Today I came upon a ginkgo tree dropping ripe “fruits.” (I know that is not the right term, because ginkgo is a gymnosperm; but visually, they look like drupes to me.) Since it has been a long time since I had ginkgo nuts, I took the opportunity to gather some. The foul odor of the “fruits” clung to my hands and the sack I was using.
That got me wondering: when a plant produces a fleshy covering for its seeds, it is because that plant relies on an animal to eat the fleshy part and disperse the seeds. What animal would eat a “fruit” as nasty as the ginkgo’s? I have a mental picture of a Stegosaurus munching on ginkgo “fruits” in a Jurassic forest, and I had the thought that those ancient reptiles must have had very different tastes than Holocene mammals like me.
But then it occurred to me that the ginkgo could not possibly have made it all the way to human times unless it adapted to other dispersers since. Who took over after the great reptiles died out? Then I found this article: Ginkgo: an icon of “ghost” mutualistic interactions. Except for the multituberculates (by analogy with Torreya today), it was rather vague, merely saying that “large and medium sized mammals” would have been the dispersers. Which still leaves me wondering: what mammals would eat something so nasty?