Oldest flower bud ever discovered, massively changing plant evolution timeline

The oldest known fossil of a flower bud has been discovered by researchers in China, pushing back the evolution of flowers in history by at least a few tens of millions of years and changing the way we think about how Brontosaurus celebrated Valentine’s Day.

“Many paleobotanists are surprised [by the fossil], because it is quite different from what is said in the books,” Xin Wang, from the Nanjing Institute of Geology and Paleontology, told Live Science. “But I’m not that surprised.”

Florigerminis jurassica and its details. Wang et al, Geological Society of London, 2022

Wang is lead author of a new paper on the discovery, published in the journal of the Geological Society of London.

The flower, named Florigerminis jurassica by the researchers who found it, is a type of angiosperm – that is, a flowering plant. The origins of angiosperms are the subject of some controversy in paleobiology: flowers are generally too fragile to survive for millions of years in the fossil record, so the evidence for their evolution is patchy.

Previously it was not known that they existed from the Cretaceous period between 66 and 145 million years ago, but there are a few fossils that have appeared in recent decades that have hinted at an older origin.

One of these fossils – an ancient Nanjinganthus dendrostyla whose discovery was the subject of a 2018 article published in eLife – is even older than F.jurassica. However, its status as a true flowering plant has proven controversial: some researchers believe N. dendrostyla was not complex enough to count as an angiosperm, while others have argued that it is too complex to be a non-flowering plant (or “gymnosperm”).

  1. F.jurassica, however, “not only includes a leafy branch, but also physically connected fruit and flower buds,” Wang explained in a statement. This removes any ambiguity: if a plant can have a flower bud and a ripe fruit, according to the team, this implies the existence of blooming flowers in the intermediate stage.
  2. The researchers hope their new discovery will spark thinking about the origins of flowering plants – and perhaps even the induction of such Jurassic “gymnosperm” fossils as N. dendrostyla in the angiosperm club. Until now, Wang told Live Science, many plants that could potentially be angiosperms were assumed to be gymnosperms simply because they originated in the Jurassic period.

“We hope that the discovery of [F. jurassica], with its physically connected branch, leaf scars, flower buds, and fruit, may help ease the pain of accepting pre-Cretaceous angiosperms,” the authors conclude in their paper. “The currently accepted theory of angiosperm evolution needs to be revised.”