A 500-million-year-old trilobite fossil shows the marine arthropod literally caught in its tracks.

Credit: O. FATKA, M. SZABAD, P. BUDIL

Palaeontologists scouring a Middle Cambrian-era outcrop west of Prague in the Czech Republic have discovered a rock bearing a 3-centimetre-long path that leads to the fossil of a small trilobite, Agraulos ceticephalus (pictured). Oldřich Fatka of Charles University in Prague and his colleague Michal Szabad say the tracks may represent debris left over from a systematic excavation of the sea floor by the creature, and show this trilobite's final meal. If so, the fossil indicates that these animals were low on the food chain, sifting through small particles at the bottom of the sea.

Paläontol.Z.http://dx.doi.org/10.1007/s12542-011-0102-4(2011)