The earliest Lepidoptera fossils date to the Triassic-Jurassic boundary, about 200million years ago. Butterflies evolved from moths. The oldest known butterfly is "Protocoeliades kristenseni" from the Palaeocene of Denmark, about 55million years ago. It belongs to the family Hesperiidae (skippers). Molecular clock estimates suggest that butterflies originated sometime in the mid-Cretaceous, but only significantly diversified during the Cenozoic. Genetic data suggest they originated in North-America 102.5–100.0million years ago from a nocturnal moth ancestor that fed on legumes. Only about 17million years ago did they colonize Europe. The oldest American butterfly is from the later Eocene from the Florissant Formation fossil beds, about 34million years old.