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Author Topic:   The 5th Limb? (Tails)
Nuggin
Member (Idle past 2492 days)
Posts: 2965
From: Los Angeles, CA USA
Joined: 08-09-2005


Message 1 of 17 (265400)
12-04-2005 3:03 AM


Been talking with Randman on a different thread about human tails and fetuses and whatnot, and it got me thinking.
Are there any mammals that don't have tail bones? I don't mean they don't have tails, I'm sure there are a few. But, can anyone think of any species that don't have at least a completely internal tailbone like we do?
For that matter, I'm trying to think of reptiles/amphibians that either don't have tails or never had tails during their various stages (ie tadpoles).
How universal are tails? Seems like a whole lot of them out there.
Stands to reason, obviously, since I don't think there are any tailless fish (save the filet o' variety).
But, in the interest of good science - can anyone think of any completely tailless animals?
{Added the "(Tails)" to the topic title. - Adminnemooseus}
This message has been edited by Adminnemooseus, 12-04-2005 03:13 AM

Replies to this message:
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AdminPD
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Message 2 of 17 (265428)
12-04-2005 11:27 AM


Thread moved here from the Proposed New Topics forum.

  
macaroniandcheese 
Suspended Member (Idle past 3927 days)
Posts: 4258
Joined: 05-24-2004


Message 3 of 17 (265459)
12-04-2005 1:48 PM
Reply to: Message 1 by Nuggin
12-04-2005 3:03 AM


oh god don't talk about tailbones... you're making mine hurt.
dinoflagelates?
coral?
i think the idea of having a backbone demands a tail. it's an extension and a stabilizer. those of us who have inutile tailbones have simply lost our need for stabilization (ground dwelling apes etc).
This message has been edited by brennakimi, 12-04-2005 01:51 PM

i'm worldwide bitch, act like ya'll don't know.

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Nuggin
Member (Idle past 2492 days)
Posts: 2965
From: Los Angeles, CA USA
Joined: 08-09-2005


Message 4 of 17 (265471)
12-04-2005 2:41 PM
Reply to: Message 3 by macaroniandcheese
12-04-2005 1:48 PM


Let me refine
Totally didn't think about corals or insects as animals.
Let's lessen the scope.
Can anyone think of any member of Cordata that lacks a tail (either obvious or not)?

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macaroniandcheese 
Suspended Member (Idle past 3927 days)
Posts: 4258
Joined: 05-24-2004


Message 5 of 17 (265480)
12-04-2005 2:49 PM
Reply to: Message 4 by Nuggin
12-04-2005 2:41 PM


Re: Let me refine
i think you're missing my point. tails are backbones. period.
part of being a spinal critter means having a head and a postanal tail. that's what it means.
This message has been edited by brennakimi, 12-04-2005 02:50 PM

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mick
Member (Idle past 4986 days)
Posts: 913
Joined: 02-17-2005


Message 6 of 17 (265541)
12-04-2005 7:42 PM
Reply to: Message 4 by Nuggin
12-04-2005 2:41 PM


Re: Let me refine
Hi Nuggin,
I found this website which claims that some human beings are born without a coccyx.
It also has some other cool facts about useless body parts:
quote:
NECK RIB
A set of cervical ribs”possibly leftovers from the age of reptiles”still appear in less than 1 percent of the population....
SUBCLAVIUS MUSCLE
This small muscle stretching under the shoulder from the first rib to the collarbone would be useful if humans still walked on all fours. Some people have one, some have none, and a few have two...
PLANTARIS MUSCLE
Often mistaken for a nerve by freshman medical students, the muscle was useful to other primates for grasping with their feet. It has disappeared altogether in 9 percent of the population.
THIRTEENTH RIB
Our closest cousins, chimpanzees and gorillas, have an extra set of ribs. Most of us have 12, but 8 percent of adults have the extras....
Creationist websites appear to claim that the coccyx fufils a useful function, as an anchor for nerve and muscle development in the embryo and adult. Quite why they think this is an argument against evolution is beyond me...
Brennakimi is correct to say that you can't be a chordate without having a tail; but when one bears in mind that snakes have over 400 vertebrae and humans only 33, it seems reasonable to suppose that at least some parts of the tail have been lost and gained over evolutionary time.
If the picture of the dolphin above is correct, then it DOESN'T have a coccyx because it lacks fused sacral bones (are they fused in the cat?). Given that dolphins evolved from terrestrial mammals with fused sacral bones(?), they must either have "un-fused" or been lost and evolved new sacral bones from the lumbar region. I don't know which. Probably one of the fossil-people can elucidate.
apologies for editing this post repeatedly.
This message has been edited by mick, 12-04-2005 07:58 PM
This message has been edited by mick, 12-04-2005 08:05 PM
This message has been edited by mick, 12-04-2005 08:09 PM

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mick
Member (Idle past 4986 days)
Posts: 913
Joined: 02-17-2005


