The Wheeler Shale (named by Charles Walcott) is a Cambrian ( 507 Ma) fossil locality world-famous for prolific agnostid and ''

Elrathia kingii ''Elrathia'' is a genus of trilobite belonging to Ptychopariacea known from the mid-Cambrian of Laurentia (North America). ''E. kingii'' is one of the most common trilobite fossils in the USA locally found in extremely high concentrations withi ...

'' 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 ''Naraoia'' is a genus of small to average size (about 2-4½ cm long) marine arthropods within the family Naraoiidae, that lived from the early Cambrian to the late Silurian period. The species are characterized by a large alimentary system and s ...

'', ''

Wiwaxia ''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 ear ...

'' and ''

Hallucigenia ''Hallucigenia'' is a genus of Cambrian animal resembling worms, known from articulated fossils in Burgess Shale-type deposits in Canada and China, and from isolated spines around the world. The generic name reflects the type species' unusual ...

'') and preservation style ( carbonaceous film) normally associated with the more famous

Burgess Shale The Burgess Shale is a fossil-bearing deposit exposed in the Canadian Rockies of British Columbia, Canada. It is famous for the exceptional preservation of the soft parts of its fossils. At old (middle Cambrian), it is one of the earliest fos ...

. As such, the Wheeler Shale also represents a Konservat-Lagerstätten. Together with the

Marjum Formation The Marjum Formation is a Cambrian The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the prece ...

and lower

Weeks Formation The Weeks Formation is a geologic formation in Utah. It preserves fossils dating back to the Cambrian period and more specifically the Guzhangian stage. Its upper part has yielded a diverse fauna dominated by trilobites and brachiopods, but als ...

, the Wheeler Shale forms 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 The House Range is a north-south trending mountain range in Millard County, of west-central Utah. The House Range was named in 1859 by James H. Simpson. It was named by Simpson because "...of its well-defined stratification and the resemblance ...

, 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

Detailed 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 ''Ptychagnostus atavus'' is a species of agnostid trilobite. It was originally described by Swedish paleontologist Sven Axel Tullberg as ''Agnostus atavus'' in 1880. It is used in biostratigraphy as an index fossil. Its first appearance at the ...

'' and uppermost-Middle Cambrian '' Bolaspidella''

trilobite zone Trilobites are used as index fossils to subdivide the Cambrian period. Assemblages of trilobites define trilobite zones. The '' Olenellus''-zone has traditionally marked the top of the Lower Cambrian, and is followed by the '' Eokochaspis'' zon ...

s (See

) for full stratigraphy).

Fauna

Incomplete 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 A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the e ...

*''

Marpolia ''Marpolia'' has been interpreted as a cyanobacterium, but also resembles the modern cladophoran green algae. It is known from the Middle Cambrian Burgess shale and Early Cambrian deposits from the Czech Republic. It comprises a dense mass of e ...

spissa'' - cyanobacteria or

green algae The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ( Embryophytes) have emerged deep in the Charophyte alg ...

*'' Morania fragmenta'' - cyanobacteria

Arthropoda Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...

*''

Branchiocaris ''Branchiocaris'' is an extinct genus of Cambrian bivalved arthropod. The type and best known species, ''Branchiocaris pretiosa,'' was described from the Burgess Shale of British Columbia, Canada, in 1929, originally placed in ''Protocaris'', and ...

pretiosa'' - hymenocarine *''Branchiocaris sp''. *'' Cambropodus gracilis'' -

uniramia Uniramia (''uni'' – one, ''ramus'' – branch, i.e. single-branches) is a group within the arthropods. In the past this group included the Onychophora, which are now considered a separate category. The group is currently used in a narrower sens ...

n *''

Canadaspis ''Canadaspis'' ("Shield of Canada") is an extinct genus of bivalved Cambrian arthropod, known from North America and China. They are thought to have been benthic feeders that moved mainly by walking and possibly used its biramous appendages to s ...

perfecta'' - hymenocarine *'' Dicerocaris opisthoeces'' *''

Emeraldella ''Emeraldella'' is a genus of arthropod known from the Middle Cambrian of North America. The type species ''E. brocki'' was described in 1912 from the Burgess Shale. 21 specimens of ''Emeraldella'' are known from the Greater Phyllopod bed, where ...

brocki'' - vicissicaudatan *''

Isoxys ''Isoxys'' (meaning "equal surfaces") is a genus of extinct bivalved Cambrian arthropod; the various species of which are thought to have been freely swimming predators. It had a pair of large spherical eyes (which are the most commonly preserv ...

