisIndeterminateLeavesA "seed fern"
TaeniopterisIndeterminateLeaf impressionA member of the extinct seed plant order Pentoxylales, youngest record of the group in Australia
TempskyaT. judithaePermineralized false trunksA tree fern

See also