Rupp at the University of Chicago had a study done during the Dino Killer contravertisity. They found that something kills off a whole lot of things about every 20 million years with a bunch of not so major killings scatted in between, I will look for a reference.
something kills off a whole lot of things about every 20 million years
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Notice that the common thread in those exinction events is large animal demise? This might indicate that there is some sort of peridic gravity change. A large dinosaur whole, living, and intact today would be crushed by its own weight - their bones are neither large enough nor dense enough to support their weight.
There was some article published years ago on local gravity fuctuations indicting that gravity is growing weaker in certain regions of the Earth. I don’t remember more than that.
Thanks Little Bill.
The paleontological strata show waves of mass extinction, some global. Massive taxa-wide dieoffs had been identified even among gradualists by 1950, and more than a century earlier data purportedly supporting Biblical catastrophism included a bed of fossil skeletons of billions of fish which clearly died in agony. And obviously they didn’t drown (as I said, purportedly). Raup:
[snip] In 1984, paleontologists David Raup and Jack Sepkoski published a paper claiming that they had identified a statistical periodicity in extinction rates over the last 250 million years using various forms of time series analysis. [/snip]
http://en.wikipedia.org/wiki/Nemesis_(hypothetical_star)#Claimed_periodicity_of_mass_extinctions
http://www.pnas.org/cgi/reprint/81/3/801.pdf
roughly 15-20 major and minor extinctions in earth’s history. The big one we currently know the most about is the Permian-Triassic extinction. 96% of all marine species and 70% of terrestrial vertebrate species becoming extinct. It is the only known mass extinction of insects.