Wonthaggi Formation

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: Valanginian–Barremian PreꞒ Ꞓ O S D C P T J K Pg N
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
Exposure of Wonthaggi Formation green in bottom-right

Geology

The Wonthaggi Formation was deposited within the extensional rift valley formed 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.

Vertebrate paleofauna

Indeterminate ornithopod remains are present in Victoria, Australia.[3] Indeterminate megaraptorid remains are present in Victoria, Australia.[4]

Dinosaurs of the Wonthaggi Formation
Genus	Species	Locality	Notes	Images
cf. Atlascopcosaurus[3]	cf. A. loadsi[3]	Flat Rocks		Atlascopcosaurus Qantassaurus
Fulgurotherium[1]	F. australe[1]		Considered a nomen dubium.[3]
Galleonosaurus[3]	G. dorisae[3]	Flat Rocks	Known from a maxilla
Qantassaurus[1]	Q. intrepidus[1]	Flat Rocks	"[Three] dentaries and teeth."[5]
Serendipaceratops[1]	S. arthurclarkei[1]	The Arch, Kilcunda
Aves[6]	Indeterminate	Possibly also present at the Eumeralla Formation (footprints).	Single furcula.
Ankylosauria[7]	Indeterminate	Flat Rocks	Teeth, dorsal vertebra, ribs, osteoderms
Noasauridae[8]	Indeterminate	San Remo Member	NMV P221202, astragalocalcaneum
Ornithopoda[3]	Indeterminate	Flat Rocks	Dentaries referred to as "Victorian ornithopodan dentary morphotype 3" including P228408, NMV P231182, NMV P199135 and isolated teeth

Amphibians of the Wonthaggi Formation
Genus	Species	Presence	Notes	Images
Koolasuchus	K. cleelandi	Tree Trunk Point, Dwyers Hill, San Remo	Chigutisaurid temnospondyl, last known temnospondyl

Mammals of the Wonthaggi Formation
Genus	Species	Presence	Material	Notes	Images
Ausktribosphenos	A. nyktos	Flat rocks	Partial dentary with teeth	Ausktribosphenid
Bishops	B. whitmorei		Partial dentary with teeth	Ausktribosphenid
Corriebaatar	C. marywaltersae		"NMV P216655, a fragment of a left dentary bearing a complete plagiaulacoid p4 and the anterior root of m1"	Multituberculate
Kryoparvus	K. gerriti		Partial dentary with teeth	?Ausktribosphenid
Teinolophos	T. trusleri		Partial dentary with teeth	Monotreme

See also

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

References

1. Weishampel, David B; et al. (2004). "Dinosaur distribution (Early Cretaceous, Australasia)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 573-574. ISBN 0-520-24209-2.
2. . "Wonthaggi Formation", Australian Stratigraphic Units Database, Geoscience Australia, retrieved 2011-09-18
3. Herne, Matthew C.; Nair, Jay P.; Evans, Alistair R.; Tait, Alan M. (2019). "New small-bodied ornithopods (Dinosauria, Neornithischia) from the Early Cretaceous Wonthaggi Formation (Strzelecki Group) of the Australian-Antarctic rift system, with revision of Qantassaurus intrepidus Rich and Vickers-Rich, 1999". Journal of Paleontology. 93 (3): 543–584. doi:10.1017/jpa.2018.95.
4. Poropat, Stephen F.; Martin, Sarah K.; Tosolini, Anne-Marie P.; Wagstaff, Barbara E.; Bean, Lynne B.; Kear, Benjamin P.; Vickers-Rich, Patricia; Rich, Thomas H. (2018-04-03). "Early Cretaceous polar biotas of Victoria, southeastern Australia—an overview of research to date". Alcheringa: An Australasian Journal of Palaeontology. 42 (2): 157–229. doi:10.1080/03115518.2018.1453085. ISSN 0311-5518.
5. "Table 18.1," in Weishampel, et al. (2004). Page 395.
6. Martin, Anthony J.; Vickers-Rich, Patricia; Rich, Thomas H.; Hall, and Michael (2014). "Oldest known avian footprints from Australia: Eumeralla Formation (Albian), Dinosaur Cove, Victoria". Palaeontology. 57 (1): 7–19. doi:10.1111/pala.12082.
7. Barrett, Paul M.; Rich, Thomas H.; Vickers-Rich, Patricia; Tumanova, Tat'yana A.; Inglis, Matthew; Pickering, David; Kool, Lesley; Kear, Benjamin P. (September 2010). "Ankylosaurian dinosaur remains from the Lower Cretaceous of southeastern Australia". Alcheringa: An Australasian Journal of Palaeontology. 34 (3): 205–217. doi:10.1080/03115511003655430. ISSN 0311-5518.
8. Brougham, Tom; Smith, Elizabeth T.; Bell, Phil R. (2020-01-29). "Noasaurids are a component of the Australian 'mid'-Cretaceous theropod fauna". Scientific Reports. 10 (1): 1428. doi:10.1038/s41598-020-57667-7. ISSN 2045-2322.