Sunday, 4 August 2019

FLAT CLAMS: BIOCHRONOLOGICAL MACROFOSSILS

Paper clams or 'flat clams' were widespread in the Triassic. We call these bivalves 'flat clams' because of their very thin shell width and narrow valve convexity. They often dominate the rocks in which they are found, as in these specimens from Pine Pass near Chetwynd in the Foothills of northeastern British Columbia.

Pine Pass is part of the Pardonet Formation. Just a short hike from the road we were able to easily find the abundant outcroppings of the paper clam, Monotis subcircularis, perfectly preserved and cemented in this strata from the Late Triassic. Because of their widespread distribution and very high species turnover rates, they make for excellent biochronological macrofossils, helping us to correlate biological events through time.