Ancient flowering plants found in amber, suggests insect pollination 100 million years ago

January 6, 2014 • 8:46 am

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:

This flower preserved in 100-million-year old amber is one of the most complete ever found. (Photo courtesy of Oregon State University)

And the pollen tubes, with the captions from the press release:

Screen shot 2014-01-06 at 9.24.11 AM
The pollen tubes penetrating the stigma on this ancient flower are the only known fossil of this type, showing the process of sexual reproduction in a flowering plant. (Photo courtesy of Oregon State University)

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.

h/t: Ant

50 thoughts on “Ancient flowering plants found in amber, suggests insect pollination 100 million years ago

  1. Poinar, Jr., George O., Kenton L. Chambers, and Joerg Wunderlich. 2013. Micropetasos, a new genus of angiosperms from mid-Cretaceous Burmese amber. Journal of the Botanical Research of Texax 7(2)745-750.

  2. 100 MYA seems awfully recent for plants to have discovered sex.

    I can easily understand why this would be the earliest fossilized evidence of such, but shouldn’t there also be some pretty strong DNA evidence of when the plants started “doing it”?


    1. I agree that the comment must mean the first fossilized evidence for sexual reproduction in plants. As far as I know, all land plants undergo an alternation of generation between sporophyte and gametophyte forms. If they have a gametophyte stage, then they’re producing gametes which means they’re having sex, or at least trying to.

      I’d be kind of surprised if there is no earlier fossil evidence for sexual reproduction in plants than these flowers. Are there no fossil gymnosperm cones showing a pollen grain fertilizing an ovule?

    2. Sex surely evolved well before any multi-cellularity, so any plants which reproduce asexually would be derivative, with sexual reproduction being the primitive condition.

      You don’t need flowers, after all, to have plant sex.

    3. Sexual reproduction per se is much older, dating to the earliest eukaryotes in the oceans. The claim this is the 1st fossil evidence of sexual reproduction in plants seems to be a case of sensational journalism.
      Fossil traces of non-vascular plants go back over 400 million years (todays examples of such plants are mosses and liverworts). The fossils include sporangia and spores, which are strong indicators of the plant sexual life cycle.
      What I suppose may be new in the present case is this is evidence of insect vectored sexual reproduction.

      1. Well, the press release specifically says it’s “the oldest evidence of sexual reproduction in a flowering plant” (my emphasis).

        1. Not even that, since there’s plenty of evidence for flowering plants in pollen long before macrofossils. And the pollen-tube fertilization was invented by gymnosperms 100 million years or so before this amber.

          Similarly, we infer insect pollination without catching a bee or beetle in the act.

          This is just a very nice prep of what we knew to be there.

  3. When my dad sent this to me yesterday, besides the coolness of the discover, I thought it was sad just like the pictures of the fossils of animals — about to get lucky but awwww, dead.

  4. I have a totally off-topic question to ask, yet a serious one. I know many scientifically knowledgable people read this website and comments. I am hoping someone can help me out.

    I have been hearing from relatives that there’s something seriously deliterious to your health about eating canola oil (the oil of the rape seed, Brassica spp.). This is not mentioned as being the results of GM plants.

    Can anyone tell me if there is any solid, scientifically sound data indicating health issues with canola/rape oil? (I’m aware that excess concentrations of erucic acid may be an issue; but the discussions have never mentioned erucic acid.)

    Any help would be much appreciated! Thanks and sorry for being off-topic. 🙂

    1. I did not know about concerns regarding canola oil, but I love to look stuff up, so I found this on the Mayo clinic web site:
      ” Health concerns about canola oil are unfounded. Canola oil, which is extracted from the seeds of the canola plant, is generally recognized as safe by the Food and Drug Administration.

      Misinformation about canola oil may stem from the fact that the canola plant was developed through crossbreeding with the rapeseed plant. Rapeseed oil contains very high levels of erucic acid, a compound that in large amounts can be toxic to humans. Canola oil, however, contains very low levels of erucic acid.

      Canola oil is also low in saturated fat and has a high proportion of monounsaturated fat, which makes it a healthy and safe choice when it comes to cooking oils.”

      Interestingly, my search had a lot of hits from the anti-GMO crowd against canola oil. Please disregard these. They are b.s.

