Wonthaggi Formation
Geological formation in Victoria, Australia
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The Wonthaggi Formation is an informal geological formation in Victoria, Australia whose strata date back to the Early Cretaceous. It is part of the Strzelecki Group within the Gippsland Basin. Dinosaur remains are among the fossils that have been recovered from the formation.[1][2] It is partially equivalent to the Eumeralla Formation.
| Wonthaggi Formation | |
|---|---|
| Stratigraphic range: | |
Flat rocks locality | |
| Type | Geological formation |
| Unit of | Strzelecki Group |
| Underlies | Unconformity with Wombat Volcanics & Kersop Arkose |
| Overlies | Paleozoic basement |
| Thickness | Up to 2,500 m (8,200 ft) |
| Lithology | |
| Primary | Volcaniclastic sandstone, siltstone |
| Other | Conglomerate, coal |
| Location | |
| Coordinates | 38.7°S 145.7°E |
| Approximate paleocoordinates | 77.0°S 117.5°E |
| Region | Victoria |
| Country | Australia |
| Extent | Gippsland Basin |
  Wonthaggi Formation (Australia) | |
Geology
The Wonthaggi Formation was deposited within Gippsland Basin, which formed part of a extensional rift valley system between Australia and Antarctica. The lithology primarily consists of fluvially deposited siliciclastics derived from volcanic rocks of the Whitsunday Silicic Large Igneous Province to the East, with suggestions that the sediments either originated from braided river and sheet flood deposits, or meandering river systems on vegetated floodplains.[3] The age of the formation is thought to be Valanginian to Barremian, with the Flat Rocks site being late Barremian (~125 Ma) in age, older than the sediments from the Eumeralla Formation, which are thought to be Aptian-Albian in age.[3]
Permafrost
Paleosol facies in the Wonthaggi have recorded periglacial cryoturbation structures. Unusual soft sediment deformation has been observed at the Flat Rocks and Kilcunda localities, representing cryogenic hummocks. At Kilcunda, clastic dykes representing thermal contraction cracks have been identified. In the coal seams of the Wonthaggi, stone rolls are interpreted as products of a distinct form of periglacial deformation in aapa mires. Periods of warmer, temperate climate conditions are recorded as Ultisols in the Valanginian interval of the sedimentary unit.[4]
Fossil content
Indeterminate ornithopod remains are present in Victoria, Australia.[3] Indeterminate megaraptorid remains are present in Victoria, Australia.[5]
Color key
|
Notes Uncertain or tentative taxa are in small text; |
Dinosaurs
Ornithischians
| Ornithischians of the Wonthaggi Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Location | Stratigraphic position | Material | Notes | Image |
| Ankylosauria indet.[6] | Indeterminate | Flat Rocks | Teeth, dorsal vertebra, ribs, osteoderms | |||
| cf. Atlascopcosaurus[3] | cf. A. loadsi[3] | Flat Rocks | known as "Victorian ornithopod maxillary morphotype 4", consists of a partial right maxilla | A elasmarian ornithopod |  | |
| Galleonosaurus[3] | G. dorisae[3] | Flat Rocks | Known from a maxilla | A elasmarian ornithopod | ||
| Qantassaurus[1] | Q. intrepidus[1] | Flat Rocks | "[Three] dentaries and teeth."[7] | A elasmarian ornithopod |  | |
| Q. ?intrepidus[3] | ||||||
| Serendipaceratops[1] | S. arthurclarkei[1] | The Arch, Kilcunda | Single damaged ulna | A dubious ornithischian | ||
| Ornithopoda indet.[3] | Indeterminate | Flat Rocks | Dentaries referred to as "Victorian ornithopodan dentary morphotype 3" including P228408, NMV P231182, NMV P199135 and isolated teeth | Different from Q. intrepidus. | ||
| Ornithopoda indet.[3] | Indeterminate | Cape Paterson | Single femur | An indeterminate ornithopod | ||
Theropods
| Theropods of the Wonthaggi Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Location | Stratigraphic position | Material | Notes | Image |
| Aves Indet.[8] | Indeterminate | Possibly also present at the Eumeralla Formation (footprints). | Single furcula. | |||
| Megaraptora indet. | Indeterminate | Flat Rocks | Numerous isolated teeth, and a left astragalus[9] | Originally referred to "Allosaurus" robustus | ||
| Megaraptoridae indet.[10] | Indeterminate | Shack Bay | a complete frontal, attached to a partial parietal | |||
| Noasauridae Indet.[11] | Indeterminate | San Remo Member | NMV P221202, astragalocalcaneum | A non-elaphrosaurine noasaurid | ||
Amphibians
| Amphibians of the Wonthaggi Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Location | Stratigraphic position | Material | Notes | Image |
| Koolasuchus | K. cleelandi | Tree Trunk Point, Dwyers Hill, San Remo | A chigutisaurid temnospondyl, last known temnospondyl |  | ||
Mammals
| Mammals of the Wonthaggi Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Location | Stratigraphic position | Material | Notes | Image |
| Ausktribosphenos | A. nyktos | Flat Rocks | Partial dentary with teeth | ausktribosphenid australosphenidan | ||
| Bishops | B. whitmorei | Flat Rocks | Partial dentary with teeth | A ausktribosphenid australosphenidan | ||
| Corriebaatar | C. marywaltersae | Flat Rocks | "NMV P216655, a fragment of a left dentary bearing a complete plagiaulacoid p4 and the anterior root of m1" | A corriebaatarid multituberculate |  | |
| Kryoparvus | K. gerriti | Flat Rocks | Partial dentary with teeth | A ausktribosphenid australosphenidan | ||
| Teinolophos | T. trusleri | Flat Rocks | Partial dentary with teeth | A teinolophid monotreme | ||