A gorgeous 100 million year-old robber

by Matthew Cobb

Anyone who’s watched Jurassic Park knows that back in the time of the dinosaurs, flies would get stuck in amber and then hove up, millions of years later, for the delectation of scientists. A paper has just come out from Torsten Dikow and David Grimaldi, describing a new species of robber fly (Asilidae) found in Cretaceous amber, around 100 million years old.

Just think. 100 million years old. All that time ago, this fly was buzzing around. The specimen is simply stunning. Even if you don’t like flies, this is just gorgeous:


This is a male of the newly described genus and species Burmapogon bruckschi. The etymology is sadly rather dull:

“From Burma, the original name of the country where this amber is deposited, and Greek pogon, “beard,” a common suffix of Asilidae generic names, referring to the mystax. The generic name, to be treated as masculine, refers to the region of the amber deposit.”

The ‘mystax’ is a cluster of hairs just above the animal’s mouth. Here’s a picture of the mystax on a modern robber fly Stichopogon albofasciatus, which is found all over Europe and in North Africa. The photo is taken from the delightfully retro www.robberflies.info

Stichopogon albofasciatus - Mystax - frontal

The Burmapogon bruckschi specimen was found in amber from Burma – this is apparently the first time that robber flies have been found in the scores of thousands of pieces of Burmese amber that contain insects. The reason for that is probably that amber was produced by trees, and Asilidae don’t like wooded areas.

Look at the detail on this left middle leg:













Amazingly, Dikow and Grimaldi found two B. bruckschi flies, a male and a female, in two separate pieces of amber. This is not the oldest robber fly – as Dikow and Grimaldo write: ‘The oldest definitive Asilidae, †Araripogon axelrodi Grimaldi, 1990, was described from limestone of the Crato Formation (Albian, ~112 myo) in Ceará state in northeastern Brazil (Grimaldi, 1990).’

Robber flies (also called assassin flies) are extremely agile predators that can catch and suck the juices out of prey much larger than them. We’ve talked about them here before. This video gives you some idea of their amazing behaviour.

Like everything else in the history of our planet, however, they are sometimes eaten, as this rather shaky video shows…

h/t @BioInFocus

Reference: T. Dikow and D. Grimaldi (2014) Robber flies in Cretaceous ambers (Insecta, Diptera, Asilidae). American Museum novitates, no. 3799. (open access)


  1. Daoud
    Posted April 22, 2014 at 1:03 pm | Permalink

    Frozen in time like that for 100 million years. This is awe-inspiring.

  2. Posted April 22, 2014 at 1:18 pm | Permalink

    An amazing find. The video of robber fly predation shows how viscous these little guys are to their prey, to insert a little anthropomorphism.
    If anyone is curious, the proboscis that you see is really the sheath covering the real tools they have, which is a couple of stiletto blades contained in the sheath. I have handled many of these, and they never seem to bite people.

    • ratabago
      Posted April 23, 2014 at 11:15 pm | Permalink

      Maybe it depends on the species? I’ve been bitten by robbers while bush walking, probably more than a dozen times over the years. Unfortunately, it usually results in their death by “reflex” slap. Aberrant behaviour on the flies part, they don’t feed on mammalian blood.

  3. John Harshman
    Posted April 22, 2014 at 1:27 pm | Permalink

    Asilids are my second favorite family of flies. It’s really fun to watch them hunt. Hey, is that tiny black blotch in the triangle formed by the robber fly’s legs another, much smaller fly? Kind of looks like a psychodid from here.

    • Posted April 22, 2014 at 1:39 pm | Permalink

      Good eyes! I see how it looks like a psychodid.

    • Gregory Kusnick
      Posted April 22, 2014 at 3:09 pm | Permalink

      But look at the scale bar. A fly with a wingspan of a quarter millimeter seems implausibly small. I’m no expert, but a quick Google (as well as personal experience with drain flies) seems to indicate that adult psychodids are about ten times that size.

      • John Harshman
        Posted April 22, 2014 at 5:49 pm | Permalink

        I hadn’t even noticed there was a scale bar. But now that you mention it, if that had been a psychodid, that would also have been one gigantic asilid.

  4. Posted April 22, 2014 at 2:01 pm | Permalink

    It’s kinda amazing to think of just how little has changed over the span of an hundred million years…and how much has changed at the same time. Really plays with the mind.


  5. Avis James
    Posted April 22, 2014 at 2:06 pm | Permalink

    You don’t like flies??!!??

  6. rodgerma
    Posted April 22, 2014 at 2:26 pm | Permalink

    Amazing, 100 million years old documentation!

  7. ladyatheist
    Posted April 22, 2014 at 6:40 pm | Permalink

    And the eyeball on the backside of the bug that eats it is pretty amazing too!

  8. Achrachno
    Posted April 22, 2014 at 8:38 pm | Permalink

    It’s interesting that the basic design for robber flies was worked out by natural selection so long ago and in such a different environment. The initial radiation of the flies found this sweet spot in evolutionary space and these flies have apparently just stayed there.

    No doubt evolution has tinkered as necessary, producing innumerable new species to fit particular niches as they’ve opened, but the robber flies are still similar after all these years. This one couldn’t be accommodated in any known extant genus, but it’s still surprisingly close to living animals. Who’d expect a smallish clade of flies to last 100 million years without diverging into something different?

  9. Kurt Lewis Helf
    Posted April 23, 2014 at 3:59 am | Permalink

    The head swiveling behavior of the Asilid in the first video is very mantid-like.

  10. Reginald Selkirk
    Posted April 23, 2014 at 6:54 am | Permalink

    Very well-preserved. I think I read about these in my Atlas of Creation. Just one thing I can’t figure out: where’s the fish hook?

  11. uglicoyote
    Posted April 23, 2014 at 7:43 am | Permalink

    Reblogged this on The Road.

  12. marksolock
    Posted April 23, 2014 at 8:04 pm | Permalink

    Reblogged this on Mark Solock Blog.

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