TREASURES OF CANADA: TRENT RIVER PALAEONTOLOGY

Dan Bowen, Chair, VIPS, Trent River

The rocks that make up the Trent River on Vancouver Island were laid down south of the equator as small, tropical islands. They rode across the Pacific heading north and slightly east over the past 85 million years to where we find them today.

The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. And it is massive. At 103 million km2 (40 million sq mi), it is the largest tectonic plate and continues to grow fed by volcanic eruptions that piggyback onto its trailing edge.

This relentless expansion pushes the Pacific Plate into the North American Plate. The pressure subducts it beneath our continent where it then melts back into the earth. Plate tectonics are slow but powerful forces. 

The island chains that rode the plates across the Pacific smashed into our coastline and slowly built the province of British Columbia. And because each of those islands had a different origin, they create pockets of interesting and diverse geology.

It is these islands that make up the Insular Belt — a physio-geological region on the northwestern North American coast. It consists of three major island groups — and many smaller islands — that stretches from southern British Columbia up into Alaska and the Yukon. These bits of islands on the move arrived from the Late Cretaceous through the Eocene — and continues to this day.

The rocks that form the Insular Superterrane are allochthonous, meaning they are not related to the rest of the North American continent. The rocks we walk over along the Trent River are distinct from those we find throughout the rest of Vancouver Island, Haida Gwaii, the rest of the province of British Columbia and completely foreign to those we find next door in Alberta.

To discover what we do find on the Trent takes only a wee stroll, a bit of digging and time to put all the pieces of the puzzle together. The first geological forays to Vancouver Island were to look for coal deposits, the profitable remains of ancient forests that could be burned to the power industry.

Jim Monger and Charlie Ross of the Geological Survey of Canada both worked to further our knowledge of the complex geology of the Comox Basin. They were at the cutting edge of west coast geology in the 1970s. It was their work that helped tease out how and where the rocks we see along the Trent today were formed and made their way north.

We know from their work that by 85 million years ago, the Insular Superterrane had made its way to what is now British Columbia. 

The lands were forested much as they are now but by extinct genera and families. The fossil remains of trees similar to oak, poplar, maple and ash can be found along the Trent and Vancouver Island. We also see the lovely remains of flowering plants such as Cupanities crenularis, figs and breadfruit.

Heading up the river, you come to a delineation zone that clearly marks the contact between the dark grey marine shales and mudstones of the Haslam Formation where they meet the sandstones of the Comox Formation. Fossilized material is less abundant in the Comox sandstones but still contains some interesting specimens. Here you begin to see fossilized wood and identifiable fossil plant material.

Further upstream, there is a small tributary, Idle Creek, where you can find more of this terrestrial material in the sandy shales. As you walk up, you see identifiable fossil plants beneath your feet and jungle-like, overgrown moss-covered, snarly trees all around you.

Walking west from the Trent River Falls at the bottom, you pass the infamous Ammonite Alley, where you can find Mesopuzosia sp. and Kitchinites sp. of the Upper Cretaceous (Santonian), Haslam Formation. Minding the slippery green algae covering some of the river rocks, you can see the first of the Polytychoceras vancouverense zone.

Continuing west, you reach the first of two fossil turtle sites on the river — amazingly, one terrestrial and one marine. If you continue, you come to the Inland Island Highway.

The Trent River has yielded some very interesting marine specimens, and significant terrestrial finds. We have found a wonderful terrestrial helochelydrid turtle, Naomichelys speciosa, and the caudal vertebrae of a Hadrosauroid dinosaur. Walking down from the Hadrosaur site you come to the site of the fossil ratfish find — one of the ocean's oddest fish.

Ratfish, Hydrolagus Collie, are chimaera found in the north-eastern Pacific Ocean today. The fossil specimen from the Trent would be considered large by modern standards as it is a bruiser in comparison to his modern counterparts. 

