JACQUES CARTIER RIVER
AT PONT ROUGE
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.
