Hylonomus
Fossils of Hylonomus have been found in the remains of fossilized club moss stumps in Joggins Fossil Cliffs, Nova Scotia, Canada. The theory is that, after harsh weather, the club mosses would crash down. The stumps eventually hollow out. Small animals such as Hylonomus, seeking shelter, might enter and become trapped, starving to death. Fossils of the basal pelycosaur Archaeothyris and the basal diapsid Petrolacosaurus are also found in the same region of Nova Scotia, higher up, dated about 6 million years later.