# Were there ever any 6-limbed animals other than insects? **URL:** \ **Category:** Factual Questions\ **Created:** [May 11, 2016, 2:53am UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521 "2016-05-11T02:53:46Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Northern\_Piper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/northern_piper/32/5304_2.png) [@Northern\_Piper](https://boards.straightdope.com/u/Northern_Piper)\ **Post date:** [May 11, 2016, 8:28pm UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/21 "2016-05-11T20:28:12Z")
> [@Sage\_Rat](#): > > No idea, but I was just reminded to not Google for “sextaped”. :eek: ---
**Author:** ![Canadjun](https://avatars.discourse-cdn.com/v4/letter/c/76d3ee/32.png) [@Canadjun](https://boards.straightdope.com/u/Canadjun)\ **Post date:** [May 11, 2016, 8:43pm UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/22 "2016-05-11T20:43:46Z")
> [@Sage\_Rat](#): > > No idea, but I was just reminded to not Google for “sextaped”. Try googling “hexapod” instead. ---
**Author:** ![GargoyleWB](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gargoylewb/32/199_2.png) [@GargoyleWB](https://boards.straightdope.com/u/GargoyleWB)\ **Post date:** [May 11, 2016, 9:17pm UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/23 "2016-05-11T21:17:55Z")
How about bird tails? The feathered tail is a critical locomotive surface for many birds in flight, and individually controllable. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [May 11, 2016, 9:32pm UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/24 "2016-05-11T21:32:48Z")
> [@GargoyleWB](#): > > How about bird tails? The feathered tail is a critical locomotive surface for many birds in flight, and individually controllable. I think that goes beyond the definition of limb, which is normally considered a jointed or prehensile organ used for locomotion or manipulation. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [May 11, 2016, 9:35pm UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/25 "2016-05-11T21:35:29Z")
> [@Der\_Trihs](#): > > Mostly, because vertebrates happened to evolve with only four limbs in the first place. Evolution is very chance-and-history driven like that. This should be emphasized. Evolution isn’t about good, it’s about good enough: There’s no vision to evolution, just a simple random walk which is pruned by die-offs of various kinds. Sometimes, the die-offs are because a specific genetic mixture is non-viable. Other times, it’s just chance randomly killing off a perfectly viable mutation that happened to be in the wrong place at the wrong time. This has two effects, one of which has been discussed already: **“Because it didn’t” is a perfectly good explanation.** As has been said, evolution does things at random. We get the path which randomly _was_ explored, not the one which randomly _wasn’t_. We also don’t get the path which was for a while before it got chopped off by a river changing course. **No Hopeful Monsters.** A “Hopeful Monster” is a species which is nonviable as it stands, but which could become viable if some other gene or group of genes flip the right way in the next few generations. Not gonna happen: If you aren’t viable _right now_ you die off _right now_. Every species which exists is a descendant of a huge long chain of other species which survived. Evolution is a rock rolling downhill. It finds _a_ path, but not _every_ path, and not necessarily _the best_ path. Every so often, the hill shakes, and the rock jumps a bit. We only get to see some of the species from where the rock happened to land. ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [May 11, 2016, 9:38pm UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/26 "2016-05-11T21:38:14Z")
> [@MLS](#): > > This is how we know “intelligent design” is false. Anyone caring for small children knows we would be better off with at least 2 more hands each. Except, the children would have two additional hands as well. Perhaps with the pre-mobile ones we would be better off, but once they can get around and get into stuff, you start to lose your advantage and probably with the children were less hand-y. ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [May 11, 2016, 10:10pm UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/27 "2016-05-11T22:10:18Z")
