Two-headed Reptile Fossil Found in China 156
[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."
Re:The ass casts the deciding vote (Score:2, Informative)
I doubt it's anything so "designed". Mother nature experimenting would assume some sort of intelligent design and my karma can't handle another ID debate.
Seriously, it is much more likely that this is just conjoined twins. Go to the Wiki [wikipedia.org] page and you see a picture of people with the same thing.
Re:The ass casts the deciding vote (Score:5, Informative)
Again, from Wiki. [wikipedia.org] Copied and pasted to save you guys a click:
But not as weird as this: (Score:2, Informative)
Re:Latin name? (Score:5, Informative)
Re:prolly a fake (Score:1, Informative)
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:The ass casts the deciding vote (Score:3, Informative)
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 nerves for the ears and eyes, except that until recently if you lost your ears and eyes you were effectively dead anyway. Besides we all know the world was created last Thursday with all our engrams pre-programmed
-nB
* even the trolls who refuse to acknowledge they know
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.
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.
Re:The ass casts the deciding vote (Score:3, Informative)
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 of the time, the frill would have stood away from the neck and formed an admirable radiator, especially if the animal had a nice cross breeze.
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.