'' *''

Perspicaris ''Perspicaris'' (from the Latin ''perspicax'', meaning “sharp-sighted,” and ''caris'', “crab/shrimp”) an extinct genus of bivalved arthropod from the Cambrian period. Fossils have been found in North America, primarily the Burgess Shale ...

dilatus'' hymenocarine *''

Pseudoarctolepis ''Pseudoarctolepis'' is an extinct genus of bivalved arthropod known from the Cambrian The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambri ...

sharpi'' - possible hymenocarine *''

Tuzoia ''Tuzoia'' (from Mount Tuzo, a mountain in the Canadian Rockies) is an extinct genus of large bivalved arthropod known from Early to Middle Cambrian marine environments from what is now North America, Australia, China, Europe and Siberia. The lar ...

''? ''peterseni'' hymenocarine *''

Waptia ''Waptia fieldensis'' is an extinct species of arthropod from the Middle Cambrian Burgess Shale ''Lagerstätte'' of Canada. It grew to a length of , and had a large bivalved carapace and a segmented body terminating into a pair of tail flaps. It ...

'' ''fieldensis'' hymenocarine *''

Alalcomenaeus ''Alalcomenaeus'' is one of the most widespread and longest-surviving arthropod genera of the Early and Middle Cambrian. Known from over 300 specimens in the Burgess Shale and the Chengjiang biota. it is a member of the group Megacheira. Morphol ...

cambricus'' - megacheiran; or alalcomenaeid *'' Dicranocaris guntherorum'' - megacheiran; or alalcomenaeid *unnamed 'Molli Sonia symmetrica' *''

Leanchoilia ''Leanchoilia'' is an megacheiran arthropod known from Cambrian deposits of the Burgess Shale in Canada and the Chengjiang biota of China. It was about long and had long, whip-like feelers mounted on frontal arm-like appendages. Its internal ...

'' superlata - megacheiran *''

Sidneyia ''Sidneyia'' is an extinct arthropod known from fossils found from the Early Cambrian-age Maotianshan Shales to the Mid Cambrian Burgess Shale formation of British Columbia. 144 specimens of ''Sidneyia'' are known from the Greater Phyllopod bed, ...

inexpectans'' - vicissicaudatan

Dinocaridida DinocarididaGreek, "Terrible crabs" – sometimes informally spelt Dinocarida, but the second 'id' is linguistically correct – see is a proposed fossil taxon of basal arthropods that flourished in the Cambrian period with occasional Ordovici ...

*''

Amplectobelua ''Amplectobelua'' (meaning "embracing beast") is an extinct genus of late Early Cambrian amplectobeluid radiodont, a group of stem arthropods that mostly lived as free-swimming predators during the first half of the Paleozoic Era. Anatomy Th ...

'' cf. ''A. stephenensis'' –

radiodont Radiodonta is an extinct order of stem-group arthropods that was successful worldwide during the Cambrian period. They may be referred to as radiodonts, radiodontans, radiodontids, anomalocarids, or anomalocaridids, although the last two original ...

Anomalocarididae Anomalocarididae (occasionally mis-spelt Anomalocaridae) is an extinct family of Cambrian radiodonts, a group of stem-group arthropods. Around 1990s and early 2010s, Anomalocarididae included all radiodont species, hence the previous equivalen ...

gen. et sp. nov. - radiodont *'' Buccaspinea cooperi''? - radiodont *''

Caryosyntrips ''Caryosyntrips'' ("nutcracker") is an extinct genus of radiodont which known from Canada, United States and Spain during the middle Cambrian. ''Caryosyntrips'' is known only from its 14-segmented frontal appendages, which resemble nutcrackers, ...

durus'' - radiodont *''Caryosyntrips serratus'' - radiodont *''

Peytoia nathorsti ''Peytoia'' is a genus of hurdiid radiodont that lived in the Cambrian period, containing two species, ''Peytoia nathorsti'' from the Miaolingian of Canada and '' Peytoia infercambriensis'' from Poland, dating to Cambrian Stage 3. Its two front ...

