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The Global Fossil Record (d2fn.com)
62 points by d2fn 4322 days ago
4 comments

Very nice visualization, but the conditions necessary for fossilization should also be considered when weighting the types of species and drawing conclusions.

The conditions for fossilization occur with lower frequency in terrestrial ecosystems compared to aquatic systems for example, so even though complex life originated in marine ecosystems, if there had been more terrestrial species than aquatic species, we would not necessarily expect to find this in fossilization as far as I know.

Plant evolution is something that is extremely interesting to me, and I liked that part of the graphic. The arms race in ecosystems (With the classic example being rainforests) driving biodiversity, and the evolution of plants from gymnosperms to angiosperms in response to this (among other factors) is fascinating!

"Paleontologists are sure that the fossil record is biased."...

"Land animals are probably very poorly represented as well. For example, most animals that are now alive, or ever have lived, are insects, but the fossil record of insects is poor."...

http://www.k5geosource.org/1content/1sc/fossils/pg6.html

Excellent points! Thank you.
the wheel graphic could suggest (though not necessarily) that we evolved from a fresh water creature. Is there any theories on this that you guys know of?

it seems like it was always assumed to be a salt water creature, but it actually makes more sense in my head as a fresh water one, as it would pop into habitats conducive to terrestrial life

You're correct, the immediate ancestors of tetrapods almost certainly lived in freshwater, as known intermediate fossils like titaalik were found in fresh water stream deposits[1]. I believe all of the immediate ancestors of and early tetrapods have been found in fresh water deposits, although I can't confirm.

[1] http://tiktaalik.uchicago.edu/searching4Tik3.html

That is a very cool visualization, one of the best I have seen.
good jub dietrich