      1. I wish there was better food science available. There is so much misinformation and pure nonsense out there that it is hard to find anything useful beyond the obvious: “eat a variety of foods in moderate amounts and avoid a lot of highly processed stuff”.

        And then I go and eat some fake-meat stuff for lunch, just to show that I can’t even follow the obvious advice.

    2. Quackwatch says it’s safe, but unfortunately doesn’t offer any links to mainstream sites that might support that.

      Snopes covers it here and says that modern canola oil has less than 1% erucic acid in it; the FDA regulates erucic acid content and US and Canadian producers remove it.

      Having said that, it’s just a cooking oil. If you’re unsure about using it or someone in your family doesn’t like it, picking another one may be a lot easier than fighting over their irrational fear of it.

      1. Thanks all. That’s about what I figured.

        They say things like ” ‘they’ are saying it’s a bad carcinogen …”

        And when I scoff at that, they say, “And you won’t look into it further will you?”

        So I feel somewhat obligated to “look into it further.” And I was hoping for more study data. If anyone is still looking or reading, if you know of good study data, I’d love to know about it.

        One of them studied aryuvedic “medicine” and the other subscribes to most of the food fads that come along. So you can see where they are coming from.

        I keep saying: Eat a balanced diet, not too much, get exercise and enough sleep. Keep your stress under control. Follow the advice of people who support it with real scientific data (e.g. Mayo, FDA). Beware the First Study Effect. Beware people’s advice who have a vested interest in selling you books that purport to tell you how to live the perfect life (and forever).

        And also: There are no magic bullets. Eating Quinoa is not going to make you live ten yeaars longer, get rid of your aches and pains as you age, or make you lose weight.

        And isn’t it just remarkable how all these supposed experts on eating (etc.) always come back ’round to the number 1 American neurosis: Losing weight. Whatever the magical new juice, seed, or whatever is, it ALWAYS makes you lose weight (not). I’ve asked them to observe this and see that it’s all just marketing nonsense and that ‘they’ (the self-help and supplements industry) are obligated to trot out a new food magic bullet or evil food every month to fill their magazines (and the Oprah and Dr. Oz shows) with. To no avail, I’m afraid.


        1. I doubt anyone is following this post anymore; but here’s what I found (canola is perfectly safe — well as safe as any other foodstuff.)

          Here’s the article that probably set it all off:

          Did any of these people who put “canola is deadly” about on the internets even read this article? Not likely.

          It basically says that if you spend your work day standing over a smoking hot fire of UNREFINED rapeseed oil, you have an increased lung cancer risk. Non one should be surprised by this. Two key points: US Canola IS refined (and has extremely low levels of erucic acid) AND: This study found that US canola oil is NOT mutatgenic (it won’t cause cancer.)

          Also debunked at Urban Legends:

          Details about rapeseed, canola, etc.:

          And these from Eric, above:

          Happy frying.

      2. My own objection to canola is that I’ve never particularly cared for the flavor. There always seems to be a much better option, gastronomically at least.


        1. When flavor matters, I usually use EV olive oil. However, sometimes I don’t want that olive oil flavor. Then I usually use canola.

          One dish I make, which is basically fried cauliflower with an amazing tahini-garlic-lemon-pepper sauce on top, the canola does wonderful things for the caramelizing cauliflower.

          1. I, too, use olive a lot — and, of course, there are times when the flavor isn’t called for or when more heat is needed than olive can handle. For the most part in those situations, I’m looking for something with its own distinct flavor, and butter, schmaltz, coconut oil, bacon drippings, or peanut oil are generally on the short list for things with heat, and sesame or other delicate oils for things without.

            And then there’re the dishes where the oil should have little or no flavor of its own to contribute. That’s the sort of situation where I think you’d go for the canola…but I’d generally go for either sunflower or grape seed instead. Both have very mild flavors and can generally take very high heats (grape especially) — and I personally prefer either to canola. Mayonnaise, for example, I’ll either make with olive oil if I’m looking for something robust or sunflower oil if I’m looking for something mild. Olive and a white balsamic vinegar and fresh garlic and ground mustard is one great combination, and sunflower and chardonnay vinegar and no other seasonings is another.



  5. Aren’t we lucky that amber preserves organisms from 100 MYA! And in such detail! Or did God give us amber to reveal the wonders of his handiwork? I’m going with the first proposition. What else out there is preserved in amber? Younger generation, get cracking.

