Volborthella

Volborthella is a genus of small Early Cambrian animal of uncertain classification, known from fossils predating 530 million years ago and found across North America, Greenland, Spitsbergen and northeastern Europe. It built a conical shell by binding together grains of silica rather than by secreting shell material, a construction method that distinguishes it from the true cephalopods it superficially resembles and for which it was originally mistaken. Because it appears in the fossil record before trilobites, Volborthella is useful for dating Lower Cambrian rock formations, and a 2025 study proposed it may in fact represent an early cnidarian rather than a mollusk-like animal.