Agnostus pisiformis — a half a billion-year old pea-shaped enigma
The Cambrian arthropod Agnostus pisiformis (Wahlenberg, 1818) is not only a beautiful fossil animal, approximately 1 cm in length when adult, but also an extinct species unusually well-known from its ‘soft’ ventral cuticular structures. It is moreover very useful for biostratigraphic correlation and has a long research history. The species occurs in huge numbers, and in all developmental stages, i