But hidden within its rocky layers lies a much older and stranger world—one that predates dinosaurs by hundreds of millions of years. That world was once ruled by creatures known as trilobites.
What Are Trilobites?
Trilobites were marine arthropods that roamed the oceans for over 270 million years, from the Early Cambrian to the end of the Permian period.
These hard-shelled creatures looked a bit like a cross between a horseshoe crab and a pill bug, with segmented bodies, jointed legs, and a wide range of sizes and shapes. Over 20,000 species have been identified, making them one of the most diverse and successful early animal groups in Earth's history.
Their fossils are found all over the world—but some of the most remarkable specimens come from the ancient seabeds now uplifted and exposed in British Columbia.
Trilobites in BC: A Window Into the Cambrian Explosion
British Columbia holds a special place in the study of early life, particularly due to the world-renowned Burgess Shale fossil site in Yoho National Park. While the Burgess Shale is famous for preserving soft-bodied organisms, it also offers stunning examples of trilobites—often found with delicate spines and appendages intact, thanks to the unique preservation conditions.
The Burgess Shale trilobites date back to around 508 million years ago, during the Cambrian period—a time often referred to as the Cambrian Explosion due to the rapid diversification of complex life. Trilobites were among the most prominent creatures of this era, and their fossils help paleontologists understand how early ecosystems functioned.
Lower Cambrian Trilobites of the Eager Formation
Just east of Cranbrook, the Eager Formation preserves fossil assemblages from the Lower Cambrian—making it one of the oldest fossiliferous units in British Columbia. In a 2003 study, paleontologist Jean-Bernard Caron, along with co-authors, examined trilobite faunas from this formation, revealing a rich and diverse array of early trilobite life.
Among the trilobites described from the Eager Formation are:
Fritzaspis – A small, early trilobite representative of the Olenellid group.Mesonacis eagerensis – A species named after the formation itself, notable for its distinctive glabella (central lobe of the head).
Caron’s work emphasized the biostratigraphic and paleobiogeographic significance of these trilobites, helping to correlate the Eager Formation with other Lower Cambrian sites across Laurentia (ancient North America).
Upper Cambrian Trilobites of the McKay Group
While the Eager Formation provides insight into the dawn of trilobite history, the McKay Group, also near Cranbrook, offers a detailed look at Upper Cambrian trilobite evolution. This group of rock formations—consisting primarily of shales and limestones—preserves an abundant and diverse trilobite fauna.
It has been the collaborative efforts of Chris New, Chris Jenkins, Guy Santucci, Don Askew and Stacey Gibb that has helped open up the region — including finding and identifying many new species or firsts including Pseudagnostus securiger, a widespread early Jiangshanian species not been previously recorded from southeastern British Columbia.
Paleontologist Brian Chatterton has published extensively on trilobites from the McKay Group, identifying a wide range of species that highlight evolutionary trends and faunal turnover toward the end of the Cambrian period.
Some of the trilobite genera and species Chatterton documented include:
Pterocephalia norfordi – A species named in honor of paleontologist B.S. Norford, noted for its distinctive broad cephalon.
Elvinia roemeri – An elegant Upper Cambrian species found throughout western North America.
Calyptaulax – With its spiny thorax and well-defined segmentation, it is a striking example of late Cambrian trilobite morphology.
Prosaukia – Often used in Upper Cambrian biostratigraphy for correlation across regions.
Orygmaspis contracta – A widespread trilobite in the Upper Cambrian that helps paleontologists understand geographic distribution.
Honouring the People Behind the Fossils
British Columbia’s trilobite story isn’t just about ancient animals—it’s also about the people who help uncover them.
Several trilobite species from the McKay and Eager formations have been named in honour of those who contributed to their discovery and study:
Pterocephalia santuccii – Named after Guy Santucci, a life-long friend and hugely respected geologist with the Geological Survey of Canada whose fieldwork and geological mapping helped bring attention to fossil-rich sites in southeastern BC. He
Orygmaspis newi – Honours Chris New, a dedicated citizen scientist and fossil enthusiast whose field observations and fossil contributions have aided formal scientific research in the region.
Calyptaulax jenkinsi – Recognizes Chris Jenkins, a citizen scientist whose careful collection and documentation of trilobite specimens played a key role in expanding the known diversity of the McKay Group fauna.
These species highlight the collaborative nature of paleontology, where discoveries often come from a blend of academic research, geological expertise, and passionate individuals in the community.
Notable BC Trilobites Across Time
Across the Cambrian layers of BC, notable trilobites include:
Olenoides serratus – From the Middle Cambrian Burgess Shale, often preserved with soft tissues.
Wanneria walcottana – An Early Cambrian form found in various parts of BC.
Mesonacis eagerensis – A Lower Cambrian species from the Eager Formation.
Pterocephalia santuccii, Orygmaspis newi, and Calyptaulax jenkinsi – Upper Cambrian trilobites named in honor of key contributors to BC paleontology.
Together, these fossils span tens of millions of years, tracing the evolutionary arc of trilobites from their origins to their diversification.
The Science (and Art) of Fossil Hunting
While fossil collection is restricted in national parks like Yoho, some other Cambrian formations near Cranbrook, including parts of the McKay and Eager Formations, are accessible for scientific study and regulated collection. These regions continue to offer paleontologists new insights into trilobite diversity, ecology, and biogeography.
Trilobite fossils are not just scientifically valuable—they’re also incredibly beautiful. Their symmetry, segmentation, and sometimes intricate ornamentation have made them prized by collectors and natural history museums alike.
If you would like to see some of the amazing specimens collected in British Columbia, I recommend a visit to the Cranbrook History Centre. Located on the Traditional territory of the Ktunaxa First Nation, it offers a look at local recent history and a deep dive into the past with many exceptional Cambrian trilobites on display along with their arthropod brethren, Tuzoia and associated species. Their collections also boast a rather nice display of Devonian fish.
Why They Matter Today
Trilobites may be extinct, but they still teach us a lot. Their evolutionary history helps scientists track how life responded to ancient climate changes, mass extinctions, and the rise of predators. In a way, trilobites are time travelers—messengers from a vanished ocean world that still speaks to the challenges and wonders of life on Earth today.
So next time you're the ancient outcrops of our beautiful province, remember: beneath your boots may lie the fossilized remains of a once-thriving marine world—where trilobites crawled, burrowed, and thrived in seas long since vanished.