This robust fellow had exceptionally large eyes and sex organs that dangled enticingly between them. You mock, but there are many ratfish who would differ. While inherently sexy by ratfish standards, this fellow was not particularly tasty to their ancient marine brethren (or humans today) — so not hugely sought after as a food source or prey.

A little further again from the ratfish site we reach the contact of the two Formations. The rocks here have travelled a long way to their current location. With them, we peel away the layers of the geologic history of both the Comox Valley and the province of British Columbia.

The Trent River is not far from the Puntledge, a river whose banks have also revealed many wonderful fossil specimens. The Puntledge is also the name used by the K'ómoks First Nation to describe themselves. They have lived here since time immemorial. Along with Puntledge, they refer to themselves as Sahtloot, Sasitla and Ieeksun.

References: Note on the occurrence of the marine turtle Desmatochelys (Reptilia: Chelonioidea) from the Upper Cretaceous of Vancouver Island Elizabeth L. Nicholls Canadian Journal of Earth Sciences (1992) 29 (2): 377–380. https://doi.org/10.1139/e92-033; References: Chimaeras - The Neglected Chondrichthyans". Elasmo-research.org. Retrieved 2017-07-01.

Directions: If you're keen to explore the area, park on the side of Highway 19 about three kilometres south of Courtenay and hike up to the Trent River. Begin to look for parking about three kilometres south of the Cumberland Interchange. There is a trail that leads from the highway down beneath the bridge which will bring you to the Trent River's north side.

PUNTLEDGE ELASMOSAUR

This toothy beauty is an elasmosaur, a large marine reptile who cruised our ancient oceans 80-million years ago. 

We have one now housed in the Courtenay and District Museum on Vancouver Island thanks to the keen eyes of  Mike Trask and his daughter. 

They found this mighty marine reptile in the winter of 1988 while fossil collecting along the Puntledge River. 

While he couldn't have known it at the time, it was this discovery and those that followed that would spark a renewed interest in palaeontology on Vancouver Island and the province of British Columbia., inspire the creation of the Vancouver Palaeontological Society, the BC Paleontological Alliance & change the face of palaeo in the province.

Mike had forged ahead, adding chalk outlines to interesting fossil and nodules in the 83 million-year-old shales along the riverbank. His daughter, Heather, was looking at the interesting features he had just outlined when they both noticed some tasty blocks and concretions in situ just a few meters away. Taking a closer look, they were thrilled to discover that they held the bones of a large marine reptile.

Unsure of what exactly they'd discovered but recognizing them as significant, Mike reached out to Dr. Betsy Nicholls a lovely researcher at the Royal Tyrell Museum.

It was Betsy who had written up the incomplete specimen of fossil turtle, Desmatochelys cf. D. lowi — Reptilia: Chelonioidea — found by Richard Bolt, Vancouver Island Palaeontological Society, in the shales of the Trent River Formation along the Puntledge River in the early 1990s. 

Dr. Nicholls wrote up the paper and published in the Canadian Journal of Earth Sciences in 1992. At that time, it was the first documented account of a Cretaceous marine vertebrate from the Pacific coast of Canada, which shows you how much we've learned about our Pacific coast in just the last few years.

The Desmatchelys find inspired the 1999 BCPA Symposium conference logo. Every second year, the BCPA hosts a symposium. The 1999 conference at UBC was the first time the Vancouver Paleontological Society had hosted a BCPA conference. The conference abstract was graced with a trilobite embedded within a turtle, celebrating recent significant contributions to Canadian palaeontology.

When Mike showed her the bones he'd found, Betsy confirmed them to be that of an elasmosaur, a large marine reptile with a small head, razor-sharp teeth and a long neck  — and the first discovery of an elasmosaur west of the Canadian Rockies — another first. It was one of those moments that lights up and inspires a whole community.

When the bones were fully excavated, this 15-meter marine beauty underwent a year of preparation to reveal the skeleton you see here. You can visit the fully prepped specimen and see the articulated bones beneath a glass case in the Courtenay Museum on Vancouver Island.

