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Wiwaxia is a genus of soft-bodied animals that were covered in carbonaceous scales and spines that protected it from predators. Wiwaxia fossils – mainly isolated scales, but sometimes complete, articulated fossils – are known from early Cambrian and middle Cambrian fossil deposits across the globe. The living animal would have measured up to 5 cm (2 inch) when fully grown, although a range of juvenile specimens are known, the smallest being 2 millimetres (0.079 in) long.
Gogia is a genus of primitive eocrinoid blastozoan from the early to middle Cambrian.
Fieldia is a genus of worms known from the Cambrian Burgess Shale, and assigned to the priapulids. It was originally interpreted as an arthropod; its trunk bears a dense covering of spines, and its proboscis is small. It fed on sea-floor mud, evidenced by the frequent presence of sediments preserved in its gut.
Odaraia is a genus of bivalved arthropod from the Middle Cambrian. Its fossils, which reach 15 centimetres (5.9 in) in length, have been found in the Burgess Shale in British Columbia, Canada. 217 specimens of Odaraia alata are known from the Greater Phyllopod Bed, where they comprise 0.41% of the community.
Burgessia is a genus of arthropod that lived during the Middle Cambrian, and one that looks a lot like a modern day Horseshoe Crab when seen from above. Burgessia was much smaller than a Horseshoe Crab however with even the largest individuals being only a little over four centimetres in length, and the smallest about half a centimetre from the front of the Carapace to the tip of the rear spine. 1383 specimens of Burgessia are known from the Greater Phyllopod bed, where they comprise 2.63% of the community.
Burgessochaeta is an extinct genus of polychaete annelids from the Middle Cambrian. Its fossils have been found in the Burgess Shale in British Columbia, Canada. A total of 189 specimens of Burgessochaeta are known from the Greater Phyllopod bed, where they comprise 0.36% of the community. Specimens have also been found at Marble Canyon. The genus was described by Conway Morris (1979) and re-examined by Eibye-Jacobsen (2004).
Canadia is a genus of extinct annelid worm present in Burgess Shale type Konservat-Lagerstätte. It is found in strata dating back to the Delamaran stage of the Middle Cambrian around 505 million years ago, during the time of the Cambrian explosion. It was about 3 centimeters in length. Charles Doolittle Walcott named Canadia in 1911 after Canada, the country from which its remains have been found. 28 specimens of Canadia are known from the Greater Phyllopod bed, where they comprise 0.05% of the community.
The fossils of the Burgess Shale, like the Burgess Shale itself, formed around 505 million years ago in the Mid Cambrian period. They were discovered in Canada in 1886, and Charles Doolittle Walcott collected over 65,000 specimens in a series of field trips up to the alpine site from 1909 to 1924. After a period of neglect from the 1930s to the early 1960s, new excavations and re-examinations of Walcott's collection continue to reveal new species, and statistical analysis suggests that additional discoveries will continue for the foreseeable future. Stephen Jay Gould's book Wonderful Life describes the history of discovery up to the early 1980s, although his analysis of the implications for evolution has been contested.
Ancalagon minor is an extinct priapulid worm known from the Cambrian Burgess Shale.
The Phyllopod bed, designated by USNM locality number 35k, is the most famous fossil-bearing member of the Burgess Shale fossil Lagerstätte. It was quarried by Charles Walcott from 1911–1917, and was the source of 95% of the fossils he collected during this time; tens of thousands of soft-bodied fossils representing over 150 genera have been recovered from the Phyllopod bed alone.
Cambrorhytium is an enigmatic fossil genus known from the Latham Shale (California), and the Chengjiang (China) and Burgess Shale lagerstätte. 350 specimens of Cambrorhytium are known from the Greater Phyllopod bed, where they comprise 0.7% of the community.
Mackenzia is an elongated bag-like animal known from the Middle Cambrian Burgess Shale. It attached directly to hard surfaces, such as brachiopod shells. 14 specimens of Mackenzia are known from the Greater Phyllopod bed, where they comprise <0.1% of the community. Mackenzia was originally described by Charles Walcott in 1911 as a holothurian echinoderm. Later, Mackenzia is thought to be a cnidarian and appears most similar to modern sea anemones.
Louisella is a genus of worm known from the Middle Cambrian Burgess Shale. It was originally described by Charles Walcott in 1911 as a holothurian echinoderm, and represents a senior synonym of Miskoia, which was originally described as an annelid. 48 specimens of Louisella are known from the Greater Phyllopod bed, where they comprise < 0.1% of the community. It has been stated to have palaeoscolecid-like sclerites, though this is not in fact the case.
Insolicorypha is a genus of polychaetes known from the Middle Cambrian Burgess Shale. A single specimen of Insolicorypha is known from the Greater Phyllopod bed. The genus was described by Conway Morris (1979) and re-examined by Eibye-Jacobsen (2004).
Oesia disjuncta is a monospecific genus known from the Middle Cambrian Burgess Shale. 1147 specimens of Oesia are known from the Greater Phyllopod bed, where they comprise 2.18% of the community. Despite some similarities to the chaetognaths, its affinity is unknown, though recent data suggest it may be affiliated with hemichordates.
Pirania is an extinct genus of sea sponge known from the Middle Cambrian Burgess Shale and the Ordovician Fezouata formation. It is named after Mount St. Piran, a mountain situated in the Bow River Valley in Banff National Park, Alberta. It was first described in 1920 by Charles Doolittle Walcott. 198 specimens of Pirania are known from the Greater Phyllopod bed, where they comprise 0.38% of the community.
Pollingeria is a problematic genus of animals of the Middle Cambrian Burgess Shale. 3080 specimens of Pollingeria are known from the Greater Phyllopod bed, where they comprise 5.85% of the community.
Selkirkia is a genus of predatory, tubicolous priapulid worms known from the Middle Cambrian Burgess Shale, Ogygopsis Shale and Puncoviscana Formation. 142 specimens of Selkirkia are known from the Greater Phyllopod bed, where they comprise 0.27% of the community. In the Burgess Shale, 20% of the tapering, organic-walled tubes are preserved with the worm inside them, whereas the other 80% are empty. Whilst alive, the tubes were probably vertical, whereas trilobite-occupied tubes are horizontal.
Stephenoscolex is a genus of polychaete worm known from the Middle Cambrian Burgess Shale. 150 specimens of Stephenoscolex are known from the Greater Phyllopod bed, where they comprise 0.29% of the community. The genus was described by Conway Morris (1979) and re-examined by Eibye-Jacobsen (2004).
Wapkia is an extinct genus of sea sponge with radial sclerites, known from the Middle Cambrian Burgess Shale. It was first described in 1920 by Charles Doolittle Walcott. 32 specimens of Wapkia are known from the Greater Phyllopod bed, where they comprise 0.06% of the community.
References
- ↑ Caron, Jean-Bernard; Jackson, Donald A. (October 2006). "Taphonomy of the Greater Phyllopod Bed community, Burgess Shale". PALAIOS. 21 (5): 451–65. doi:10.2110/palo.2003.P05-070R. JSTOR 20173022.
- ↑ Conway Morris, S. (1979). "Middle Cambrian Polychaetes from the Burgess Shale of British Columbia". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 285 (1007): 227–274. Bibcode:1979RSPTB.285..227M. doi: 10.1098/rstb.1979.0006 . JSTOR 2418139.
- ↑ Eibye-Jacobsen, D. (2004). "A reevaluation of Wiwaxia and the polychaetes of the Burgess Shale". Lethaia. 37 (3): 317–335. doi:10.1080/00241160410002027.
