Along the Jacques Cartier River, at Pont Rouge, are nice riverside exposures of Trenton Group limestones (upper Middle Ordovician).  The fossiliferous limestones here include good horizons with burrows and body fossils.






Above: Nice receptaculitid in fossiliferous limestone.  Receptaculitids have a distinctive center-of-sunflower shaped structure.  They are considered by modern paleontologists to represent fossil green algae (Chlorophyta).



Above & below: A surprising find of a cystoid head & complete stem.  “Cystoid” is an obsolete umbrella term for two unrelated, extinct echinoderm classes: the rhombiferans and the diploporans.  These specimens appear to be rhombiferans (Phylum Echinodermata, Class Rhombifera).  Rhombiferans have a crinoid-like body plan, but they have shorter stems that taper rapidly.




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