Fossilized remains of flowers from Kansas are demonstrating a species divergence that occurred 100 million years ago.
In 1984, David Dilcher from Indiana University published his research describing the genus Archaeanthus, a woody angiosperm (flowering plant) the flourished in the Albian period (113 to 100 million years ago). At the time of this report, Dilcher hypothesized that Archaeanthus was a close relative of the living family known as Magnoliaceae – which includes the Magnolias – and Liriodendroidae – tulip trees. But no hard and fast evidence has been provided for its assignment to this family.
Dilcher worked alongside Mikhail S. Romanov from the Russian Academy of Science in Moscow to put Archaeanthus on the evolutionary map and gain a new understanding of how prehistoric plants developed. In a study from the American Journal of Botany published last month, the two scientists conducted a close analysis of the fruit and pericarp – the part of a flowering plant at the top of the stem, right below where the petals begin – of Archaeanthus fossils and compared them with extant plants belonging to Magnoliaceae.
Archaeanthus showed morphology very close to that of Magnoliaceae, but specific features were much more similar to the tulip trees than to the magnolias. Both Archaeanthus and the Liriodendroidae group have fruits of similar size, longer beaks within fruitlets, and had similar seed dispersal modes, among other similarities. The scientists concluded that Archaeanthus was probably a species among the tulip tree lineage – which suggests something even more interesting: Liriodendroidae and Magnolioideae diverged before Archaeanthus came about – much earlier than paleontologists had estimated.
Modern tulip trees include species living in both North America and Asia. In the spring, they blossom tulip-like pink or yellow flowers, though they aren’t related to the tulip family. Tulip trees diverged from their close relatives magnolias long ago – the tulip tree was a sight probably enjoyed by the dinosaurs.
This new insight into the ancient history of flowering plants may help botanists and paleontologists alike form a better understanding of the evolution, survival, and fitness of long-standing groups such as Magnoliaceae.
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