Pelican spiders (again)

In January I called your attention to “pelican spiders” (also called “assassin spiders”), a group once known only from amber fossils but which has recently been described from Madagascar, Australasia, and Southern Africa (as you’ll see in the video, that distribution makes evolutionary sense). The “assassin” name comes from their extraordinarily long chelicerae (jaws), which enables them to grab other spiders (their usual prey) holding them at jaw’s length so they can’t be bitten back during the attack.

At the time I put up my post, I couldn’t find any videos of this predatory behavior. Since then one has appeared in the New York Times, which I’ve embedded below (the predation takes place about one minute into the video) . Take two minutes to acquaint yourself with one of the weirdest arthropods around. (Click on the white arrow to start the video.)

Here’s the paper whose first author, Hannah Wood, appears in the video (free link):

Wood, H. M. and N. Scharff. 2018. A review of the Madagascaran pelican spiders of the genus Eriauchenius O. Pickard-Cambridge, 1881, and Madagascarahaea gen. n. (Araneaa, Archaeidae). ZooKeys 727:1096.

24 Comments

  1. busterggi
    Posted March 28, 2018 at 2:22 pm | Permalink

    Considering the age of the lineage, isn’t it the pelicans who evolved converged looks rather than the spiders?

    • Michael Fisher
      Posted March 28, 2018 at 3:16 pm | Permalink

      As far as I’m able to ascertain, via Mr. Google, there’s no date for the beginning of the Pelican bird lineage – all we know is it’s more than 30 million years – from a fossil bird with a bill that’s mostly the same as today’s pelicans.

      • Posted March 28, 2018 at 6:54 pm | Permalink

        A wonderful bird is the pelican,
        His bill will hold more than his belican,
        He can take in his beak
        Enough food for a week
        But I’m damned if I see how the helican!
        ~~ Dixon Lanier Merritt

  2. ThyroidPlanet
    Posted March 28, 2018 at 2:24 pm | Permalink

    Sub

  3. Jessy Smith
    Posted March 28, 2018 at 2:39 pm | Permalink

    “These ancient assassins eat their own kind”

    So they are regressive liberals?

    Sorry, I couldn’t resist.

  4. glen1davidson
    Posted March 28, 2018 at 2:40 pm | Permalink

    The brief pelican.

    Glen Davidson

  5. Posted March 28, 2018 at 3:17 pm | Permalink

    Sorting through the berlesate samples of the Australian National Insect Collection (25+ years ago in Canberra, Australia) I came across a number of these strange little critters. It’s great that they’re now being studied in detail.

    rz

    • loren russell
      Posted March 28, 2018 at 4:06 pm | Permalink

      Props to the first non-entomologist who can define “berlesate” without looking it up!

      • Mark R.
        Posted March 28, 2018 at 6:15 pm | Permalink

        I didn’t know, but looked it up. Simple yet effective device.

        • loren russell
          Posted March 28, 2018 at 9:03 pm | Permalink

          I travel with a couple “Berleses” powered by electric heating pads. Sometimes I catch bugs, sometimes I iron out my sore back.

          • Mark R.
            Posted March 29, 2018 at 11:58 am | Permalink

            🙂

  6. Posted March 28, 2018 at 4:37 pm | Permalink

    This is why I love WEIT. I never know what wonders I’m going to discover next.

  7. Dave
    Posted March 28, 2018 at 4:53 pm | Permalink

    Fascinating creatures, and amazing footage. However, I wish the commentator on the film had avoided the sloppy language about these spiders “eating their own kind”. Unless their prey is a conspecific, they are no more “eating their own kind” than we are when we eat a beefsteak or a pork chop. Probably less so, in fact. Given the apparent antiquity of this spider clade, in evolutionary terms they may be further removed from their spider prey than we are from cattle and pigs.

    • infiniteimprobabilit
      Posted March 28, 2018 at 5:30 pm | Permalink

      Yes, that phrase didn’t seem to fit with the description in the post.

      Praying mantises notoriously ‘eat their own kind’ but not, apparently, these spiders.

      cr

  8. Posted March 28, 2018 at 5:12 pm | Permalink

    Cool! Interesting to see how their extraordinary feeding appendages work. Other spiders sport long chelicerae (long-jawed orb weavers), but far as I know those are long because of their ways of mating.

