Ediacaran biota may have been displaced by burrowing animals.

[PB666]

http://smithsonianscience.si.edu/2015/09/did-mystery-worms-cause-worlds-first-mass-extinction/

For those interested in Ediacaran evolution.

Edited September 30, 2015 by PB666

[KerikBalm]

Why would you title this "Origin of Life on Earth"

Misleading titles can get you responses that you won't like

[smjjames]

Interesting.....

[PB666]

Why would the assumption not be that the new creatures just ate the old ones?

It sounds like a super-abundant, stationary food source was just sitting there waiting to be preyed upon. This sounds much more likely than a worldwide issue with plant beds being 'disturbed by tunneling'. Am I missing something?

Possibly, one problem, not to much oxygen in the burrows, to eat you need to catabolize. It is known that some worms altered their biochemistry to make themselves work more efficiently in low oxygen environments. Most of the shale that we see that is rich in organics comes before the cambrian, so it is possible that these innovations in metabolism were novel for complex eucaryotes of the period. Because catabolism in oxygen poor layers was essentially stopped those layers once penetrated would have been rich in hydrogen sulfide and metal salts thereof. We know this is true because some of the most ancient bacteria utilize sulfate as an oxygen source when oxygen is in short supply for other organisms, and the end result is sulfide. So the sub benthic would have been diificult to access but a rich sourceof energy once mastered.

Of course, no one can travel back to the period and see for certain, and the sampling of this papers results are small so ............