Originally posted by /^Blackmagik^\
now that i've had a few minutes to research, i doubt that they used carbon dating to date this particular specimen, since carbon-14 has a halflife of 5700 years, carbon dating is only reliable up to 50,000 years. most likely they used potassium-40 dating which has a half life of 1.3 billion years.
here's a brief explanation fo how carbon dating works...
(from www.howstuffworks.com)
potassium-40 is created in a similar way and is found naturally in all organisms. since it's halflife is so long, potassium-40 dating is used for dating fossils that are over 50,000 years old.
Thank you this is exactly the kind of thing I was getting at...skeptics can be right sometimes
So I am assuming that potassium-40 as of now is the accepted standard until proven otherwise.
I still think 425 million years old is a bit unbelievable.