  9. Christopher
    Posted March 28, 2018 at 6:13 pm | Permalink

    To hell with the Nobel Prize, I’d be more honored to describe a new species of anything, much less 18 new species. Hats off to Wood et al. for their nifty work.

  10. Mark R.
    Posted March 28, 2018 at 6:30 pm | Permalink

    I love seeing a specie’s overlay on Pangaea and where it ended up. I’ve never uncovered any creationists who dispute evolution by denying Pangaea and its implications (though I admit not trying very hard). Maybe there aren’t enough creationists (religious folk in general) who understand or connect the geological support for evolution; therefore the evolution-deniers don’t bother bringing it up or disputing it. They have enough on their hands with Lucy et al.

    • Michael Fisher
      Posted March 28, 2018 at 6:51 pm | Permalink

      There’s been some dodgy or shoddy work on Lucy over the years – a bone or two added to Lucy that was found a kilometre or so from the Lucy collection at a later time. A lot more lab work could be done on Lucy & heck more investigation of the two main sites as well. I dunno why it hasn’t been a top priority to understand more about her, her environment & her hips & feet. Five decades of not much work. Creationists should be all over it.

      Regarding continental drift – the virgin Antarctic continent waits under that crushing ice – something like a fossil Amazon jungle. NASA should spend a hefty billion on bots that can melt through & return samples – good training for missions to the ice moons Europa, Titan, Enceladus, Ganymede & Callisto.

      • loren russell
        Posted March 29, 2018 at 12:51 am | Permalink

        Michael — I doubt that you can back up the ‘dodge’ you speak of. The ‘Lucy’ partial skeleton is from a single individual at a single site. It includes most of the diagnostic and mechanically significant structures — knee and hip joints, upper torso and shoulder, skull base and jaw — to support the basic claims of bipedality. Over the years, a number of fossils were found nearby, including the so-called “first family”. These fill in structures missing in ‘Lucy’ and give a picture of variability including sexual dimorphism and development.

        We have a lot more hominines now — some better preserved than ‘Lucy’, most not. And some, like the H. naledi fossils are being studied in a more ‘open’ way than Lucy was. The results are certainly quicker than the Don Johanson/Tim white methods. Whether more accurate — we’ll see.

        • Michael Fisher
          Posted March 29, 2018 at 6:03 am | Permalink

          I think I can support it, but if you can show where I’m wrong that would be good too. I’m off to collect pictures [photos] of the various reconstructions of Lucy I’ve seen online, the fossils found at the 2nd site & a map showing the physical relation of the two sites. Will take a day.

  11. Posted March 28, 2018 at 6:53 pm | Permalink

    Evolution is astounding!

    I am a bit surprised that this has only evolved once. I have enough fat spiders in my yard to feed an army of pelican spiders.

    • Posted March 29, 2018 at 1:29 am | Permalink

      Perhaps there are other spider-eating spiders that aren’t pelican-esque?

  12. Jason G
    Posted March 28, 2018 at 6:58 pm | Permalink

    Response to your post on guns yesterday

    1. It seems a bit hypocritical to me that that the people criticizing the second amendment are taking a very originalist of it, while not taking a very originalist view of the rest of the constitution.

    2. Watching the news might make you think that young people are very supportive of gun control, when in fact polls shown them having similar views as other generations. Some recent polls actually show them being the least supportive of gun control. See here:
    http://polling.reuters.com/#poll/PV21B_3/filters/RESP_AGE:-99|-9|-8|-2|-1,SC_RACE:1|2|3|5|-1/dates/20180223-20180306/type/overall
    So laws aren`t necessarily going to change anytime soon.
    3. Slate Star Codex did an in-depth look at this here:
    http://slatestarcodex.com/2016/01/06/guns-and-states/
    And here:
    http://slatestarcodex.com/2016/01/10/guns-and-states-2-son-of-a-gun/
    The main conclusions:
    1. While guns probably have an effect on homicides, the evidence might not be as strong as you think.
    2. The difference between homicide rates in the USA and Europe is mostly not due to guns.
    3. More people in countries like Canada, Australia, and Germany own guns that you might think.

  13. Posted March 29, 2018 at 1:29 am | Permalink

    Pelican spiders are fascinating. Thanks for another post on them.


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