Emu Bay Shale Stratigraphic range: Cambrian Stage 4("Lower Cambrian") |
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North Coast of Kangaroo Island, Emu Bay
© David Simpson |
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Type | Geological formation |
Lithology | |
Primary | Shale |
Location | |
Coordinates | 35°35′S 137°30′E / 35.583°S 137.500°E |
Region | The north coast of Kangaroo Island, around Emu Bay and Cape D'Estaing |
Country | South Australia, Australia. |
The Emu Bay Shale is a geological formation in Emu Bay, South Australia, containing a major Konservat-Lagerstätten (fossil beds with soft tissue preservation). It is one of two in the world containing Redlichiidan trilobites. The Emu Bay Shale is dated as Cambrian Series 2, Stage 4, correlated with the upper Botomian Stage of the Lower Cambrian.
Its mode of preservation is the same as the Burgess shale, but the larger grain size of the Emu Bay rock means that the quality of preservation is lower.
The Emu Bay Shale of Kangaroo Island, South Australia, is Australia's only known Burgess-Shale-type Konservat-Lagerstätte, and includes faunal elements such as Anomalocaris, Tuzoia, Isoxys, and Wronascolex, in common with other Burgess-Shale-type assemblages, notably the Chengjiang Biota in China, the closest palaeogeographically, although somewhat older. A few genera of non-biomineralized arthropods, among them Squamacula, Kangacaris, and the megacheiran Tanglangia, are known only from the Emu Bay Shale and Chengjiang. The site is also the source of high-quality specimens of trilobites such as Redlichia takooensis, Emuella polymera, Balcoracania dailyi, Megapharanaspis nedini, Holyoakia simpsoni, and Estaingia (=Hsuaspis) bilobata.Balcoracania and Emuella are the only known genera of the distinctive Redlichiina family Emuellidae, known for possessing the greatest number of thoracic segments known for Trilobita as a whole (a record of 103 in one Balcoracania specimen), and so far entirely restricted to Australia and Antarctica.