Eumeralla Formation
Geological formation in Victoria, Australia
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The Eumeralla Formation is a geological formation in Victoria, Australia whose strata date back to the Early Cretaceous. It is Aptian to Albian in age. Dinosaur remains are among the fossils that have been recovered from the formation, particularly from the Dinosaur Cove locality.[1]
| Eumeralla Formation | |
|---|---|
| Stratigraphic range: | |
Eric the Red West fossil locality, with AS and ES representing Anchor Sandstone and ETRW Sandstone, respectively | |
| Type | Geological formation |
| Unit of | Otway Group |
| Sub-units | Windermere Sandstone Member, Heathfield Sandstone Member |
| Underlies | Sherbrook Group |
| Overlies | Katnook Sandstone, Laira Formation (Crayfish Subgroup) |
| Thickness | Up to 3,000 m (9,800 ft) |
| Lithology | |
| Primary | Volcanilithic sandstone, siltstone, mudstone, conglomerate |
| Location | |
| Coordinates | 38.8°S 143.3°E |
| Approximate paleocoordinates | 74.8°S 115.8°E |
| Region | Victoria |
| Country | Australia |
| Extent | Otway Basin |
| Type section | |
| Named for | Eumeralla River |
| Named by | Reynolds, M.A |
| Year defined | 1971 |
  Eumeralla Formation (Australia) | |
Geology
The Eumeralla Formation was deposited within the Otway Basin, which at the time of deposition was part of an extensional rift valley system formed between Australia and Antarctica. The lithology primarily consists of fluvially deposited siliciclastics derived from volcanic material. The strata of the Eumeralla Formation are folded as a result of northwest–southeast crustal compression during the Neogene, which also reactivated some Cretaceous aged normal faults.[2] It is one of three major fossiliferous deposits in Victoria dating to the Early Cretaceous, including the older Wonthaggi Formation and the Koonwarra fossil bed (which some authors have considered part of the Eumeralla Formation).[3]
Paleoclimate
Paleosol facies in the Eumeralla Formation record climate fluctuations between warm and cool intervals. Warm, temperate periods are represented by Ultisols while cooler intervals at the Cape Paton locality record associated thin, gleyed Inceptisols and Entisols, which are characteristic of modern boreal forests.[4]
Paleobiota
Invertebrate traces named as Skolithos sp. and Arenicolites sp.,[5] as well as indeterminate ornithischian tracks are present in Victoria, Australia.[1] Indeterminate ornithopod remains are present at Eric the Red West locality and Elliot River, including material that possibly belongs to a new taxon.[6] Indeterminate theropod and possible indeterminate dromaeosaurid remains are present in Victoria, Australia.[1] An indeterminate unenlagiine is known from the formation.[7]
Dinosaurs
Ornithischians
| Ornithischians of the Eumeralla Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Ankylosauria[8] | Indeterminate | Dinosaur Cove | Dorsal vertebra | ||
|
A. loadsi[1] |
|
"Maxilla [and] teeth."[9] |
Elasmarian ornithopod |  | |
| D. pickeringi[2] | Eric the Red West locality | Partial postcranial skeleton.[2] | Elasmarian ornithopod |  | |
| cf.Galleonosaurus | G. dorisae[6] | Eric the Red West locality | Maxillae | Elasmarian ornithopod | |
| Leaellynasaura[1] | L. amicagraphica[1] |
|
Skull fragments, teeth, maxillae. Postcranial remains associated with the taxon cannot be confidently referred to it | Elasmarian ornithopod |  |
Theropods
| Dinosaurs of the Eumeralla Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| cf. Australovenator[10] | cf. A. wintonensis | Eric the Red West locality | "two teeth, two manual unguals, and a right astragalus" | Megaraptoran theropod |  |
| Indeterminate | Footprints belonging to a crane-sized bird, determined to be an ornithurine or enantiornithe. | Possibly from a species also found at the Wonthaggi Formation (single furcula). | |||
| Carcharodontosauria[12] | Indeterminate | "Isolated, distal end of a right tibia" | First probable record of carcharodontosaurian theropod in Australia | ||
| Elaphrosaurinae[13] | Indeterminate | Eric the Red West locality | Single cervical vertebra | ||
| Indeterminate | Dinosaur Cove |
Known from a left ulna. |
Probably a megaraptorid. Previously referred to Megaraptor.[16] | ||
| Megaraptoridae[10] |
Indeterminate |
Eric the Red West locality | Known from a single cervical vertebra. | Previously thought to be a Baryonyx-related spinosaurid.[7] |  |
| Timimus[1] | T. hermani[1] | Dinosaur Cove | Femur | Possible tyrannosauroid theropod | |
| Unenlagiinae[7] | Indeterminate | Proximal portion of right femur | Probable record of unenlagiine theropod in Australia | ||
Fish
Mammals
| Mammals of the Eumeralla Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Kryoryctes | K. cadburyi | Dinosaur Cove | A monotreme | ||
| Sundrius | S. ziegleri | A monotreme | |||
Reptiles
| Reptiles of the Eumeralla Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Otwayemys | O. cunicularius | Dinosaur Cove | A meiolaniform turtle | ||
| Pterosauria | Indeterminate | Dinosaur Cove | |||
| Plesiosauria | Indeterminate | Dinosaur Cove | |||
| Mesoeucrocodylia[17] | Indeterminate | Dinosaur Cove | Distinct from other known Australian crocodilians | ||
