Trilobites from Canada
latimarginatus (Canadian Trilobites)
Trilobita; Trilobite Order
Asaphida; Family Asaphidae; Subfamily Isotelinae
Time: Middle Ordovician
Whitby Formation, Ontario, Canada
latimarginatus is an Asaphid trilobite (Order: Asaphida; Family:
Asaphidae Subfamily Isotelinae) coming from the Ordovician Whity
Formation strata of Ontario, Canada. This trilobite was first known
as Pseudogygites canadensis until it was found that the name Asaphus
latimarginata had precedence over Asaphus canadensis. Once the trilobite
was placed in the current species, the generic name became latimarginatus.
They are similar in morphology to the genus Ogyginus of the United
Kingdom, differing in the hypostome and facial suturing. This is
a good pair of counterpart examples. Like Isotelus,
the genal spines became smaller as the trilobites got older, with
full-grown examples having none detectable. Note the strange-looking
item near the Pseudogygites to the lower left in the first photo.
It looks very much like the vertebral column of a fish! There are
several partial cephalons to be seen on the reverse, making this
a nice death assemblage plaque.
trilobite pictures to enlarge