"Impact from the Deep" by Peter D. Ward

http://www.chicagocleanpower.org/ward.pdf

This short article from Scientific American, by Peter D. Ward, provides short overview with clear illustration of the mechanism of Mass Extinction he describes in detail in his book, Under a Green Sky: Global Warming, the Mass Extinctions of the Past, and What They Can Tell Us About Our Future.

Mass Extinctions have fascinated me since I was a little boy reading about Dinosaurs,  Peter Ward's books are the primary way I indulge that fascination as an adult.

I recommend the pdf if you want a short concise explanation, but strongly suggest the book if your looking for a deeper understanding, or if like me your fascinated by Mass Extinctions or Paleontology.

Ediacaran fossils

The authors have essentially performed a CAT scan of these tiny fossils, except they use energies high enough to fry human tissues. This is sufficient to reveal subtle internal features, including what appears to be a nucleus inside many of the cells, as shown above. The authors argue that this isn't not just a matter of similar appearance. The object has a consistent location within the cells, takes up a consistent fraction of the cell's volume, and only appears once per cell, all of which are features of a nucleus.

Source and full story: http://arstechnica.com/science/news/2011/12/precambrian-fossils-once-thought-to-be-embryos-reinterpreted-as-somethign-else.ars

Mass Extinctions have long been an area of interest to me, so I find this deeply interesting.  As much for the advances of Technology in Paleontology/Paleobiology, as for the actual fossils being discussed.

Video of Peter Ward lecture on Earth's mass extinctions

Here is the link to his lecture.

Peter Ward is a paleontologist.  I have been reading his books for a decade or so, he focuses on Mass Extinctions (Dinosaur die off is the Mass Extinction most people are familiar with) the study of which is a hobby of mine.

Here is a short bio of his from the University of Washington webite, he is faculty there.

Here is a list of some of his books Peter Ward books