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The Marjum Formation is a Cambrian geological formation that overlies the Wheeler Shale in the House Range, Utah.[1][3] It is named after its type locality, Marjum Pass, and was defined in 1908.[2] The formation is known for its occasional preservation of soft-bodied tissue, and is slightly younger than the Burgess Shale,[4] falling in the Ptychagnostus praecurrens trilobite zone.[5]
Marjum Formation | |
---|---|
Stratigraphic range: Middle Cambrian | |
Type | Geological formation |
Overlies | Wheeler Shale |
Thickness | Up to 430 meters[1] |
Lithology | |
Primary | limestone |
Other | shale, metasedimentary rocks |
Location | |
Region | Utah |
Country | USA |
Extent | House Range |
Type section | |
Named for | Marjum Pass[2] |
Named by | Charles D. Walcott |
Year defined | 1908[2] |
Color key
|
Notes Uncertain or tentative taxa are in small text; |
Ambulacrarians reported from the Marjum Formation | |||||
---|---|---|---|---|---|
Genus | Species | Presence | Material | Notes | Images |
Castericystis | C. vali | Numerous specimens.[6] | A solutan. | ||
Eldonia | E. ludwigi | Marjum Pass (Ptychagnostus punctuosus Zone).[7] | SM X.50204.1 (part) & SM X.50204.2 (counterpart).[7] | A cambroernid. | |
Marjumicystis | M. mettae | 7 specimens.[6] | An eocrinoid. | ||
Mastigograptus | M. sp. | A single specimen.[8] | A mastigograptid graptolite. | ||
Totiglobus | T.? lloydi | Locality 811.[9] | 1 specimen (USNM 172047).[9] | An edrioasteroid. | |
Arthropods reported from the Marjum Formation | |||||
---|---|---|---|---|---|
Genus | Species | Presence | Material | Notes | Images |
Anomalocaris | A. nathorsti | Sponge Gully.[10] | Partial body (USNM 374593).[10] | Species moved to the genus Peytoia. | |
Asaphiscus | A. wheeleri | Bathyuriscus fimbriatus Subzone.[11] | A ptychopariid trilobite. | ||
Baltagnostus | B. eurypyx | All subzones of the Bolaspidella Zone.[11] | Multiple specimens.[11] | A diplagnostid trilobite. | |
Bathyuriscidella | B. aff. B. amplicauda | Bolaspidella contracta Subzone.[11] | 3 pygidia.[11] | A dolichometopid trilobite. | |
Bathyuriscus | B. elegans | Bolaspidella contracta Subzone.[11] | Numerous specimens.[11] | A dolichometopid trilobite. | |
B. fimbriatus | Bathyuriscus fimbriatus & lower Bolaspidella contracta Subzone.[11] | Numerous specimens.[11] | A dolichometopid trilobite. | ||
Bolaspidella | B. contracta | Bolaspidella contracta & lower Lepojyge calva Subzones.[11] | A menomoniid trilobite. | ||
B. housensis | Bathyuriscus fimbriatus Subzone.[11] | A menomoniid trilobite. | |||
B. jarrardi | Localities 347, 391, and 716 (mid-Bolaspidella Zone).[12] | Multiple specimens.[12] | A menomoniid trilobite. | ||
Branchiocaris | B. pretiosa | Sponge Gully.[10][13] | 3 specimens.[10] | A hymenocarine. | |
Buccaspinea | B. cooperi | Kells Knolls locality.[14] | An almost complete specimen (BPM 1108).[14] | A hurdiid, originally reported as Hurdia sp. | |
Burlingia | B. halgedahlae | Localities 347 and 716 (mid-Bolaspidella Zone).[12] | Multiple specimens.[12] | A burlingiid trilobite. | |
Caryosyntrips | C. camurus | 'Red Wash' locality.[14] | 2 isolated frontal appendages.[14] | A panarthropod of uncertain classification. | |
Cotalagnostus | C. laevus | Bolaspidella contracta Subzone.[11] | Over 50 specimens.[11] | A diplagnostid trilobite. | |
C. sp. | Bolaspidella contracta Subzone.[11] | A pygidium. | A diplagnostid trilobite. | ||
Dicranocaris | D. guntherorum | Red Wash, Modocia Flats & Sponge Gully.[13] | 4 specimens.[13] | An arthropod of uncertain classification. | |
Dytikosicula | D. desmatae | West of Delta, House Range.[7] | 1 specimen (SM X.50203).[7] | A putative megacheiran. | |
