Trilobite (Irvingella species B) & an unnamed species - Bull River Valley, Cranbrook, British Columbia, Canada

This Canadian specimen has two special trilobites. The larger trilobite is Irvingella (species B). It has not yet been fully described - hence the odd name - while the smaller one has not be named at all and is new to science. The specimen was recently been collected from the Upper Cambrian McKay Group in the Bull River Valley, east of Cranbrook and Fort Steele, BC.

The Irvingella is 1.25 cm long and shows several of its diagnostic spines. Both pleural (lower thoraic) spines are present and well-defined. The left pleural (cephalon or head) spine is present and prominent while the right side is either missing or still hidden within the slate matrix. All three body segments (cephalon, thorax and pygidium) are all complete with good definition. The smaller, complete trilobite is also complete with some interesting features (note the tiny pygidial spines emanating from the tail). Compare and contrast the cephalons of both trilobites as there are notable differences between them. This fossil has great three-dimensionality to it (please see all photos) and is certainly not a flatten smudge. Additionally, the plate shows a feature appearing to layover the smaller, unnamed trilobite. This is interpreted to be a burrow but is difficult to be certain. Between the two complete trilobites is a piece of yet another. Again, I am not certain but I believe this to be a partial cephalon (head) to an agnostid trilobite but I could be wrong. There is much here to investigate under further magnification!

British Columbia fossils are illegal to sell, except under special circumstances. I represent a team that has claims on several trilobite localities in BC that have been legally grandfathered into older legislation. This allows them to legally excavate, prepare and sell fossils from these particular claims, including this specimen. Mostly, they collect for themselves and only sell specimens to fund their collecting expenses. They simply love fossils and field collecting. Additionally, they have done a terrific job allowing the scientific community and local fossil clubs and school groups onto their claims for research, collecting and education. In my opinion, they are going above and beyond any legal requirements. As the Star Wars character The Mandalorian says, this is the way. 

For those interested in learning more about the trilobites of the McKay Group I recommend the following scientific paper: Furongian (Upper Cambrian) trilobites from the McKay Group, Bull River Valley, near Cranbrook, southeastern British Columbia, Canada (2016) by Brian D. E. Chatterton and Stacey Gibb in Palaeontographica Canadiana No 35. It is jointly published by the Canadian Society of Petroleum Geologists (now known as the Canadian Energy Geoscience Association) and the Geological Association of Canada.

Fossil: Trilobite
Species: Irvingella (species B) & an unnamed species
Age: Upper Cambrian
Formation: McKay Group
Locality: Bull River Valley, East of Cranbrook, British Columbia, Canada
Dimensions: Largest trilobite size: 1.25cm long
Plate size: 15 x 12 cm