A team of Chinese researchers has discovered the oldest known fossil of a flower bud, pushing back the evolution of flowers in history by at least a couple dozen million years. It is 164 million years old.
The origins of angiosperms are the subject of some controversy in paleobiology
The naturalist Charles Darwin questioned when and how the first flowering plants evolved and this finding could solve this mystery.
The fossil includes a physically connected leafy branch, fruit, and flower bulb, suggesting that angiosperms, the flowering and seed-producing plants, were present in the Jurassic period (201.3 million to 145 million years ago). ). This being the case , it could be the transitional stage that finally answers Darwin’s enigma that first came to light in 1879.
In a letter to his closest friend, the botanist and explorer Joseph Hooker, Darwin wrote: “As far as we can judge, the rapid development of all higher plants in recent geological times is an abominable mystery.”
a historical fossil
The fossil shoot, which was discovered in the Inner Mongolia region of China, measures 4.2 centimeters long and 2 centimeters wide . The tiny flower bud is about 3 square millimeters in size. The plant’s tissues are preserved in yellowish rock made from volcanic ash that was ejected during an eruption, leaving only its scars embedded in the rock deposit. The researchers have named the new species Florigerminis jurassica.
“Although more than 100 blooming flowers of Nanjinganthus dendrostyla— another fossil that was not considered an angiosperm at its 2018 publication—exemplify the true existence of angiosperms in the Jurassic, our current understanding of early angiosperms is still scant, ” the authors write. in their study published in the special publications of the Geological Society of London . “Here we report Florigerminis jurassica, a fossil plant that includes physically connected flower buds, fruits, and leafy branches, from the Jiulongshan Formation of Inner Mongolia, China.”
The flower bud and fruit on the fossil are strong indicators that F. jurassica was an angiosperm and not a gymnosperm (or nonflowering plant) , which was the dominant plant type during the Jurassic period.
The information we had until now (not much, because flowers are a very delicate component for the fossil record) had shown us that angiosperms did not arise until the Cretaceous period, between 66 million and 145 million years ago, but the new fossil is the most compelling evidence that this was clearly not the case. It is a true angiosperm. Meets all criteria.
“The currently accepted theory of angiosperm evolution needs to be revised, ” the experts conclude.
The researchers hope their new discovery will prompt a rethinking of the origins of flowering plants, and perhaps even the induction of those Jurassic “gymnosperm” fossils like N. dendrostyla into the angiosperm family.
Referencia: A Jurassic flower bud from China
Da-Fang Cui, Yemao Hou, Pengfei Yin and Xin Wang
Geological Society, London, Special Publications, 521, 6 January 2022, https://doi.org/10.1144/SP521-2021-122
