The Mount Stephen trilobite beds (UNSM locality 14s) are a series of fossil strata on

Mount Stephen Mount Stephen, , is a mountain located in the Kicking Horse River Valley of Yoho National Park, km east of Field, British Columbia, Canada. The mountain was named in 1886 for George Stephen, the first president of the Canadian Pacific Railway. ...

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

that contain exceptionally preserved fossil material. Part of the same stratigraphic unit as the

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 foss ...

deposit, many non-mineralized parts (such as

anomalocarid 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 origi ...

claws, sponges, and

trilobite 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 ...

legs) are preserved; in addition, a high density of trilobite fossils is present.

History

The trilobite beds were the first

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 foss ...

locality to be discovered. The richness of fossils in the Field area was first identified by workers associated with the construction of the Trans-Canada railway, which had (somewhat controversially) been routed through the Kicking Horse valley. Richard McConnell, of the Geological Survey of Canada, was pointed to the beds by a railway worker whilst mapping the geology around the railway line in September 1886. Several unusual fossils were subsequently described from this site, including sponges, worms, and the appendages of the unusual ''Anomalocaris'', identified at that time as the bodies of crabs. These fossils prompted Charles Doolittle Walcott to make forays into the area, and led to his discovery of the

Walcott Quarry The Walcott Quarry is the most famous quarry of the Middle Cambrian Burgess Shale, located in the Canadian Rockies of British Columbia, bearing the Phyllopod beds. This lies at the base of the Walcott Quarry member, on a ridge between Wapta Mou ...

on Fossil Ridge.

Stratigraphy

The trilobite beds are in the Campsite Cliff member, and contain the marker trilobite ''

Ogygopsis ''Ogygopsis'' is a genus of trilobite from the Cambrian of Antarctica and North America, specifically the Burgess Shale. It is the most common fossil in the Mt. Stephen fossil beds there, but rare in other Cambrian faunas. Its major characteristi ...

''.

Location

The strata are located on Mount Stephen in British Columbia.

References

Paleozoic paleontological sites of North America Yoho National Park Paleontology in Canada Cambrian paleontological sites {{trilobite-stub