Baythurus
17 Feb
Bufoceraurus
14 Feb
Bufoceraurus sp., Bobcaygeon Fm., Victoria County, Ontario
Gabriceraurus
The largest of the Cheirurid trilobites of eastern North America, this genus is found in the Bobcaygeon and Verulam Trenton Group of the upper Ordovician of Ontario.
Near Ottawa, Ontario. Author’s collection.
Lateral preservation on a plate with multiple Flexicalymene sp., Hastings County Ontario. Author’s collection
Ottawa, Ontario. Author’s collection.
Near Ottawa, Ontario. Found by the author, prepared by Jerry Kloc. Now in the collection of the Royal Ontario Museum.
Near Ottawa, Ontario. Private collection.
Found near Ottawa. Note deformed geenal spine on the top specimen.
Author’s colelction.
Isotelus
23 Oct
An Asaphid trilobite that is very common in the Cobourg Fm. and found in almost all strata above the base of the Gull River Fm. This trilobite could be quite large: specimens found at Colborne, Ontario, show Isotelus latus could grow to at least 18 inches. Isotelus maximus in the younger Cincinnatian (equiavalent to the Georgian Bay Fm in Central Ontario, the Russell Fm in the Ottawa area and the Nicolet Fm. in Quebec) could reach similar sizes. Isotelus rex, found in Ordovician rocks near Churchill, Manitoba, is the largest complete trilobite ever found.
Isotelus platycephalus, Gull River Fm.
Isotelus (undescribed, similar to Isotelus iowensis), Ottawa
Multiple specimen from same strata as above trilobite
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8″ dorsal specimen from same strata. Note the forked hypostome (mouth plate)
Isotelus ottawensis, near Picton, Ontario
Isotelus gigas, Port Hope, Ontario
Isotelus gigas, near Picton, Ontario
Triarthrus
23 OctTriarthrus is a common trilobite in the “Billings Shale” of eastern Ontario and the Lorraine Shales of New York State and Quebec.