> [@Colibri](#): > > Since octopuses don’t fossilize well, it’s possible some species might have in the past. Today none have six arms aside from [very rare mutants.](http://edition.cnn.com/2008/TECH/03/04/octopus.uk/) There is a [seven armed octopus](https://en.wikipedia.org/wiki/Seven-arm_octopus), so theoretically some species could/may have six. But in this case it’s not missing an arm, it’s just tucked away and used for breeding instead of locomotion/grasping. It still has 8 arms like all non-mutant, non-amputated octopuses. > [@Colibri](#): > > I was very glad to see that they used “octopodes” as the plural in that article. “Octopi” is a pet peeve of mine since it’s pseudo-Latin instead of real Latin. I would have said either octopuses or octopods, but octopodes is at least correct a correct plural. I’m on to you. You’re a bunch of hummingbirds in a suit, or else you’d be a Colibrus. ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [May 11, 2016, 10:32pm UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/28 "2016-05-11T22:32:30Z")
How do you know he’s not one hummingbird with 6 limbs? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [May 11, 2016, 11:02pm UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/29 "2016-05-11T23:02:40Z")
To be fair, you could have a sort of “hopeful monster”, if the first mutation isn’t enough to kill it off immediately. You could have a creature that’s less fit than its peers, but which manages to just get lucky enough to survive anyway, or possibly which is supported by its social circle (as happens with humans). Though that second mutation that makes it viable after all had better come along very quickly, because the less-fit trait isn’t going to last for very long. ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [May 12, 2016, 12:29am UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/30 "2016-05-12T00:29:17Z")
> [@Derleth](#): > > This should be emphasized. Evolution isn’t about good, it’s about good enough: There’s no vision to evolution, just a simple random walk which is pruned by die-offs of various kinds. Sometimes, the die-offs are because a specific genetic mixture is non-viable. Other times, it’s just chance randomly killing off a perfectly viable mutation that happened to be in the wrong place at the wrong time… As I understand it, this is not entirely accurate. The chemicals involved in the process are very elaborate. They respond to various environmental influences in the lifetime of the organism, and some of the responses may affect offspring. To describe evolution as an entirely random process does not do it justice, as that is one of the arguments the creationists try to poo-fling at it. Yes, natural selection itself is indifferent to outcomes and affected organisms. It has no preferred goals because it is a process, not some sort of thoughtful entity. But it is most decidedly not random. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [May 12, 2016, 1:04am UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/31 "2016-05-12T01:04:07Z")
Random doesn’t mean every outcome is equally likely, or that all information gets thrown away. _That_ is a misunderstanding of randomness. ---
**Author:** ![bibliophage](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bibliophage/32/7615_2.png) [@bibliophage](https://boards.straightdope.com/u/bibliophage)\ **Post date:** [May 12, 2016, 1:37am UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/32 "2016-05-12T01:37:39Z")
> [@Der\_Trihs](#): > > I [note](https://en.wikipedia.org/wiki/Hexapoda) that insects are the most well known of a subphylum called Hexapoda, which is named after their characteristic possession of six limbs. One of the more familiar non-insect hexapods around these parts is the tiny black [snow flea](https://en.wikipedia.org/wiki/Hypogastrura_nivicola), which is a kind of springtail and not a true flea. I often see them by the thousands on top of the snow on warm days in late winter and early spring. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [May 12, 2016, 2:12am UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/33 "2016-05-12T02:12:39Z")
> [@Canadjun](#): > > Try googling “hexapod” instead. No pornography there. Jeez. :dubious: ---
**Author:** ![Northern\_Piper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/northern_piper/32/5304_2.png) [@Northern\_Piper](https://boards.straightdope.com/u/Northern_Piper)\ **Post date:** [May 12, 2016, 2:13am UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/34 "2016-05-12T02:13:08Z")
I still think it would be neat to have Tars Tarkas around. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [May 12, 2016, 2:19am UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/35 "2016-05-12T02:19:24Z")
> [@Northern\_Piper](#): > > I still think it would be neat to have Tars Tarkas around. If you were his buddy John Carter, yeah. Otherwise, a radium pistol, screw four arms. Don’t let him get close enough to use them. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [May 12, 2016, 4:37am UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/36 "2016-05-12T04:37:11Z")
