[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Who died at the K/T?



With all of the talk here about the catastrophic extinctions at the
K/T boundary, I'm starting to get mightily confused.  I haven't caught
up to the reference Ralph just posted, but I have just read an article
in the Apr 7 issue of Science (yeah, I'm that far behind...):

Benton, M. J. (1995). "Diversification and Extinction in the History
     of Life", 268:52-58.

Using a relatively new database, _The Fossil Record 2_ (see my
p.s. below) the article examines the number of families from the
Vendian (late Precambrian) to the present.  By most ways of looking at
the data, the terminal Cretaceous extinction just doesn't look that
bad relative to other events.  There's a pretty big spike in the total
number of families that went extinct at that time, but given that
family level diversity appears to have been shooting up since the end
Permian extinction, the percentage of families extincted isn't that
dramatic in comparison to prior and even a couple of later
extinctions.  I can't wait to see the paper Ralph mentioned because in
the Benton paper it's said (pg. 55):

    The end Cretaceous event is more clearly marked for marine groups
    than for continental, perhaps because most continental plants and
    animals, except the dinosaurs and pterosaurs, were little
    effected.

Since that seems counter to most of what we're hearing here, does
anyone want to comment?

-- 
Mickey Rowe     (rowe@lepomis.psych.upenn.edu)

P.S. The data set used for the Benton paper will be available for our
perusal via www.  I just tried to look at it, but they're having
problems with it.  Good luck getting it to work, Clive!