Favreinidae with internal canals crescent- or hook-shaped in cross-section.
Source: Knaust, Dirk. (2020). Invertebrate coprolites and cololites revised. 10.1002/spp2.1297.This cluster of coprolites was found on a beach near the mouth of Middlesex County beach on the Rappahannock River. Decapods (a type of crustacean), such as ghost shrimp and crayfish, produce fascinating rod-shaped fecal pellets containing little canals. The canals can have all different shapes. Each of the pellets in this specimen have 10 crescent-shaped canals.
This little cluster of coprolites was found on a beach near the mouth of Middlesex County beach on the Rappahannock River. Crustaceans such as ghost shrimp and crayfish produce fascinating rod-shaped fecal pellets containing little canals. The canals can have all different shapes. These have crescent-shaped canals.
The pellets likely accumulated in an empty burrow, shell or other crevice near the home of crustacean that created them.