Elrathia | E. alapyge | Bolaspidella contracta & Lejopyge calva Subzones.[11] | Numerous specimens.[11] | A ptychopariid trilobite. | |
E. marjumi | Bathyuriscus fimbriatus & Bolaspidella contracta Subzones.[11] | Numerous specimens.[11] | A ptychopariid trilobite. | ||
Emeraldella | E.? sp. | Red Wash.[10] | Part & counterpart (KUMIP 204791).[10] | An artiopod. | |
Hemirhodon | H. amplipyge | Bolaspidella contracta Subzone.[11] | 14 incomplete specimens.[11] | A dolichometopid trilobite. | |
Holteria | H. problematica | Marjum Pass (Lejopyge calva Subzone).[11] | A pygidium.[11] | A corynexochid trilobite. | |
Homagnostus | H. incertus | Bolaspidella contracta Subzone.[11] | Multiple specimens.[11] | An agnostid trilobite. | |
Hypagnostus | H. parvifrons | All subzones of the Bolaspidella Assemblage Zone.[11] | Numerous specimens.[11] | A diplagnostid trilobite. | |
Itagnostus | I. interstrictus | House Range.[15] | A peronopsid trilobite originally reported as Peronopsis interstricta. | ||
Leanchoilia | L.? cf. protogonia | Sponge Gully.[13] | Part & counterpart of a complete specimen (UU 06011.01).[13] | A megacheiran. | |
Lejopyge | L. calva | Marjum Pass (Lejopyge calva Subzone).[11] | Numerous specimens.[11] | A ptychagnostid trilobite. | |
Linguagnostus | L. perplexus | Bolaspidella contracta Subzone.[11] | Over 20 specimens.[11] | A diplagnostid trilobite. | |
Marjumia | M. callas | Bolaspidella contracta Subzone.[11] | A marjumiid trilobite. | ||
M. typa | Bolaspidella contracta Subzone.[11] | A marjumiid trilobite. | |||
Modocia | M. laevinucha | Bathyuriscus fimbriatus & Bolaspidella contracta Subzones.[11] | Many specimens.[11] | A marjumiid trilobite. | |
M. nuchaspina | Bolaspidella contracta Subzone.[11] | A marjumiid trilobite. | |||
M. typicalis | 50 or more specimens.[11] | A marjumiid trilobite. | |||
Naraoia | N. compacta | Sponge Gully.[16] | 4 specimens.[16] | A naraoiid. | |
Neolenus | N. inflatus | East of Antelope Springs.[17] | Multiple specimens & fragments.[17] | A trilobite. | |
N. intermedius | East of Antelope Springs.[17] | A trilobite. | |||
N. intermedius pugio | East of Antelope Springs.[17] | 4 specimens of a pygidium.[17] | A trilobite. | ||
N. superbus | East of Antelope Springs.[17] | Multiple specimens & fragments.[17] | A trilobite. | ||
Nettapezoura | N. basilika | Sponge Gully.[13] | An arachnomorph. | ||
Olenoides | O. decorus | Bolaspidella contracta Subzone.[11] | 7 specimens.[11] | A dorypygid trilobite. | |
O. inflatus | Bolaspidella contracta Subzone.[11] | A dorypygid trilobite. | |||
O. marjumensis | Bolaspidella contracta Subzone.[11] | A dorypygid trilobite. | |||
O. pugio | Bolaspidella contracta Subzone.[11] | Numerous specimens.[11] | A dorypygid trilobite. | ||
O. superbus | Bolaspidella contracta Subzone.[11] | 7 specimens.[11] | A dorypygid trilobite. | ||
Pahvantia | P. hastata | Precise localities unknown.[14] | 3 specimens.[14] | A hurdiid. | |
Peronopsis | P. interstricta | House Range.[15] | Numerous specimens.[11] | Reassigned to the genus Itagnostus. | |
P. segmenta | House Range.[15] | Multiple specimens.[11] | A peronopsid trilobite. | ||
Perspicaris | P.? ellipsopelta | Ptychagnostus punctuosus Zone.[18] | Valves & carapaces.[18] | A bivalved arthropod. | |
Peytoia | P. nathorsti | Sponge Gully.[10] | Partial body (USNM 374593) & partial mouthpart (KUMIP 314095).[19] | A hurdiid, formerly named Anomalocaris nathorsti. | |
Ptychagnostus | P. akanthodes | Bolaspidella contracta Subzone.[11] | Numerous specimens.[11] | A ptychagnostid trilobite. | |
P. atavus | House Range.[15] | A ptychagnostid trilobite. | |||