        1. Hahahahaha!

          Seems like that must have been posted before, but I’ve missed it till now.

          “Eternal Litterbox.” Bwah ha ha!

          1. Yeah, that’s an ancient one from the golden days of USENET.

            <sigh />

            On the plus side, at least now I’m well familiar with the sensation of being an old fart….


              1. Blast — you mean I’ve gotta have people feed me and change my diapers? And I’m gonna have to be a teenager again.

                Damn. A dude can never get a break in this universe….


  6. Structural preservation in amber can be amazing. Many years ago it was my privilege to serve on a Masters dissertation committee of a student who did an electron microscope study on the preservation of insects in Cretaceous amber. These insects were living in the shadow of dinosaurs! Since I was the ‘buggy’ one I was also asked to help key the insects out to order and family, which I was very glad to do. They were mostly muscoid flies and parasitic wasps, and many could be clearly identified to family using modern insect keys.
    Anyway, the EM study revealed that even subcellular details of cells, like the fine sarcomere structure of muscle cells, could be ‘preserved’ in these amber specimens. It is important to bear in mind that these structures were not organic cell structures, but were instead carbon ‘ghosts’, impressed into the ancient tree resin. Still, the EM level details were totally amazing!

    1. Wow that would be amazing! You can tell how good the insect looks in amber but I had no idea it was actually so well preserved as you detail in your post. Of course, thinking about it, why wouldn’t it.

      Maybe I should amber myself on death for fixing me up later. 🙂 It’s a bit like the TV Series, Fringe.

      1. Again, the preserved details were ‘only’ carbon (or what looked like carbon anyway) impressed into the amber. Dreams of resurrection or even Jurassic Park cloning would be very much out of reach.

    2. So the amber is sort of like the resins commonly used for embedding EM specimens. I was an electron microscopist long ago; I wish I’d tried sectioning amber with insects in it!

  7. This is interesting but in NO WAY is the earliest example of sexual reproduction in plants. The presence of spore tetrads (products of meiosis) is very ancient and has been found in the earliest known vascular plants. This claim is just plain wrong. Land plants have been reproducing sexually from the beginning (well over 400 million years).

    1. Thank you for the correction; I meant sexual reproduction in angiosperms, of course, not all plants and have changed it to reflect that.

      But you needn’t have been so vehement in calling out the mistake, using both NO WAY in all caps and “just plain wrong.”

      As I keep saying, I’d appreciate it if people would be a little more civil around here, both to the host and to each other. Professor Ceiling Cat is getting tired of incivility.

  8. Sexual reproduction doesn’t necessarily involve copulation, nor even sexes. As several commenters have pointed out, land plants and their green algal ancestors nearly all reproduce sexually, in land plants by sperm and eggs produced from their multicellular haploid stages, the gametophytes. In seed plants (gymnosperms and angiosperms) the gametophytes are unisexual. The male gametophyte is dispersed as the pollen grain and the female gametophyte is retained on the (diploid) sporophyte and enclosed in the ovule. Pollination is a means of transporting the male gametophyte into very close proximity to the female gametophyte, so that sperm can be delivered to the egg by a pollen tube. It occurs in both Gymnosperms and Angiosperms, so it’s very much older than these fossils. What’s characteristic of flowering plants is the stigma, part of the carpel that encloses the ovules. It’s nice to see this happening in actual fossils, but I don’t find it surprising, since it’s characteristic of flowering plants.

  9. This was actually one inflorescence with 18 flowers, hence only one individual plant represented.

    This is important, as mentioned in the paper, because these fls. are all attached and hence known to be one species/individual. Fossil flowers are usually found as fallen individual flowers and so we can’t know if they’re all from the same individual, even if from the same blob of amber. In this case the form of the inflorescence can be determined!

    This is also from fairly early in the history of the angiosperms and represents a plant not readily placed close to known eudicot angiosperm. An additional view of early angiosperm diversity.

  10. I myself am always amazed at how recent grasses have only developed. That always makes me think evolution missed something obvious for a long time.

    (yes yes I know there probably wasn’t a habitat for grasses etc etc)

  11. I think this thread would be the best place to ask for this help:

    I need a suggestion regrading any good, reliable book on ‘plant evolution’ written for general audience, like Dr Coyne did with his Why Evolution is True.. if not then something for the expert will do ( I will try)

    Thanks in advance..

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