Eumeralla Formation

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: Aptian–Albian PreꞒ Ꞓ O S D C P T J K Pg N
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 / -38.8; 143.3
Approximate paleocoordinates	74.8°S 115.8°E / -74.8; 115.8
Region	Victoria
Country	Australia
Extent	Otway Basin
Type section
Named for	Eumeralla River
Named by	Reynolds, M.A
Year defined	1971
Exposure of the Eumeralla Formation in green at the bottom-left

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]

Paleobiota

Invertebrate traces named as Skolithos sp. and Arenicolites sp.,^[4] 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.^[5] Indeterminate theropod and possible indeterminate dromaeosaurid remains are present in Victoria, Australia.^[1] An indeterminate unenlagiine is known from the formation.^[6][7]

Dinosaurs

Ornithischians

Ornithischians of the Eumeralla Formation
Genus	Species	Presence	Material	Notes	Images
Ankylosauria[8]	Indeterminate	Dinosaur Cove	Dorsal vertebra
Atlascopcosaurus[1]	A. loadsi[1]	Dinosaur Cove Eric the Red West locality[5]	"Maxilla [and] teeth."[9]	Elasmarian ornithopod
Diluvicursor[2]	D. pickeringi[2]	Eric the Red West locality	Partial postcranial skeleton.[2]	Elasmarian ornithopod
cf.Galleonosaurus	G. dorisae[5]	Eric the Red West locality	Maxillae	Elasmarian ornithopod
Leaellynasaura[1]	L. amicagraphica[1]	Dinosaur Cove Eric the Red West locality[5]	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
Aves[11]	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
Megaraptora[14][15]	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.[17]
Timimus[1]	T. hermani[1]	Dinosaur Cove	Femur	Possible tyrannosauroid theropod
Unenlagiinae[18]	Indeterminate		Proximal portion of right femur	Probable record of unenlagiine theropod in Australia

Fish

Fish of the Eumeralla Formation
Genus	Species	Presence	Material	Notes	Images
Ceratodus	C. nargun			A lungfish	Ceratodus

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	Indeterminate		Dinosaur Cove[19]	Distinct from other known Australian crocodilians

See also

• List of dinosaur-bearing rock formations
• South Polar region of the Cretaceous