Re: Geological timescale

[Tetanurae@aol.com]

Tom Holtz wrote:
<<That was a decision I had already heard about.  Bother.  I still prefer
Vendian to Ediacaran.>>

You're not the only one.  This period was refered to as "Neoproterozoic III" 
on the last time scale I could get ahold of (circa 2000).  I am annoyed that 
it has been named Ediacaran for a few reasons, most importantly:

1) Ediacaran has always refered to a fauna of distinct fossils, Vendian to a 
time period or a series of rocks
2) When a time period is named for the Ediacaran fauna, Vendian has 
universally been used for that time period (well other than "latest 
Precambrian")
3) Most importantly: the Ediacaran fauna DOES NOT coincide with the upper and 
lower bounds of the Ediacaran Period, as fossils of the Ediacaran fauna don't 
show up until the mid-Ediacaran Period, and become extinct in the Early 
Cambrian!  Heck, there's even a Ediacaran-type sea-pen which is in the Middle 
Cambrian Burgess Shale!

That would be like renaming the Mesozoic the "Avian Era:" Birds don't show up 
until the middle of the "Avian" and continue to live past the end of the 
"Avian."  Sheesh, I think I'll continue using the name Vendian....

Pete Buchholz
tetanurae@aol.com