Life › The age of dinosaurs
Flowering plants
by c. 130 million years ago (fossils); origin debated· Evolutionary innovation· Plants & fungi
Strong evidenceGood evidence; dates or details still being refined.
Plants with flowers and seeds enclosed in fruit; they appear in the Cretaceous and now make up about 90% of land plant species.
See it on the Life map →What happened
Flowering plants (angiosperms) enclose their seeds in an ovary that ripens into a fruit, and many use flowers to attract animal pollinators. The oldest widely accepted fossils are pollen grains from about 135–130 million years ago, then early flowers such as Archaefructus from Liaoning, China, around 125 million years ago. They spread fast and dominated many landscapes by the end of the Cretaceous. Grasses, fruit trees and nearly all crops are flowering plants.
Why it matters
They transformed land ecosystems, fed the rise of the insects, birds and mammals that pollinate or eat them, and supply almost all human food.
The evidence (fossils, genes, rocks)
Early Cretaceous fossil pollen and flowers from Portugal, China and the eastern US; DNA-based family trees and molecular clocks; living early branches such as Amborella of New Caledonia.
Still debated
Molecular clocks often place their origin in the Jurassic or Triassic, long before the first fossils. Darwin called their sudden rise an "abominable mystery".
Inside this (1)
Connections (5)
▸Seeds led eventually to Flowering plantsWell established
The connection
Flowering plants are a late branch of the seed plants. They added key twists: the seed develops inside a closed ovary that ripens into a fruit, and a second fertilization builds a food store for the embryo. Flowers, fruits and faster life cycles helped them overtake conifers and other older seed plants.
When and how
Seeds evolved by about 365 million years ago; flowering plants appear in the fossil record about 130 million years ago.
The evidence
DNA family trees place flowering plants within the seed plants, and their seeds share basic structure with those of conifers and cycads.
Debates and open questions
Which older seed plants are their closest relatives is unresolved, and the long gap between the first seeds and the first flowers is a puzzle.
▸Flowering plants formed Flower–pollinator partnershipsWell established
The connection
Flowering plants turned pollination into a trade. Instead of releasing clouds of pollen into the wind, they offered nectar, pollen and scent in showy flowers to animals that carried pollen straight to another flower of the same kind. As flowering plants diversified in the mid-Cretaceous, flower shapes increasingly matched particular visitors.
When and how
Mid-Cretaceous, about 125–90 million years ago, as flowering plants spread; key fossils come from Myanmar amber and fossil-flower beds in Portugal and North America.
The evidence
Fossil flowers with features for insect pollination, sticky pollen clumps, and amber insects carrying flower pollen, including a 99-million-year-old beetle described in 2019.
Debates and open questions
How much flowers co-evolved with insects, versus borrowing insect habits already formed on cone-bearing plants, is debated.
▸Bees spread pollen for Flowering plantsWell established
The connection
While collecting food, a bee gets dusted with pollen and carries it to the next flower, fertilizing it. This service helps flowering plants reproduce across distances and keeps related species from mixing. Many wild plants and crops, from almonds to blueberries, depend heavily on bee visits to set seed and fruit.
When and how
Worldwide, ongoing for roughly 100 million years; today honeybees, bumblebees and about 20,000 wild bee species do much of the world's animal pollination.
The evidence
Field experiments that exclude bees show sharp drops in seed and fruit set; a 2007 review found most leading food crops benefit from animal pollination.
Debates and open questions
How much wild bees versus managed honeybees contribute, and how bee declines will affect wild plants and the food supply, are active research questions.
▸Flowering plants include the grasses of Grasslands spreadWell established
The connection
Grasses are flowering plants, though their flowers are small and wind-pollinated. The grass family evolved in the Cretaceous, but grass-dominated landscapes spread only from about 20 million years ago, when cooler, drier climates favored plants that regrow from the base after grazing, drought and fire.
When and how
Grass origins in the late Cretaceous (phytoliths in Indian dinosaur dung, about 67–65 million years old); grasslands spread from the Miocene, about 20 million years ago.
The evidence
DNA places grasses among the flowering plants, close to sedges and rushes; fossil phytoliths and pollen trace their rise from scattered plants to dominant cover.
Debates and open questions
Why grasses took tens of millions of years to dominate, and how widespread they were in dinosaur times, are still open questions.
▸Flowering plants were an 'abominable mystery' to Charles DarwinWell established
The connection
Flowering plants appear in the fossil record fairly suddenly in the Cretaceous and diversify quickly, which seemed to clash with Darwin's gradual evolution. In an 1879 letter to Joseph Hooker he called their rapid rise 'an abominable mystery'. He speculated about an undiscovered landmass and welcomed Gaston de Saporta's idea that insects drove their spread.
When and how
Letter of 22 July 1879 from Darwin to botanist Joseph Hooker at Kew; Cretaceous fossils from roughly 130 million years ago onward.
The evidence
The letter survives in the Darwin Correspondence Project, and the Cretaceous fossil record still shows flowering plants spreading quickly.
Debates and open questions
Still partly unsolved: molecular clocks suggest flowering plants arose far earlier than their oldest fossils, perhaps over 200 million years ago, and their closest ancestors remain unclear.