Geological Time:
Upper Ordovician Epoch; Lindsay formation (Rafferty, 2010)
Location:
Bowmanville, Ontario, Canada (Rafferty, 2010)
Information:
- Known to be relatively large for a trilobite
- Characterized by its flat shape
- Head and tail were well developed and larger when compared to the whole animal
- this fossil is 40 cm in length
- Thoracic parts were small and they had large eyes which had a crescent shape (Rafferty, 2010)
History of the Isotelus genus:
Canadian paleontologists were examining rocks one day up in Hudson Bay (northern Manitoba), and there was a discovery of a one of the largest trilobite fossil (Isotelus Gigas Trilobite). This fossil measured up to 70 cm in length. (The encyclopedia of Manitoba, 2007)
The Isotelus genus is divided into two species, I. maximus and I. gigas. Both species have very defined and developed spinal features. The broad, flat, hard upper shelled creature was given the name I. brachycephalus. An observation was made which revealed that I. maximus and I. brachycephalus occurred in the same strata, the paleontologist, Foerste, suggested that because I. brachycephalus is broader this might be a representation of females within the genus and the narrow I. maximus the males of the species (Davis et al., 2009)
Geological Time:
Upper Ordovician Epoch; Whitby formation (Whiteley, 2002)
Location:
Blue Mountain, Ontario Canada (Whitely, 2002)
Information:
- Appendages found in this trilobites suggested that it fed off of particles. It used its thoracic appendages to sort the particles and is then transferred to the mouth
- Enlarged spine
- Basal segments underneath resembled jaws to allow the food to be transferred (Davis et al., 2009)
History of the Triarthrus genus:
Parks was an investigator who studied fossils at the University of Toronto, he noticed the abundance of trilobites, specifically Triarthrus, found in the Collingwood and Blue Mountain strata (Rancourt, 2009).
He was able to construct a biostratigraphic scheme based on the fossils found in the regions. A consensus was made and there was a higher abundance of T. etoni in the Collingwood strata and a higher abundance of T. canadensis, T. rougensis and T. spinosus in the Blue Mountain strata (Tuffnell, 1984).