Scientists found fossilised butterfly scales the size of a speck of dust inside ancient rock from Germany.
The find pushes back the date for the origins of the Lepidoptera, one of the most prized and studied insect groups, the BBC reported.
"We found the microscopic remains of these organisms in the form of these scales," said Bas van de Schootbrugge from Utrecht University in the Netherlands.
"These finds push back the evolution of this group with proboscises - with a tongue - by about 70 million years," said van de Schootbrugge.
"Our finds show that the group that was supposed to co-evolve with flowers is actually much older."
The early Lepidopterans survived the mass extinction at the end of the Triassic, which wiped out many other living things, the BBC report said.
"This knowledge will help inform modern conservation efforts," said Timo van Eldijk, also of Utrecht University and the lead researcher on the study.
The information is "paramount to help us piece together how current manmade climate change might affect insects and their evolution in the future", he said.
Scientists have relied largely on DNA evidence from modern butterflies and moths, which can be used to make an evolutionary tree of life.