With over a thousand species worldwide, the Rhamnaceae family of floral plants, popularly known as Buckthorn, emerged 50 million years before dinosaurs roamed the Earth. The discovery is part of a study published this Tuesday (30) in the journal Trends in Plant Science.
The authors of the research say that this group of flowering plants is 150 million years older than previously thought. Scientists who contributed to the study are Byron B. Lamont, an evolutionary ecologist at Curtin University, and Tianhua He, a molecular geneticist at Murdoch University, both in Australia.
The pair analyzed ancient Myanmar flower fossils and compared them to related living plants around the world. With this, experts found that the Rhamnaceae family is 260 million years old. Previously, the species in the group were estimated to be 100 million years old.
“Flowering plants are the foundation of our entire existence, producing oxygen, food, wood, medicine, habitats for animals and the parks and gardens where we live,” says Lamont in a statement. “The Buckthorn family is spread across Africa, Australia, North and South America, Asia and Europe, and produces the popular Chinese edible date,” he reports.
The researchers also say that the group of flowers appeared before the Triassic period, when dinosaurs existed on the planet. To arrive at these results, they used a technique similar to one made famous in the “Jurassic Park” film series. This consisted of dating the Rhamnaceae based on the sap of a flowering plant preserved intact in amber.
The professor explains that the charcoal, also in the amber, “provided a view of the conditions in which this group of plants evolved”. He claims his team analyzed the DNA of the family’s Phylica species, which was previously believed to be dated to just 20 million years ago.
According to him, the team traced fire-related traits across as many living species of the family tree as possible, using a technique called “ancestral trait attribution.” Sap, for example, can be released by fire-wounded coniferous trees, flowing over the Phylica flowers and preserving them intact as amber.
Almost all living Phylica, by the way, have hard seeds that require fire to stimulate them. “Together with the knowledge of the need for heat to promote the germination of most living species, this showed that the family [Rhamnaceae] probably arose in vegetation subject to regular fires”, the ecologist concludes.
