A horrifying arachnid attacks a man’s hand

This isn’t really a spider, but, like real spiders, it’s an arachnid. This is an amblypygid, or “whip spider”.  The formal difference: both real spiders and whip spiders are in the class of arachnids, but true spiders are in the order Aranae, while amblypygids are in the order Amblypygi.  (I can’t find the divergence time between the two groups, but it’s probably about 200 million years ago.) Whip spiders aren’t venomous and can’t bite, but they can “pince” you with their pincers, as this one—in the species Euphrynichus amanica—is doing. There are about 35,000 species of spiders, but only about 190 species of amblypygids. Amblypygids walk on six legs and use the front two for probing and defense.

I didn’t know much about this group until I found this old post among the 1700 draft posts that languish on my dashboard (most will never see the light of day), but it’s worth learning about a new group. To see how weird looking they all are, go here. They’re scary, but can’t really hurt you.

 

Here’s the arachnid phylogeny; you can see that these are in a sister clade to true spiders, and are more distantly related to other arachnids like scorpions and ticks.

p.s. You can keep these things as pets, but I wouldn’t tease them the way this guy is doing.

24 Comments

  1. Mark R.
    Posted September 29, 2017 at 3:06 pm | Permalink

    Wow, I’ve never heard or seen one of these. Thanks for the new creature feature. It looks fragile, and I thought the hand was going to harm it when it clutched down. Brave hand. 🙂

  2. busterggi
    Posted September 29, 2017 at 3:15 pm | Permalink

    Heck, any Paul Newman fan knows about these.

    Judge Roy Bean: Have you ever been here before?
    Bart Jackson: Nope. I don’t even know where I am now.
    Judge Roy Bean: Well, it’s the eagle’s nest. Vinegarroon County, Texas.
    Bart Jackson: Vinegarroon? What is a Vinegarroon?
    Judge Roy Bean: Well, it’s a Mexican word. It means whiptail scorpion – mean as hell.

    • Posted September 29, 2017 at 3:37 pm | Permalink

      No, these aren’t the same as vinegaroon or whiptailed scorpions. Those are in the Thelyphonida, a different group (see phylogeny above).

  3. ethologist
    Posted September 29, 2017 at 4:02 pm | Permalink

    Cool! I notice that before each attack it extends the thin structure, which I believe is its left front leg. It seems to be localizing the target of the attack. Also, I think the pincers used for attacking aren’t actually legs, but rather modified pedipalps.

    • darrelle
      Posted September 30, 2017 at 4:27 pm | Permalink

      I don’t know what’s what on these creatures but it looks to me as if they have 10 appendages not 8. I assume that 8 of them are legs and that the other two are something else that has evolved for highly specialized use, perhaps pedipalps as you suggest.

      The long feeler it was probing with is matched by an appendage on the opposite side that is much shorter. It looks like it may have been a mirror image of the one it was probing with but it has been broken off. In addition to those two structures there are also 4 others on each side of the critter, three legs and 1 long, clawed appendage.

  4. lkr
    Posted September 29, 2017 at 4:19 pm | Permalink

    Garwood et al. just described a late Carboniferous [ca. 315mya] amblypygid from collections made at least a century ago in the British midlands coal measures. [BMC Evol. Biol. 17:105, 2017, open access]

    The specimens are characterized as crown-group amblypygi, possessing similar appendages including the antenniform first legs.

    The authors note that amblypygi are rare as fossils. Prior to this, the oldest crown-group amblypygi were Cretaceous Bermese amber.

    In general the major groups of arachnids arose in the Palaeozoic.

    • Posted September 29, 2017 at 4:27 pm | Permalink

      I also thought that 200 Mya seems too low as the divergence time. In contrast to you I haven’t been thorough enough to check the primary literature, but the intro of the Wikipedia article on spiders says that true spiders have been found in the Carboniferous, which seems more in line with what I remember from textbooks.

      • loren russell
        Posted September 29, 2017 at 5:55 pm | Permalink

        Yes — divergence was likely even earlier — the early Carboniferous is notoriously poor for terrestrial fossils. The so-called Romer’s Gap for tetrapods is mirrored by a somewhat longer gap in representation of terrestrial arthropods. Pity.