'' - radiodont *''

Pahvantia ''Pahvantia'' is an extinct genus of hurdiid radiodont from the Cambrian. It is known by a single species, ''Pahvantia hastata'', described from Wheeler Shale and Marjum Formation in Utah. Although it was once considered as filter feeder using large ...

hastata'' - radiodont *''

Stanleycaris ''Stanleycaris'' is an extinct, monotypic genus of hurdiid radiodont from the middle Cambrian (Miaolingian). The type species is ''Stanleycaris hirpex''. ''Stanleycaris'' was described from the Stephen Formation near the Stanley Glacier and Bu ...

'' sp. - radiodont *''

Utaurora ''Utaurora'' is an extinct genus of opabiniid, which were bizarre stem-arthropods closely related to true arthropods and radiodonts; the type species is ''U. comosa''. The animal's fossils come from the Cambrian of Utah. This genus is so far ...

comosa -''

opabiniid Opabiniidae is an extinct family of bizarre marine stem-arthropods. Its type and best-known genus is ''Opabinia''. It also contains ''Utaurora''. Opabiniids closely resemble radiodonts, but their frontal appendages were basally fused into a prob ...

Trilobita Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the At ...

*''

compacta'' - naraoiid nectaspid *'' Hypagnostus parvifrons'' - agnostid *''

Peronopsis ''Peronopsis'' (meaning "broach-like" or possibly "boot-like") is a genus of trilobite restricted to the Middle Cambrian. Its remains have been found in Asia, Australia, Europe, and North America. Etymology The subgenus ''Svenax'' is a cont ...

amplaxis'' - peronopsid agnostid *''Peronopsis bidens'' *''Peronopsis fallax'' *''Peronopsis gaspensis'' *''Peronopsis intermedius'' *''Peronopsis interstrictus'' *''Peronopsis montis'' *''Peronopsis segmentis'' *''

'' (= ''Acidusus atavus'') - ptychagnostid agnostid *''

Ptychagnostus ''Ptychagnostus'' is a member of the agnostida that lived during the Cambrian The Cambrian Period ( ; sometimes symbolized Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 mi ...

germanus'' *''Ptychagnostus gibbus'' *P''tychagnostus intermedius'' *''Ptychagnostus michaeli'' *''Ptychagnostus occultatus'' *''Ptychagnostus seminula'' *'' Glyphaspis concavus'' - asaphid *''

Bathyuriscus ''Bathyuriscus'' is an extinct genus of Cambrian trilobite. It was a nektobenthic predatory carnivore. The genus Bathyuriscus is endemic to the shallow seas that surrounded Laurentia. Its major characteristics are a large forward-reaching glabella ...

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 ''Zacanthoides'' is an extinct Cambrian genus of corynexochid trilobite. It was a nektobenthic predatory carnivore. Its remains have been found in Canada ( British Columbia, especially in the Burgess Shale, and Newfoundland), Greenland, Me ...

divergens'' - zacanthoidid corynexochid *''Zacanthoides sp.'' *'' Altiocculus harrisi'' - ptychopariid (specific name may be confused with ''Alokistocare'') *'' Alokistocare harrisi'' - alokistocarid ptychopariid *''

Asaphiscus ''Asaphiscus'' is a genus of trilobite that lived in the Cambrian. Its remains have been found in Australia and North America, especially in Utah. Distribution * A. wheeleri'' occurs in the Middle Cambrian of the United States (Delamaran, L ...

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 The Cambrian Warrior Formation is a mapped limestone bedrock unit in Pennsylvania. Description The Warrior Formation is described by Berg and others as gray, thin- to medium-bedded, fossiliferous, cyclic limestone bearing stromatolites, interbedde ...

*'' Elrathia kingii'' - alokistocarid ptychopariid *''Elrathia sp.'' *''

Elrathina Ptychoparioidea is a superfamily of the Ptychopariida order of trilobites.Pour M. G., Popov L. E. (2009) Silicified Middle Cambrian trilobites from Kyrgyzstan, Palaeontology, 1039-1056 Taxonomy *Family Acrocephalitidae *Family Alokistocaridae ...

wheeleri'' = ''Ptychoparella wheeleri''? - ptychopariid *'' Jenkinsonia varga'' *'' Modocia brevispina'' *''Modocia laevinucha'' *''Modocia typicalis'' *'' Ptychoparella sp.'' - ptychopariid *''Ptychoparella wheeleri'' *'' Spencella sp.'' - ptychopariid

Brachiopoda

*'' Acrothele subsidua''

Chordata A chordate () is an animal of the phylum Chordata (). All chordates possess, at some point during their larval or adult stages, five synapomorphies, or primary physical characteristics, that distinguish them from all the other taxa. These five ...