The Puntledge Elasmosaur has graced the cover of Canada's stamps and was voted as British Columbia's Provincial Fossil in 2019. This honour has the Puntledge Elasmosaur cosied up to other provincial symbols and emblems that include the Pacific Dogwood, Jade, the Steller's Jay, Western Red Cedar, Spirit Bear and Pacific Salmon. 

The runner-up for BC's Provincial Fossil was Shonisaurus sikanniensis, a massive 21-metre ichthyosaur found in Triassic outcrops in northern British Columbia. That beauty is a worthy reminder of what hunted in our ancient oceans some 220 million years ago.

Since that first moment of discovery, many wonderful events transpired. In the Fall of 1991, Mike Trask was teaching a course on palaeontology at the North Island College.

Heidi Henderson, Mike Trask & Adam Melzac, BCPA Symposium

Two of his students were Ann and Joe Zanbilowitz. With the classroom portion of the course finished up, the group set out for a fossil expedition on the Puntledge River. 

Within minutes of their search, Joe found a few small articulated vertebrae that we now know to be the type specimen of the mosasaur, Kourisodon puntledgensis. That find, along with some of the other paleontological goodies from the area, prompted the formation of the Vancouver Island Palaeontological Society from an idea to a registered society in 1992. By 1993 membership had grown from a dozen to 250.

In 1992, the Vancouver Island Palaeontological Society passed a motion to encourage the formation of a provincial umbrella group to act as an advocate to promote interaction amongst various paleontological organizations. Through the efforts of Mike Trask, Dan Bowen, Rolf Ludvigsen and others, the first meeting of the Board of Directors of the B.C. Paleontological Alliance was held in 1993 and a BCPA Symposium held every two years thereafter.

If you like podcasts, check out the Fossil Huntress — Palaeo Sommelier Podcast at https://anchor.fm/fossil-huntress

Fossil Huntress Geeky Goodness on YouTube: https://www.youtube.com/channel/UCUerL9urNX8fHb6nHc_vrBQ

PUNTLEDGE ELASMOSAUR

Puntledge Elasmosaur found by Mike Trask

This lengthy beauty is an elasmosaur, a large marine reptile now housed in the Courtenay and District Museum on Vancouver Island.

This specimen was found by Mike Trask and his daughter in the winter of 1988 while fossil collecting along the Puntledge River. While he couldn't have known it at the time, it was this discovery and those that followed that would spark a renewed interest in palaeontology on Vancouver Island and the province of British Columbia.

Mike had foraged ahead, adding chalk outlines to interesting fossil and nodules in the 83 million-year-old shales along the riverbank. His daughter, Heather, was looking at the interesting features he had just outlined when they both noticed some tasty blocks and concretions in situ just a few meters away. Taking a closer look, they were thrilled to discover that they held the bones of a large marine reptile.

Unsure of what exactly they'd discovered but recognizing them as significant, Mike reached out to Dr. Betsy Nicholls at the Royal Tyrell Museum.

It was Betsy who'd written up the incomplete specimen of fossil turtle, Desmatochelys cf. D. lowi — Reptilia: Chelonioidea — found by Richard Bolt, VIPS, in the shales of the Trent River Formation along the Puntledge River in the early 1990s. Dr. Nicholls wrote up the paper and published in the Canadian Journal of Earth Sciences in 1992.

At that time, it was the first documented account of a Cretaceous marine vertebrate from the Pacific coast of Canada, which shows you how much we've learned about our Pacific coast in just the last few years.

The Desmatchelys find inspired the 1999 BCPA Symposium conference logo. Every second year, the BCPA hosts a symposium. The 1999 conference at UBC was the first time the Vancouver Paleontological Society had hosted a BCPA conference. The conference abstract was graced with a trilobite embedded within a turtle, celebrating recent significant contributions to Canadian palaeontology.

