This piece, from ZME Science, doesn’t contain a reference to an article, but the Oregon State University press announcement notes that the paper is in the Journal of the Botanical Institute of Texas. I don’t have access to that journal electronically, so I’ll just summarize the results briefly. (Note to science bloggers: please give the reference to a published paper when summarizing its contents. Note to press offices: please cite the full paper instead of just the name of the journal!)
At any rate the announcement from the OSU press office reveals the discovery of a group of 18 flowering plants (all of a single species) preserved in amber from the Cretaceous, about 100 million years ago. The plants have sticky pollen, indicative of an insect pollinator, and the amber preservation allow us to see pollen tubes growing down into the style as well as incipient seed formation, both indications of sexual reproduction—the earliest sexual reproduction seen in flowering plants.
Here are the flowers:
And the pollen tubes, with the captions from the press release:
As the OSU press release note, “The fossils were discovered from amber mines in the Hukawng Valley of Myanmar, previously known as Burma. The newly-described genus and species of flower was named Micropetasos burmensis.”
Now if this pollen really is fertilizing the ovule, then it truly is sexual reproduction. It’s another question entirely whether this is cross-fertilization (pollen from another individual) or self-fertilization (pollen from the same individual). Selfing doesn’t require insects, and cross-pollination can occur by other mechanisms, such as wind. But since the “selfing” condition is invariably evolved from outcrossing ancestors, this does at least provide the earliest date for known cross-pollination in flowering plants. And since we know that “thrips” (small insects) were pollinating gymnosperms (“naked seed” plants like gingkos and confers) in the early Cretaceous, there were already insects around whose descendants or relatives could pollinate flowering plants.
Finally, do remember that flowering plants arrived relatively late on the evolutionary scene: probably about 160 million years ago. That is roughly 400 million years after the Cambrian explosion, and shows that not all “major groups” of organisms or their “Baupläne” (“body plans”) appeared suddenly in the Cambrian. If Jesus made the Cambrian explosion in one big party, as Stephen Meyer maintains, then the Savior forget to bring flowers.