Guelph Formation

The Guelph Formation is a geologic formation in New York and in Ontario, Canada. It preserves fossils dating back to the Silurian period.

Fossils

Fossils within the formation include:

• Pentamerus occidentalis (Hall)
• Megalomus canadensis (Hall)
• Murchisonia bivittata (Hall)
• M. macrospira (Hall)
• M. boydii (Hall)
• M. logani
• M. longispira
• M. uvittata
• M. turritiformis
• M. tullia
• Subulites ventricosus (Hall)
• Pleurotomaria solaroides (Hall)
• P. elora (Billings)
• P. galtensis (Billings)
• P. mora
• Cyclonema sulcata (Hall)
• C. galtensis
• C. thysbe
• C. psyche
• C. depressa
• Holopea guelphensis (Billings)
• Bellerophon angustata (Hall)
• Favosites gothlandica
• F. polymorpha
• Halysites catenulatus
• Columnaria galtensis
• Obolus sp.
• Orikoceras sp.
• Orthoceras darwini
• Cyrtoceras arcticameratum
• C. Jonesi
• Phragmoceras hector
• Calymene blumenbachii
• Diphyphyllum irregulare
• Amplexus laxatus
• Rhynchonella sp.
• Athyris sp.

References