>> If anyone is willing to play the game. Lets play the index fossil
>> game. A lot depends on them and surprizingly I can't seem to find a
>> book telling me how index fossils are assigned.
It's not a on/off type thing; there's a sliding scale of usefulness.
I think the important attributes of an index are that it be common,
widespread, easy to fossilize, and have a good chance of fossilizing.
That means hard-bodied marine inverterbrates are the best candidates.
Land-dwelling vertebrates are not useful; they're too rare as fossils.
The people in sci.bio.paleontology should know a lot, lot more.
-- Jim Foley Symbios Logic, Fort Collins, COJim.Foley@symbios.com (303) 223-5100 x9765 I've got a plan so cunning you could put a tail on it and call it a weasel. -- Edmund Blackadder