Post by Matthew von der Ahe on Nov 23, 2014 23:29:19 GMT -5
Dear Palaeocasters:
I try to love your show, really I do. And I suppose the people who hunt and find a Therizinosaurus cheloniformus or an Anomalocaris canadensis, a Bicornucopina Hofmann or a Uvigerina semiornata are very clever and interesting (especially the Uvigerina hunters). But really, the initial fossilization of each and every one of those fossils depended upon the palaeomicrobes and the geochemistry of the sediment and porewater that the organism was first deposited in. And the ongoing preservation of each and every one of the fossils depended upon the geochemistry (and maybe the palaeomicrobes) of the groundwater in the rock that the sediment subsequently became.
For example, in your interview, I think John Paterson said that the eyes of his Emu Bay Anomalocaridid were first preserved by microbially mediated pyrite precipitation and that the pyrite was then replaced by microbially mediated hematite precipitation. Except that of course he didn't mention the microbial mediation, nor did he discuss the geochemistry of the porewater that allowed those microbes to preserve those eyes that look so good in Nature.
It seems to me that any discussion of taphonomy in a lagerstatten should address the microbes who allow, or in fact who cause, exceptionally good preservation by mediating the precipitation of just the right mineral at just the right time.
I do love your show. I will continue to listen to it and recommend it, even if you don't start asking macropalaeotonlogists pointed questions about how their sexy macrofossils were preserved.
Thanks.
I try to love your show, really I do. And I suppose the people who hunt and find a Therizinosaurus cheloniformus or an Anomalocaris canadensis, a Bicornucopina Hofmann or a Uvigerina semiornata are very clever and interesting (especially the Uvigerina hunters). But really, the initial fossilization of each and every one of those fossils depended upon the palaeomicrobes and the geochemistry of the sediment and porewater that the organism was first deposited in. And the ongoing preservation of each and every one of the fossils depended upon the geochemistry (and maybe the palaeomicrobes) of the groundwater in the rock that the sediment subsequently became.
For example, in your interview, I think John Paterson said that the eyes of his Emu Bay Anomalocaridid were first preserved by microbially mediated pyrite precipitation and that the pyrite was then replaced by microbially mediated hematite precipitation. Except that of course he didn't mention the microbial mediation, nor did he discuss the geochemistry of the porewater that allowed those microbes to preserve those eyes that look so good in Nature.
It seems to me that any discussion of taphonomy in a lagerstatten should address the microbes who allow, or in fact who cause, exceptionally good preservation by mediating the precipitation of just the right mineral at just the right time.
I do love your show. I will continue to listen to it and recommend it, even if you don't start asking macropalaeotonlogists pointed questions about how their sexy macrofossils were preserved.
Thanks.