> [@Derleth](#): > > **No Hopeful Monsters.** A “Hopeful Monster” is a species which is nonviable as it stands, but which could become viable if some other gene or group of genes flip the right way in the next few generations. Not gonna happen: If you aren’t viable _right now_ you die off _right now_. Every species which exists is a descendant of a huge long chain of other species which survived. > [@Chronos](#): > > To be fair, you could have a sort of “hopeful monster”, if the first mutation isn’t enough to kill it off immediately. You could have a creature that’s less fit than its peers, but which manages to just get lucky enough to survive anyway, or possibly which is supported by its social circle (as happens with humans). Though that second mutation that makes it viable after all had better come along very quickly, because the less-fit trait isn’t going to last for very long. To clarify, that’s not the actual definition of a [hopeful monster.](http://rationalwiki.org/wiki/Hopeful_monster) “Hopeful monsters” are not non-viable, they are just the result of mutations that cause a very large morphological change. It was originated by Richard Goldschmidt starting in the 1940s as a counter to the idea that evolution could only take place by small steps. He believed such mutations were the source of new species. Of course, most large mutations will be lethal, but hopeful monsters are the result of ones that are not. More recently, evolutionary biologists like Stephen Jay Gould and Richard Dawkins have proposed that hopeful monsters are indeed possible through mutations that affect entire developmental pathways in a correlated way, and speculate that they may have been responsible for some large evolutionary transitions. ---
**Author:** ![wevets](https://avatars.discourse-cdn.com/v4/letter/w/e9a140/32.png) [@wevets](https://boards.straightdope.com/u/wevets)\ **Post date:** [May 12, 2016, 5:56am UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/37 "2016-05-12T05:56:00Z")
There are some echinoderms with six limbs - like [this one](http://www.seastarsofthepacificnorthwest.info/species/drab_sixarmed_star.html) for example. I, too, have never heard, read, or otherwise encountered “algar” as the singular of algae - only alga. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [May 12, 2016, 6:19am UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/38 "2016-05-12T06:19:46Z")
> [@MLS](#): > > This is how we know “intelligent design” is false. Anyone caring for small children knows we would be better off with at least 2 more hands each. > [@eschereal](#): > > Except, the children would have two additional hands as well. Perhaps with the pre-mobile ones we would be better off, but once they can get around and get into stuff, you start to lose your advantage and probably with the children were less hand-y. As usual, duct tape is the simpler solution. ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [May 12, 2016, 6:31am UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/39 "2016-05-12T06:31:51Z")
The plural of Algar is Garths. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [May 12, 2016, 6:32am UTC](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521/40 "2016-05-12T06:32:52Z")
> [@Chronos](#): > > To be fair, you could have a sort of “hopeful monster”, if the first mutation isn’t enough to kill it off immediately. You could have a creature that’s less fit than its peers, but which manages to just get lucky enough to survive anyway, or possibly which is supported by its social circle (as happens with humans). Though that second mutation that makes it viable after all had better come along very quickly, because the less-fit trait isn’t going to last for very long. True - the whole process is statistical - which means the less likely (or less ‘proper’) outcomes can still happen, at the edges of the bell curve. And external ‘luck’ factors that bear no specific fitness-selection can still intervene to accidentally deplete the ‘fitter’ population (although it’s unlikely, but so is winning the lottery). For example, a local catastrophe (meteorite strike, flood, forest fire) could just happen to wipe out all of the ‘fitter’ variants of a population by sheer accident of geography, rather than any trait-specific factor - with the ‘less-fit’ variants just happening to survive because they were located on the geographic fringe. [Previous page](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521.md?page=1) [Next page](https://boards.straightdope.com/t/were-there-ever-any-6-limbed-animals-other-than-insects/754521.md?page=3)