Elasmosaur skull and teeth found by Mike Trask

When Mike showed her the bones he'd found, Betsy confirmed them to be that of an elasmosaur, a large marine reptile with a small head, razor-sharp teeth and a long neck  — and the first discovery of an elasmosaur west of the Canadian Rockies — another first. It was one of those moments that lights up and inspires a whole community.

When the bones were fully excavated, this 15-meter marine beauty underwent a year of preparation to reveal the skeleton you see here. You can visit the fully prepped specimen and see the articulated bones beneath a glass case in the Courtenay Museum on Vancouver Island.

The Puntledge Elasmosaur has graced the cover of Canada's stamps and was voted as British Columbia's Provincial Fossil in 2019. This honour has the Puntledge Elasmosaur cozied up to other provincial symbols and emblems that include the Pacific Dogwood, Jade, the Steller's Jay, Western Red Cedar, Spirit Bear and Pacific Salmon. The runner-up for BC's Provincial Fossil was Shonisaurus sikanniensis, a massive 21-metre ichthyosaur found in Triassic outcrops in northern British Columbia. That beauty is a worthy reminder of what hunted in our ancient oceans some 220 million years ago.

BCPA Symposium / Heidi Henderson, Mike Trask, Adam Melzak

Since that first moment of discovery, many wonderful events transpired. In the Fall of 1991, Mike Trask was teaching a course on paleontology at the North Island College.

Two of his students were Ann and Joe Zanbilowitz. With the classroom portion of the course finished up, the group set out for a fossil expedition on the Puntledge River. Within five minutes of their search, Joe found a few small articulated vertebrae that we now know to be the type specimen of the mosasaur, Kourisodon puntledgensis. That find, along with some of the other paleontological goodies from the area, prompted the formation of the Vancouver Island Palaeontological Society from an idea to a registered society in 1992. By 1993 membership had grown from a dozen to 250.

In 1992, the Vancouver Island Palaeontological Society passed a motion to encourage the formation of a provincial umbrella group to act as an advocate to promote interaction amongst various paleontological organizations. Through the efforts of Mike Trask, Dan Bowen, Rolf Ludvigsen and others, the first meeting of the Board of Directors of the B.C. Paleontological Alliance was held in 1993.

Mike Trask hiking up at Landslide Lake, British Columbia

In 1994 the membership of the VIPS split into three regional societies, the original VIPS, the new VanPS in Vancouver, and the new VIPMS, the Vancouver island Paleontological Museum Society based in Qualicum.

In 1995, the Victoria Palaeontological Society, the VicPS, was formed. This was followed by the Tumbler Ridge Foundation (TRMF) and opening of the Dinosaur Discovery Gallery in Tumbler Ridge.

The British Columbia Paleontological Alliance and various regional societies, particularly the Vancouver Island Palaeontological Society (VIPS), continue to make significant contributions to paleontology. We've now found the fossil remains of an elasmosaur and two mosasaurs along the banks of the Puntledge River, says Dan Bowen, Chair of the Vancouver Island Palaeontological Society.

The first set of about 10 mosasaurs vertebrae (Platecarpus) was found by Tim O’Bear and unearthed by a team of VIPS and Museum enthusiasts led by Dr. Rolf Ludvigsen. Dan Bowen and Joe Morin of the VIPS later prepped these specimens for the Museum.

In 1993, just a few years later, a new species of mosasaur, Kourisodon puntledgensis, a razor-toothed mosasaur, was found upstream of the elasmosaur site by Joe Zembiliwich on a field trip led by Mike Trask. A replica of this specimen now calls The Canadian Fossil Discovery Centre in Morden home.
What is significant about this specimen is that it is a new genus and species. At 4.5 meters, it is a bit smaller than most mosasaurs and similar to Clidastes, but just as mighty.

