Monday, 24 January 2011

Dickinsonia, still alive?

Look, photographic evidence of the Ediacaran form Dickinsonia on the modern sea floor, taken using specialist cameras:

OK, so I lied... this is actually a picture of a Dickinsonia cast which I played around with for a bit. The photo was poor quality so I tried to improve it and ended up finding different settings which made it look like a possible modern photo. A much better job could be done in faking this (not that I am advocating that) as this was a mess around for a few minutes.

Though imagine the implications of finding this thing alive, having been absent from the fossil record for over 540 million years. So many questions would be answered by simply observing it. Does it move? This is constantly being debated as the trace fossils found accompanying some dickinsoniid fossils may not be trace fossils at all. Interpretations range from it being highly mobile, to it moving rarely, to not moving at all but producing the traces through being buffeted by currents. How does it feed? We'd be able to tell whether it sucked up nutrients from algal mats or whether it carried endosymbiotic organisms, or whether it used some completely different mode of feeding. A proper analysis of its morphology would be possible, giving much better insight into its habits, but most importantly its taxonomy. And of course, genetic testing would be possible, answering some of the fundamental questions which might potentially never be answered using fossil evidence alone. Ah, one can dream...

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