Archive | October, 2018

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.

20180905_152630

Isotelus platycephalus, Gull River Fm.

163027_10150095218566291_1265935_n

Isotelus (undescribed, similar to Isotelus iowensis), Ottawa

 

320866_10150356973781291_1143992559_n

Multiple specimen from same strata as above trilobite

 

unlisted-isotelusventrl\

8″ dorsal specimen from same strata. Note the forked hypostome (mouth plate)

 

DSC_0118

Isotelus ottawensis, near Picton, Ontario

 

 

porthopeiso

Isotelus gigas, Port Hope, Ontario

 

DSC_0081

Isotelus gigas, near Picton, Ontario

Triarthrus

23 Oct

Triarthrus is a common trilobite in the “Billings Shale” of eastern Ontario and the Lorraine Shales of New York State and Quebec.198507_10150152281896291_5380657_n