Message 7 of 17 (265548)
12-04-2005 8:32 PM
Reply to: Message 6 by mick
12-04-2005 7:42 PM


whales, their sacrum and coccyx
Okay, I did a bit more reading and found that the sacrum did indeed unfuse itself during the evolution of cetacea.
The sacrum is the set of bones (often fused together in terrestrial mammals) which support the pelvic girdle.
The sacrum, however, is not the coccyx:
So, basically, Brennakimi is correct, unless somebody can come up with an animal with no backbone lower than its pelvis.
Nevertheless, the loss of the fused sacrum in whales is pretty remarkable.
Mick
This message has been edited by mick, 12-04-2005 08:35 PM

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mick
Member (Idle past 4986 days)
Posts: 913
Joined: 02-17-2005


Message 8 of 17 (265552)
12-04-2005 8:46 PM
Reply to: Message 7 by mick
12-04-2005 8:32 PM


found one!
Okay, there's a couple of breeds of manx cat called "rumpy riser" and "rumpy" which have no caudal vertebrae (no backbone below the pelvic girdle) and therefore are completely tailless in every sense of the word.
link
Mick

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mick
Member (Idle past 4986 days)
Posts: 913
Joined: 02-17-2005


Message 9 of 17 (265556)
12-04-2005 8:58 PM
Reply to: Message 7 by mick
12-04-2005 8:32 PM


megachiroptera
It also seems that some families of megachiroptera (a suborder including the vampire bats) have no caudal vertebrae, i.e. no tail beneath the pelvic girdle.

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jar
Member (Idle past 394 days)
Posts: 34026
From: Texas!!
Joined: 04-20-2004


Message 10 of 17 (265558)
12-04-2005 9:04 PM
Reply to: Message 9 by mick
12-04-2005 8:58 PM


Re: megachiroptera
How about the tailess dogs, for example Corgis, Schiprerke, Rottweilers and such?

Aslan is not a Tame Lion

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mick
Member (Idle past 4986 days)
Posts: 913
Joined: 02-17-2005


Message 11 of 17 (265564)
12-04-2005 9:15 PM
Reply to: Message 10 by jar
12-04-2005 9:04 PM


tailless dogs
I think that the "tail-less" dogs are generally the product of the tail being snipped off by the owner. As far as I know, and a dog fan here might correct me, it's a middle-ages idea that it was supposed to help the dogs run through thick undergrowth in search of prey.
It kind of makes you wince when you read Brennakimi's view that the tail is part of our spine... There's no way I'd dock the tail of one of my dogs.
Mick
This message has been edited by mick, 12-04-2005 09:24 PM

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MangyTiger
Member (Idle past 6353 days)
Posts: 989
From: Leicester, UK
Joined: 07-30-2004


Message 12 of 17 (265565)
12-04-2005 9:28 PM
Reply to: Message 11 by mick
12-04-2005 9:15 PM


Re: tailless dogs
Certainly most pedigree dogs like Rotties have their tails docked at a few days old.
I don't know about the middle ages idea but in modern times tail docking is all down to the breed standards that the Kennel Club and associated Breed societies use. In reality these are nothing more than Victorian fashion statements that have produced many problems in the various breeds and need to be seriously overhauled.
[/rant]

I wish I didn't know now what I didn't know then

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Coragyps
Member (Idle past 734 days)
Posts: 5553
From: Snyder, Texas, USA
Joined: 11-12-2002


Message 13 of 17 (265569)
12-04-2005 9:37 PM
Reply to: Message 11 by mick
12-04-2005 9:15 PM


Re: tailless dogs
Schipperkes, at least, are born with a tail - my sister has an undocked one. She (the dog, not the sister) carries her tail arched over her back, and I don't remember it wagging at all.

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RAZD
Member (Idle past 1404 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 14 of 17 (265574)
12-04-2005 10:00 PM
Reply to: Message 6 by mick
12-04-2005 7:42 PM


Re: Let me refine
Creationist websites appear to claim that the coccyx fufils a useful function, as an anchor for nerve and muscle development in the embryo and adult. Quite why they think this is an argument against evolution is beyond me...
The argument is that it isn't the left over remains of a 'monkey' tail, it is there for a purpose other than a tail from a common ancestor.
Of course it is an invalid argument as coccygectomies are done that completely remove the coccyx with no adverse effects on most of the patients.
Summary of seven studies of coccygectomy for coccydynia

we are limited in our ability to understand
by our ability to understand
RebelAAmerican.Zen[Deist
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Asgara
Member (Idle past 2302 days)
Posts: 1783
From: Wisconsin, USA
Joined: 05-10-2003


Message 15 of 17 (265585)
12-04-2005 11:26 PM
Reply to: Message 13 by Coragyps
12-04-2005 9:37 PM


Re: tailless dogs
Pembroke corgis can be born with or without tails, and many lengths in between, this tail is generally docked.
The cardigan corgi has a tail that isn't docked.

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