Scientists have identified what may have been the world's earliest flower that grew in the freshwater of the ancient Earth between 125 million and 130 million years ago.
The finding could change commonly-held ideas about the worlds earliest flowering plants, known of as angiosperms, Indiana University reported.
"This discovery raises significant questions about the early evolutionary history of flowering plants, as well as the role of these plants in the evolution of other plant and animal life," said David Dilcher, an emeritus professor in the IU Bloomington College of Arts and Sciences' Department of Geological Sciences.
The Montsechia vidalii once grew abundantly in lakes around the region of modern day Spain. The aquatic plant Archaefructus sinensis from China had previously been proposed as one of the world's earliest flowers.
"A 'first flower' is technically a myth, like the 'first human,'" Dilcher said. "But based on this new analysis, we know now that Montsechia is contemporaneous, if not more ancient, than Archaefructus."
To make their findings, the researchers looked at 1,000 fossilized remains of Montsechia using a stereomicroscope, light microscope and scanning electron microscope. The samples were compared to other fossilized plants such as the freshwater algae charophytes. The careful analysis was crucial, because the plant's structure could cause modern scientists to miss the fact that it was a flower at all.
"Montsechia possesses no obvious 'flower parts,' such as petals or nectar-producing structures for attracting insects, and lives out its entire life cycle under water," Dilcher said. "The fruit contains a single seed"-the defining characteristic of an angiosperm-"which is borne upside down."
The plant appears to resemble its most recent descendent, Ceratophyllum, which is a dark green aquatic plant often used to decorate today's aquariums and koi ponds.
In the future, the researchers hope to gain more insight into these ancient plants, and determine where and when other angiosperms branched off from their direct ancestor.
"There's still much to be discovered about how a few early species of seed-bearing plants eventually gave rise to the enormous, and beautiful, variety of flowers that now populate nearly every environment on Earth," Dilcher concluded.
The findings were published in a recent edition of the journal Proceedings of the National Academy of Sciences.
