Comley limestone

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Comley limestone
Stratigraphic range: 519-509 Ma
Location
Location Comley, Shropshire, UK

The Comley Limestone is an Early Cambrian Lagerstätte exposed in Comley, Shropshire, England. It is known for its phosphatic microfossils, which can be extracted by acid maceration and are preserved in three dimensions in a similar fashion to the Orsten fossils. [1] It represents around 10 million years of deposition, and was deposited from 519 to 501 million years ago. [2]

Lagerstätte sedimentary deposit that exhibits extraordinary fossils with exceptional preservation

A Lagerstätte is a sedimentary deposit that exhibits extraordinary fossils with exceptional preservation—sometimes including preserved soft tissues. These formations may have resulted from carcass burial in an anoxic environment with minimal bacteria, thus delaying decomposition. Lagerstätten span geological time from the Neoproterozoic era to the present. Worldwide, some of the best examples of near-perfect fossilization are the Cambrian Maotianshan shales and Burgess Shale, the Devonian Hunsrück Slates and Gogo Formation, the Carboniferous Mazon Creek, the Jurassic Solnhofen limestone, the Cretaceous Santana and Yixian formations, and the Eocene Green River Formation.

Comley human settlement in United Kingdom

Comley is a hamlet in Shropshire, England. It is near the A49 road, to the northeast of Church Stretton.

Shropshire County of England

Shropshire is a county in the West Midlands of England, bordering Wales to the west, Cheshire to the north, Staffordshire to the east, and Worcestershire and Herefordshire to the south. Shropshire Council was created in 2009, a unitary authority taking over from the previous county council and five district councils. The borough of Telford and Wrekin has been a separate unitary authority since 1998 but continues to be included in the ceremonial county.

See also

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<i>Vernanimalcula</i>

Vernanimalcula guizhouena is an acritarch dating from 600 to 580 million years ago; it was between 0.1 and 0.2 mm across. Vernanimalcula means "small spring animal", referring to its appearance in the fossil record at the end of the Marinoan Glaciation and the belief upon discovery it was an animal.

Sirius Passet

Sirius Passet is a Cambrian Lagerstätte in Greenland. The Sirius Passet Lagerstätte was named after the Sirius sledge patrol that operates in North Greenland. It comprises six places on the east shore of J.P. Koch Fjord in the far north of Greenland. It was discovered in 1984 by A. Higgins of the Geological Survey of Greenland. A preliminary account was published by Simon Conway Morris and others in 1987, but since then, expeditions led by J. S. Peel and Simon Conway Morris have returned to the site several times between 1989 and the present. A field collection of perhaps 10,000 fossil specimens has been amassed.

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The evolution of the molluscs is the way in which the Mollusca, one of the largest groups of invertebrate animals, evolved. This phylum includes gastropods, bivalves, scaphopods, cephalopods, and several other groups. The fossil record of mollusks is relatively complete, and they are well represented in most fossil-bearing marine strata. Very early organisms which have dubiously been compared to molluscs include Kimberella and Odontogriphus.

<i>Latouchella</i> genus of molluscs (fossil)

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Orsten

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Ediacaran biota Enigmatic tubular and frond-shaped, mostly sessile organisms that lived during the Ediacaran Period (ca. 635–542 Mya)

The Ediacaranbiota consisted of enigmatic tubular and frond-shaped, mostly sessile organisms that lived during the Ediacaran Period. Trace fossils of these organisms have been found worldwide, and represent the earliest known complex multicellular organisms. The Ediacaran biota may have radiated in a proposed event called the Avalon explosion, 575 million years ago, after the Earth had thawed from the Cryogenian period's extensive glaciation. The biota largely disappeared with the rapid increase in biodiversity known as the Cambrian explosion. Most of the currently existing body plans of animals first appeared in the fossil record of the Cambrian rather than the Ediacaran. For macroorganisms, the Cambrian biota appears to have completely replaced the organisms that dominated the Ediacaran fossil record, although relationships are still a matter of debate.

<i>Chancelloria</i>

Chancelloria is a genus of early animals known from the Middle Cambrian Burgess Shale, the Comley limestone, the Wheeler Shale, the Bright Angel Shale and elsewhere. It is named after Chancellor Peak. It was first described in 1920 by Charles Doolittle Walcott, who regarded them as one of the most primitive groups of sponges. This appears unlikely, and it is currently placed in the enigmatic group Coeloscleritophora. 178 specimens of Chancelloria are known from the Greater Phyllopod bed, where they comprise 0.34% of the community.

Evidence suggesting that a mass extinction occurred at the end of the Ediacaran period, 542 million years ago, includes:

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Stephen Formation

The Stephen Formation is a geologic formation exposed in the Canadian Rockies of British Columbia. Its rocks were formed during the middle Cambrian. It is famous for the exceptional preservation of soft-bodied fossils: the Burgess Shale biota. The formation overlies the Cathedral escarpment, a submarine cliff; consequently it is divided into two quite separate parts, the 'thin' sequence deposited in the shallower waters atop the escarpment, and the 'thick' sequence deposited in the deeper waters beyond the cliff. Because the 'thick' Stephen Formation represents a distinct lithofacies, some authors suggest it warrants its own name, and dub it the Burgess Shale Formation. The stratigraphy of the Thin Stephen Formation has not been subject to extensive study, so except where explicitly mentioned this article applies mainly to the Thick Stephen Formation.

Mount Cap formation

The Mount Cap Formation is a geologic formation exposed in the Mackenzie Mountains, northern Canada. It was deposited in a shallow shelf setting in the late Early Cambrian, and contains an array of Burgess Shale-type microfossils that have been recovered by acid maceration.

Mongolitubulus is a form genus encapsulating a range of ornamented conical small shelly fossils of the Cambrian period. It is potentially synonymous with Rushtonites, Tubuterium and certain species of Rhombocorniculum, and owing to the similarity of the genera, they are all dealt with herein. Organisms that bore Mongolitubulus-like projections include trilobites, bradoriid arthropods and hallucigeniid lobopodians.

<i>Weymouthia</i> (trilobite) genus of arthropod (fossil)

Weymouthia is an extinct genus of eodiscinid agnostid trilobites, which lived at the end of the Lower Cambrian, in what are now the eastern United States, England, Siberia and China.

Orstenotubulus is a genus of lobopodian known from Orsten deposits of the latest 'middle' Cambrian (Miaolingian). It is believed by some to be an ancestor of the Tardigrades.

References

  1. "Center of 'Orsten' Research and Exploration".
  2. Harvey, T. H. P.; Williams, M.; Condon, D. J.; Wilby, P. R.; Siveter, D. J.; Rushton, A. W. A.; Leng, M. J.; Gabbott, S. E. (2011). "A refined chronology for the Cambrian succession of southern Britain". Journal of the Geological Society. 168 (3): 705–716. doi:10.1144/0016-76492010-031.