Wheeler Shale | |
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Stratigraphic range: Middle Cambrian ~507 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓ | |
Elrathia kingii, famed trilobite of the Wheeler Shale. | |
Type | Geological formation |
Thickness | 100–200 m (330–660 ft) |
Lithology | |
Primary | Calcareous shale |
Other | Mudstone, shaley limestone and limestone |
Location | |
Coordinates | 39°15′N 113°20′W / 39.25°N 113.33°W / 39.25; -113.33 |
Region | House Range and Drum Mountains, Millard Co., west Utah |
Country | United States |
Type section | |
Named for | House Amphitheater (Geographic feature and type locality) |
Named by | Charles Doolittle Walcott |
Part of a series on |
The Cambrian explosion |
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Fossil localities |
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Evolutionary concepts
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The Wheeler Shale (named by Charles Walcott) is a Cambrian (c. 507 Ma) fossil locality world-famous for prolific agnostid and Elrathia kingii trilobite remains (even though many areas are barren of fossils) and represents a Konzentrat-Lagerstätte. Varied soft bodied organisms are locally preserved, a fauna (including Naraoia, Wiwaxia and Hallucigenia) and preservation style (carbonaceous film) normally associated with the more famous Burgess Shale. As such, the Wheeler Shale also represents a Konservat-Lagerstätten.
Together with the Marjum Formation and lower Weeks Formation, the Wheeler Shale forms 490 to 610 m (1,610 to 2,000 ft) of limestone and shale exposed in one of the thickest, most fossiliferous and best exposed sequences of Middle Cambrian rocks in North America.
At the type locality of Wheeler Amphitheater, House Range, Millard County, western Utah, the Wheeler Shale consists of a heterogeneous succession of highly calcareous shale, shaley limestone, mudstone and thin, flaggy limestone. The Wheeler Formation (although the Marjum & Weeks Formations are missing) extends into the Drum Mountains, northwest of the House Range where similar fossils and preservation are found.
Taphonomy and sedimentology
Further information: Burgess Shale-type preservationDetailed work recognises a number of ~10 m thick lagerstätten sequences in the formation, each of which formed at a sea-level high stand in deep water. The lagerstätte were deposited by turbidities and mudslides onto an oxygenated sea floor. The productive layers comprise mud and clay particles, with a tiny fraction of wind-blown quartz.
Stratigraphy
The Wheeler Shale spans the Ptychagnostus atavus and uppermost-Middle Cambrian Bolaspidella trilobite zones (See House Range for full stratigraphy).
Fauna
Main article: Burgess Shale-type faunaIncomplete list of the fauna of the Wheeler Shale: (Note: the preservation of hard bodied trilobite remains and soft bodied animals seems to be mutually exclusive within particular horizons.)
Protista
- Marpolia spissa - cyanobacteria or green algae
- Morania fragmenta - cyanobacteria
Arthropoda
- Branchiocaris pretiosa - hymenocarine
- Branchiocaris sp.
- Cambropodus gracilis - possible myriapod
- Canadaspis perfecta - hymenocarine
- Dicerocaris opisthoeces
- Emeraldella brocki - vicissicaudatan
- Isoxys
- Perspicaris dilatus hymenocarine
- Pseudoarctolepis sharpi - possible hymenocarine
- Tuzoia? peterseni hymenocarine
- Waptia fieldensis hymenocarine
- Alalcomenaeus cambricus - megacheiran; or alalcomenaeid
- Dicranocaris guntherorum - megacheiran; or alalcomenaeid
- unnamed 'Molli Sonia symmetrica'
- Leanchoilia superlata - megacheiran
- Sidneyia inexpectans - vicissicaudatan
Dinocaridida
- Amplectobelua cf. A. stephenensis – radiodont
- Anomalocarididae gen. et sp. nov. - radiodont
- Buccaspinea cooperi? - radiodont
- Caryosyntrips durus - radiodont
- Caryosyntrips serratus - radiodont
- Peytoia nathorsti - radiodont
- Pahvantia hastata - radiodont
- Stanleycaris sp. - radiodont
- Utahnax vannieri - kerygmachelid lobopodian, also possible that is from Marjum Formation
- Utaurora comosa - opabiniid
Trilobita
- Naraoia compacta - naraoiid nectaspid
- Hypagnostus parvifrons - agnostid
- Peronopsis amplaxis - peronopsid agnostid
- Peronopsis bidens
- Peronopsis fallax
- Peronopsis gaspensis
- Peronopsis intermedius
- Peronopsis interstrictus
- Peronopsis montis
- Peronopsis segmentis
- Ptychagnostus atavus (= Acidusus atavus) - ptychagnostid agnostid
- Ptychagnostus germanus
- Ptychagnostus gibbus
- Ptychagnostus intermedius
- Ptychagnostus michaeli
- Ptychagnostus occultatus
- Ptychagnostus seminula
- Glyphaspis concavus - asaphid
- Bathyuriscus fimbriatus - dolichometopid corynexochid
- Bathyuriscus sp.
