Seed germination typically occurs in the ground after a seed has fallen, but several embryonic stems were captured emerging from the ancient pine cone in a rare botanical feat known as precocious germination, or viviparity, in which seeds sprout before leaving the fruit.
“I find it fascinating that the seeds in this small pine cone could start to germinate inside the cone and the sprouts could grow out so far before they perished in the resin.”
Precocious germination in pine cones is so rare that only one naturally occurring example of this condition, from 1965, has been described in scientific literature, Poinar said in the statement.
When seed germination does occur inside plants, it tends to be in things like fruit — think of the baby pepper you sometimes see when you cut open a bell pepper — but it’s rare in gymnosperms such as conifers that produce “naked” or non-enclosed seeds.
The fossilized pine cone is from an extinct species of pine tree called Pinus cembrifolia. Preserved in Baltic amber, clusters of needles are visible, some in bundles of five.
Based on their position, some of the stems’ growth, if not most, occurred after the pine cone came into contact with the sticky tree resin, Poinar said. The research was published in the journal Historical Biology last week.
Poinar has worked on amber fossils for decades, first discovering in a 1982 study that amber could preserve intracellular structures in an organism trapped inside. His work inspired the fictional science in the “Jurassic Park” book and movie franchise, where DNA is extracted from dinosaur blood inside a mosquito trapped in amber to recreate the prehistoric creatures.