Tripeds in Nature?

[FalTorPan]

Are there any examples in nature of tripedal species?

 

[James Bond]

A quick Google revealed nothing, so I guess there aren't any known tripedal species. Oddly enough, the first result was Species 8472.

 

[FalTorPan]

I'm far from an expert in biology, but the only creature I can think of with an odd number of locomotive appendages greater than one is a starfish.

 

[Bill Morris]

Okay, then, a riddle: What goes up the hill on three legs and back down the hill on four legs?

 

[Timo]

A dog with a lame leg, provided there's a vet on top of the hill.

One might well argue that the seal or sea lion means of locomotion counts as tripodal: two forward limbs, one aft limb. And basically, critters like hares and rabbits fall in the same category, there being two legs spread out laterally, and one centerline (pair of) leg(s). This tripodal type of locomotion is just performed using a bilaterally symmetrical and hence four-legged body.

Timo Saloniemi

 

[Bill Morris]

A dog with a lame leg, provided there's a vet on top of the hill.

One might well argue that the seal or sea lion means of locomotion counts as tripodal: two forward limbs, one aft limb. And basically, critters like hares and rabbits fall in the same category, there being two legs spread out laterally, and one centerline (pair of) leg(s). This tripodal type of locomotion is just performed using a bilaterally symmetrical and hence four-legged body.

Timo Saloniemi

For the riddle, that works. This is not some riddle going around that was invented by starting with an answer but rather an exercise in coming up with something that works. One possibility I can offer is "A puma leg-lassoed and reeled in by a cowboy with an empty gun" (or "A wild sehlat leg-lassoed and reeled in by an overconfident Vulcan"). Either way, the animal is no longer forced to walk on three legs and walks away not only on four legs but a full stomach.

If you want just tripedal locomotion without loss of a limb, the way kangaroos and other macropods will use the tail and hind legs when milling around is sometimes referred to as tripedal locomotion, but it's more often called pentapedal locomotion (counting use of all four llimbs and the tail).

 

[Meredith]

Does Ron Jeremy count?

 

[Psion]

Participants in a three-legged race? They go up with one leg each joined, but after the race come down separated.

 

[Bill Morris]

Participants in a three-legged race? They go up with one leg each joined, but after the race come down separated.

Ha! That's a good one!

 

[RevdKathy]

An old man with a stick. I'm at the top of the hill to steal the stick, and force him to crawl back down. Nasty malicious me.

 

[trekkiedane]

As i remember there once was a televised thought experiment where exo-biologists had imagined life like ours (chemically) where the number of limbs favoured one in the middle…

Didn't seem to unlikely given the primitive 'starfish'-pattern as some sort of origin.

On Earth the 'third limb' of some species is either the two rear limbs not having emerged yet or re-combining into one (or disappearing altogether)
Evolution on Earth seems to have gone in favour of beings with limbs to either side of their spine (once that had developed) there is no reason to believe it should be the same elsewhere. -A tail is immensely useable -I sometimes long for one...