Comox Valley Elasmosaur / Dino Stamps of Canada

Interestingly, this species has been found in this one locality in Canada and across the Pacific in the basal part of the Upper Cretaceous — middle Campanian to Maastrichtian — of the Izumi Group, Izumi Mountains and Awaji Island of southwestern Japan. We see an interesting correlation with the ammonite fauna from these two regions as well.

The Courtenay and District Museum, the community surrounding it and allied organizations like the Vancouver Island Palaeontological Society (VIPS), have a lot to be proud of. Their outreach and educational programs continue to inspire young and old alike. These discoveries led to the expansion of the local museum, the elasmosaur excavation area becoming a provincial heritage site and the impetus for many, many teaching programs since.

Oh, and Mike Trask — he continues to be deeply awesome, intuitive and exceptionally observant. The good Master Trask went on to find the first hadrosauroid in the province. While Alberta is littered with them, a Hadrosauroid dinosaur is a rare occurrence in this part of Canada and further evidence of the terrestrial influence in the Upper Cretaceous, Nanaimo Group of Vancouver Island. Perhaps one day we'll be seeing a duck-billed dinosaur from British Columbia gracing Canada's stamps. Fancy that.

References: Nicholls, E. L. and Meckert, D. (2002). Marine reptiles from the Nanaimo Group (Upper Cretaceous) of Vancouver Island. Canadian Journal of Earth Science 39(11):1591-1603.
Tanimoto, M. (2005). "Mosasaur remains from the Upper Cretaceous Izumi Group of Southwest Japan" (PDF). Netherlands Journal of Geosciences. 84: 373–378. doi:10.1017/s0016774600021156.
Ferocious new mosasaur skeleton coming to Morden | CBC News". CBC. Retrieved 2018-07-16.

BCPA Regional Paleontology Societies: https://bcfossils.ca/regional-societies

UNEARTHING A JUVENILE ELASMOSAUR ON THE TRENT RIVER

Pat Trask with a Fossil Rib Bone. Photo: Rebecca Miller

A mighty marine reptile was excavated on the Trent River near Courtenay on the east coast of Vancouver Island, British Columbia, Canada in August 2020.

The excavation is the culmination of a three-year palaeontological puzzle.

The fossil remains are those of an elasmosaur — a group of long-necked marine reptiles found in the Late Triassic to the Late Cretaceous some 215 to 80 million years ago. 

In the case of the Trent River, it is closer to 85 million years old. The rocks that make up this riverbed today were laid down south of the equator as small, tropical islands. They rode slow-moving tectonic plates across the Pacific — heading north and slightly east over the past 85 million years to where we find them today.

The marine reptile fossil was excavated 10-meters up high on the cliffs that line the river. It took a month of careful planning, building scaffolding, and amassing climbing gear to aid the team of dedicated souls in unearthing this juvenile elasmosaur. 

Bits and pieces of him have been eroding out for years — providing clues to the past and a jigsaw puzzle that has finally had the last pieces put together. The first piece of this marine reptile puzzle was found three years ago. 

The Courtenay Museum hosts regular fossil tours here, led by Pat Trask. On one of those field trips back in 2017, Pat was leading a trip with a family and one of the field trip participants picked up a marine reptile finger bone. It was laying in the river having eroded out from a nearby cliff. She showed it to Pat and he immediately recognized it as being diagnostic — it definitely belonged to a marine reptile — possibly an elasmosaur — but what species and just where on the river it had eroded from were still a mystery. She kindly donated it to the museum and that was that.

While it was an exciting find, it was a find without origin. Just where the material was coming from was unknown. It could have eroded from anywhere upstream and while many had searched the river, no other bone bits were found.   

Pat Trask Wrapping the plaster casing

Then in 2018, another piece of this paleontological puzzle was revealed. Pat was leading yet another Courtenay Museum Fossil Tour on the Trent River when one of the participants showed him a specimen that looked like a really tiny hockey puck. This second find was a wrist bone — again possibly from an elasmosaur but hard to be sure. Contemplating out loud where this material could be coming from, Pat looked down and found a vertebra in the water below his feet.

