Two-headed Reptile Fossil Found in China

[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."

Comments

The ass casts the deciding vote

[Harmonious Botch]

Seriously, I wonder if there is any evolutionary connection between the placement of some neural processing in the hindquarters and the frequency of two heads in the reptilian class, as if mother nature was experimenting with protecting brainpower by moving it around to a safer location, or by duplicating it. Since reptiles had the first big brains, this may have been the first occasion to arise in which trying to protect brains might be worth the expense.

Re:The ass casts the deciding vote

[ArcherB]

After about two seconds more research, I found that the condition is called Polycephaly:

Again, from Wiki. Copied and pasted to save you guys a click:

Polycephaly is the condition of having more than one head. By far the most common use is in relation to the anatomical head, though the word has also been used for other meanings of "head". The term is derived from the stems poly- meaning 'many' and kephal- meaning "head", and encompasses bicephaly and dicephaly (both referring to two-headedness). A variation is an animal born with two faces on a single head, a condition known as diprosopus. In medical terms these are all congenital cephalic disorders.

There are many occurrences of multi-headed animals, in real life as well as in mythology. Many fantasy universes contain races of creatures with multiple heads. In heraldry and vexillology, the double-headed eagle is a common symbol, though no such animal is known to have ever existed.

Bicephalic animals are the only type of multi-headed creatures seen in the real world and form by the same process as conjoined twins: the zygote begins to split but fails to completely separate. One extreme example of this is the condition of craniopagus parasiticus, whereby a fully developed body has a parasitic twin head joined at the skull.

Re:The ass casts the deciding vote

[data1]

Evolve radiating appendages that are highly vascularized to move blood rapidly away from the hot "core" with the brain.
Doesnt't sound plausible because high blood flow at those rates exposes you to serious damage by relatively small injuries.

Re:The ass casts the deciding vote

[Sique]

Dual-headed miscreants are also common with amphibia (frogs, newts), not only with reptilia. But because amphibia are often prey to a lot of predators, the dual-heads don't survive very long. An interesting exception is the site of the Tchernobyl nuclear plant, where after the nuclear catastrophe in 1986 most of the predators have left, and now the nearby lake shows miscreated newts and frogs more often. It's not because of the background radiation (it's back to normal levels at least in the lake), but because of the lack of predators that those animals survive so often.

Re:The ass casts the deciding vote

[vtcodger]

***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.***

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.

I totally believe it

[gardyloo]

Especially after seeing the photo of a sketch of some cartoon character at the story.

Latin name?

[Anonymous Coward]

I don't know what Latin name they're going to give this two-headed creature, but it seems like they should try to squeeze "zaphod" in there somewhere.

Re:Latin name?

[aeschenkarnos]

Things only get Latin names if they're new species. This is a malformation that afflicts an individual member of a species that may or may not already be known. It certainly deserves an individual name (like the Australopithecus "Lucy"), and Zaphod is a good choice.

Two headed reptile fossil in China?

[monoqlith]

So that's where Karl Rove went!

beeb article and questions

[gsn]

The beebs article has slightly more details and a picture of the actual fossil and a two headed snake.

http://news.bbc.co.uk/1/hi/sci/tech/6195345.stm

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?

Developmental Flaw?

[rhkenji]

Why is it when something is out of the ordinary, its a flaw? axial bifurcation ('two-headedness') (a well-known developmental flaw among reptile species today such as turtles and snakes).. Every species on earth has a flaw that helps it survive in its environment. As far as I can see, Two Heads are the same as having two hands. Its not a flaw, its a step in evolution. When we see something like 6 fingers in a human, we think its a flaw. Why do we think that these defects are flaw not as step to human evolution? I see no flaw but evolution.

Re:Developmental Flaw?

[McWilde]

It's probably called a flaw because the development of the extra head isn't determined by the creature's genes. It's a trait that can't be passed to its offspring, so it has no part in evolution.

Re:prolly a fake

[krayzkrok]

Everyone seems to be missing the point of this discovery (including most news agencies who think it's a cool story). Bifurcation of the head is a pretty common genetic abnormality in a number of vertebrates, but especially reptiles because eggs are exposed to a wider range of temperature extremes. High temperatures during incubation, particularly early in incubation, very often lead to genetic abnormalities. A "hot" crocodile or turtle nest, for example, will give you a lot of dead, deformed embryos including those with two tails, no jaws, two heads, and any other number of strange mutations. It's exceptionally rare for one to survive past hatching, but it has happened.

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.