- Kootenia sp. - dorypygid corynexochid, perhaps a synonym of Olenoides
- Olenoides expansus - dorypygid corynexochid
- Olenoides nevadensis
- Olenoides serratus
- Tonkinella breviceps
- Zacanthoides divergens - zacanthoidid corynexochid
- Zacanthoides sp.
- Altiocculus harrisi - ptychopariid (specific name may be confused with Alokistocare)
- Alokistocare harrisi - alokistocarid ptychopariid
- Asaphiscus wheeleri - ptychopariid; second-most common species in the formation
- Bathyocos housensis - ptychopariid
- Bolaspidella drumensis
- Bolaspidella housensis
- Bolaspidella sp.
- Bolaspidella wellsvillensis
- Brachyaspidion microps
- Brachyaspidion sulcatum
- Cedaria minor - known from the Warrior Formation
- Elrathia kingii - alokistocarid ptychopariid
- Elrathia sp.
- Elrathina wheeleri = Ptychoparella wheeleri? - ptychopariid
- Jenkinsonia varga
- Modocia brevispina
- Modocia laevinucha
- Modocia typicalis
- Ptychoparella sp. - ptychopariid
- Ptychoparella wheeleri
- Spencella sp. - ptychopariid
Brachiopoda
- Acrothele subsidua
Chordata
Cnidaria
- Cambromedusa sp. - jellyfish
Mollusca
Echinodermata
- Castericystis sprinklei - carpoid
- Castericystis sp.
- Cothurnocystis sp. - stylophoran
- Ctenocystis sp. - ctenocystoid
- Gogia spiralis - eocrinoid
- Eocrinoid holdfasts believed to belong to Gogia spiralis; may belong to other species
Porifera
- Choia carteri - choiid monaxonid demosponge
- Choia utahensis
- Crumillospongia sp. - hazeliid monaxonid demosponge
- Diagonella sp.
Priapulida
- Ottoia prolifica - a stem group and it was an archaeopriapulid
- Selkirkia sp. - archaeopriapulid
- "Selkirkia willoughbyi" (Note: S. columbia is the only recognized species)
Unclassified
- Hallucigenia sparsa - ?xenusiid lobopod
- Allonnia cf. tintinopsis - a chancelloriid
- Chancelloria pentacta - chancelloriid coeloscleritophoran, perhaps a sponge?
- Eldonia sp. - eldoniid paropsonemid cambroernid
- Skeemella clavula - Possible vetulicolian
- Hylolithellus sp. - annelid?
- Wiwaxia corrugata - halwaxiid? lophotrochozoan
- Yuknessia simplex - pterobranch
- Margaretia dorus - possibly organic tube associated with hemichordate
References
- Johnson, Kirk; Troll, Ray (2007), Cruising the fossil freeway: An epoch tale of a scientist and an artist on the ultimate 5,000-Mile paleo road trip, Golden, CO.: Fulcrum Publishing, ISBN 978-1-55591-451-6
- Robert R. Gaines; Mary L. Droser (2003), "Paleoecology of the familiar trilobite Elrathia kingii: An early exaerobic zone inhabitant" (PDF), Geology, 31 (11): 941–4, Bibcode:2003Geo....31..941G, doi:10.1130/G19926.1
- Robert R. Gaines; Derek E.G. Briggs; Zhao Yuanlong (2008), "Cambrian Burgess Shale–type deposits share a common mode of fossilization", Geology, 36 (10): 755–758, Bibcode:2008Geo....36..755G, doi:10.1130/G24961A.1
- ^ Gaines, R; Kennedy, M; Droser, M (2005), "A New Hypothesis for Organic Preservation of Burgess Shale Taxa in the Middle Cambrian Wheeler Formation, House Range, Utah", Palaeogeography, Palaeoclimatology, Palaeoecology, 220 (1–2): 193–205, Bibcode:2005PPP...220..193G, doi:10.1016/j.palaeo.2004.07.034
- Robison, R.A. (1964), "Late Middle Cambrian faunas from western Utah", Journal of Paleontology, 38 (3): 510–566
- ^ Gunther, L.F.; Gunther, V.G. (1981), "Some Middle Cambrian Fossils of Utah", Brigham Young University Geology Studies, 28: 1–81
- ^ Brett, C. E.; Allison, P. A.; Desantis, M. K.; Liddell, W. D.; Kramer, A. (2009). "Sequence stratigraphy, cyclic facies, and lagerstätten in the Middle Cambrian Wheeler and Marjum Formations, Great Basin, Utah". Palaeogeography, Palaeoclimatology, Palaeoecology. 277 (1–2): 9–33. Bibcode:2009PPP...277....9B. doi:10.1016/j.palaeo.2009.02.010.