P. hybridus | Bolaspidella contracta Subzone.[11] | About 10 specimens.[11] | A ptychagnostid trilobite. | ||
P. richmondensis | Bathyuriscus fimbriatus Subzone.[11] | Numerous specimens.[11] | A ptychagnostid trilobite. | ||
P. sp. | Bolaspidella contracta Subzone.[11] | At least 5 pygidia. | A ptychagnostid trilobite. | ||
Trymataspis | T. depressa | Bolaspidella contracta Subzone.[11] | Over 30 specimens.[11] | A lonchocephalid trilobite. | |
T. lomaleie | Bolaspidella contracta Subzone.[11] | 10 cranidia.[11] | A lonchocephalid trilobite. | ||
T. pristina | Bolaspidella contracta Subzone.[11] | Over 20 cranidia.[11] | A lonchocephalid trilobite. | ||
Tuzoia | T. guntheri | Ptychagnostus punctuosus Zone.[18] | Multiple valves & carapaces.[18][20] | A hymenocarine. | |
Utagnostus | U. trispinulus | Bolaspidella contracta & Lejopyge calva Subzones.[11] | Multiple specimens.[11] | An agnostid trilobite. | |
Utaspis | U. marjumensis | House Range & Wheeler Amphitheater.[11] | A ptychopariid trilobite. | ||
Zacanthoides | Z. sp. | Wheeler Amphitheater (Bolaspidella contracta Subzone).[11] | A cranidium.[11] | A zacanthoidid trilobite. |
Chancelloriids reported from the Marjum Formation | |||||
---|---|---|---|---|---|
Genus | Species | Presence | Material | Notes | Images |
Chancelloria | C. sp. | Bathyuriscus fimbriatus & Bolaspidella contracta Subzones.[11] | About 20 spicules.[11] | A chancelloriid. | |
Chordates reported from the Marjum Formation | |||||
---|---|---|---|---|---|
Genus | Species | Presence | Material | Notes | Images |
Megasiphon | M. thylakos | House Range.[21] | One specimen (UMNH.IP.6079).[21] | A tunicate. | |
Nuucichthys | N. rhynchocephalus | House range.[22] | One specimen (UMNH.IP.6084)[22] | A basal chordate related to Metaspriggina. | |
Skeemella | S. clavula | North of Red Wash (Ptychagnostus punctuosus Biozone).[23] | 2 specimens (KUMIP 314102 & KUMIP 314103).[23] | A vetulicolian. | |
Moon, Caron & Moysiuk (2023) considered these fossils would be ctenophores instead.[24]
Cnidarians reported from the Marjum Formation | |||||
---|---|---|---|---|---|
Genus | Species | Presence | Material | Notes | Images |
Coronatae? | Indeterminate | Sponge Gully.[25] | 1 specimen (UU07021.05).[25] | A scyphozoan jellyfish, may be referrable to the crown jellyfish family. | |
Cubozoa? | Indeterminate | Sponge Gully.[25] | 2 specimens (UU07021.01 & UU07021.02).[25] | Specimens possibly referrable to box jellyfish. | |
Narcomedusae? | Indeterminate | Sponge Gully.[25] | 5 specimens (UU07021.03, UU07021.04, UU07021.06, UU07021.07 & UU07021.08).[25] | A hydrozoan tentatively assigned to this family. | |
Semaeostomeae? | Indeterminate | Sponge Gully.[25] | 2 specimens (UU07021.09 & UU07021.10).[25] | A scyphozoan jellyfish tentatively assigned to this family. | |
Ctenophores reported from the Marjum Formation | |||||
---|---|---|---|---|---|
Genus | Species | Presence | Material | Notes | Images |
Ctenorhabdotus | C. campanelliformis | House Range (likely from the lower Ptychagnostus punctuosus Zone).[26] | 1 specimen (UMNH.IP.6125).[26] | A ctenophore. | |
Thalassostaphylos | T. elegans | House Range (lower Ptychagnostus punctuosus Zone).[26] | 1 specimen (UMNH.IP.6086).[26] | A ctenophore. | |
Lophotrochozoans reported from the Marjum Formation | |||||
---|---|---|---|---|---|
Genus | Species | Presence | Material | Notes | Images |
Acrothele | A. subsidua | Bathyuriscus-Elrathina & Bolaspidella Zones.[11] | A brachiopod. | ||
Helcionella | "H." arguta | Bathyuriscus fimbriatus & Bolaspidella contracta Subzones.[11] | More than 100 specimens.[11] | A helcionellid. | |
Hyolithes | H. sp. | All subzones of the Bolaspidella Zone.[11] | More than 100 specimens.[11] | A hyolith. | |
