A slab of dark grey rock, about 30 cm x 40 cm, bearing a roughly fan-shaped bundle of bifurcating, flattened tubular structures that stand in low relief. Each individual "tube" is about 1 cm in width and marks a sediment-filled tunnel excavated within the soft lime muds and silts on a shallow marine sea bed. The whole array is a the result of systematic "mining" of the sea floor sediment for organic detritus and is the work of a single small burrowing invertebrate animal whose precise identity is unknown.
#Tracefossils record interactions btwn ancient organisms & their surroundings, often in the form of tracks, trails & burrows in/on sediment, but the trace maker is seldom preserved. Phycodes is a complex feeding burrow system excavated in an #Ordovician (~450 MYA) seabed. #Ontario 🇨🇦 #FossilFriday