*''

Hertzina ''Hertzina'' is an extinct genus of conodonts in the family Furnishinidae Furnishinidae is an extinct family of conodonts in the order Paraconodontida. Genera Genera are: * †''Furnishina'' * †'' Muellerodus'' * †'' Proacodus'' * †'' ...

sp.'' -

conodont Conodonts ( Greek ''kōnos'', " cone", + ''odont'', " tooth") are an extinct group of agnathan (jawless) vertebrates resembling eels, classified in the class Conodonta. For many years, they were known only from their tooth-like oral elements, w ...

Cnidaria Cnidaria () is a phylum under kingdom Animalia containing over 11,000 species of aquatic animals found both in Fresh water, freshwater and Marine habitats, marine environments, predominantly the latter. Their distinguishing feature is cnidocyt ...

*'' Cambromedusa sp.'' -

jellyfish Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbrella- ...

Mollusca

*'' Pelagiella sp.'' - pelagiellid

helcionelloid Helcionellid or Helcionelliformes is an order of small fossil shells that are universally interpreted as molluscs, though no sources spell out why this taxonomic interpretation is preferred. These animals are first found about in the late Nemak ...

Echinodermata An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea ...

*'' Castericystis sprinklei'' -

carpoid Homalozoa is an obsolete extinct subphylum of Paleozoic era echinoderms, prehistoric marine invertebrates. They are also referred to as carpoids. Description The Homalozoa lacked the typical pentamer body form of other echinoderms, but all were ...

*''Castericystis sp.'' *''

Cothurnocystis ''Cothurnocystis'' is a genus of small enigmatic echinoderms that lived during the Ordovician. Individual animals had a flat boot-shaped body and a thin rod-shaped appendage that may be a stem, or analogous to a foot or a tail. Fossils of ''Cothu ...

sp.'' -

stylophora The stylophorans are an extinct, possibly polyphyletic group allied to the Paleozoic Era echinoderms, comprising the prehistoric cornutes and mitrates. It is synonymous with the subphylum Calcichordata. Their unusual appearances have led to a v ...

n *'' Ctenocystis sp.'' - ctenocystoid *'' Gogia spiralis'' - eocrinoid *Eocrinoid holdfasts believed to belong to ''Gogia spiralis''; may belong to other species

Porifera Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate throug ...

*''

Choia ''Choia'' is a genus of extinct demosponge ranging from the Cambrian until the Lower Ordovician periods. Fossils of ''Choia'' have been found in the Burgess Shale in British Columbia; the Maotianshan shales of China; the Wheeler Shale in Ut ...

carteri'' - choiid monaxonid

demosponge Demosponges (Demospongiae) are the most diverse class in the phylum Porifera. They include 76.2% of all species of sponges with nearly 8,800 species worldwide (World Porifera Database). They are sponges with a soft body that covers a hard ...

*''Choia utahensis'' *''

Crumillospongia ''Crumillospongia'' is a genus of middle Cambrian sponges known from the Burgess Shale and other localities from the Lower and Middle Cambrian. Its name is derived from the Latin ''crumilla'' ("money purse") and ''spongia'' ("sponge"), a reflec ...

sp.'' - hazeliid monaxonid demosponge *''

Diagonella ''Diagoniella'' is a genus of sponge known from the Middle Cambrian Burgess Shale. 128 specimens of ''Diagoniella'' are known from the Greater Phyllopod bed, where they comprise 0.24% of the community. References

Hexactinellida genera Pr ...

sp.''

Priapulida Priapulida (priapulid worms, from Gr. πριάπος, ''priāpos'' ' Priapus' + Lat. ''-ul-'', diminutive), sometimes referred to as penis worms, is a phylum of unsegmented marine worms. The name of the phylum relates to the Greek god of fertilit ...

