| Gogo Formation | |
|---|---|
| Stratigraphic range: Middle-Late Devonian (Givetian to Frasnian), | |
| Type | Geological formation |
| Unit of | Fairfield Group |
| Underlies | Napier Formation, Virgin Hills Formation |
| Overlies | Pillara Limestone, Sadler Limestone |
| Thickness | Up to 700 m (2,300 ft) |
| Lithology | |
| Primary | Shale, Siltstone |
| Other | Limestone |
| Location | |
| Location | Kimberley, Western Australia |
| Coordinates | 18°18′S 126°30′E / 18.3°S 126.5°E |
| Approximate paleocoordinates | 16°42′S 136°42′E / 16.7°S 136.7°E |
| Region | Western Australia |
| Country | Australia |
| Extent | Canning Basin |
| Type section | |
| Named for | Gogo Station |
| Thickness at type section | ~425 m (1,394 ft) |

The Gogo Formation in the Kimberley region of Western Australia is a Lagerstätte that exhibits exceptional preservation of a Devonian reef community. The formation is named after Gogo Station, a cattle station where outcrops appear and fossils are often collected from, as is nearby Fossil Downs Station.
The reef, which now stands up abruptly in the western Australian desert (as the Windjana Limestone), was first identified in 1940 by paleontologist Curt Teichert, who discovered the first fossil fish from the region.
The type section of the Gogo Formation is an approximately 430-meter-thick sequence of organic-rich, grey to black fine-grained shales and siltstones, interbedded with calcarenite and lenses of limestone. Horizons of resistant, silty calcareous concretions range from 3 to 50 centimeters in dimension (most commonly 5 to 20 cm). As the surrounding softer matrix eroded away, these weather-resistant concretions produce extensive nodule fields across the ground.
Deposition occurred between the middle Givetian (based on miospores) and early Frasnian (based on conodonts), dating the formation to approximately 384 to 382 million years ago.
The Gogo sediments represent deep, hypoxic seafloor deposits in the vicinity of a large tropical reef composed primarily of algae and stromatoporoids during the Frasnian faunal stage of the Late Devonian. Associated stratigraphic units which comprise this ancient reef system are the Windjana Formation (the actual reef structures), Pillara Limestone (reef platform) and the Sadler Formation (fore-reef deposits).
The fossils of the Gogo Formation display three-dimensional soft-tissue preservation of tissues as fragile as nerves and embryos with umbilical cords. Over fifty species of fish have been described from the formation, and arthropods, including phyllocarids and eurypterids are similarly well-preserved. Nautiloids, goniatites and tentaculids are also known from the formation, but their soft tissue is not preserved. However, the most diverse group by far are the radiolarians, known from over 100 species split between 17 genera. The excellent preservation of a sheer number of species has allowed for the identification of a wide range of morphotypes, and clarified the structure of different skeletal elements, permitting better taxonomic resolution.
The calcareous concretions formed around objects from the shallow reef areas which sank into the deep anoxic basins. The concretions sometimes contain the remains of fish, whose bodies are often preserved complete in three-dimensions due to rapid encasement and the slow rate of decay in the oxygen-poor surroundings. By repeated baths in a dilute acid solution, the matrix is dissolved away via a process of acid etching to reveal delicate fish fossils, some retaining impressions of soft tissues.
The discovery of Materpiscis, a placoderm preserved with an embryonic juvenile still attached by its umbilical cord, has revealed that at least some placoderms gave birth to live young.
| Actinopterygians of the Gogo Formation | |||
|---|---|---|---|
| Genus | Species | Clade | Images |
| Gogosardina | G. coatesi | Actinopterygii incertae sedis | |
| Mimipiscis | M. toombsi | Actinopterygii incertae sedis | |
| M. bartrami | |||
| Moythomasia | M. durgaringa | Actinopterygii, | |
| Pickeringius | P. acanthophorus | Actinopterygii incertae sedis | |
| Ammonoids of the Gogo Formation | |||
|---|---|---|---|
| Genus | Species | Clade | Images |
| Hoeninghausia | H. pons | Goniatitida, | |
| Ponticeras | P. discoidale | Goniatitida, | |
| Probeloceras | P. lutheri holzapfeli | Agoniatitida, | |
| Timanites | T. angustus | Agoniatitida, | |
| Tornoceras | T. (T.) simplex | Goniatitida, | |
| Arthropods of the Gogo Formation | |||
|---|---|---|---|
| Genus | Species | Clade | Images |
| Montecaris | M. gogoensis | Archaeostraca, | |
| M. sp. indet. | |||
| Schugurocaris | S. wami | Archaeostraca, | |
| S. sp. indet. | |||
| Dithyrocaris | D. sp. indet. | Archaeostraca, | |
| Concavicaris | C. campi | Thylacocephala
(Concavicarida incertae sedis) |
|
| C. glenisteri | |||
| C. milesi | |||
| C. playfordi | |||
| C. sp. | |||
| Harrycaris | H. whittingtoni | Thylacocephala
(Concavicarida incertae sedis) |
|
| Adelophthalmus | A. waterstoni | Eurypterida, | |
| Undescribed eurypterid | sp. indet. | Eurypterida incertae sedis | |
| 'Mushia' | sp. indet. | Crustacea? incertae sedis | |
| Chondrichthyans of the Gogo Formation | |||
|---|---|---|---|
| Genus | Species | Clade | Images |
| Gogoselachus | G. lynbeazleyae | Chondrichthyes incertae sedis | |
| Halimacanthodes | H. ahlbergi | Acanthodiformes, | |
| Conodonts of the Gogo Formation | |||
|---|---|---|---|
| Genus | Species | Clade | Images |
| Polygnathus | P. varca | Ozarkodinida, | |
| P. normalis | |||
| P. asymmetrica asymmetrica | |||
| P. asymmetrica ovalis | |||
| Playfordia | P. primitiva | Prioniodontida, | |
| Gnamptognathus | G.? lipperti | Uncertain | |
| G.? cf. G.? lipperti | |||
| Ancyrodella | A. rotundiloba alata | Ozarkodinida, | |
| A. rotundiloba rotundiloba | |||
| Icirodus | I. symmetricus | Uncertain | |
| Roundya | A. aurita | Uncertain | |
| Sarcopterygians of the Gogo Formation | |||
|---|---|---|---|
| Genus | Species | Clade | Images |
| Adololopas | A. moyasmithae | Speonesidrionina incertae sedis | |
| Asthenorhynchus | A. meemanae | Dipnoi, | |
| Cainocara | C. enigma | Dipnoi incertae sedis | |
| Chirodipterus | C. australis | Dipnoi, | |
| Ngamugawi | N. wirngarri | Coelacanthiformes incertae sedis | |
| Gogodipterus | G. paddyensis | Dipnoi, | |
| Gogonasus | G. andrewsae | Osteolepiformes, | |
| Griphognathus | G. whitei | Dipnoi, | |
| Holodipterus | "H" (Holodipteroides) elderae | Dipnoi, | |
| H. gogoensis | |||
| Onychodus | O. jandemarrai | Onychodontiformes, | |
| Pillararhynchus | P. longi | Dipnoi, | |
| Rhinodipterus | R. kimberleyensis | Dipnoi incertae sedis | |
| Robinsondipterus | R. longi | Dipnoi, | |
| Xeradipterus | X. hatcheri | Dipnoi, | |