Fossils of Ontario

Fossils of Ontario Identification Key and Activity

If you live in Southern Ontario, there are fossils containing history from millions of years ago right under your feet! They might be in rocks in your neighbourhood, your school yard or even a stone wall along a path. We challenge you to go on a #fossilfieldtrip. Venture out into your community and search for Limestone or Dolostone landscape blocks. They are light or dark grey, big square blocks that came from local quarries! Sometimes that material was used for building stone stairs or buildings. Next time you are walking around town, take a look at any big grey rocks you see- there is a good chance that fossils are hiding within!

Use the Fossils of Ontario key when you go on your #fossilfieldtrip with your family or a friend. Click on the pamphlet below to download a free pdf of the fossil key to bring it with you on your hunt, and you can circle or check them off as you go! 

Found a fossil, tried your best to ID but still have no idea what you're looking at? Send us a photo via email or connect with us through social media on Twitter @EarthSciMuseum or on Instagram @uwearthmuseum. Please make sure all emails include the location of where the fossil was found.

Image of Fossils of Ontario key linking to printable pdf

Listen to our curator, Corina, talk about the fossils you can find in your Southern Ontario community. 

About fossils in Ontario

The landscape of Southern Ontario has changed very little since the glaciers receded from the area 12,000 years ago. The top surface we see now was deposited and scrulpted by the glaciers during the Laurentian Ice Age. Underneath this thick overburden layer of sand and gravel lies Southern Ontario’s bedrock: mainly sedimentary rocks like sandstone, shale, limestone and dolostone. This bedrock originally began as mud and limy oozes at the bottom of a shallow, tropical sea between 360 and 500 million years ago. Over a long period of time, the sediments underwent shallow burial and lithification, meaning the individual sediment particles were cemented together and turned into hard rock via diagenesis. 

Fossil Brachiopod from Hungry Hollow. University of Waterloo Earth Sciences Museum

fossilized bivalveThe rocks that underlie Southwestern Ontario are of the Lower and Middle Paleozoic Era, ranging from 485  to 360 million years in age. They are further subdivided by age into rocks from the Ordovician, Silurian and Devonian Periods. There is a small portion of eastern ontario that has rocks from the Upper Paleozoic Era, the Cambrian Period, which can be up to 500 million years old! For an immersive story-map that contains images and descriptions of different rock ages across Southern Ontario, check out Paleozoic of Ontario Virtual Field-trip created by Nick Eyles with the Univeristy of Toronto.

common fossils in southern Ontario

Although some Precambrian fossils such as stromatolites can be found in northern Ontario in the Canadian Shield, most of the fossils in Ontario recorded life beneath the shallow seas in the Paleozoic Era. On Manitoulin Island, Silurian corals formed reefs that are now exposed at the surface as fossils, and on the shore of Lake Huron near Kettle Point, there are abundant corals, trilobites, sea lilies and other marine invertebrates that can be found.

Recommended fossil collecting sites:

Please note that you may need to ask permission to collect fossils at these sites. Don't assume that just because you found it, you can have it. Remember, the land doesn't belong to you!

Learn more about the local Kitchener-Waterloo fossils.

Recommended fossil collecting sites

Arkona-Kettle Point and Hungry Hollow

Please note: There has been a "No Trespassing" sign installed at the Hungry Hollow site.

Fossil collecting at Hungry Hollow quarries is only allowed by members of mineral clubs associated with the Central Canadian Federation of Mineralogical Societies (CCFMS) on organized trips. (Families with children) are allowed into this site on these field trips. Contact the CCFMS to see if you can access the site.

crinoid stem

Fossil Crinoid Stem from Hungry Hollow. University of Waterloo Earth Sciences Museum

3 fossil coral pieces from ontario

Fossil Coral from Hungry Hollow. University of Waterloo Earth Sciences Museum



Craigleith, Ontario rests on the southern shore of the Georgian Bay. The bedrock exposed in the area consists of slightly tilted layers of limestone and shale, which were originally deposited approximately 445 million years ago. Fossils of the once abundant sea-creatures in this area can be seen in some of the weathered surfaces. Some common fossils which may be found in the Craigleith Area include: Trilobites, Brachiopods, Grapolites, Cephalopods, Pelecypods, Gastropods, and Conularids

Nearby Craigleith are three Provincial Parks, each with their own unique set of geological features:

Rock Glen

Rock Glen Conservation Area is located in Arkona, close to Hungry Hollow, Ontario. It is located in a 67-acre preserved area and houses natural trails, waterfalls, and Arkona Lions Museum. The area is well-known for its rich fossils, which are as old as 400 million years from the Devonian era.

About 600 million years ago, rain and wind washed sediments from rocky areas into a shallow sea where millions of creatures like trilobites, corals and sea shells lived. Whenever the sea retreated the creatures would be buried by the sediment and fossilized. This process was occurred three or more times through 200 million years, creating layers of fossil-rich sedimentary rock.

About 1 million years ago, the Wisconsin Glacier covered Ontario, and as it advanced layers of gravel, sand and clay were deposited. The glacier retreated from the area 16,000 years ago, creating Lake Arkona. The fossils were hidden until 10,000 years ago, when a strong earthquake shook the area, causing a section of the bedrock to drop, creating a gorge and unearthing the rich fossil deposits.

Kincardine and Southampton

Informally known as “fossil beach”, the region around Southampton is prime fossil hunting territory. Countless specimens have washed up on the beaches and have been gathered by private collectors and researchers.

The predominant rock is Ordovician limestone, formed by ancient warm seas which once covered this area. These were ideal conditions for a vast group of creatures like brachiopods. Boulders and pebbles from the ancient rocks north of Lake Huron were brought down by the glaciers.