Trilobites of the Mural Formation



Mural Formation (= Tah Formation), Lower Cambrian, Cinnamon Peak-Whitehorn Mountain, Mumm Peak, and type Tah, B.C./Alberta border area, (Mount Robson Provincial Park and Jasper National Park), Rocky Mountains, Canada:


Medial Bonnia-Olenellus Zone:


Gabriellus lanceatus Fritz, 1992

Proliostracus sp. (see Fritz, 1992)

Labradoria? sp. (see Fritz, 1992)

Bonnia sp. (see Fritz, 1992)

Olenellus sp. cf. O. laxocules Fritz, 1972

Mummaspis sp. cf. M. oblisooculatus Fritz, 1992

Proliostracus contractus Fritz, 1972


Lower Bonnia-Olenellus Zone:


Mummaspis oblisooculatus Fritz, 1992

Olenellus truncatooculatus Fritz, 1992

Olenellus muralensis Fritz, 1992

Laudonia bispinata Harrington, 1956

Olenellus truemani Walcott, 1913

Mummaspis occidens (Walcott, 1913)

Laudonia amputata Fritz, 1992

Olenellus sp. (see Fritz, 1992)


------Boundary between Nevadella and Bonnia-Olenellus Zones------


Upper Nevadella Zone:


Nevadella perfecta (Walcott, 1913)

Nevadella eucharis (Walcott, 1913)

Nevadella mountjoyi Fritz, 1992 (see also Lieberman, 2001)

Nevadia parvoconica Fritz, 1992

Nevadia n. sp. (see Fritz, 1992)

Nevadia weeksi Walcott, 1910

Gen. aff. Bradyfallotaspis sp. (see Fritz, 1992)

Gen. aff. Judomia sp. (see Fritz, 1992)

Nevadia sp. (see Fritz, 1992)

Mickwitzia? sp. (see Fritz, 1992)

Helcionella sp. (see Fritz, 1992)


Nevadella Zone, near Geraldine Lakes, Jasper National Park, Alberta:


Cirquella espinata Fritz, 1993

Geraldinella corneiliana Fritz, 1993





The Mural Formation outcrops in the Rocky Mountains in Mt. Robson Provincial Park and Jasper National Park in the Alberta-British Columbia border area. Almost all known outcrops are in Canada's Rocky Mountain Parks, so collecting is forbidden. This Formation is bounded below by the McNaughton Formation, and above by the Mahto Formation. The boundary between the Nevadella and Bonnia-Olenellus Zones falls in the medial member of the Mural Formation. The Mural is 805 feet thick at the type Tah section, and consists of a basal limestone unit, a medial siltstone, and an upper dolomite unit. Some regional North American correlations with the Mural Formation may be:  Sekwi Fm., MacKenzie Mountains; the Cassier Mountains; Mural Fm., Cariboo Mountains; Poleta Fm., Slate Ridge, Nevada; Poleta Fm., White-Inyo Mountains, California; and the Puerto Blanco Fm. (and maybe Buelna Fm.), Carborca area, Mexico.


Note: -Walcott’s 1913 61K locality, Mount Robson area falls within the Lower Bonnia-Olenellus Zone and the upper part of the Upper Nevadella Zone (from the Nevadella eucharis subzone to the Mummaspis oblisooculatus subzone (see Fritz, 1992)


Note: -Olenellus robsonensis is debated and is suggested (by Fritz, 1992) to come from a higher horizon, probably within the Mahto Fm.





Lieberman, B. S. (2002) Phylogenetic analysis of some basal early Cambrian trilobites, the biogeographic origins of the Eutrilobita, and the timing of the Cambrian radiation. Journal of Paleontology, Vol. 76, No. 4, pp. 692-708.


Fritz, W. H. (1993) New Lower Cambrian olenelloid trilobite genera Cirquella and Geraldinella from southwestern Canada. Journal of Paleontology, V. 67(5), pp. 856-868.


Fritz, W. H. (1992) Walcott's Lower Cambrian olenellid trilobite collection 61K, Mount Robson area, Canadian Rocky Mountains. Geological Survey of Canada, Bulletin 432, 65 pp.


Fritz, W. H. (1972) Lower Cambrian trilobites from the Sekwi Formation type section, Mackenzie Mountains, northwestern Canada. Geological Survey of Canada, Bulletin 212, 90 pp.


Fritz, W. H. and Mountjoy (1975)  Lower and Early Middle Cambrian Formations near Mt. Robson, British Columbia and Alberta. Canadian Journal of Earth Sciences, Volume 12, No. 2, pp. 119-131

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