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Two-headed Reptile Fossil Found in China
Posted by
samzenpus
on Thu Dec 21, 2006 12:47 AM
from the better-than-one dept.
from the better-than-one dept.
[TheBORG] writes "A tiny skeleton from the Early Cretaceous shows an embryonic or newborn reptile with two heads and two necks, called axial bifurcation ('two-headedness') (a well-known developmental flaw among reptile species today such as turtles and snakes) was found in China by French and Chinese paleontologists recovered from the Yixian Formation, which is nearly 150 million years old."
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The ass casts the deciding vote (Score:5, Interesting)
Re: (Score:2, Informative)
I doubt it's anything so "designed". Mother nature
Re:The ass casts the deciding vote (Score:5, Informative)
Again, from Wiki. [wikipedia.org] Copied and pasted to save you guys a click:
Parent
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We often refer to mother nature "experimenting" with evolution. We here all know* that there is no ID in the experiment part of the statement, it is more a euphamism for some random mutation that may or may not stick. To that end the only intelligent thing about having your brain in your head is the bandwith available for visual and auditory perception and processing. I'd venture to say a brain in the chest cavity would make a hell of a lot more sense and invest in faster nerv
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How would you dissipate heat from a brain in your chest?
Re:The ass casts the deciding vote (Score:5, Insightful)
Doesnt't sound plausible because high blood flow at those rates exposes you to serious damage by relatively small injuries.
Parent
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But really if there was enough impedimus to have the brain even better protected than the skull and dura, then I'm relatively sure that there would be some way to move the heat away... Deeply embedded sweat glands such that vascular flow is not needed, pre-heated sweat instead? Dehydration risk I guess. Does the brain really generate that much heat? I'm really not all that educated on the finer points of the thermodynamics of the br
Re:The ass casts the deciding vote (Score:4, Funny)
-nB
Parent
Re:The ass casts the deciding vote (Score:4, Funny)
thanks
Parent
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I was fortunate enough to get to help a palentologist some years ago when he was attaching a horn to a magnificent specimen, and got a tour of the thing. The frill was shot full of veins, which makes you wonder whether it was any less vulnerable than the animal's shoulders and neck which (according to my childhood education via stop motion animation) the frill supposedly "armored".
However, if you imagine the animal nose down grazing, as it must have done much
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What?! Thats news to me!
Love,
Troll
Re:The ass casts the deciding vote (Score:4, Insightful)
If it made more "sense" to have the brain in the chest, we would have brains in our chests. It's just pointless to argue with mother nature when it comes to design. You can probably point to some kinks that specific species are still working out, but anything this universal is so damn near optimal that it's awe-inspiring.
I suspect the answer here is that there's no such thing as "faster nerves"; you'd have to increase nerve cell length to cut down on the number of synapses, which would make them more fragile, and, more importantly, less manageable (and still wouldn't make up for the comparatively huge distance). Come to think of it, it's the old "higher throughput" == "lowered responsiveness" problem.
Plus, the head is better protected than the chest; it would probably add an inordinate amount of weight to the skeletal structure to fortify it to the same degree. Also, maintaining the blood-brain barrier would probably be tricky without the separation that the neck provides (not to mention that your circulatory system would be right next to the thing).
Parent
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no argument from me.
-nB
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Re:The ass casts the deciding vote (Score:5, Informative)
Mother nature doesn't necessarily come up with optimal designs, just non-lethal ones. "Tradition" has a lot of influence. In the case of heads and brains, our (hypothetical) bilateran ancestor probably was a segmented animal with a tendancy to merge the segments at one end into a specialized structure with things like eyes, mouth's et al slapped together from pre-existing structures. As a result, chordates, arthropods, mollusks, and various kinds of "worms" all have their heads on one end of the body.
At least that's what most people think is the reason for the architecture shared by many (not all) phyla. The fossil evidence from the time period where the various phyla probably diverged is scant and not entirely helpful.
Yes, if there were an enormous advantage to locating the brain in the torso, it'd probably be there. But if the advantage is small, and getting to that arrangement involves a number of steps with no particular advantage, it might very well never happen.
Parent
Re:The ass casts the deciding vote (Score:4, Informative)
You're clearly very ignorant of how evolution works. Here's a quick counter example to disprove your "if it made more sense we'd have it" claim: The photoreceptor cells in your eye actually point backwards - toward the back wall of your eye. The nerve ending that transmits the captured light to the brain is on the front of the cell, and therefore has to be longer than strictly necessary (imagine a bunch of harddrives in a case. You would position the drives so that the cables all went out the back of the case. Now turn the drives around - you'll need longer cables and you'll have to route them along the side of each drive, taking up more room. Your eye is like that.)
