I've made a number of return visits to my local spot, but sadly have nothing remarkable to show for it. There is only one type of rock that is both fossiliferous and containing trilobites, and that rock type is a very thin minority at this location. I may have encountered nearly every example of it by now, including boulder-sized ones that make granite seem like butter when it comes to getting into without just creating powder and shards. So my attention turns to other things, such as creating a kind of an updated master list of trilobites in Ontario. By drawing on the key sources, such as Ludvigsen and Isotalo (among others), this forms a basis for creating such a list. Formation names and taxonomic classification changes have been reflected in creating this list. I've added reasonable correlations based on similar strata in the US, both the Michigan and Appalachian basin. Those correlations appear in a separate column, and are not included in the Ontario species count until they can be found and confirmed in Ontario rocks. I've also excluded Hudson Bay and James Bay trilobites on account of a lack of more sustained formal description. The list therefore only includes paleozoic rocks south of the Canadian Shield, or simply "southern Ontario." I am told that there is some anticipated and ongoing taxonomic revision that may result in having to update this list, but revisions are to be expected anyway.
It should also be noted that more than half of these specimens could be classed as quite rare, or known only as fragments. Finding accessible outcrops remains the perennial problem for trilobite collectors and researchers in Ontario, and so even attempting to perform a reliable volumetric analysis of certain formations is imperiled by a lack of substantive sample size. But this revised list is a good start which tells us something about the trilobite record here in Ontario. I expect to be updating this master list as new resources come available. Comments are closed.
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Kane Faucher
Archives
February 2024
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