Lingulella | L. sp. | Bathyuriscus fimbriatus & Bolaspidella contracta Subzones.[11] | An obolid brachiopod. | ||
Micromitra | M. modesta | Multiple specimens.[11] | A paterinide brachiopod. | ||
Nisusia | N. sulcata | 18 specimens.[27] | A kutorginate brachiopod. | ||
Pegmatreta | P. bellatula | Bathyuriscus fimbriatus & Bolaspidella contracta Subzones.[11] | Numerous specimens.[11] | A brachiopod. | |
P. ophirensis | All subzones of the Bolaspidella Zone.[11] | A brachiopod. | |||
Pelagiella | P. sp. | Bolaspidella contracta Subzone.[11] | More than 50 internal molds.[11] | A pelagiellid. | |
Prototreta | P. attenuata | Bathyuriscus-Elrathina Zone & Bolaspidella Zone.[11] | A brachiopod. | ||
P. mimica | Bolaspidella contracta Subzone.[11] | A brachiopod. | |||
Stenothecoides | S. elongata | Bathyuriscus fimbriatus Subzone.[11] | Over 30 valves.[11] | A stenothecoid. | |
Scalidophorans reported from the Marjum Formation | |||||
---|---|---|---|---|---|
Genus | Species | Presence | Material | Notes | Images |
Arrakiscolex | A. aasei | Grey Marjum locality (Ptychagnostus punctuosus Zone).[28] | Cuticle fragments.[28] | A palaeoscolecid also known from the Upper Weeks Formation. | |
Ottoia | O. prolifica | Sponge Gully.[5] | A complete individual (KUMIP 204770).[5] | Referral of the specimen to this species is insecure, better classified as O.? sp.[28][29] | |
O.? sp. | Sponge Gully.[28] | A complete individual (KUMIP 204770).[28] | A stem-priapulid, specimen formerly referred to Ottoia prolifica or Scathascolex minor.[28] | ||
Scathascolex | S. minor | Sponge Gully.[5] | A complete individual (KUMIP 204770).[5][30] | Specimen reassigned to Ottoia? sp.[28] | |
Selkirkia | S. willoughbyi | Sponge Gully.[5] | Tube with associated soft parts (KUMIP 204788).[5] | A stem-priapulid. | |
Sponges reported from the Marjum Formation | |||||
---|---|---|---|---|---|
Genus | Species | Presence | Material | Notes | Images |
Choia | C. carteri | Sponge Gulch.[31] | A demosponge. | ||
C. hindei | Red Cliffs Wash.[31] | 2 specimens & 3 other fragments.[31] | A demosponge. | ||
C. utahensis | Sponge Gulch.[31] | Several specimens.[31] | A demosponge. | ||
Diagoniella | D. cyathiformis | Red Cliffs Wash & Kells Knolls Gulch.[31] | Numerous specimens.[31] | A reticulosan. | |
D. hindei | Sponge Gulch.[31] | Approximately 40 specimens.[31] | A reticulosan. | ||
D. magna | Kells Knolls Gulch (Bathyuriscus fimbriatus zone).[32] | A fragment (USNM 535922).[32] | A reticulosan. | ||
D. sp. | Sponge Gulch.[31] | 2 large fragments.[31] | A reticulosan. | ||
Hamptonia | H. bowerbanki | Red Cliffs Wash & Sponge Gulch.[31] | Multiple specimens.[31] | A demosponge. | |
Hazelia | H. palmata | Near Marjum Pass.[33] | One specimen.[33] | A demosponge. | |
Hintzespongia | H. bilamina | Kells Knolls Gulch (Bathyuriscus fimbriatus zone).[31][32] | Multiple specimens.[31][32] | A reticulosan. | |
Hexactinellida | Indeterminate | Miscellaneous spicules.[11] | Indeterminate glass sponges, originally reported as Hyalospongiae (now a junior synonym). | ||
Kiwetinokia | Drum Mountains.[31] | 4 large slabs.[31] | A reticulosan. | ||
Leptomitus | L. metta | Red Cliffs Wash locality.[31] | 22 specimens.[31] | A demosponge. | |
Protospongia | P.? elongata | Sponge Gulch.[31] | 1 specimen.[31] | A reticulosan. | |
Testiispongia | T. venula | Sponge Gulch.[31] | Several specimens.[31] | A glass sponge. | |
Valospongia | V. gigantis | Sponge Gulch.[31] | A reticulosan. | ||
V.? gigantus | Kells Knolls Gulch (Bathyuriscus fimbriatus zone).[32] | A fragment (USNM 535917).[32] | A reticulosan. |
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