Pseudogygites latimarginatus trilobite from the Whitby formation

The main reason to collect in the black shales of the Collingswood member of the Whitby formation is in the hopes of finding an articulated Pseudogygites latimarginatus. Most of the time the only parts found are the isolated pygidiums.  I have been fortunate enough to find one mostly intact example.

Specimen #1 - The large slab with a partially disarticulated example

Closer view of the specimen

This the the counterpart on a smaller flake of shale

Specimen #2 - An isolated pygidium

Specimen #3 - another pygidium

The Whitby formation is Ordovician in age (late Ordovician, Katian/Mohawkian stage).
These fossils were collected from the St. Mary's Limestone Quarry in Bowmanville, Ontario. I used William Hessin's book "South Central Ontario Fossils", 2009, Self Published, pg. 200 to help identify these fossils.