- Halgedahl, S. L.; Jarrard, R. D.; Brett, C. E.; Allison, P. A. (2009). "Geophysical and geological signatures of relative sea level change in the upper Wheeler Formation, Drum Mountains, West-Central Utah: A perspective into exceptional preservation of fossils". Palaeogeography, Palaeoclimatology, Palaeoecology. 277 (1–2): 34–56. Bibcode:2009PPP...277...34H. doi:10.1016/j.palaeo.2009.02.011.
- Gaines, R. R.; Kennedy, M. J.; Droser, M. L. (2005). "A new hypothesis for organic preservation of Burgess Shale taxa in the middle Cambrian Wheeler Formation, House Range, Utah". Palaeogeography, Palaeoclimatology, Palaeoecology. 220 (1–2): 193–205. Bibcode:2005PPP...220..193G. doi:10.1016/j.palaeo.2004.07.034.
- Lieberman, B. S. (2003). "A New Soft-Bodied Fauna: the Pioche Formation of Nevada". Journal of Paleontology. 77 (4): 674–690. doi:10.1666/0022-3360(2003)077<0674:ANSFTP>2.0.CO;2. ISSN 0022-3360. S2CID 130145927.
- Briggs, D.E.G.; Robison, R.A. (1984), Exceptionally preserved nontrilobite arthropods and Anomalocaris from the Middle Cambrian of Utah, The Paleontological Institute, The University of Kansas
- Photos of Wheeler Shale fossils from UC Berkeley
- Rigby, J.K. (1978), "Porifera of the Middle Cambrian Wheeler Shale, from the Wheeler Amphitheater, House Range, in western Utah", Journal of Paleontology, 52 (6): 1325–1345, JSTOR 1303938
- Utah's Cambrian Life from University of Kansas Natural History Museum
- Cambrian fossils from Utah by the University of Utah
- Comprehensive treatment from The Virtual Fossil Museum
- Gaines, Robert R.; Droser, Mary L.; Kennedy, Martin J. (2001), "Taphonomy of soft-bodied preservation and ptychopariid Lagerstätte in the Wheeler Shale (Middle Cambrian), House Range, USA; controls and implications", PaleoBios, 21 (Suppl.2): 1–55
- ^ Pates, Stephen; Lerosey-Aubril, Rudy; Daley, Allison C.; Kier, Carlo; Bonino, Enrico; Ortega-Hernández, Javier (2021-01-19). "The diverse radiodont fauna from the Marjum Formation of Utah, USA (Cambrian: Drumian)". PeerJ. 9: e10509. doi:10.7717/peerj.10509. ISSN 2167-8359. PMC 7821760. PMID 33552709.
- Lerosey‐Aubril, Rudy; Ortega‐Hernández, Javier (2022). Zhang, Xi‐Guang (ed.). "A new lobopodian from the middle Cambrian of Utah: did swimming body flaps convergently evolve in stem‐group arthropods?". Papers in Palaeontology. 8 (3). doi:10.1002/spp2.1450. ISSN 2056-2799. S2CID 250076505.
- Pates, Stephen; Wolfe, Joanna M.; Lerosey-Aubril, Rudy; Daley, Allison C.; Ortega-Hernández, Javier (2022-02-09). "New opabiniid diversifies the weirdest wonders of the euarthropod stem group". Proceedings of the Royal Society B: Biological Sciences. 289 (1968): 20212093. doi:10.1098/rspb.2021.2093. PMC 8826304. PMID 35135344.
- Foster, John R.; Howells, Thomas F.; Sroka, Steven D. (2022). "First record of the chancelloriid Allonnia from the middle Cambrian Wheeler Formation (Drumian, Miaolingian) of western Utah". PaleoBios. 39 (4). doi:10.5070/P939455661. ISSN 0031-0298. S2CID 251544727.
- Nanglu, Karma; Caron, Jean-Bernard; Conway Morris, Simon; Cameron, Christopher B. (2016-07-07). "Cambrian suspension-feeding tubicolous hemichordates". BMC Biology. 14: 56. doi:10.1186/s12915-016-0271-4. ISSN 1741-7007. PMC 4936055. PMID 27383414.
Burgess Shale-type preservation | |
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Cambrian localities | |
Ordovician localities |
Modes of preservation in the Cambrian | ||
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Exceptional | ||
Conventional |