Pat put the bones in the lab at the museum. Intrigued by their origin, he began heading down to the river on his off hours to see where they might be coming from and thinking about where the erosion occurs on the Trent. 

In 2019, "I came down here and I started thinking about where the water flow would go." He could see a ledge along the river where eroded material might gather. Once he checked, he found a crack and cleaned out all the rock gathered there, finding more than a dozen bones. Pat teamed up with members of the Vancouver Island Palaeontological Society (VIPS) to scale the cliff faces above that section of the river. Jason Hawley, VIPS, did some rappelling but missed the site by a matter of feet.  

Pat had his neighbour fly a drone along the cliff face but it, too, turned up with nothing. Then at the beginning of August, Pat was back on the river in the morning with a family and said to one of the kids, "Hey, let's go look for baby elasmosaur." then they walked right over and saw a neckbone or tailbone in the river. Pat knew it hadn't been there the day before. He looked up and thought it must be coming from right up here. He came back later in the day with Deb Griffiths, his wife, set up his telescope on the river aimed at the likely portion of the cliff and bingo — he could see a bone sticking out.

He returned the next day with his brother Mike Trask. Mike found the elasmosaur on the Puntledge River back in 1988.  "We took a long pole and I said here's my target — and I hit one little piece, maybe three inches by three inches. When it fell down it had bones in it." Excited, they began planning a larger excavation that would include scaffolding, safety planning, climbing gear, permits... a lot of work in a short time. 

Plesiosaur Gastrolith

Initially, they thought there would be a small amount of fossil material, perhaps a few finger bones but over the past few weeks, they have found bones of at least half a marine reptile. 

And the beauty of this find is that most of the bones do not have to be prepared. They are literally eroding out of the matrix. No prep means no tools. Tools can impact the shape of a bone as you prepare it. They've found the pelvis bones, humerus, radius — all diagnostic to identify the genus. And this may be a new species. If it is, there is a good chance it will be named after the Trask family. 

I caught up with Pat and the team from the VIPS out on the river on August 23, 2020 — the day of the excavation. Loose rib bones, gastroliths, wrist bones, finger bones and part of the back and pelvis were recovered — and possibly the head, too. 

The bulk of the specimen was wrapped in plaster and carefully lowered to the ground by Pat and members of the VIPS, under Mike Trask's careful eye. We know that there is a femur in that jacket and possibly all the bones associated with that. Also included are the fibula and tibia and their associated bones — and I'm truly hoping there is a skull in there, too! I've popped a link below of a wee video showing the final moments as the plaster cast is lowered down from the excavation site. Take a look! It was quite an exciting moment.

It is not quite a baby, but this diminutive fellow is about four-metres long, making it a juvenile of his species. We have prepped enough of the material now to safely call it an elasmosaur. James Wood of the VIPS has done an amazing job on the preparation of this specimen using a new smaller air abrasive purchased by the Courtenay Museum. 

I hope to see it published with the Trask family name. Their paleontological history is forever tied to the Comox Valley and the honour would be fitting.  

Photo One: Rebecca Miller, Little Prints Photography — she is awesome!

Photo Two: James Wood prepped the material and Pat Trask labelled and oriented the bones.

Photo Three: Pat Trask perched atop scaffolding along the Trent River. And yes, he's attached to a safety line to secure him in case of fall. 

Photo Four: A gastrolith recovered amongst the stomach contents of the Trent River excavation. A gastrolith is a rock held inside a gastrointestinal tract. Gastroliths in some species are retained in the muscular gizzard and used to grind food in animals lacking suitable grinding teeth. The grain size depends upon the size of the animal and the gastrolith's role in digestion. Other species, including marine reptiles, use gastroliths as ballast — which may have been the case here. 

See the Excavation Moment via Video Link: https://youtu.be/r82EcEF7Pfc