So why does your eye have this curious and non-optimal design? Beats the hell out of me. It's just a quirk of evolution. Invertebrates evolved their eyes separately (convergent evolution), and they actually got the correct design. This is why an octopus' eye is so good. The cells are pointed the right way, so you can pack more of them together. It's a more efficient design. But you can't point to humans and say, "no no, don't argue with mother nature, if there was a better way we'd have it!" because that just isn't true. There is a better way. We don't have it. Octopuses have it. We got the shaft.
Evolution is random mutation and non-random selection. The best of the group survives. That in no way implies that the best is optimal. It was just the best available.
Parent
Re: (Score:2, Interesting)
Re:The ass casts the deciding vote (Score:5, Interesting)
Parent
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I tried to claim credit for this... (Score:2, Funny)
I totally believe it (Score:5, Insightful)
But not as weird as this: (Score:2, Informative)
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I remember a story about a guy who was found to have the dead embryo of his identical twin brother inside his body. Looks like the twin got too close to him in early development and developed for a while inside his body. I wonder if this is a similar case. Perhaps there is another deer inside this deer.
Latin name? (Score:5, Funny)
Re:Latin name? (Score:5, Informative)
Parent
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Two-headed Reptile... (Score:2)
Two headed reptile fossil in China? (Score:5, Funny)
beeb article and questions (Score:5, Informative)
http://news.bbc.co.uk/1/hi/sci/tech/6195345.stm [bbc.co.uk]
I'm not a biologist so does anyone know if the second head is fully functional? I'd have thought there'd be serious blood flow issues and it'd be unlikely for these animals to live very long but the snake at the bottom of the article doesn't look young. Does it act as a redundant system used only if the primary one fails or do they actually process stimuli from both heads? What happens if the stimuli are conflicting? Can someone point me towards anything on decesion making in these creatures or are they just not enough to study this. The beeb article says something vague about the condition being due to damage to the embryo possibly. What sort of damage? and how accepted is this?
Re: (Score:3, Interesting)
As far as I know, animals don't work that way - all "redundant" systems are always active, they just have enough "capacity" to pick up the slack if one part fails.
I seem to recall and article about a two-headed turtle. The dude who owned it said that it generally seemed to get around ok; though sometimes the heads would fight over food and such. But then it's a turtle, they aren't
Polycephaly in NON-reptiles (Score:4, Interesting)
You DO [wikipedia.org] see polycephaly in things more advanced than reptiles, although it's less frequent.
(And a greater part of the organism is redundant in mammals that survive, as in the above Siamese twins).
Parent
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Obligatory (Score:3, Funny)
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And the lesson is: if you're going to be a pedant expect the same treatment back. Oh and the gp was making a joke.
Developmental Flaw? (Score:4, Interesting)
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You are right on the mark. Deciding what is a 'flaw' is a cultural decision, a matter of opinion. There is no objective truth here. Is short stature a 'flaw' in Pygmies? Perhaps the Pygmies think otherwise; perhaps we all might think otherwise if tomorrow some predator existed that attacked only tall people and virtually wiped them all out, or a food source app
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Well, the fact that there isn't a species (that I know of) of animal that consistantly has multiple heads, I'm going to assume that this phenomenon is detrimental. Nature has allowed a lot of strange things to survive and perpetuate, but it hasn't encourage multiple-headed animals. So it probably is a flaw.
That said, I do see your reasoning. I see this all the time in psychology and whatnot. Anything that hinders a person's ability to function
Re:Developmental Flaw? (Score:4, Insightful)
Parent
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As far as I can see, Two Heads are the same as having two hands. Its not a flaw, its a step in evolution.
I saw in an article about a two-headed snake that 1 of 10,000 snakes have that flaw and that they usually don't live long mainly because they got trouble eating. Please next time don't claim with so much confidence such a thing as "it's not a flaw but a step in evolution" when it couldn't be a step in evolution since two headed reptiles hardly can make it to reproduction. It's not about deciding whethe
Sounds like grandma... (Score:2, Funny)
Yup, that's her.
pfft... (Score:3, Insightful)
P.S. Also, don't mention his little brother Chimi. That dog will bite you...
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Not to be outdone ... (Score:3, Funny)
Tokyo residents are fearfully awaiting the appearance of a giant moth and two tiny priestesses...
reminds me of the ancient race of skeleton people (Score:2)
http://www.theonion.com/content/node/29976 [theonion.com]
...so Noah had to had more food onboard... (Score:2)
So what does this mean to me? (Score:3, Funny)
Re:prolly a fake (Score:5, Informative)
So basically these guys have discovered a fossilised embryo that was deformed during incubation, not a two-headed monster that terrorised the Cretaceous. It's neat to find one, but it's not a particularly novel discovery IMO.
Parent
Probably real (Score:2)