Montsechia vidalii possessed no petals or nectar to attract insects, living its entire life cycle underwater, but did contain a single seed, the defining characteristic of an angiosperm. Researchers say the plant would have looked like its most modern descendent"?uCeratophyllum"?ualso known as coontails or hornworts.
Image: Indiana University

The flowering plants (angiosperms) are the most diverse group of land plants. Montsechia vidalii, an ancient aquatic angiosperm, was identified over 100 years ago in limestone deposits in central Spain.

Now research published as "Montsechia, an ancient aquatic angiosperm,"¹ asserts these fossil plants in Spain are 130 million years old (dinosaurs existed from 66 to 231 million years ago), and have been poorly understood and misinterpreted.

The study examined 1,000 carefully prepared specimens of Montsechia. Researcher David Dilcher (Indiana University) notes: "The morphology and anatomy of the plant, including aspects of its reproduction, suggest that Montsechia was an aquatic angiosperm living and reproducing below the surface of the water." Given that aquatic plants were locally common at a very early stage of angiosperm evolution, the researchers believe aquatic habitats may have played a major role in the very early evolution and diversification of flowering plants.

Previously, the oldest flowering plant was thought to be Archaefructus sinensis, an aquatic plant found in China. "Based on this new analysis, we know now that Montsechia is contemporaneous, if not more ancient, than Archaefructus," Dilcher said.

^{1. Gomez B, Dilcher D, et al. Proceedings of the National Academy of Science of the United States of America, Aug. 17, 2015 https://tinyurl.com/p9eyezx}