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  • Writer's pictureShahin Dashtgard

What did Vancouver Island look like when dinosaurs ruled the Earth?

Updated: 6 days ago

I love geology for a lot of reasons that go beyond exploring new and cool parts of our planet. One aspect that really interests me and drives a lot of my research is reconstructing Earth's past, and this post takes a look at what Vancouver Island looked like about 80 to 90 million years ago when the dinosaurs ruled the Earth.


On the eastern side of Vancouver Island and the Gulf Islands, and below both the Strait of Georgia and Lower Mainland are sedimentary rocks that were deposited in the Georgia Basin (1). The sedimentary rocks on eastern Vancouver Island record deposition between about 90 and 80 million years ago. Younger rocks are exposed on the Gulf Islands and in the Lower Mainland, but they won't be discussed in this post.

Georgia Basin in southwest B.C.
Sedimentary rocks exposed in southwest B.C. Green colours show the extent of rocks deposited when dinosaurs roamed the Earth, and the orange and blue coloursthe extent of sedimentary rocks exposed at surface that were deposited after the dinosaurs went extinct. The term OA refers to outcrop areas and SB to sub-basins. The red dashed line shows the extent of sedimentary rocks in the Georgia Basin, many of which occur below ground (image courtesy of Chuqiao Huang).

If you have not already done so, I strongly encourage you to visit the Courtenay Museum and Palaeontology Centre in Courtenay, B.C. (Courtenay Museum & Palaeontology Centre, Vancouver Island, BC. They have on display an absolutely spectacular Elasmosaur (marine reptile) skeleton that was found in 1988 and is now B.C.'s official provincial fossil! They also have a pretty amazing collection of marine invertebrates found in the rocks on Vancouver Island and the Gulf Islands, and have put together a few videos on some of their other finds, including a Tylosaur (another marine reptile).


When Dinosaurs Ruled the Earth

It is hard to image Vancouver Island with it's 2000+ m high mountains has bobbed up and down over the past 90 million years, but it has. In fact, it went from being part of the ocean floor to soaring mountains and back again atleast twice during the time of the dinosaurs (90 to 80 million years ago).


Our story begins about 90 million years ago, after the rocks that form the core of Vancouver Island had smushed themselves onto the west side of North America and in the process had risen up to form an island. The oceanic plate to the west (Farallon Plate) was subducting under North America, and the newly emergent island was slowly drowning as the edge of the continent was being dragged down with the subducting oceanic plate. Many of the sediments  from this time period record deposition on the edge of the very young, and sinking, Vancouver Island and the rocks tell a story of a land surface covered in swamps with rivers that emptied into a nearby shallow seaway (shallow marine). The old swamp deposits form the coal beds that were and continue to be exploited in the Comox Coalfield.

Vancouver Island 85 to 90 million years ago
Reconstruction of Vancouver Island and the mainland of B.C. (red outlines) between 90 and 85 million years ago. The different rock types are preserved in the sedimentary record and used to reconstruct what the area looked like (source: 2).

By about 84 million years ago, continued drowning had completely submerged all of Vancouver Island and the whole area would have looked like a continuation of the Pacific Ocean. It was during this time that the Elasmosaur and Tylosaur were buried in the sediment at the ocean floor, and in water that was probably several 100s of meters deep. The mudstone beds deposited at this time are the source of nearly all of the fossils hunted for by the island's numerous amateur palaeontologists.

Vancouver Island 83 to 84 million years ago
Reconstruction of Vancouver Island and the mainland of B.C. (red outlines) between 84 and 83 million years ago. The light bluish overlay signifies ocean and below this is where mudstone was deposited. The mudstone is what most palaeontologists dig through when fossil hunting (source: 2).

Instead of staying below the ocean, the island experienced a second emergence between 83 and 80 million years ago, and around the towns of Parksville and Nanaimo. The emergent island was covered in swamps and rivers, and it was during this time that the Nanaimo Coalfield was formed.

Vancouver Island 80 to 83 million years ago
Reconstruction of Vancouver Island and the mainland of B.C. (red outlines) between 83 and 80 million years ago. The light bluish overlay signifies ocean and below this is where mudstone was deposited. The emergent island around the town of Nanaimo is where many of the swamps formed that eventually became the Nanaimo coalfield (source: 2).

So, were there dinosaurs on Vancouver Island? The short answer is no. An Elasmosaur or Tylosaur are very cool but are not dinosaurs, and no dinosaur bones have been found to date in the Georgia Basin. The long answer is yes, but not in the form of skeletons. There is evidence that dinosaurs lived on the island although that evidence remains secret. I will update this post once word is shared.


Fossil Hunting in BC

Just a quick reminder to all aspiring palaeontologists, fossils in BC are protected under the Land Act, which stipulates that “Provincial approval is required to collect fossils from Crown land. Fossils found on land administered by the Park Act, Ecological Reserve Act or Protected Areas of British Columbia Act, are under the authority of the Ministry of Environment.” This means that any fossils you collect remain the property of British Columbia and cannot be sold or given transferred. However, “Surface collection, of small amounts of fossils common at the site is allowed, using hand tools. 'Common' refers to types of fossils not considered scientifically significant, and that occur in abundance such that collecting a few specimens would not deplete the resource at the site. “ – BC Government Website. Many of the marine invertebrates found in the sedimentary rocks on Vancouver Island are relatively common, but the work of amateur palaeontologists is extremely important in advancing our knowledge of BC's fossil history. If you find any skeletons of marine invertebrates or unique fossils or have questions regarding your fossil finds, please contact the Curator of Palaeontology, Dr. Victoria, Arbour, at the Royal British Columbia Museum.


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Info Sources:

1) Huang, C., Dashtgard, S. E., Haggart, J. W., and Girotto, K., 2022, Synthesis of chronostratigraphic data and methods in the Georgia Basin, Canada, with implications for convergent-margin basin chronology: Earth-Science Reviews, v. 231, no. 104076, 25 p.


2) Girotto, K., Dashtgard, S. E., Huang, C., MacEachern, J. A., Gibson, H. D., and Cathyl‐Huhn, G., 2024, Stratigraphy, palaeogeography and evolution of the lower Nanaimo Group (Cretaceous), Georgia Basin, Canada: Basin Research, v. 36, no. e12830, 31 p.







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2 Comments


rlhf31
6 days ago

Very nice summary of the formation of the coal fields. As a retired geologist I think your blogs are invaluable in educating people. Thanks

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Shahin Dashtgard
Shahin Dashtgard
6 days ago
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Thanks for the feedback!

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