Scientists combined models of flower evolution with the largest data set of features from living flowers ever assembled.
From this the team was able to infer the appearance of the ancestral flower.
The flower had many concentric cycles of petal-like organs in sets of three, arranged in whorls, and was bisexual.
Hervé Sauquet, from Université Paris-Sud, France, one of the authors of the paper published this week in Nature Communications said: "There is no living flower that looks exactly like the ancestral one - and why should there be? This is a flower that existed at least 140 million years ago and has had considerable time to evolve into the incredible diversity of flowers that exist today."
We are all familiar with the beauty of flowers - the reproductive structures produced by about 90 % of all living land plants. But their origin and early evolution is a mystery. This is mainly owing to the lack of fossil flowers from the time period when the ancestor of living flowers is thought to have existed.