​Fossilised remains of world’s oldest flower discovered in Spain

A beautiful aquatic plant, dating back to the start of the Cretaceous period, is believed by scientists to be the oldest flowering plant on Earth.

New analysis of the fossilised remains from central Spain and the Pyrenees show that the plant is about 130 million-years-old, meaning it was around at the same time as feathered dinosaurs.

The plant, Montsechia vidalii, resembles the modern-day coontail - commonly used to populate aquariums - and is thought to have grown underwater in shallow lakes.

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The plant snatches the title of world’s oldest flower from the hands of another ancient plant, Archaefructus sinensis, discovered in 125 million-year-old fossils from Liaoning Province in China.

“The ‘first flower’ is a bit of a poetic concept, but that aside, we do believe this is the oldest we have discovered so far,” says David Dilcher at Indiana University, who led the analysis.

To study the ancient plant, Dilcher and his team slowly dissolved the limestone around more than 1000 fossils. This left them with small fragments of the plant that could then be bleached and their structure examined using powerful microscopes.

The plant appears to have had no roots or petals. Its leaves were arranged in two forms: either in a spiral or opposite one another along an axis. The plant sprouted several tiny flowers, each of which contained a single seed.

Animals in this time period hadn’t developed any role in the dispersal of seeds, says Dilcher. Instead, the plant is thought to have separate male and female flowers. It seems likely that the seeds were released straight into the water, where they floated off to fertilise another plant.

“This is a fascinating and provocative analysis of the new fossils,” says Sam Brockington, a research fellow in the department of plant sciences at Cambridge University. “It has always been difficult to say whether the first flowering plants emerged in aquatic conditions, but this paper emphasises how important aquatic environments were for the earliest flowering plants.”

Sometime in the middle of the Cretaceous period the diversification of the flowering plant population exploded, developing into the beautiful blooms we know today, as well as influencing the wildlife that evolved alongside. Dilcher says that we wouldn’t be here at all if it weren’t for plants like Montsechia vidalii. “We are a product of the many stages of evolution that went hand-in-hand with the evolution of flowering plants,” he says.

Bernard Gomez of Claude Bernard University, Lyon, and co-author of the paper, which is published today in PNAS, says that there may yet be an even older flowering plant. There’s evidence of pollen dispersed in fossils that are around 140 million years old, he says.

One thing is for sure, says Dilcher, “we need to understand as much as we can about flowering plant evolution because right now we’re facing a world crisis.” Most modern flowering plants need animal pollinators to reproduce, with bees serving that role for many of our most important crops. Yet bees are declining in the US and Europe.

“This plant shows us where it all began,” says Dilcher. “If we know more about their evolution, we might come across alternative pollinators that are hidden out of sight today but played a role in the past that we could encourage again.”