Two-Headed Dinosaur Fossil Discovered
Yes, it's true--Those pictures of gallant warriors fighting two-headed dragons may be at least partially based on fact. From that bottomless pit of headline-making dino fossils (China) comes a truly remarkable Choristoderan specimen. It has two heads.
This dinosaur was a long-necked aquatic species, and was a juvenile when it died. A malformation caused it to develop with two necks and skulls, a growth abnormality called axial bifurcation. The is the first example of a two-headed fossil.
Axial bifurcation is known to occur in many reptile, though it is rare. About 400 instances of two-headed snakes have been recorded, according to Dr. Eric Buffetaut, a lead researcher of the fossil. Two-headed turtles are also reported on occasion.
Rare as two-headed specimens are, it's remarkable that one was fossilized. Fossilization is relatively rare in and of itself, since organisms are apt to decay quickly once they die. An organism needs to be buried quickly, freeze, or be enveloped in some type of oxygen-free environment.
So what are the odds of finding two-headed dinos? Pretty slim. At this rate we might even find a missing link.
Image courtesy the Royal Society.
Daniel James Devine
in Paleontology
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Reader Comments (6)
Hey -- I was going back through the October Creation Matters, and your website was mentioned in it! Just thought I'd say congrats.
Was it? Cool deal--and thanks for letting me know.
For anyone who doesn't know, Creation Matters is a newsletter of the Creation Research Society, published six times a year. You can view adobe formatted back issues online here, but right now you must be member to view 2006 issues.
I don't agree with the missing link assessment. There are documented cases of two headed humans. Also, I recently (past 2 days) saw the video recently of a two headed girl - I can't remember the site - but it was some from some educational TV program (like TLC, but wasn't). This finding is merely an aberration.
AlexG --
Just to note -- two-headed humans often take a lot of medical intervention to get past their early childhood.
AlexG:
Dicephaly does occur in humans, but I don't believe it's precisely the same thing as what occurs in two-headed snakes and turtles. The latter is an example of axial bifurcation, as I noted above post, in which the spine splits at the base of the neck. Two-headed humans are conjoined twins, and the degree of their "conjoinedness" varies according to case.
The twins you saw on video might have been Abigail and Brittany Hensel, whose spines are joined at the pelvis.
Axial bifurcation is, as you say, an aberration, but does occur on a regular, rare basis. (If I remember the figure rightly, there have been about 200 documented two-headed snakes. [Edit: Oops! That's a mistake--there have been about four hundred cases reported, according to Dr. Eric Buffetaut, who I mentioned above.]) If you're saying that we're much more likely to find another two-headed dinosaur fossil than we are a genuine missing link, I'd agree with you.
And they say fossils are rare (rare IS the scientific term, right?). They are soooo rare that even VERY rare things get fossilized!
There is a one-in-25 million chance that a two-headed lizard will even survive if born. Axial bifurcation among reptiles is so rare that only about 400 instances of two-headed snakes have been recorded.
Sorry fellas I gotta ask... They cannot find millions of years of transitional fossils, but they CAN find a 2-headed lizard? What are the odds?