    • Posted October 2, 2017 at 4:27 am | Permalink

      Thanks… here is the link https://www.ncbi.nlm.nih.gov/labs/articles/28431496/

  5. Darren Garrison
    Posted September 29, 2017 at 4:32 pm | Permalink

    I like the pincers–the are small enough to seem like little hands instead of like big claws.

    • Posted October 2, 2017 at 4:28 am | Permalink

      If only they had opposeable thumbs!

  6. ladyatheist
    Posted September 29, 2017 at 4:33 pm | Permalink

    There’s such a thing as a book scorpion?!?! :-O

    • Simon Hayward
      Posted September 29, 2017 at 4:40 pm | Permalink

      Read it here…

      • loren russell
        Posted September 29, 2017 at 5:56 pm | Permalink

        They feed on book lice!

  7. jaxkayaker
    Posted September 29, 2017 at 7:19 pm | Permalink

    timetree.org suggests time to the most recent common ancestor of spiders and amblypygids is 362 mya.

  8. Posted September 29, 2017 at 10:44 pm | Permalink

    It’s worth mentioning that Aranae are divided into two suborders, namely Mesothelae and Opisthothelae. Mesothelae contains only one living family, namely Liphistiidae, and several extinct families. Opisthothelae, on the other hand, is divided into two infraorders, namely Mygalomorphae and Araneomorphae. Over 90% of all spiders are araneomorphs (including orb weavers, jumping spiders and wolf spiders), while tarantulas, ctenizid trapdoor spiders and Australian funnel-web spiders are mygalomorphs. Mygalomorphs are pretty ancient (first appearing in the Triassic period), while araneomorphs are regarded as modern spiders. The major anatomical difference between the two is that mygalomorphs have fixed downward-facing fangs, while araneomorphs have movable opposing fangs that cross each other in a pinching action. There are also differences in their silk (mygalomorphs cannot produce sticky silk that araneomorphs like orb weavers use so successfully to trap their prey), their lungs (mygalomorphs have book lungs that require moist environments) and their life-spans (araneomorphs typically live for one year, while mygalomorphs can live as long as 25 years).

    Here in Australia, we are fortunate to have lots of really interesting spider fauna. In my garden I have Sydney brown trapdoor spiders (Misgolas rapax), which I often feed with crickets from the local pet shop. As a result, I ended up with a large colony of them, which attracted the attention of the local tawny frogmouths, who like to eat them. Unlike many mygalomorphs in the region (e.g. funnel-webs and mouse spiders), Sydney brown trapdoor spiders are neither aggressive nor venomous; but unfortunately they look sufficiently like funnel-web spiders for many people kill them out of misplaced fear.

    I also have wolf spiders, golden orb weavers, St. Andrew’s Cross spiders, several species of jumping spider, and huntsman spiders (which I encourage to live in my house, since they are expert cockroach killers). But the best thing is when I occasionally spot an ogre-faced net-casting spider (Deinopsis sp.). In my opinion, this animal has the most interesting hunting strategy in all of the spider kingdom, since it folds its web into a net which it clutches with its front legs and throws at passing prey (in the same way that some tribal fishermen cast large nets to into shallow water to catch passing fish).

  9. Posted September 30, 2017 at 1:17 am | Permalink

    I did not know of ones with pincy thingies on the pedipalps. That is real cool.

  10. infiniteimprobabilit
    Posted September 30, 2017 at 5:50 am | Permalink

    Awww, that’s so cute! 😉

    cr

  11. Diana MacPherson
    Posted September 30, 2017 at 8:05 am | Permalink

    Whip spiders: because spiders are way better with hands!

    • Posted October 2, 2017 at 4:29 am | Permalink

      yeay! Little hands to… TICKLE YOU AT NIGHT!

  12. Justin Hughes
    Posted September 30, 2017 at 9:15 am | Permalink

    Defends itself*
    These are not aggressive, some can be defensive as is there case here. (Owner of several amblypygi species)

  13. David Coxill
    Posted September 30, 2017 at 9:44 am | Permalink

    KEEP AS PETS ,i would rather french kiss a skunk .

    • Posted October 2, 2017 at 4:30 am | Permalink

      French kissing a skunk is ok – it is the other end that matters!

  14. Bob Bottemiller
    Posted September 30, 2017 at 3:46 pm | Permalink

    We can now hope for a remake of the movie “Arachnophobia” featuring whip spiders.


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