*''

Ottoia ''Ottoia'' is a stem-group archaeopriapulid worm known from Cambrian fossils. Although priapulid-like worms from various Cambrian deposits are often referred to ''Ottoia'' on spurious grounds, the only clear ''Ottoia'' macrofossils come from the ...

prolifica'' - a stem group and it was an

archaeopriapulid Archaeopriapulida is a group of priapulid-like worms known from Cambrian lagerstätte. The group is closely related to, and very similar to, the modern Priapulids. It is unclear whether it is mono- or polyphyletic. Despite a remarkable morphol ...

*''

Selkirkia ''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 The Phyllopod b ...

sp.'' -

*"Selkirkia willoughbyi" (Note: ''S. columbia'' is the only recognized species)

Unclassified

*''

sparsa'' - ?xenusiid

lobopod The lobopodians, members of the informal group Lobopodia (from the Greek, meaning "blunt feet"), or the formally erected phylum Lobopoda Cavalier-Smith (1998), are panarthropods with stubby legs called lobopods, a term which may also be used as ...

*''

Utahnax ''Utahnax vannieri'' is a genus of kerygmachelid lobopodian from the Drumian of Utah, either from the Marjum or Wheeler formation. Description ''Utahnaxs preserved section is roughly long, with at least eight pairs of ventral flaps simila ...

vannieri'' - stem-arthropod lobopod, also possible that is from

*'' Allonnia'' cf. ''tintinopsis'' - a

chancelloriid The Chancelloriids are an extinct family of superficially sponge-like animals common in sediments from the Early Cambrian to the early Late Cambrian. Many of these fossils consists only of spines and other fragments, and it is not certain that t ...

*''

Chancelloria ''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 Charle ...

pentacta'' -

coeloscleritophoran, perhaps a

sponge Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate throug ...

? *''

Eldonia ''Eldonia'' is an extinct soft-bodied cambroernid animal of unknown affinity, best known from the Fossil Ridge outcrops of the Burgess Shale, particularly in the 'Great ''Eldonia'' layer' in the Walcott Quarry. In addition to the 550 collected by ...

sp.'' - eldoniid

paropsonemid ''Paropsonema'' is a discoidal animal known from the Cambrian Chengjiang biota and classified with the eldoniid Eldoniids are an extinct clade of enigmatic disc-shaped animals which lived in the early to middle Paleozoic (Cambrian to Devonian). ...

cambroernid The cambroernids are an informally-named clade of unusual Paleozoic animals with coiled bodies and filamentous tentacles. They include a number of early to middle Paleozoic (Cambrian to Devonian) genera noted as 'bizarre" or "orphan" taxa, meani ...

*''

Skeemella clavula ''Skeemella clavula'' is an elongate animal from what is now the Middle Cambrian Wheeler Shale lagerstätte, of Utah. It has been classified with the vetulicolians VetulicoliaThe taxon name, Vetulocolia, is derived from the type genus, ''Vetul ...

'' - Possible

vetulicolia VetulicoliaThe taxon name, Vetulocolia, is derived from the type genus, ''Vetulicola'', which is a compound Latin word composed of ''vetuli'' "old" and ''cola'' "inhabitant". is a taxon (either phylum or subphylum in rank) encompassing several ex ...

n *'' Hylolithellus sp.'' -

annelid The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecol ...

? *''

corrugata'' -

halwaxiid Halwaxiida or halwaxiids is a proposed clade equivalent to the older orders Sachitida He 1980 and Thambetolepidea Jell 1981, loosely uniting scale-bearing Cambrian animals, which may lie in the stem group to molluscs or lophotrochozoa. Some pala ...

lophotrochozoa Lophotrochozoa (, "crest/wheel animals") is a clade of protostome animals within the Spiralia. The taxon was established as a monophyletic group based on molecular evidence. The clade includes animals like annelids, molluscs, bryozoans, bra ...

n *'' Yuknessia simplex'' - pterobranch *''

Margaretia ''Margaretia'' is a frondose organism known from the middle Cambrian Burgess shale and the Kinzers Formation of Pennsylvania. Its fronds reached about 10 cm in length and are peppered with a range of length-parallel oval holes. It was ori ...

dorus'' - possibly organic tube associated with

hemichordate Hemichordata is a phylum which consists of triploblastic, enterocoelomate, and bilaterally symmetrical marine deuterostome animals, generally considered the sister group of the echinoderms. They appear in the Lower or Middle Cambrian and inclu ...

References

{{Cambrian preservational modes Geologic formations of Utah Cambrian System of North America Cambrian geology of Utah Paleontology in Utah