Carnivorous fungi dating back to the age of the dinosaurs have been found fossilized in circa-100-million-year-old amber. The fossil fungi used hyphal rings as trapping devices and are preserved together with their prey, small nematodes. The excellent preservation in amber allowed comparison with extant groups: On the basis of the mode of ring formation and the dimorphic mode of life, the fossils cannot be assigned to any recent carnivorous fungus, providing evidence that different groups occupied this ecological niche in the Cretaceous and that trapping devices were developed independently multiple times in the course of Earth history.